RSS

Marine & Offshore Division92571 Neuilly-sur-Seine Cedex- France

Tel: + 33 (0)1 55 24 70 00 - Fax: + 33 (0)1 55 24 70 25Marine Website: http://www.veristar.comEmail: [email protected]

© 2014 Bureau Veritas - All rights reserved

PART D – Service Notations

Chapters 13 – 14 – 15 – 16 – 17 – 18 – 19 – 20 – 21

NR 467.D3 DT R07 E July 2014

Rules for the Classification ofSteel Ships

ARTICLE 1

1.1. - BUREAU VERITAS is a Society the purpose of whose Marine & Offshore Division (the "Society") isthe classification (" Classification ") of any ship or vessel or offshore unit or structure of any type or part ofit or system therein collectively hereinafter referred to as a "Unit" whether linked to shore, river bed or seabed or not, whether operated or located at sea or in inland waters or partly on land, including submarines,hovercrafts, drilling rigs, offshore installations of any type and of any purpose, their related and ancillaryequipment, subsea or not, such as well head and pipelines, mooring legs and mooring points or otherwiseas decided by the Society.The Society:

• "prepares and publishes Rules for classification, Guidance Notes and other documents (" Rules ");

• "issues Certificates, Attestations and Reports following its interventions (" Certificates ");• "publishes Registers.

1.2. - The Society also participates in the application of National and International Regulations or Stand-ards, in particular by delegation from different Governments. Those activities are hereafter collectively re-ferred to as " Certification ".1.3. - The Society can also provide services related to Classification and Certification such as ship andcompany safety management certification; ship and port security certification, training activities; all activi-ties and duties incidental thereto such as documentation on any supporting means, software, instrumen-tation, measurements, tests and trials on board.

1.4. - The interventions mentioned in 1.1., 1.2. and 1.3. are referred to as " Services ". The party and/or itsrepresentative requesting the services is hereinafter referred to as the " Client ". The Services are pre-pared and carried out on the assumption that the Clients are aware of the International Maritimeand/or Offshore Industry (the "Industry") practices.

1.5. - The Society is neither and may not be considered as an Underwriter, Broker in ship's sale or char-tering, Expert in Unit's valuation, Consulting Engineer, Controller, Naval Architect, Manufacturer, Ship-builder, Repair yard, Charterer or Shipowner who are not relieved of any of their expressed or impliedobligations by the interventions of the Society.ARTICLE 2

2.1. - Classification is the appraisement given by the Society for its Client, at a certain date, following sur-veys by its Surveyors along the lines specified in Articles 3 and 4 hereafter on the level of compliance ofa Unit to its Rules or part of them. This appraisement is represented by a class entered on the Certificatesand periodically transcribed in the Society's Register.

2.2. - Certification is carried out by the Society along the same lines as set out in Articles 3 and 4 hereafterand with reference to the applicable National and International Regulations or Standards.

2.3. - It is incumbent upon the Client to maintain the condition of the Unit after surveys, to presentthe Unit for surveys and to inform the Society without delay of circumstances which may affect thegiven appraisement or cause to modify its scope.2.4. - The Client is to give to the Society all access and information necessary for the safe and efficientperformance of the requested Services. The Client is the sole responsible for the conditions of presenta-tion of the Unit for tests, trials and surveys and the conditions under which tests and trials are carried out.

ARTICLE 33.1. - The Rules, procedures and instructions of the Society take into account at the date of theirpreparation the state of currently available and proven technical knowledge of the Industry. Theyare a collection of minimum requirements but not a standard or a code of construction neither aguide for maintenance, a safety handbook or a guide of professional practices, all of which areassumed to be known in detail and carefully followed at all times by the Client.Committees consisting of personalities from the Industry contribute to the development of those docu-ments.3.2. - The Society only is qualified to apply its Rules and to interpret them. Any reference to themhas no effect unless it involves the Society's intervention.3.3. - The Services of the Society are carried out by professional Surveyors according to the applicableRules and to the Code of Ethics of the Society. Surveyors have authority to decide locally on matters re-lated to classification and certification of the Units, unless the Rules provide otherwise.

3.4. - The operations of the Society in providing its Services are exclusively conducted by way of ran-dom inspections and do not in any circumstances involve monitoring or exhaustive verification.

ARTICLE 44.1. - The Society, acting by reference to its Rules:

• "reviews the construction arrangements of the Units as shown on the documents presented by the Cli-ent;

• "conducts surveys at the place of their construction;

• "classes Units and enters their class in its Register;• "surveys periodically the Units in service to note that the requirements for the maintenance of class are

met. The Client is to inform the Society without delay of circumstances which may cause the date or theextent of the surveys to be changed.ARTICLE 5

5.1. - The Society acts as a provider of services. This cannot be construed as an obligation bearingon the Society to obtain a result or as a warranty.

5.2. - The certificates issued by the Society pursuant to 5.1. here above are a statement on the levelof compliance of the Unit to its Rules or to the documents of reference for the Services provided for.

In particular, the Society does not engage in any work relating to the design, building, productionor repair checks, neither in the operation of the Units or in their trade, neither in any advisory serv-ices, and cannot be held liable on those accounts. Its certificates cannot be construed as an im-plied or express warranty of safety, fitness for the purpose, seaworthiness of the Unit or of its valuefor sale, insurance or chartering.

5.3. - The Society does not declare the acceptance or commissioning of a Unit, nor of its construc-tion in conformity with its design, that being the exclusive responsibility of its owner or builder.

5.4. - The Services of the Society cannot create any obligation bearing on the Society or constitute anywarranty of proper operation, beyond any representation set forth in the Rules, of any Unit, equipment ormachinery, computer software of any sort or other comparable concepts that has been subject to any sur-vey by the Society.

ARTICLE 6

6.1. - The Society accepts no responsibility for the use of information related to its Services which was notprovided for the purpose by the Society or with its assistance.

6.2. - If the Services of the Society or their omission cause to the Client a damage which is provedto be the direct and reasonably foreseeable consequence of an error or omission of the Society,its liability towards the Client is limited to ten times the amount of fee paid for the Service havingcaused the damage, provided however that this limit shall be subject to a minimum of eight thou-sand (8,000) Euro, and to a maximum which is the greater of eight hundred thousand (800,000)Euro and one and a half times the above mentioned fee. These limits apply regardless of fault in-cluding breach of contract, breach of warranty, tort, strict liability, breach of statute, etc.The Society bears no liability for indirect or consequential loss whether arising naturally or not asa consequence of the Services or their omission such as loss of revenue, loss of profit, loss of pro-duction, loss relative to other contracts and indemnities for termination of other agreements.

6.3. - All claims are to be presented to the Society in writing within three months of the date when the Serv-ices were supplied or (if later) the date when the events which are relied on of were first known to the Client,and any claim which is not so presented shall be deemed waived and absolutely barred. Time is to be in-terrupted thereafter with the same periodicity. ARTICLE 7

7.1. - Requests for Services are to be in writing.

7.2. - Either the Client or the Society can terminate as of right the requested Services after givingthe other party thirty days' written notice, for convenience, and without prejudice to the provisionsin Article 8 hereunder.

7.3. - The class granted to the concerned Units and the previously issued certificates remain valid until thedate of effect of the notice issued according to 7.2. here above subject to compliance with 2.3. here aboveand Article 8 hereunder.7.4. - The contract for classification and/or certification of a Unit cannot be transferred neither assigned.

ARTICLE 8

8.1. - The Services of the Society, whether completed or not, involve, for the part carried out, the paymentof fee upon receipt of the invoice and the reimbursement of the expenses incurred.

8.2. - Overdue amounts are increased as of right by interest in accordance with the applicable leg-islation.

8.3. - The class of a Unit may be suspended in the event of non-payment of fee after a first unfruitfulnotification to pay.

ARTICLE 9

9.1. - The documents and data provided to or prepared by the Society for its Services, and the informationavailable to the Society, are treated as confidential. However:

• "Clients have access to the data they have provided to the Society and, during the period of classifica-tion of the Unit for them, to the classification file consisting of survey reports and certificates which have been prepared at any time by the Society for the classification of the Unit ;

• "copy of the documents made available for the classification of the Unit and of available survey reports can be handed over to another Classification Society, where appropriate, in case of the Unit's transfer of class;

• "the data relative to the evolution of the Register, to the class suspension and to the survey status of the Units, as well as general technical information related to hull and equipment damages, may be passed on to IACS (International Association of Classification Societies) according to the association working rules;

• "the certificates, documents and information relative to the Units classed with the Society may be reviewed during certificating bodies audits and are disclosed upon order of the concerned governmen-tal or inter-governmental authorities or of a Court having jurisdiction.

The documents and data are subject to a file management plan.

ARTICLE 10

10.1. - Any delay or shortcoming in the performance of its Services by the Society arising from an eventnot reasonably foreseeable by or beyond the control of the Society shall be deemed not to be a breach ofcontract.

ARTICLE 11

11.1. - In case of diverging opinions during surveys between the Client and the Society's surveyor, the So-ciety may designate another of its surveyors at the request of the Client.

11.2. - Disagreements of a technical nature between the Client and the Society can be submitted by theSociety to the advice of its Marine Advisory Committee.

ARTICLE 1212.1. - Disputes over the Services carried out by delegation of Governments are assessed within theframework of the applicable agreements with the States, international Conventions and national rules.12.2. - Disputes arising out of the payment of the Society's invoices by the Client are submitted to the Courtof Nanterre, France, or to another Court as deemed fit by the Society.12.3. - Other disputes over the present General Conditions or over the Services of the Society areexclusively submitted to arbitration, by three arbitrators, in London according to the ArbitrationAct 1996 or any statutory modification or re-enactment thereof. The contract between the Societyand the Client shall be governed by English law.

ARTICLE 13

13.1. - These General Conditions constitute the sole contractual obligations binding together theSociety and the Client, to the exclusion of all other representation, statements, terms, conditionswhether express or implied. They may be varied in writing by mutual agreement. They are not var-ied by any purchase order or other document of the Client serving similar purpose.13.2. - The invalidity of one or more stipulations of the present General Conditions does not affect the va-lidity of the remaining provisions. 13.3. - The definitions herein take precedence over any definitions serving the same purpose which mayappear in other documents issued by the Society.

BV Mod. Ad. ME 545 L - 7 January 2013

MARINE & OFFSHORE DIVISIONGENERAL CONDITIONS

RULES FOR THE CLASSIFICATION OF SHIPS

Part DService Notations

Chapters 1 2 3 4 5 4 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Chapter 1 RO-RO CARGO SHIPS

Chapter 2 CONTAINER SHIPS

Chapter 3 LIVESTOCK CARRIERS

Chapter 4 BULK CARRIERS

Chapter 5 ORE CARRIERS

Chapter 6 COMBINATION CARRIERS

Chapter 7 OIL TANKERS AND FLS TANKERS

Chapter 8 CHEMICAL TANKERS

Chapter 9 LIQUEFIED GAS CARRIERS

Chapter 10 TANKERS

Chapter 11 PASSENGER SHIPS

Chapter 12 RO-RO PASSENGER SHIPS

Chapter 13 SHIPS FOR DREDGING ACTIVITY

Chapter 14 TUGS

Chapter 15 SUPPLY VESSELS

Chapter 16 FIRE FIGHTING SHIPS

Chapter 17 OIL RECOVERY SHIPS

Chapter 18 CABLE-LAYING SHIPS

Chapter 19 NON-PROPELLED UNITS

Chapter 20 FISHING VESSELS

Chapter 21 OFFSHORE PATROL VESSELS

July 2014

The English wording of these rules take precedence over editionsin other languages.

Unless otherwise specified, these rules apply to ships for which contracts aresigned after July 1st, 2014. The Society may refer to the contents hereofbefore July 1st, 2014, as and when deemed necessary or appropriate.

2 Bureau Veritas July 2014

CHAPTER 13SHIPS FOR DREDGING ACTIVITY

Section 1 General

1 General 27

1.1 Application1.2 Documents to be submitted

Section 2 Hull and Stability

1 Stability 29

1.1 Intact stability1.2 Damage stability where the additional class notation SDS has been requested

2 Structure design principles 31

2.1 General2.2 Longitudinal members in the area of the hopper well2.3 Transverse members in the area of the hopper well2.4 Arrangements relating to suction pipes2.5 Chafing areas2.6 Reinforcements for grounding2.7 Bolted structures

3 Design loads 34

3.1 General3.2 Loading conditions3.3 Hull girder loads for dredgers, hopper dredgers and hopper units of more than

65 m in length3.4 Hull girder loads for split hopper dredgers and split hopper units of more than

65 m in length3.5 Internal pressures for hopper well in dredging situation

4 Hull girder strength of dredgers, hopper dredgers and hopper units 37

4.1 General4.2 Midship section modulus4.3 Ultimate strength check for ships of more than 65 m in length

5 Hull girder strength of split hopper dredgers and split hopper units 38

5.1 General5.2 Definitions5.3 Hull girder stress5.4 Checking criteria

6 Hull scantlings 39

6.1 General6.2 Hull girder normal stress for split hopper dredgers and split hopper units of more

than 65 m in length6.3 Minimum net thicknesses of plating6.4 Bottom plating6.5 Ordinary stiffeners6.6 Well bulkhead and cellular keel platings6.7 Transversely framed bottoms

July 2014 Bureau Veritas 3

7 Hopper dredgers and hopper units: checking of hopper well structure 41

7.1 General7.2 Floors, webs, trunks, strongbeams and girders

8 Split hopper dredgers and split hopper units: superstructure hinges 42

8.1 General8.2 Arrangements8.3 Materials used for the hinges8.4 Forces 8.5 Scantlings of the hinges

9 Split hopper dredgers and split hopper units: decks hinges, hydraulic jack connections and chocks 44

9.1 General9.2 Arrangements9.3 Static forces9.4 Dynamic forces9.5 Scantlings

10 Split hopper dredgers and split hopper units: hydraulic jacks and associated piping systems 47

10.1 General10.2 Definitions10.3 Arrangements10.4 Scantling of jacks10.5 Inspection and testing10.6 Relief valve setting

11 Rudders 48

11.1 General11.2 Additional requirements for split hopper dredgers and split hopper units

12 Equipment 48

12.1 General12.2 Additional requirements for split hopper dredgers and split hopper units12.3 Towlines and mooring lines

Section 3 Machinery and Dredging Systems

1 General 51

1.1 Application

2 Dredging system 51

2.1 Attachment of dredging equipment to the hull

3 Steering gear of split hopper dredgers and split hopper units 51

3.1 General3.2 Design of the steering gear3.3 Synchronisation

4 Testing of dredging equipment 51

4.1 On board testing


Appendix 1 Guidance on calculation of transverse strength hopper well structure

1 Hopper dredgers and hopper units: checking of hopper well structure 52

1.1 General

2 Floors 52

2.1 General2.2 Different types of bottom and valves used2.3 Load borne by floors2.4 Shear force diagrams2.5 Bending moments for each elementary load2.6 Resultant bending moment2.7 Normal load2.8 Differential opening valves2.9 Buckling of upper flange

3 Strong beams at deck level 56

3.1 Forces acting on strong beams3.2 Sectional area of strong beams

4 Brackets for trunks 56

4.1 General4.2 4.3

5 Girders supporting the hydraulic cylinder in the hopper spaces (bottom door types 1, 2 and 3) 57

5.1 5.2


CHAPTER 14TUGS

Section 1 General

1 General 61

1.1 Application


1 General 62

1.1 Application

2 Tugs, salvage tugs, escort tugs and anchor handling vessels 62

2.1 General2.2 Stability2.3 Structure design principles2.4 Hull scantlings2.5 Other structures2.6 Rudder and bulwarks2.7 Equipment2.8 Towing arrangements2.9 Construction and testing

3 Additional requirements for salvage tugs 66

3.1 General3.2 Equipment

4 Additional requirements for escort tugs 67

4.1 General4.2 Stability4.3 Structural design principles4.4 Equipment4.5 Construction and testing

5 Additional requirements for anchor handling vessels 69

5.1 General5.2 Stability5.3 Structural design principles5.4 Testing

Section 3 Integrated Tug/Barge Combination

1 General 76

1.1 Application1.2 Permanent connections1.3 Removable connections

2 General arrangement design 76

2.1 Bulkhead arrangement


3 Integrated tug/barge combinations with permanent connection: stability, freeboard, design loads, hull scantlings and equipment 77

3.1 Stability calculations3.2 Freeboard calculation3.3 Still water hull girder loads3.4 Wave hull girder loads3.5 Still water local loads3.6 Wave local loads3.7 Hull girder strength3.8 Scantlings of plating, ordinary stiffeners and primary supporting members3.9 Equipment

4 Integrated tug/barge combination with removable connection:stability, freeboard, design loads, hull scantlings and equipment 78

4.1 Stability calculations4.2 Freeboard calculation4.3 Still water hull girder loads4.4 Wave hull girder loads4.5 Still water local loads4.6 Wave local loads4.7 Hull girder strength4.8 Scantlings of plating, ordinary stiffeners and primary supporting members4.9 Equipment

5 Connection 78

5.1 General5.2 Scantlings

6 Other structures 79

6.1 Tug fore part6.2 Tug aft part6.3 Barge fore part6.4 Barge aft part

7 Hull outfitting 80

7.1 Rudder and steering gear

8 Construction and testing 80

8.1 Test of the disconnection procedure of removable connection


CHAPTER 15SUPPLY VESSELS

Section 1 General

1 General 83

1.1 Application1.2 Maximum bulk liquid cargo capacity1.3 Definitions


1 General 87



2.1 Compartment arrangement for all supply vessels2.2 Compartment arrangement for supply vessels with additional service feature oil

product2.3 Compartment arrangement for supply vessels with additional service feature

LHNS or WS

3 Access arrangement and access to spaces 88

3.1 Access arrangement for supply vessels with additional service feature oil product

3.2 Access arrangement for supply vessels with additional service feature LHNS or WS

4 Stability 89

4.1 General4.2 Intact stability for all supply vessels4.3 Damage stability for all supply vessels where the additional class notation SDS

has been requested4.4 Damage stability for supply vessels with additional service feature WS where

the additional class notation SDS has been requested


5.1 General5.2 Side structure exposed to bumping5.3 Deck structure5.4 Structure of cement tanks and mud compartments5.5 Acid spill protection for supply vessels with additional service feature LHNS or

WS

6 Design loads 92

6.1 Dry uniform cargoes


7.1 Plating7.2 Ordinary stiffeners7.3 Primary supporting members


8 Other structure 93

8.1 Aft part8.2 Superstructures and deckhouses8.3 Arrangement for hull and forecastle openings8.4 Structure of cargo tanks


9.1 Rudders9.2 Bulwarks9.3 Equipment

Section 3 Machinery and Cargo Systems

1 General 95


2 Machinery systems for supply vessels with additional service feature oil product, LHNS or WS 95

2.1 Bilge system 2.2 Ballast system2.3 Cargo heating systems2.4 Exhaust pipes2.5 Inert gas system2.6 Other machinery systems

3 Cargo piping design for supply vessels with additional service feature oil product, LHNS or WS 96

3.1 Cargo separation 3.2 Design and Materials3.3 Piping arrangement

4 Cargo tanks 97

4.1 Supply vessels with additional service feature LHNS or WS4.2 Supply vessels with additional service feature oil product

5 Cargo pumping system 97

5.1

6 Cargo tank fittings for supply vessels with additional service feature oil product, LHNS or WS 98

6.1 Level gauging systems and overflow control6.2 Cargo tank venting systems6.3 Cargo tank purging and/or gas freeing

7 Arrangement of cargo pump-rooms 99

7.1 Cargo pump-room ventilation7.2 Measures to prevent explosions

8 Cargo transfer system for supply vessels with additional service feature oil product, LHNS or WS 99

8.1


9 Special requirements for supply vessels with additional service feature LHNS or WS 99

9.1 Prevention of pollution9.2 Special requirements for acids9.3 Special requirements for the carriage of liquefied gases

Section 4 Electrical Installations

1 General 101

1.1 Application1.2 Documentation to be submitted

2 Hazardous location and types of equipment 101

2.1 Supply vessels with additional service feature oil product2.2 Supply vessels with additional service feature LHNS or WS

Section 5 Fire Prevention, Protection and Extinction

1 General 102


2 Fire prevention and protection 102

2.1 Structure, bulkheads within accommodation and service spaces and details of construction

2.2 Fire integrity of bulkheads and decks2.3 Vapour detection system

3 Fire fighting 103

3.1 General3.2 Protection of the deck area3.3 Special requirements for supply vessels with additional service feature LHNS or

WS3.4 Fire-extinguishing systems for cargo pump-rooms

4 Personnel protection for supply vessels with the additional service feature LHNS or WS 103

4.1 Decontamination showers and eyewashes4.2 Protective and safety equipment


CHAPTER 16FIRE FIGHTING SHIPS

Section 1 General

1 General 107

1.1 Application


1 Stability 108

1.1 Intact stability


2.1 Hull structure2.2 Water and foam monitors


3.1 Arrangement for hull and superstructure openings

Section 3 Machinery and Systems

1 General 110


2 Design of machinery systems 110

2.1 Manoeuvrability2.2 Fuel oil capacity2.3 Scuppers

3 General requirements for fire-fighting systems 111

3.1 General3.2 Independence of pumping and piping systems3.3 Design and construction of piping systems3.4 Monitors3.5 Monitor control

4 Water fire-fighting system 112

4.1 Characteristics4.2 Monitors4.3 Piping

5 Fixed foam fire-extinguishing system 113

5.1 General5.2 Characteristics5.3 Arrangement

6 Portable fire-fighting equipment 113

6.1 Portable high expansion foam generator6.2 Hydrants and fire hoses


7 Firemen’s outfits 113

7.1 Number and characteristics7.2 Compressed air system for breathing apparatuses

8 Testing 114

8.1 General8.2 Workshop tests8.3 On board tests

Section 4 Fire Protection and Extinction

1 General 115


2 Fire protection of exposed surfaces 115

2.1 Structural fire protection2.2 Deadlights and shutters

3 Self-protection water-spraying system 115

3.1 General3.2 Capacity3.3 Arrangement3.4 Pumps3.5 Piping system and spray nozzles


CHAPTER 17OIL RECOVERY SHIPS

Section 1 General

1 General 119

1.1 Application1.2 Definitions


1 General 121

1.1 Documents to be submitted1.2 General arrangement

2 Stability 122



3.1 Additional loads

4 Construction and testing 122

4.1 Testing


1 General 123

1.1 Documents to be submitted

2 Machinery installation and piping system other than oil recovery system 123

2.1 Sea water cooling system2.2 Water fire-extinguishing system2.3 Exhaust gas systems

3 Pumping system, piping system and pump-rooms intended for recovered oil 123

3.1 Design of pumping and piping systems3.2 Arrangement of piping systems3.3 Oil recovery pumps3.4 Oil recovery pump-rooms

4 Oil recovery tank fittings 124

4.1 Vent pipes4.2 Level gauging and overfilling control

5 Heating systems 125

5.1


6 Additional requirements 125

6.1 Ships assigned with the additional service feature OILTREAT


1 General 126

1.1 Application1.2 Documentation to be submitted

2 Design requirements 126

2.1 System of supply2.2 Earth detection

3 Hazardous locations and types of equipment 126

3.1 Electrical equipment permitted in hazardous areas3.2 Additional requirements for machinery installations in hazardous areas3.3 Openings, access and ventilation conditions affecting the extent of hazardous

areas

Section 5 Fire Protection, Detection and Extinction

1 General 128


2 Mechanical ventilation in the oil recovery area 128

2.1 General2.2 Ventilation of recovered oil pump rooms2.3 Ventilation of enclosed spaces normally entered during oil recovery operation

other than recovery oil pump rooms

3 Fire protection and fighting 128

3.1 Vapor detector3.2 Structural fire protection3.3 Fire-fighting


CHAPTER 18CABLE-LAYING SHIPS

Section 1 General

1 General 133

1.1 Application


1 General 134

1.1 Application

2 Stability 134

2.1 Intact stability2.2 Damage stability for ships where the notation SDS has been required


3.1 Cable tanks3.2 Connection of the machinery and equipment with the hull structure


4.1 Fore part


5.1 Equipment


1 General 136

1.1 Propulsion and manoeuvrability1.2 Documents to be submitted

2 Arrangements for cable laying, hauling and repair 136

2.1 Typical machinery and equipment of cable laying ships2.2 Design of cable handling machinery and equipment2.3 Safety2.4 Testing of cable handling machinery and equipment

3 On board trials 137

3.1 Ship trials3.2 Equipment trials

Section 4 Fire Protection

1 Cable tanks 138

1.1 Means for fire fighting


CHAPTER 19NON-PROPELLED UNITS

Section 1 General

1 General 141

1.1 Application


1 General 142

1.1 Application1.2 Additional class notations for lifting appliances of ships with service notation

pontoon - crane

2 Stability 142

2.1 Intact stability for ships with service notation pontoon or pontoon - crane2.2 Additional intact stability criteria for ships with service notation pontoon - crane


3.1 Hull structure3.2 Lifting appliances

4 Hull girder strength 145

4.1 Yielding check


5.1 General5.2 Hull scantlings of non-propelled units with the service notation pontoon fitted

with arrangements and systems for launching operations5.3 Hull scantlings of non-propelled units with service notation pontoon - crane


6.1 Reinforcement of the flat bottom forward area of ships with one of the service notations pontoon and pontoon - crane


7.1 Equipment

Section 3 Machinery Systems

1 General 149


2 Bilge system 149

2.1 Bilge system in ships having no source of electrical power2.2 Bilge system in ships having a source of electrical power


CHAPTER 20FISHING VESSELS

Section 1 General

1 General 153

1.1 Application

Section 2 Ship Arrangement


1.1 Subdivision arrangement

1.2 Cofferdams


1 Stability 155



2.1 Design loads

2.2 Bottom, side and decks plating

2.3 Aft ramp

2.4 Machinery casings

2.5 Hatch covers


3 Lifting appliances and fishing devices 158

3.1 General

3.2 Design loads

3.3 Strength check


4.1 Rudder stock scantlings

4.2 Equipment

5 Protection of hull metallic structures 160

5.1 Protection of deck by wood sheathing

5.2 Protection of cargo sides by battens

5.3 Deck composition


Section 4 Machinery

1 General 161

1.1 Application1.2 Documents to be submitted1.3 Tests - Trials in ships L ≥ 24 m1.4 Tests - Trials in ships L < 24 m1.5 General requirements applicable to all piping systems in ship L ≥ 24 m 1.6 General requirements applicable to all piping systems in ship L < 24 m 1.7 Sea inlets and overboard discharges in ships L ≥ 24 m1.8 Sea inlets and ship side valves in ships L < 24 m1.9 Non-metallic rigid pipes in ships L ≥ 24m1.10 Non-metallic rigid pipes in ships L < 24m1.11 Flexible hoses and expansion joints1.12 Metallic flexible pipes and joints

2 Bilge system in ships L ≥ 24 m 165

2.1 General2.2 Design of the bilge system2.3 Bilge pumps2.4 Size of bilge pipes2.5 Bilge piping arrangement2.6 Materials

3 Bilge system in ships L < 24 m 167

3.1 General3.2 Pumps and ejectors3.3 Size of bilge pipes3.4 Arrangement of bilge lines and their accessories

4 Scuppers and sanitary discharges 169

4.1 Principle4.2 General4.3 Discharges through manned machinery spaces4.4 Materials

5 Air pipes and sounding devices in ships L ≥ 24 m 169

5.1 Air pipes5.2 Sounding and level gauging devices

6 Air pipes and sounding devices in ships L < 24 m 170

6.1 Air pipes6.2 Sounding and level gauging devices

7 Ventilation in ships ≥ 24 m 171

7.1

8 Ventilation in ships < 24 m 171

8.1 8.2 8.3 8.4

9 Engine cooling systems in ships L ≥ 24 m 171

9.1


10 Engine cooling systems in ships L < 24 m 171

10.1 Principle10.2 Motorships10.3 Fresh water cooling system10.4 Cooling pumps10.5 Sea inlets10.6 Filters10.7 Operating control10.8 Materials

11 Oil fuel systems in ships L ≥ 24m 172

11.1

12 Oil fuel systems in ships L < 24m 172

12.1 General12.2 Oil fuel tanks and bunkers 12.3 Transfer pipes12.4 Oil fuel supply to engines 12.5 Materials - Construction

13 Lubricating oil systems in ships L ≥ 24 m 173

13.1

14 Lubricating oil systems in ships L < 24 m 173

14.1 General14.2 Lubricating pumps 14.3 Filters14.4 Safety devices

15 Hydraulic systems in ships L ≥ 24 m 174

15.1

16 Hydraulic systems in ships L < 24 m 174

16.1 General16.2 Safety and monitoring devices

17 Compressed air systems in ships L ≥ 24 m 174

17.1

18 Compressed air systems in ships L < 24 m 174

18.1 18.2 Accessories for compressed air systems18.3 Arrangement of compressed air systems18.4 Construction - Material

19 Exhaust gas systems in ships L ≥ 24 m 174

19.1

20 Exhaust gas systems in ships L < 24 m 174

20.1 Hull outlet20.2 Cooling and lagging20.3 Water-cooled exhaust gas pipes


21 Refrigeration systems for the preservation of the catch 175

21.1 General21.2 Design of refrigeration systems21.3 Arrangement of the refrigerating machinery spaces and refrigerating rooms21.4 Breathing apparatus

22 Propelling and auxiliary machinery in ships L ≥ 24 m 175

22.1

23 Propelling and auxiliary machinery in ships L < 24 m 175

23.1 Shafting23.2 Shaft accessories

24 Steering gear 176

24.1 Application24.2 General24.3 Strength, performance and power operation of the steering gear24.4 Control of the steering gear24.5 Availability


1 General 178

1.1 Application

2 Documentation to be submitted 178

2.1

3 Type approved components 178

3.1

4 General requirements for system design, location and installation 178

4.1 Design and construction4.2 Distribution4.3 Main source of electrical power4.4 Emergency source of electrical power4.5 Precaution against shock, fire and other hazards of electrical origin4.6 Engineers’ alarm4.7 Steering gear4.8 Fire detection and fire alarm4.9 Alarm - Communication4.10 Final sub-circuits4.11 Electric cables4.12 Switchboard4.13 Rotating electrical machines4.14 Batteries

5 Lightning protection 184

5.1 Application


Section 6 Fire Protection

1 General 185

1.1 Application

1.2 Type approved products

1.3 Definitions

2 Water fire-fighting system 186

2.1 General

2.2 Number and type of fire pumps

2.3 Characteristics and arrangement of fire pumps

2.4 Fire main, hydrants and hoses

3 Fire-extinguishing appliances in machinery spaces 188

3.1

3.2

3.3

3.4

4 Fire extinguishers 188

4.1 Design and installation of fire extinguishers

4.2 Arrangement of fire extinguishers in accommodation and service spaces

5 Structural fire protection 189

5.1

5.2 Ships of 45 m in length and over

5.3 Ships of 24 m in length and over but less than 45 m

5.4 Ships of less than 24 m in length

6 Ventilation systems 191

6.1

7 Prevention of fire 192

7.1

8 Means of escape 192

8.1

9 Fire detection 193

9.1

10 Storage of gas cylinders and dangerous materials 193

10.1


CHAPTER 21OFFSHORE PATROL VESSELS

Section 1 General

1 General 197

1.1 Application

1.2 Number of persons on board

Section 2 Stability

1 General 199

1.1 Application

2 Intact Stability 199

2.1 Maximum turning angle

2.2 Crowding angle for offshore patrol vessels carrying more than 60 persons

3 Damage stability 199

3.1 Offshore patrol vessels carrying more than 60 persons

3.2 Bottom damages

Section 3 Machinery

1 General 200

1.1 Application

1.2 Capacity of service tanks for offshore patrol vessels with GT ≥ 500

1.3 Offshore patrol vessels for which damage stability is required

Section 4 Electricity and Automation

1 General 201

1.1 Application

1.2 General alarm for ships with GT < 500

1.3 Emergency source of electrical power for ships with GT ≥ 500

1.4 Public address system for ships with GT ≥ 500


Section 5 Fire safety

1 General 202

1.1 Application

2 Materials 202

2.1 Steel or equivalent

3 Specific requirements 202

3.1 Offshore patrol vessels carrying more than 60 persons3.2 Ammunition storage compartments



Chapter 13

SHIPS FOR DREDGING ACTIVITY

SECTION 1 GENERAL

SECTION 2 HULL AND STABILITY

SECTION 3 MACHINERY AND DREDGING SYSTEMS

APPENDIX 1 GUIDANCE ON CALCULATION OF TRANSVERSE STRENGTH HOPPER WELL STRUCTURE


Pt D, Ch 13, Sec 1

SECTION 1 GENERAL

1 General

1.1 Application

1.1.1 Ships complying with the requirements of this Chap-ter are eligible for the assignment of one of the followingservice notations:• dredger• hopper dredger• hopper unit• split hopper dredger• split hopper unit

as defined in Pt A, Ch 1, Sec 2, [4.6].

1.1.2 Ships dealt with in this Chapter are to comply with:

• Part A of the Rules

• NR216 Materials and Welding

• applicable requirements according to Tab 1.


1.2.1 The document listed in Tab 2 are to be submitted forapproval, as applicable.

1.2.2 The document listed in Tab 3 are to be submitted forinformation, as applicable.

Table 1 : Applicable requirements

Item Greater than or equal to 500 GT Less than 500 GT

Ship arrangement • Part B • NR566

Hull

L ≥ 65 m• Part B• Ch 13, Sec 2

• Part B• Ch 13, Sec 2

L < 65 m• NR600• Ch 13, Sec 2

• NR600• Ch 13, Sec 2

Stability• Part B• Ch 13, Sec 2

• NR566• Ch 13, Sec 2

Machinery and cargo systems• Part C• Ch 13, Sec 3

• NR566• Ch 13, Sec 3

Electrical installations • Part C • NR566

Automation • Part C • NR566

Fire protection, detection and extinction • Part C • NR566

Note 1:NR566: Hull Arrangement, Stability and Systems for Ships less than 500 GTNR600: Hull Structure and Arrangement for the Classification of Cargo Ships less than 65 m and Non Cargo Ships less than 90 m.


Pt D, Ch 13, Sec 1

Table 2 : Documents to be submitted for approval Table 3 : Documents to be submitted for information

Item n° Description of the document

1 Construction of suction inlet tube

2 Gantry foundations

3 Bottom door and cylinder integrations

4 Overflow

5 Calculation of clearances

6 Hinges, chocks and cylinder integrations

7 Integration of spuds

8 Couplings

9 Integration cutter ladder

10 Integration anchor booms

11 Foundation excavator

12 General arrangement of the dredging equipement

13 Specification of the dredging equipement opera-tion test

Item n° Description of the document

1 Calculation of SWBM and shear forces in sailing and working conditions

2 Design loads on all components of the dredging equipment


Pt D, Ch 13, Sec 2


Symbols

For symbols not defined in this Section, refer to the list atthe beginning of this Chapter.T : Navigation draught, in m, corresponding to the

international freeboardTD : Dredging draught, in m, corresponding to the

dredging freeboardC : Wave parameter defined in Pt B, Ch 5, Sec 2 or

NR600, Ch 3, Sec 2, [5], as applicableH : Wave parameter defined in Pt B, Ch 5, Sec 2k : Material factor for steel, defined in Pt B, Ch 4,

Sec 1, [2.3]n, n1 : Navigation coefficients, defined in Pt B, Ch 5,

Sec 1, [2.6] or NR600, Ch 3, Sec 2, [4], asapplicable

nD : Navigation coefficient in dredging situation,defined in [3.3.3]

s : Spacing, in m, of ordinary stiffenersδ : Specific gravity of the mixture of sea water and

spoil, taken equal to:

PD : Maximum mass, in t, of the spoil contained inthe hopper space

VD : Volume of the hopper space, in m3, limited tothe highest weir level

g : Gravity acceleration, in m/s2:

g = 9,81 m/s2

p : Maximum length, in m, of the hopper wellbp : Maximum breadth, in m, of the hopper wellCFA : Combination factor, to be taken equal to:

• CFA = 0,7 for load case “c”

• CFA = 1,0 for load case “d”

a : Distance from the bottom to the sealing jointlocated at the lower part of the hopper well, inm

h1 : Distance, in m, from spoil level to base linewhen working at the dredging freeboard (see Fig7)

h2 : Distance, in m, from spoil level to base linewhen working at the international freeboard(see Fig 7)

h4 : Distance, in m, from the lowest weir level tobase line

T3 : Navigation draught, in m, with well filled withwater up to waterline

T4 : Navigation draught, in m, with well filled withwater up to the lowest weir level

Ry : Minimum yield stress, in N/mm2, of the mate-rial, to be taken equal to 235/k N/mm2, unlessotherwise specified

ReH : Minimum yield stress, in N/mm2, of the material

Rm : Minimum ultimate tensile strength, in N/mm2,of the material.

1 Stability


1.1.1 General

The intact stability of the ship is to be sufficient to complywith the criteria indicated in [1.1.3] for the operationalloading conditions of Pt B, Ch 3, App 2, [1.2.10] and thecalculation method described in [1.1.2].

1.1.2 Calculation method

The calculation of the righting lever curves is to take intoaccount:

• the change of trim due to heel

• the inflow of seawater or outflow of liquid cargo at theupper edge of the hopper coaming in the case of anopen hopper

• the inflow of water at the lower edge of the overflow,located at cargo level or at the lowest possible positionabove cargo level, or at the lower edge of the lowestoverflow ports or spillways.

1.1.3 Intact stability criteria

The area under the righting lever curve is not to be less than0,07 m.rad up to an angle of 15° when the maximum right-ing lever GZmax occurs at 15° and 0,055 m.rad up to anangle of 30° when the maximum righting lever GZmaxoccurs at 30° or above. Where the maximum righting leverGZmax occurs at angles of between 15° and 30°, the corre-sponding area under the righting lever curve is to be equalto or greater than A, where A is to be obtained, in m.rad bythe following formula:

A = 0,055 + 0,001 (30° − θmax)

θmax being the angle of heel in degrees at which the right-ing lever curve reaches its maximum.

The area under the righting lever curve between the anglesof heel of 30° and 40° or between 30° and the down-flood-ing angle θf, if this angle is less than 40°, is to be not lessthan 0,03 m.rad.

The righting lever GZ is to be at least 0,20 m at an angle ofheel equal to or greater than 30°.

δ PD

VD

------=


Pt D, Ch 13, Sec 2

The maximum righting lever GZmax should occur at anangle of heel not less than 15°.

The initial metacentric height GM0 as corrected for the freesurface effect of the tanks and the hopper(s) containing liq-uids is not to be less than 0,15 m.

1.1.4 Weather criterion at the international freeboard

At the international freeboard, the dredger is to comply withthe requirements of Pt B, Ch 3, Sec 2, [3.2] considering:

• the state of the cargo as a liquid

• 10% stores and fuel

• and the hopper(s) loaded with a homogeneous cargo upto the upper edge of the hopper coaming if the densityof the cargo is not less than 1000 kg/m3; otherwise thehopper is considered to be partially loaded with a cargoof density equal to 1000 kg/m3.

1.1.5 Weather criterion at the dredging freeboard

At the dredging freeboard, the dredger is to comply with therequirements of Pt B, Ch 3, Sec 2, [3.2] considering areduced wind pressure equal to 270 N/m2 for the mostsevere of the loading conditions in Pt B, Ch 3, App 2,[1.2.10]. The most severe loading condition is defined asthe loading condition where the area under the rightinglever curve between 0° and 40° is the least.

1.1.6 Dredgers with open hopper(s)

When the height of the hopper coaming overflow edgeabove the dredging draught is less than the minimum bowheight as specified in the International Load Line Conven-tion 1966, the loading conditions in Pt B, Ch 3, App 2,[1.2.10] at the dredging draught are to take into account alayer of seawater on top of the cargo up to the overflowedge of the hopper coaming. However, if overflow ports orspillways of a size sufficient to enable a fast freeing of thewater in the hopper on top of the cargo are fitted in the hop-per coaming above the freeboard deck, the layer of seawater may be reduced up to the lower edge of the overflowports or spillways.

The area of the overflow ports or spillways is to be at leastequivalent to the area required by Regulation 24(1) of theInternational Convention on Load Lines, 1966.

1.1.7 Dredgers with bottom doors or similar means

Dredgers with bottom doors or similar means at port sideand at starboard side are to comply with the following crite-ria considering an asymmetric discharging:

• the angle of equilibrium is not to exceed 25°

• the righting lever GZ within the 30° range beyond theangle of equilibrium is to be at least 0,10 m

• the range of stability is not to be less than 30°.

The dredger is assumed loaded up to the dredging draughtwith solid cargo of a density equal to 1900 kg/m3, when dis-charging, 20% of the total hopper load is assumed to be dis-

charged only at one side of the longitudinal centreline ofthe hopper, horizontally equally distributed at the discharg-ing side.

1.2 Damage stability where the additional class notation SDS has been requested

1.2.1 General

When the dredger is assigned a dredging freeboard which isless than B/2, where B is the statutory freeboard as calcu-lated in accordance with the International Convention onLoad Lines 1966, the dredger is to comply with the require-ments of Pt B, Ch 3, App 3, [1], modified by [1.2.2], [1.2.3]and [1.2.5]. The dredger may not be assigned a freeboardless than B/3.

1.2.2 Calculation method of the righting lever curves

The calculation of the righting lever curves is to take intoaccount:

• the change of trim due to heel

• the inflow of seawater or outflow of cargo at the upperedge of the hopper coaming in the case of an open hop-per

• the inflow of water at the lower edge of the overflow,located at the highest possible position or at the loweredge of the lowest overflow ports or spillways

• the sliding of the cargo in the hopper, in transverse andlongitudinal direction, according to the following shift-ing law:

- for ρ ≤ 1400 (liquid cargo):

θr = θg

- for 1400 < ρ < 2000 (sliding cargo):

θr = θg (2000 − ρ) / 600

- for ρ ≥ 2000 (solid cargo):

θr = 0

where:

ρ : Cargo density, in kg/m3

θr : Angle of heel or angle of trim, in degrees

θg : Shifting angle of the cargo, in degrees.

1.2.3 Progressive flooding

Internal and external progressive floodings are to be consid-ered in accordance with the requirements of Pt B, Ch 3, Sec3, [3.3].

1.2.4 The attained subdivision index AU

The attained subdivision index AU is to be calculated for thedraught dU and the corresponding initial trim assuming thedredger in the unloaded condition, i.e. loaded with 50%fuel and stores, no cargo in the hopper(s) and the hopper(s)in direct communication with the sea.


Pt D, Ch 13, Sec 2

1.2.5 The attained subdivision index AL

The attained subdivision index AL is to be calculated assum-ing the dredger loaded at the dredging draught dl with 50%fuel and stores, for each of the densities ρd and ρi definedby:

• the design density ρd corresponding to the dredgingdraught and obtained from the following formula:

ρd = M2 / V2

where:

M2 : Mass of cargo in the hopper when thedredger is loaded at the dredging draughtwith 50% fuel and stores

V2 : Volume of the hopper at the highest over-flow position

• each density ρi greater than ρd, obtained from the fol-lowing formula:

ρi = 2200 − 200 i

where i is equal to 0; 1; 2; 3; etc.

The damage stability calculations are to be performed tak-ing into account the initial trim of the dredging draught, anassumed permeability of the cargo in the hopper equal to0% and a permeability of the space above the cargo equalto 100%.

1.2.6 Damage stability criteria

The dredger is to comply with the following criteria:

A ≥ R

AU ≥ 0,7 R

AL ≥ 0,7 R

where:

R : Required index as defined in Pt B, Ch 3, App 3,[1.3]

AU : Attained subdivision index at the unloadeddraught dU, as defined in [1.2.4]

AL : Attained subdivision index at the loadeddraught dl and for the cargo densities defined in[1.2.5].

2 Structure design principles

2.1 General

2.1.1 The attention of Designers is drawn to the fact thatstructural arrangement of ships for dredging activitiesinvolves discontinuities and that particular care is to betaken to avoid cracks or fractures.

2.1.2 Where dredgers are likely to work in association withhopper barges, the sheerstrake is to be protected, slightlybelow the deck, by a fender efficiently secured to the shellplating and extending over at least two thirds of the ship’slength. Compensation is to be provided in way of the gang-way port in raised deck, if fitted.

2.1.3 Where dredgers are likely to work in association withhopper barges, the shell plating is to be protected by afender extending from the load waterline to the lowestwaterline.

Additional structural reinforcements are to be provided inway of fenders and submitted to the Society for approval.

2.1.4 On bucket dredgers, in order to prevent dangerousflooding in the event of damage to the shell plating by metaldebris (e.g. anchors), a watertight compartment is to be pro-vided at the lower part of the caissons on either side of thebucket well in the area of the buckets. The compartment isto be of adequate size to allow surveys to be carried out.

2.1.5 Reinforcements are to be provided at locations wherethe hull is heavily stressed, such as:

• beneath the suction pipe gallows

• in way of the gallow frame on bucket dredgers

• points where tow ropes are secured

• connections of piles, etc.

2.1.6 The reinforcement of the flat bottom area forward isto comply with Pt B, Ch 8, Sec 1, [3] or NR600, Ch 3, Sec3, [3], as applicable, considering TF as equal to the mini-mum ballast draft forward in heavy weather.

Flat bottom areas, other than flat bottom area forward, wheredynamic pressures due to the bottom impact might occur areto be examined by the Society on a case by case basis.

2.1.7 Weirs are to be provided in the hopper spaces. Theirsectional area is to be large enough, taking into account thedensity of the water-spoil mixture to be drained off.

The disposition and location of the weirs are to be such that:

• they prevent the maximum authorised draught frombeing exceeded during loading

• trim and stability are always in accordance with thereviewed loading conditions

• draining off is made without any overflowing on thedecks.

2.1.8 The corners of the cut-outs in the bottom plating areto be rounded and the radius is to be as large as possible,especially near the bottom doors.

The shape and the radius of cut-out corners are to be inaccordance with Pt B, Ch 4, Sec 6 or NR600, Ch 2, Sec 1,as applicable.

2.1.9 Where hopper barges and suction dredgers areintended for deep sea navigation, it is recommended, as faras possible, that sidescuttles should not be fitted in the shellplating.

2.1.10 The brackets are generally to be of a swept shape. Aflange is to be fitted on the free edge if the length of thisedge exceeds 60 times the web thickness.

2.1.11 For ships with one of the service notations split hop-per dredger or split hopper unit, where panting beams areprovided as stated in Pt B, Ch 8, Sec 1, [2.7], stringers andweb frames are to be fitted on the centreline bulkheads ofthe two half-hulls to take up the reactions.


Pt D, Ch 13, Sec 2

2.2 Longitudinal members in the area of the hopper well

2.2.1 The scantlings of the midship region are generally tobe kept over the full length of the hopper well.

2.2.2 Attention is to be paid to the structural continuity oflongitudinal members, especially coaming and hopper wellbulkheads.

2.2.3 The upper deck stringer plate is to extend to the lon-gitudinal bulkhead over the full length of the hopper well.

2.2.4 The fore and aft ends of the longitudinal bulkheads ofthe hopper spaces are to be extended by large brackets gen-erally having a length and a width equal to D/4. It is recom-mended that a swept shape should be provided for thesebrackets (see Fig 1).

The upper bracket is to be welded to the deck and extendedby a longitudinal deck girder.

The lower bracket, which is generally oblique, is to bewelded to the bottom or to the tank top. In the latter case,the lower bracket is to be extended inside the double bot-tom by means of a solid keelson extending at least overthree frame spaces beyond the end of the bracket.

Figure 1 : Brackets at fore and aft ends oflongitudinal bulkheads of the hopper spaces

2.2.5 The fore and aft ends of the centreline cellular keelare to be extended by means of brackets having a length atleast equal to the depth of this keel.

In areas where a double bottom is provided, the bracketsmay be arranged in accordance with Fig 2.

2.2.6 The vertical sides of the trunks are to be extendedbeyond the end of the hopper spaces over a distance of atleast 1,5 times their height.

Figure 2 : Brackets at fore and aft ends of cellular keel

2.2.7 The Society may, on a case-by-case basis, require thatlongitudinal members of the double bottom structure areextended, by means of brackets, inside the side compart-ments bounding the hopper spaces.

2.2.8 Arrangements other than those described in [2.2.4] to[2.2.7] are to be considered by the Society on a case-by-case basis.

2.3 Transverse members in the area of the hopper well

2.3.1 Transverse primary supporting rings

Within the hopper well area, transverse primary supportingrings are to be provided and are to involve:

• deep floors inside hopper spaces

• side vertical primary supporting members

• hopper well vertical primary supporting members

• strong beams inside hopper spaces, at deck or trunklevel

• where necessary, cross-ties connecting either the sidevertical primary supporting members to the hopper wellvertical primary supporting members or the floor to thehopper well vertical primary supporting members.

The spacing of the transverse rings is generally to be takennot greater than five frame spaces.

2.3.2 The cellular keel is to be rigidly connected to thetransverse rings required in [2.3.1].

2.3.3 The upper part of the cellular keel may be connectedto the deck or trunk structure by means of axial or inclinedpillars in association with strong beams, or by a centrelinewash bulkhead.

2.3.4 The connection of hopper space floors with the longi-tudinal bulkheads and the cellular keel is to be arrangedsuch that the continuity of the strength is ensured.

Where the floor is made of a box with sloping sides, partic-ular attention is to be paid to the continuity of the lowerflange. Fig 3 shows an example of possible connection.

bracket

hopper space shell

in the same plane

knuckle

inclined bulkhead

��

strengthening flat

foldin the verticalplane

bracket

knuckle

in the same plane

cellular keel


Pt D, Ch 13, Sec 2

Figure 3 : Example of connection with floormade of box with sloping sides

2.3.5 The connection between the flanges of the strongbeams and the adjacent structure is generally to be made bymeans of brackets having the thickness of these flanges andextending inside the adjacent structure.

2.4 Arrangements relating to suction pipes

2.4.1 Where a cut-out is necessary in the side shell platingto fit the suction pipe guides, continuity of members is to berestored, for example by means of knuckled plates as thickas the side shell plating and with a knuckle angle as smallas possible.

The knuckles are to be stiffened by reinforced vertical pri-mary supporting members and intercostal girders of thesame web height (see Fig 4 and Fig 5).

Figure 4 : Transversely framed side - Cut-out rein-forced by means of knuckled plate

Figure 5 : Longitudinally framed side - Cut-out rein-forced by means of knuckled plate

The fillet welding between the web of vertical primary sup-porting members and the knuckled plates is not to be madeonto the knuckles, but about 50 mm apart.

2.4.2 The suction pipe guides are to be fitted as far as pos-sible from the hopper space ends or from any cut-out in thebottom or deck plating.

A 60% reinforced deck plate, not exceeding 38 mm, is to beprovided in way of the cut-out of the guides. This plate is toextend over at least one frame space forward and aft of thevertical primary supporting members provided for in[2.4.1].

2.4.3 In areas where, during suction pipe operations, thedrag head and the joint may run against the hull, one orseveral of the following arrangements are generally to beprovided:

• thickness plating in excess of thickness obtainedaccording to Pt B, Ch 7, Sec 1 or NR600, Ch 4, Sec 3, asapplicable, for bilge and side shell

• reinforcement of the structure by means of vertical pri-mary supporting members, girders, intermediate framesor longitudinals, depending on the construction type

• fenders to be provided outside the hull; these fenderstogether with the bilge shape are not to impede the suc-tion pipe operation

• cofferdam to be provided to limit the possible floodingof side compartments.

2.4.4 The suction pipes are generally to be fitted with:

• auxiliary devices able to lift the suction pipe, in additionto the suction pipe davits

• a sufficient number of attachment points on the suctionpipe itself, to facilitate handling

• a load limiting device to avoid any overload, if the suc-tion pipe is equipped with cutting teeth

• accessories fitted onto the suction pipe built in severalparts to facilitate partial replacements in case of damage.

2.5 Chafing areas

2.5.1 Some parts of the structure subjected to heavy wear,such as longitudinal bulkheads of hopper spaces, may beprotected or reinforced to avoid frequent replacement.

2.5.2 If protection is provided by means of removableplates, called chafing plates, attention is to be paid to avoidcorrosion between the facing sides of these plates and thehopper space plating.

2.5.3 If reinforcement is made by increasing the thickness,the section moduli may be determined taking into accountthe extra thickness, provided that the chafing limits, beyondwhich the plates are to be replaced, are determined accord-ing to the extra thickness values.

If this extra thickness is disregarded in the section modulicalculation, this is to be clearly indicated on the midshipsection drawing.

2.6 Reinforcements for grounding

2.6.1 If grounding is considered for normal operation of theship, the bottom plating and the bottom structure are to bereinforced as indicated in [2.6.2] to [2.6.5].

2.6.2 Along the full length of the ship, in the area of flatbottoms, the bottom net thickness obtained according to PtB, Ch 7, Sec 1 or NR600, Ch 4, Sec 3, as applicable, is to beincreased by 2,5 mm.

2.6.3 Where the ship has a transversely framed double bot-tom, floors are to be fitted at each frame space and associ-ated with intercostal longitudinal girders, the mean spacingof which is to be not greater than 2,10 m.

pillar

longitudinal bulkhead

cellular keel

floor


Pt D, Ch 13, Sec 2

Moreover, intercostal longitudinal ordinary stiffenerslocated at mid-spacing of bottom girders are to be provided.

2.6.4 Where the ship has a longitudinally framed doublebottom, the floor spacing may not exceed three framespaces and the bottom girder spacing may not exceed threelongitudinal ordinary stiffener spaces.

intercostal transverse stiffeners are to be provided at mid-span of longitudinal ordinary stiffeners.

Floors are to be stiffened by vertical stiffeners having thesame spacing as the longitudinal ordinary stiffeners.

2.6.5 Where the ship is built with open hopper spaces (bot-tom doors provided on the bottom), reinforcements asrequired in [2.6.3] or [2.6.4] are to be provided within theside compartments, the cellular keel and, in general, withinthe limits of the flat bottom area.

2.7 Bolted structures

2.7.1 Where the dredger is made of several independentmembers connected by bolting, the connection is to beexamined by the Society on a case-by-case basis.

3 Design loads

3.1 General

3.1.1 Design loads are to be determined for the variousload cases in the following two situations:

• navigation situation, considering the draught T and thenavigation coefficient n

• dredging situation, considering the dredging draught TD

and the navigation coefficient nD.

3.1.2 For dredgers made of bolted structure, the Societymay require the hull girder loads calculated with the maxi-mum length of the unit when mounted to be applied toeach individual element.

3.2 Loading conditions

3.2.1 In addition to the requirements in Pt B, Ch 5, Sec 2,[2.1], as applicable, still water loads are to be calculated forthe following loading conditions:

• homogeneous loading at maximum dredging draught ifhigher than the maximum service draught

• partial loading conditions

• any specified non-homogeneous loading condition, inparticular where dredgers are fitted with several hopperspaces

• navigation conditions with hopper space(s) filled withwater up to the load line

• working conditions at international freeboard with thehopper space(s) filled with spoil

• ballast navigation conditions, with empty hopperspace(s), if applicable.

Calculation of the still water bending moment and shearforce for any loading case corresponding to a special use ofthe ship may be required by the Society on a case-by-casebasis. In particular, in the case of stationary dredgers, thecurve of the still water bending moment, where the suctionpipe is horizontal, is to be submitted to the Society forapproval.

3.3 Hull girder loads for dredgers, hopper dredgers and hopper units of more than 65 m in length

3.3.1 Application

The provisions in [3.3.2] to [3.3.5] apply to ships with oneof the service notations dredger, hopper dredger or hopperunit.

3.3.2 Vertical still water bending moments

In addition to the vertical still water bending momentsMSW,H and MSW, S in navigation situation defined in Pt B, Ch5, Sec 2, [2.2], the vertical still water bending moments indredging situation MSW,H,D and MSW,S,D are also to be consid-ered, in hogging and sagging conditions, respectively.

If the design vertical still water bending moments in dredg-ing situation are not defined at a preliminary design stage,at any hull transverse section, the longitudinal distributionsshown in Pt B, Ch 5, Sec 2, Fig 2 may be considered, whereMSW is the vertical design still water bending moment amid-ships, in dredging hogging or sagging conditions, whoseabsolute values are to be taken not less than the valuesobtained, in kN.m, from the following formulae:

• in hogging conditions:

MSWM, H, D = 175 n1 C L2 B (CB + 0,7) 10−3 − MWV, H, D

• in sagging conditions:

MSWM, S, D = 175 n1 C L2 B (CB + 0,7) 10−3 + MWV, S, D

where MWV, H, D and MWV, S, D are the vertical wave bendingmoments in dredging situation, in kN.m, defined in [3.3.3].

3.3.3 Vertical wave bending moments

In addition to the vertical wave bending moments MWV, H

and MWV, S in navigation situation defined in Pt B, Ch 5, Sec2, [3.1], the vertical wave bending moments in dredging sit-uation at any hull transverse section are to be obtained, inkN.m, from the following formulae:

• in hogging conditions:

MWV, H, D = 190 FM nD C L2 B CB 10−3

• in sagging conditions:

MWV, S, D = − 110 FM nD C L2 B (CB + 0,7) 10−3

where:

FM : Distribution factor defined in Pt B, Ch 5, Sec 2,Tab 1 (see also Pt B, Ch 5, Sec 2, Fig 3)

nD : Coefficient defined in Tab 1 depending on theoperating area, without being taken greater thann.


Pt D, Ch 13, Sec 2

Table 1 : Coefficient nD in dredging situation

3.3.4 Horizontal wave bending moments

In addition to the horizontal wave bending moment MWH innavigation situation defined in Pt B, Ch 5, Sec 2, [3.2], thehorizontal wave bending moment in dredging situation atany hull transverse section is to be obtained, in kN.m, fromthe following formula:

MWH, D = 0,42 FM nD H L2 TD CB

3.3.5 Vertical wave shear forces

In addition to the vertical wave shear force QW in naviga-tion situation defined in Pt B, Ch 5, Sec 2, [3.4], the verticalwave shear force in dredging situation at any hull transversesection is to be obtained, in kN, from the following formula:

QW, D = 30 FQ nD C L B (CB + 0,7) 10−2

where FQ is the distribution factor defined in Pt B, Ch 5, Sec2, Tab 3 (see also Pt B, Ch 5, Sec 2, Fig 6).

3.4 Hull girder loads for split hopper dredgers and split hopper units of more than 65 m in length

3.4.1 Application

The provisions in [3.4.2] to [3.4.8] apply to ships with oneof the service notations split hopper dredger or split hopperunit.

3.4.2 General

Horizontal bending moments are to be calculated assumingthat the hopper well is simply supported at each end.

The clearance between the two half-hulls is to be largeenough not to be suppressed when the hopper well is fullup.

Details of the calculation of the necessary clearances are tobe submitted to the Society for review.

However, the calculation of the horizontal moments is car-ried out assuming that both ends of the hopper well arepartly clamped, on condition that at deck and bottom levelchocks are provided forward and aft of the well so that:

• the clearance between the two half-hulls is nil

• the chocks are long enough to withstand the endmoments due to the horizontal forces developed alongthe hopper well.

3.4.3 Vertical still water bending moments

The vertical still water bending moments to be applied onone half-hull in navigation and dredging situations are to betaken equal respectively to half the vertical still water bend-ing moments defined in:

• Pt B, Ch 5, Sec 2, [2.2] for navigation situation

• [3.3.2] for dredging situation.

3.4.4 Vertical wave bending moments

The vertical wave bending moments to be applied on onehalf-hull in navigation and dredging situations are to betaken equal respectively to half the vertical wave bendingmoments defined in:

• Pt B, Ch 5, Sec 2, [3.1] for navigation situation

• [3.3.3] for dredging situation.

3.4.5 Horizontal still water bending moments

The horizontal still water bending moments to be appliedon one half-hull in navigation and dredging situations are tobe obtained, in kN.m, from the formulae given in Tab 2,assuming that the hopper well is simply supported at eachend.

If the hopper well may not be considered as simply sup-ported at each end, the horizontal still water bendingmoments to be applied on one half-hull in navigation anddredging situations are to be determined on a case by casebasis.

Table 2 : Split hopper dredgers and split hopper units Horizontal still water bending moment on half-hulls

Operating area nD

Associated HS , in m

L ≤ 110 m 110 m < L ≤ 150 m 150 m < L ≤ 180 m

dredging within 8 miles from shore 1/3 HS < 1,5 HS < 2,0 HS < 2,0

dredging within 15 miles from shore or within 20 miles from port

2/3 1,5 ≤ HS < 2,5 2,0 ≤ HS < 3,0 2,0 ≤ HS < 3,5

dredging over 15 miles from shore 1 HS ≥ 2,5 HS ≥ 3,0 HS ≥ 3,5

Note 1:HS : Maximum significant wave height, in m, for operating area in dredging situation, according to the operating area nota-

tion assigned to the ship (see Pt A, Ch 1, Sec 2, [4.6.3]).

Horizontal still water bending moment MSHH , in kN.m

Hopper well mid-section (1) Hopper well ends (1)

0

(1) Between hopper well mid-section and ends, the valueof the horizontal still water bending moment is to beobtained by linear interpolation.

Note 1:p : Load per metre, in kN/m, applied along the hop-

per well, defined in Tab 3 depending on theloading condition

c1 : Distance, in m, from deck hinges to ends ofhopper well (see Fig 6).

18--- c1

2p--------+

pp2–


Pt D, Ch 13, Sec 2

Table 3 : Load per metre applied along the hopper well

Figure 6 : Definitions of dimensionsin hopper well area

Figure 7 : Definitions of distances for calculationof the load applied along the hopper well

3.4.6 Horizontal wave bending moments

The horizontal wave bending moments to be applied onone half-hull in navigation and dredging situations are to beobtained, in kN.m, from the formulae given in Tab 4,assuming that the hopper well is simply supported at eachend.

If the hopper well may not be considered as simply sup-ported at each end, the horizontal still water bendingmoments to be applied on one half-hull in navigation anddredging situations are to be determined on a case by casebasis.

Table 4 : Split hopper dredgers and split hopper unitsHorizontal wave bending moment on half-hulls

3.4.7 Combined still water and wave vertical bending moment

In the midship area, the total vertical bending moment MV

to be applied on half-hull is to be obtained, in kN.m, fromTab 5.

At hopper well ends, the total bending moment MV is to bedetermined in accordance with Tab 5 considering:

• for the still water vertical bending moment: the greaterof the values at the fore and aft hopper well ends

• for the vertical wave bending moment: the longitudinaldistribution defined in Pt B, Ch 5, Sec 2, Tab 1.

3.4.8 Combined still water and wave horizontal bending moment

The total horizontal bending moment MH applied on half-hull at hopper well mid-section and at hopper well ends, innavigation and dredging situations, is to be obtained, inkN.m, from the following formula:

MH = MSHH + MWHH

where:

MSHH : Horizontal still water bending moment, definedin [3.4.5] at hopper well mid-section and athopper well ends, in navigation and dredgingsituations

MWHH : Horizontal wave bending moment, defined in[3.4.6] at hopper well mid-section and at hop-per well ends, in navigation and dredging situa-tions.

Loading condition p, in kN/m

Maximum loading atdredging draught

Loading corresponding tointernational freeboard withwell full of spoil

Service condition with wellfilled with water up to thewaterline

0

Service condition with wellfilled with water up to thelowest weir level

δ h1 a–( )2 1 025 TD a–( )2,–2

---------------------------------------------------------------------g

δ h2 a–( )2 1 025 T a–( )2,–2

------------------------------------------------------------------g

1 025 h4 a–( )2 T4 a–( )2–[ ],2

----------------------------------------------------------------------g

hopper well

�p

hinges

C1 C1

�D

T o

r TD

h o

r h

12

a

Horizontal wave bending moment MWHH , in kN.m

Hopper well mid-section (1)Hopper well

ends (1)

Navigation situation:

0

Dredging situation:

0

(1) Between hopper well mid-section and ends, the valueof the horizontal wave bending moment is to beobtained by linear interpolation.

Note 1:T : Draught, in m, corresponding to the loading

condition consideredMWV : Vertical wave bending moment, in kN.m,

defined in:• Pt B, Ch 5, Sec 2, [3.1] for the navigation

situation• [3.3.3] for the dredging situation.

T 0 079Cn 2D

L----- 1–

CB 0 7,+( ),+MWV

B------------

T 0 079CnD 2D

L----- 1–

CB 0 7,+( ),+MWV

B------------


Pt D, Ch 13, Sec 2

Table 5 : Vertical bending moment applied on half-hull

3.5 Internal pressures for hopper well in dredging situation

3.5.1 Still water pressure for hopper wellThe still water pressure to be used in connection with theinertial pressure in [3.5.2] is to be obtained, in kN/m2, fromthe following formula:

pS = g δ1 dD , to be taken not less than 11,0

where:δ1 : Coefficient equal to:

δ1 = δ for δ < 1,4 δ1 = δ + (1,4 − δ) sin2α for δ ≥ 1,4

dD : Vertical distance, in m, from the calculationpoint to the highest weir level with the corre-sponding specific gravity of the mixture of seawater and spoil

α : Angle, in degrees, between the horizontal planeand the surface of the hull structure to whichthe calculation point belongs.

3.5.2 Inertial pressure for hopper wellThe inertial pressure is to be obtained from Tab 6.

4 Hull girder strength of dredgers, hopper dredgers and hopper units

4.1 General

4.1.1 The hull girder strength of ships with one of the serv-ice notations dredger, hopper dredger or hopper unit is tobe checked for navigation situation and dredging situationaccording to the criteria of:• Part B, Chapter 6 for ships of more than 65 m in length,

considering the still water and wave bending momentsdefined in [3.3]

• NR600, Ch 4, Sec 2 for ships of less than 65 m in length.

Table 6 : Ships for dredging activitiesInertial pressure for hopper well

4.1.2 For dredgers made of bolted structure, the Societymay require the hull girder strength criteria to be applied toeach individual element, considering the loads calculatedaccording to [3.1.2].

4.2 Midship section modulus

4.2.1 In the determination of the midship section modulusaccording to Pt B, Ch 6, Sec 1, [2.3] or NR600, Ch 4, Sec 2,as applicable, account is to be taken of both 85% and100% effectiveness of the sectional area of the cellular keel.

However the 85% and 100% effectiveness of the sectionalarea of the cellular keel may be replaced by the actualeffectiveness of the cellular keel determined by a threedimensional finite element analysis.

4.2.2 Where cut-outs in the side shell are needed to fit thesuction pipe guides, a section modulus calculation not tak-ing account of the side shell plating may be required by theSociety on a case-by-case basis, if the structural continuityis not correctly achieved.

4.3 Ultimate strength check for ships of more than 65 m in length

4.3.1 In addition to requirements of Pt B, Ch 6, Sec 3, theultimate strength of the hull girder is to be checked, indredging situation, for ships of more than 65 m in lengthwhich comply with the following formula:

where:

ZR,MIN : Minimum gross section modulus, in m3, definedin Pt B, Ch 6, Sec 2, [4.2.2]

MSW,D : Vertical still water bending moment in dredgingsituation, in kN.m, as defined in [3.3.2], in hog-ging and sagging conditions

MWV,D : Vertical wave bending moment in dredging situ-ation, in kN.m, as defined in [3.3.3], in hoggingand sagging conditions.

ConditionVertical bending moment MV , in kN.m

Navigation situation Dredging situation

Hogging

Sagging

Note 1:MSW, H , MSW, S : Still water vertical bending moment in naviga-

tion situation in hogging and sagging condition,respectively, defined in Pt B, Ch 5, Sec 2, [2.2]

MWV, H , MWV, S : Wave vertical bending moment in navigationsituation in hogging and sagging condition, respec-tively, defined in Pt B, Ch 5, Sec 2, [3.1]

MSW, H, D , MSW, S, D : Still water vertical bending moment indredging situation, in hogging and sagging con-dition, respectively, defined in [3.3.2]

MWV, H, D , MWV, S, D : Wave vertical bending moment in dredg-ing situation, in hogging and sagging condition,respectively, defined in [3.3.3].

MSW H, MWV H,+2

-------------------------------------- MSW H D,, MWV H D,,+2

----------------------------------------------

MSW S, MWV S,+2

------------------------------------ MSW S D,, MWV S D,,+2

--------------------------------------------

Ship condition Load case Inertial pressure pW, in kN/m2

Uprightcondition

“a” No inertial pressure

“b” The greater of:

Inclinedcondition

“c” and “d”

The greater of:

Note 1: The accelerations aX1, aZ1, aY2 and aZ2 are to be deter-mined according to Pt B, Ch 5, Sec 3, [3.4], considering theship in dredging situation, i.e. considering the draught equalto the dredging draught TD.

δ1 aX12 aZ1

2+ dD

11 0,

CFAδ1 aY22 aZ2

2+ dD

11 0,

ZR MIN,MSW D, MWV D,+

175 k⁄--------------------------------------------10 3–<


Pt D, Ch 13, Sec 2

5 Hull girder strength of split hopper dredgers and split hopper units

5.1 General

5.1.1 The yielding check of ships with one of the servicenotations split hopper dredger or split hopper unit and ofmore than 65 m in length is to be carried out for navigationsituation and dredging situation according to [5.2] to [5.4]considering:

• each half-hull as being subjected to independent bend-ing

• the deck hinges and the hydraulic jacks acting as sup-ports at the ends of the hopper well.

Both the vertical bending moment and horizontal bendingmoment acting within the well area are to be taken intoaccount.

5.1.2 The hull section modulus, considered with the twohalf-hulls connected is to be checked for navigation situa-tion and dredging situation according to the criteria of:

• Pt B, Ch 6, Sec 2, [4] for ships of more than 65 m inlength, considering the still water and wave bendingmoments defined in [3.4]

• NR600, Ch 4, Sec 2 for ships of less than 65 m in length.

See also [4.2] for the determination of the midship sectionmodulus.

5.2 Definitions

5.2.1 Co-ordinate system

The hull girder strength is defined with reference to the fol-lowing co-ordinate system, as shown in Fig 8:

G : Centre of gravity of the transverse section

GY : Transverse axis, parallel to Y defined in Pt B, Ch1, Sec 2, [4] and crossing through G

GZ : Vertical axis, parallel to Z defined in Pt B, Ch 1,Sec 2, [4] and crossing through G

Gy, Gz : Main axes of the transverse section, defined in[5.2.2].

Figure 8 : Half-hull co-ordinate system

5.2.2 Main axesThe main axes Gy and Gz are obtained from the axes GYand GZ by a rotation around the centre of gravity G of anangle α obtained from the following formula:

where:IY : Moment of inertia, in m4, of the transverse sec-

tion around the axis GYIZ : Moment of inertia, in m4, of the transverse sec-

tion around the axis GZIYZ : Inertia product, in m4, of the transverse section,

in the reference (G, GY, GZ).

5.2.3 Bending momentsThe bending moments My and Mz in relation to the mainaxes Gy and Gz, respectively, are to be obtained, in kN.m,from the following formulae:

My = MV cos α + MH sin α

Mz = − MV sin α + MH cos α

where:MV : Vertical bending moment defined in [3.4.7], in

kN.m, to be considered in hogging and saggingconditions, for the navigation and dredging situ-ations

MH : Horizontal bending moment defined in [3.4.8],in kN.m, to be considered for the navigationand dredging situations

α : Angle defined in [5.2.2].As the main inertia axes of each half-hull are oblique, thebending of each half-hull is a deviated bending.

5.3 Hull girder stress

5.3.1 At any point of the transverse section of each half-hull, the hull girder normal stresses are to be obtained, inN/mm2, from the following formula:

where:My, Mz : Bending moments, in kN.m, in hogging and

sagging conditions, for the navigation anddredging situations, defined in [5.2.3]

IyM, IzM : Moments of inertia, in m4, of the transverse sec-tion around its main axes

y, z : y and z coordinates, in m, of the calculationpoint with respect to the main axes Gy and Gz.

5.3.2 In the case of partly clamped ends of the hopper well(see [3.4.2]), the hull girder normal stresses are to be calcu-lated in the hopper well mid-section and at hopper wellends. In this case, the stresses are also to be calculated in themidship area assuming the ends supported as regards thehorizontal moment. This calculation relates to the begin-ning of the hopper well drainage by opening of the twohalf-hulls.

Z

z

y

YG

α

α 12--- 2IYZ

IZ IY–-------------- atan=

σ1 zMy

IyM

------- yMz

IzM

-------– 10 3–=


Pt D, Ch 13, Sec 2

5.3.3 In the case of supports at hopper well ends, the cal-culation of the hull girder normal stress is to be carried outin the hopper well mid-section.

5.3.4 For each section of calculation, the most unfavoura-ble combination of moments is to be considered.

5.4 Checking criteria

5.4.1 It is to be checked that the normal stresses calculatedaccording to [5.3.1] are in compliance with the followingformula:

σ1 ≤ σ1,ALL

where:

σ1,ALL : Allowable normal stress, in N/mm2, defined inPt B, Ch 6, Sec 2, [3.1.2].

6 Hull scantlings

6.1 General

6.1.1 Hull scantlings are to be checked according to theapplicable requirements of Part B, Chapter 7 or NR600, Ch4, Sec 3, as applicable, for the following two situations:

• navigation situation, considering the draught T and thenavigation coefficient n

• dredging situation, considering the dredging draught TD

and the navigation coefficient nD.

For ships with one of the service notations split hopperdredger or split hopper unit, and of more than 65 m inlength, the hull girder normal stresses to be used in theapplication of requirements of Part B, Chapter 7 are definedin [6.2].

6.2 Hull girder normal stress for split hopper dredgers and split hopper units of more than 65 m in length

6.2.1 Strength check of plating and yielding check of ordinary stiffeners and primary supporting members

The hull girder normal stress σX1 to be considered for thestrength check of plating according to Pt B, Ch 7, Sec 1, [3],for the yielding check of ordinary stiffeners according to PtB, Ch 7, Sec 2, [3] and for the yielding check of primarysupporting members analysed through an isolated beamstructural model according to Pt B, Ch 7, Sec 3, [3] is to beobtained, in N/mm2, from Tab 7.

where:

My, Mz : Bending moments, in kN.m, in hogging andsagging conditions, for the navigation anddredging situations, taken equal to:

My = MV cos α + MH sin α

Mz = − MV sin α + MH cos α

IyM, IzM : Net moments of inertia, in m4, of the transversesection around its main axes

Table 7 : Hull girder normal stress for hull scantlings of split hopper dredgers and split hopper units

y, z : y and z coordinates, in m, of the calculationpoint with respect to the main axes Gy and Gz

MV : Vertical bending moment applied on half-hulldefined in Tab 8, in kN.m, to be considered inhogging and sagging conditions, for the naviga-tion and dredging situations

MH : Horizontal bending moment applied on half-hull, in kN.m, to be considered for the naviga-tion and dredging situations and taken equal to:

α : Angle defined in [5.2.2]

MSHH : Horizontal still water bending moment, definedin [3.4.5] in hopper well mid-section and athopper well ends

MWHH : Horizontal wave bending moment, defined in[3.4.6] in hopper well mid-section and at hop-per well ends

CFV, CFH : Combination factors defined in Tab 9.

6.2.2 Buckling check of plating, ordinary stiffeners and primary supporting members

The hull girder normal stress σX1 to be considered for thebuckling check of plating according to Pt B, Ch 7, Sec 1,[5], for the buckling check of ordinary stiffeners accordingto Pt B, Ch 7, Sec 2, [3] and for the buckling check of platepanels constituting primary supporting members accordingto Pt B, Ch 7, Sec 3, [6.1] is to be taken as the maximumcompressive stress obtained according to [6.2.1].

Structural elementNormal stress σX1,

in N/mm2

• Plating contributing to the hullgirder longitudinal strength

• Longitudinal primary supportingmembers contributing to the hullgirder longitudinal strength

• Longitudinal stiffeners contribut-ing to the hull girder longitudi-nal strength

to be taken not less than 60/k

• Plating not contributing to thehull girder longitudinal strength

• Longitudinal stiffeners not con-tributing to the hull girder longi-tudinal strength

• Transverse stiffeners • Longitudinal primary supporting

members not contributing to thehull girder longitudinal strength

• Transverse primary supportingmembers

0

zMy

IyM

------- yMz

IzM

-------– 10 3–

zMy

IyM

------- yMz

IzM

-------– 10 3–

MH γS1MSHH 0 625γW1CFHMWHH,+=


Pt D, Ch 13, Sec 2

Table 8 : Vertical bending moment applied on half-hull

Table 9 : Combination factors CFV and CFH

6.3 Minimum net thicknesses of plating

6.3.1 The net thickness of plating is to be not less than thegreater of the following values:

• 5 mm

• thickness, in mm, obtained from Tab 10.

Table 10 : Ships for dredging activitiesMinimum net thicknesses of plating

6.3.2 When no protection is fitted on the deck areas whereheavy items of dredging equipment may be stored for main-tenance, the net thickness of the deck plating is to be notless than the value obtained, in mm, from the following for-mula:

t = 5,1 + 0,040 L k1/2 + 4,5 s

6.4 Bottom plating

6.4.1 Where the bottom is longitudinally framed and thebilge is made of a transversely framed sloped plate, the bot-tom is to be assumed as being transversely framed whencalculating the plating thickness.

6.4.2 The net thickness of the bottom strake, to which thelongitudinal bulkheads of the hopper space are connected,is to be not less than the greater of the following thick-nesses: • bottom plating thickness increased by 15%• keel thickness.

6.5 Ordinary stiffeners

6.5.1 The partial safety factor γR to be considered for theyielding checking of ordinary stiffeners in dredging situation,according to Pt B, Ch 7, Sec 2, [3], is defined in Tab 11.

6.5.2 In addition to the requirements of Pt B, Ch 7, Sec 2,[3] the net section modulus w, in cm3, of bottom, lowerhopper and side ordinary stiffeners is to be not less than thevalue obtained from the following formula:

where:γm, γS2, γW2: Partial safety factors as defined in Pt B, Ch 7,

Sec 2, [1.2.1]γR : Partial safety factor for resistance as specified in

Tab 11βb : Coefficients as defined in Pt B, Ch 7, Sec 2,

[3.4.2]

ConditionVertical bending moment MV , in kN.m

Navigation situation Dredging situation

Hogging

Sagging

Note 1:MSW, H , MSW, S : Still water vertical bending moment in navigation situation in hogging and sagging condition, respectively, defined in

Pt B, Ch 5, Sec 2, [2.2]MWV, H , MWV, S : Wave vertical bending moment in navigation situation in hogging and sagging condition, respectively, defined in Pt B,

Ch 5, Sec 2, [3.1]MSW, H, D , MSW, S, D : Still water vertical bending moment in dredging situation, in hogging and sagging condition, respectively, defined

in [3.3.2]MWV, H, D , MWV, S, D : Wave vertical bending moment in dredging situation, in hogging and sagging condition, respectively, defined in

[3.3.3].

γS1MSW H, 0 625γW1CFVM, WV H,+2

---------------------------------------------------------------------------------γS1MSW H D,, 0 625γW1CFVM, WV H D,,+

2-----------------------------------------------------------------------------------------

γS1MSW S, 0 625γW1CFVM, WV S,+2

-------------------------------------------------------------------------------γS1MSW S D,, 0 625γW1CFVM, WV S D,,+

2---------------------------------------------------------------------------------------

Load case CFV CFH

“a” 1,0 1,0

“b” 1,0 1,0

“c” 0,4 1,0

“d” 0,4 1,0

PlatingMinimum net thickness,

in mm

Keel 5,1 + 0,040 L k1/2 + 4,5 s

Bottom• transverse framing• longitudinal framing

4,3 + 0,036 L k1/2 + 4,5 s3,4 + 0,036 L k1/2 + 4,5 s

Inner bottom outside hopperspaces

2,0 + 0,025 L k1/2 + 4,5 s

Side• below freeboard deck• between freeboard deck and

strength deck

2,5 + 0,031 L k1/2 + 4,5 s2,5 + 0,013 L k1/2 + 4,5 s

Strength deck within 0,4Lamidships• transverse framing• longitudinal framing

2,5 + 0,040 L k1/2 + 4,5 s2,5 + 0,032 L k1/2 + 4,5 s

Hopper well• transverse and longitudinal

bulkheads• cellular keel plating

2,7 + 0,034 L k1/2 + 4,5 s

2,7 + 0,034 L k1/2 + 4,5 s

w γRγmβbγS2pS γW2pW+

24 RY γRγmσX1–( )------------------------------------------- 1 s

2------–

s2103=


Pt D, Ch 13, Sec 2

Table 11 : Ordinary stiffenersValue of γR in dredging situation

ps, pw : Still water and wave pressures corresponding todredging situation considering only load cases"a" and "c"

σX1 : Hull girder normal stress, in N/mm2, obtainedfrom the following formula:

• for hopper dredgers:

• for split hopper dredgers, σX1 is to be calcu-lated in accordance with Tab 7

σS1, σWV1, σWH1: Hull girder normal stresses, in N/mm2,defined in Tab 12

CFV, CFH : Combination factors defined in Pt B, Ch 7, Sec2, [3]

6.6 Well bulkhead and cellular keel platings

6.6.1 The net thickness of hopper well bulkhead platingand cellular keel plating is to be not less than the net thick-ness obtained:

• in dredging situation, considering the internal pressuresdefined in [3.5].

• in navigation situation, where the hopper well bulkheadslimit tank compartments, considering the internal pres-sures defined in Pt B, Ch 5, Sec 6, [1] or NR600, Ch 4,Sec 2, as applicable.

6.6.2 The net thickness of the longitudinal bulkhead abovethe deck or within 0,1D below the deck is to be not lessthan the net thickness of the strength deck abreast of thehatchways.

6.6.3 The net thickness of the transverse and longitudinalbulkhead of a dredgepipe well is to be determined as for theside shell net thickness.

6.7 Transversely framed bottoms

6.7.1 Floors

The scantlings of floors located inside large compartments,such as pump rooms, are to be obtained from a direct cal-culation, according to Pt B, Ch 7, App 1 as applicable, andtaking into account the following assumptions:

• floors are simply supported at ends

• local discontinuities in strength, due to the presence ofwells, are to be considered.

7 Hopper dredgers and hopper units: checking of hopper well structure

7.1 General

7.1.1 The requirements in [7.1] to [7.2] apply to ships withone of the service notations hopper dredger or hopper unit.

7.1.2 At the ends of the hopper spaces, the transverse bulk-heads are to extend over the full breadth of the ship. Wherethis is not the case, web rings with special scantlings are tobe provided.

7.2 Floors, webs, trunks, strongbeams and girders

7.2.1 Stresses in transverse primary members (such asfloors, webs, trunks, strongbeams and girders) are to beobtained by a 2D or 3D beam model or FEM with the fol-lowing assumptions:

• design loads as specified by the Designer

• load cases according to Part B, Chapter 5 or NR600, asapplicable. Load cases "c" and "d" may be disregardedon a case-by-case basis.

7.2.2 Stresses obtained according to [7.2.1] need to becombined with hull girder longitudinal stresses obtainedaccording to Part B, Chapter 6 or NR600, as applicable.

7.2.3 It is to be checked that stresses obtained according to[7.2.1] and [7.2.2] are not greater than the allowable stressesdefined in Pt B, Ch 7, Sec 3 or NR600, as applicable, con-sidering the partial safety factor γR defined in Tab 13.

Table 12 : Hull girder normal stresses for hopper dredgers

Condition γR

Defined in Pt B, Ch 7, Sec 2,Tab 1

• σX1 ≤ 60/k (1) Defined in Pt B, Ch 7, Sec 2,Tab 1

• σX1 > 60/k (1) 1,20

(1) σX1 : Hull girder normal stress in dredging situa-tion, in N/mm2, obtained according to PtB, Ch 7, Sec 2, [3.3.6].

Note 1:ZR,MIN, MSW and MWV are defined in [4.3.1].

ZR MIN,MSW MWV+

175 k⁄-----------------------------------10 3–≥

ZR MIN,MSW MWV+

175 k⁄-----------------------------------10 3–<

σX1 γS1σS1 γW1 CFVσWV1 CFHσWH1+( )+=

Condition σS1 σWV1 σWH1

Lateral pressure applied on the side opposite to the ordinary stiffener, with respect to the plating

Lateral pressure applied on the same side as the ordinary stiffener

Need not be considered.

MSW S,

IY--------------- z N–( ) 10 3– 0.625FDMWV S,

IY------------------------------------- z N–( ) 10 3– 0.625MWH

IZ----------------------------y 10 3–


Pt D, Ch 13, Sec 2

Table 13 : Partial safety factor γR

7.2.4 Alternatively, the transverse strength of the hopperwell structure can be calculated considering the guidanceprovided in Ch 13, App 1.

8 Split hopper dredgers and split hopper units: superstructure hinges

8.1 General

8.1.1 For ships with one of the service notations split hop-per dredger or split hopper unit, a check of the superstruc-ture hinges according to [8.5] is to be carried outconsidering the forces defined in [8.4].

8.2 Arrangements

8.2.1 Chocks able to withstand the longitudinal forcesinduced by the superstructures are generally to be fitted onthe deck located below the superstructures.

8.2.2 When the chocks are fitted on one side only, atten-tion is to be paid to the longitudinal take over of forces bythe hinges located on the side opposite to the chocks.

8.2.3 Chocks are to be able to work when the half-hullsswing apart to discharge the spoil.

8.2.4 Special attention is to be paid to the reinforcementbelow the deck in way of the hinges and chocks, as well asto the fixing of the hinge to the strength members of thesuperstructures.

The scantlings of these members are to be calculated con-sidering the forces given in [8.4.3] applied at the level of thehinge pin.

8.2.5 Generally, no cut-out is to be fitted immediately nearto hinges or chocks.

8.3 Materials used for the hinges

8.3.1 Grades of hull steel plates

In normal service conditions, the hull steel plates are to beof the grade defined in Tab 14.

Moreover, in low temperature service conditions, thechoice of the steel grade is to be made with the Society on acase-by-case basis, according to the actual service condi-tions and to the design detail of the welded assembly.

Table 14 : Material grade requirements for superstructure hinges

8.3.2 Grades of steel castings and steel forgings

The steel grade of the steel castings and steel forgings is tobe defined according to the service temperature of the partand to the weld location on the part.

8.3.3 Grades of steel for hinge pins

The hinge pins are generally to be made of forged steel.

In addition to the rule checks defined in NR216 Materials,Part D, Chapter 2, a series of impact tests is to be carried outon three Charpy V test pieces and the minimum mean valueof impact energy KVL is to be equal to or greater than 27 J at0°C.

8.3.4 Inspections and tests of weld connections

For welds concerning the main members of the hinges, non-destructive examinations are to be carried out along the fulllength of the joint:

• for butt welds: 100% radiographic and ultrasonic exam-ination

• for fillet welds with deep penetration: 100% ultrasonicexamination and 100% magnetic particle inspection orpenetrant fluid test

• for fillet welds with small penetration: 100% magneticparticle inspection or penetrant fluid tests.

8.4 Forces

8.4.1 The forces defined in [8.4.2] to [8.4.4] may bereplaced by results from model tests or by representativecalculations.

In such case, the method used and the assumed conditionsfor model tests or calculation are to be submitted to theSociety for information.

8.4.2 The forces applied on superstructures are to beobtained, in kN, from the following formulae:

• in x direction:

FX = FW,X

• in y direction:

FY = FW,Y

• in z direction:

FZ = FS + FW,Z

where FS , FW,X , FW,Y , FW,Z are to be obtained from the formu-lae in Pt B, Ch 5, Sec 6, [5] or NR600, Chapter 3, as appli-cable, in which M is, in t, the mass of the superstructures.

Type of calculation Partial safety factor γR

Beam model 1,10

Coarse mesh finite element model 1,05

Fine mesh finite element model 1,02

Gross thickness,in mm

Normal strength steel

Higher strength steel

t ≤ 20 A AH

20 < t ≤ 25 D DH

25 < t ≤ 30 E DH

t > 30 E EH


Pt D, Ch 13, Sec 2

8.4.3 In the case of superstructures connected to the shipby means of two simple hinges and two hinges with con-necting tie-rods (as shown in Fig 9 and Fig 10), the forcesare to be obtained, in kN, from the following formulae:

• force in line with a tie-rod:

• vertical force in a simple hinge:

• transverse force in a hinge:

• longitudinal force for each chock:

where:

β : Angle of tie-rods with respect to the verticalline, in degrees

dT : Transverse distance between a simple hinge anda tie-rod hinge, in m

dV : Vertical distance from the centre of gravity ofthe superstructures to the horizontal plane pass-ing through the hinge centreline, in m

dL : Longitudinal distance between the fore and afthinges, in m

εT : Transverse eccentricity of the centre of gravity ofthe superstructures (taken as positive if the cen-tre of gravity is on the side of the simple hinges,and as negative otherwise), in m

εL : Longitudinal eccentricity of the centre of gravityof the superstructures (positive), in m

nB : Number of longitudinal chocks.

Where a longitudinal chock is provided on one side only,the hinges are to be able to withstand the longitudinal forceFX.

The distribution of forces in the case of other arrangementsis to be examined by the Society on a case-by-case basis.

Figure 9 : Connection between superstructureand ship - Transverse direction

Figure 10 : Connection between superstructureand ship - Longitudinal direction

8.4.4 The force F to be considered for the check of thehinge scantlings is to be taken equal to:• for a simple hinge:

the resultant of the horizontal and vertical forces• for a hinge with tie-rod:

the force in the tie-rod centreline.

Moreover, the horizontal force in the hinges due to with-standing of the longitudinal force FX in the case of a hori-zontal chock on one side only is to be considered alone.

8.5 Scantlings of the hinges

8.5.1 The hinges consist generally of two side straps and acentre eye connected by a pin, as shown in Fig 11.

Figure 11 : Superstructure hinge arrangement

The two main types of hinges are generally the following:• type I: welded assembly made of plates, as shown in Fig

12• type II: welded assembly made of plates and of cast

steel or forged steel parts, as shown in Fig 13.

The check of scantlings in [8.5.2] applies to the case ofdirect bearing of the pin on the side straps and the centreeye (see Fig 14) and to the case of load transfer by bearings(see Fig 15). In the second case, the designer is to demon-strate that the bearings can withstand the calculated forces.

Hinges whose manufacture is different from these two casesare to be examined by the Society on a case-by-case basis.

Figure 12 : Type I superstructure hinges

F 1βcos

------------- 12--- εL

dL

-----+ 1

2--- εT

dT

-----– FZ

dV

dT

-----FY+=

F 12--- εL

dL

-----+ 1

2--- εT

dT

-----+ FZ

dV

dT

-----FY+=

F 12--- εL

dL

-----+ 1

2--- εT

dT

-----– FZ βtan 1

dV

dT

----- βtan– FY+=

FFX

nB

-----=

�

�G

dv

d

T

T

G�L

dL

e


Pt D, Ch 13, Sec 2

8.5.2 For the pins, centre eye and side straps of the hinges,the applied forces are to comply with the formulae given inTab 15.

Figure 13 : Type II superstructure hinges

Figure 14 : Superstructure hinges:case of direct bearing

Figure 15 : Superstructure hinges:case of load transfer by bearings

9 Split hopper dredgers and split hopper units: decks hinges, hydraulic jack connections and chocks

9.1 General

9.1.1 For ships with one of the service notations split hop-per dredger or split hopper unit, the scantlings of the deckhinges and the hydraulic jack attachments connecting thetwo half-hulls are to be determined according to [9.5] or bydirect calculation.

The loads to be considered are the result of the most unfa-vourable combination of simultaneous static and dynamicforces (see [9.3] and [9.4]), calculated for the loading con-ditions in [3.2.1].

9.1.2 The locking devices of the two half-hulls, if any, areto be examined by the Society on a case-by-case basis.

9.2 Arrangements

9.2.1 Transverse chocks to be used upon closing the twohalf-hulls are to be provided in the bottom area, preferablyin way of the hydraulic cylinders. These chocks may consistof heavy plates inserted in the bottom plating. They are tobe arranged to come into contact before the end of thestroke of the jack, upon closing.

Moreover, if the calculation of the longitudinal strength iscarried out assuming the hopper well ends are partly fixed,transverse chocks are to be provided at deck level.

9.2.2 Longitudinal chocks are to be provided at bottom anddeck level, to prevent relative displacement of the two half-hulls.

Deck longitudinal chocks must also act in the open posi-tion.

For units of a capacity less than 700 m3, longitudinal deckchocks need not be provided; in such case, one of the twodeck hinges is to be designed to fulfil the function of achock. The other hinge is then to have sufficient clearance.

9.3 Static forces

9.3.1 The method of calculation in [9.3.2] to [9.3.9] ena-bles the determination of the static forces in the hydraulicjack, in the chocks and in the deck hinges only if the follow-ing conditions are met:

• the total number of hydraulic jacks connecting the twohalf-hulls is even

• there are no superposed jacks in the same section

• there is a deck hinge at each end of the hopper well.

Any other arrangement is to be examined by the Society ona case-by-case basis.

9.3.2 In the case of maximum loading corresponding to thedredging freeboard, the forces exerted on a half-hull to beconsidered to calculate the static forces in the hinges, trans-verse bottom chocks and jacks are shown in Fig 16 as wellas their lever arm in relation to the deck hinge pins.

bd

t c

t0

Dc

ba

c0

t c

tc

t2

t0

t1

t�

t2

d ao d a

b cd a

c

b o

DC1

tc


Pt D, Ch 13, Sec 2

Table 15 : Scantling check of superstructures hinges

Figure 16 : Forces exerted on a half-hull

9.3.3 The horizontal static forces to be considered are thefollowing:

• horizontal hydrostatic buoyancy Fh on the full length ofthe well, in kN. This force takes into account the hydro-static buoyancy due to the water located between thetwo half-hulls below the sealing joint situated at thelower part of the hopper well, taken equal to:

Fh = 5,026 (TD − a)2 p

• horizontal pressure of the spoil Fd, in kN, taken equal to:

Fd = 4,904 δ (h1 − a)2 p

• force FCY in each jack, in kN, equal to the greater of FMC

and Fp

• force FCH in each hinge, in kN, taken equal to:

CaseElements to be checked

Pins Centre eye Side straps

Direct bearing

• if t0 < da:

• if t0 ≥ da:

Load transfer by bearings

• if t3 < da:

• if t3 ≥ da:

Note 1:Rrad : Admissible radial pressure on the bearing, to be taken equal to 100 N/mm2.

Fda

2Rm

5 76,-------------10 3–<

F 23---dat0ReH10 3–<

Fda

3

2DC t0–---------------------Rm

5-------10 3–<

Fda

3

2DC 2t0– da+------------------------------------Rm

5-------10 3–<

Fb0t0ReH

2 27,-------------------10 3–<

F dat0Rrad10 3–<

FbCtCReH

1 14,--------------------10 3–<

F 2datCRrad10 3–<

Fda

2Rm

5 76,-------------10 3–<

F 23---dat3ReH10 3–<

Fda

3

2DC1 t3–-----------------------Rm

5-------10 3–<

Fda

3

2DC1 2t3– da+---------------------------------------Rm

5-------10 3–<

Fb0t0ReH

2 27,-------------------10 3–<

F 23---da0t1ReH10 3–<

FbCtCReH

1 14,--------------------10 3–<

F 43---daCt2ReH10 3–<

Fch

Q/2

b3

a4

a2

a 1

b2

Fd

Fbut b1

Fcy

h 1

T 1

Fh

a

� /2i

�/2

FCH 0 5 Fh Fd– n1 1a3

a4

-----– FCY

Ma4

-----+ +,=


Pt D, Ch 13, Sec 2

• force FB in each bottom transverse chock, in kN, takenequal to:

where:FMC : Minimum force required to keep the dredger

closed in the loading case considered, obtainedfrom the following formula:FMC = M / n1 a3

For a tendency to close, FMC is negative and isnot to be taken into account to determine FCY

Fp : Force in the jack corresponding to a pressure onthe rod side equal to the maximum pressure Pp

of the pumps and of their pressure limitingdevice

M : Moment with respect to the hinge chocks, posi-tive for a tendency to open, negative in theopposite case, taken equal to:

n1 : Number of jacksn2 : Number of bottom transverse chocks

Δ, Δ1, Q: Vertical forces, defined in [9.3.4]a1, a2, a3, a4: Lever arms of horizontal forces, as shown in

Fig 16b1, b2, b3: Lever arms of vertical forces, as shown in Fig

16.

9.3.4 The vertical static forces to be considered are the fol-lowing:• vertical hydrostatic buoyancy Δ/2 on a half-hull, in kN

• weight Δ1 / 2 of the half-hull without spoil, in kN

• weight Q / 2 of the half spoil loading, in kN

where:Δ : Total displacement of the ship with spoil

Δ1 : Total displacement of the ship without spoil,including superstructures

Q : Total weight of the spoil in the well.The following relation between vertical static forces is to beverified:

Δ = Δ1 + Q

9.3.5 For every other loading case, the forces FCY, FCH andFB are to be calculated according to [9.3.3], by replacing:

• a1, a2, b1, b2, b3, Δ, Δ1 and Q by the corresponding val-ues for the loading case considered

• TD, δ and h1 by values of external draught, density ofwater or spoils in the well and level inside the well forthe loading case considered, i.e.:- in working condition, at the international freeboard:

T, δ and h2

- in navigation condition with the well filled up to thewaterline: T3, 1,025 and h3 taken equal to T3

- in navigation condition with well filled with water tothe lowest weir level: T4, 1,025 and h4.

9.3.6 If, in the maximum loading condition correspondingto the dredging freeboard or the international freeboard,densities of spoil higher than δ may be considered withreduced heights (for constant mass of spoils), calculation ofFCY, FCH and FB is also to be carried according to [9.3.3],using the parameters corresponding to the maximum densi-ties of spoil likely to be considered with draughts TD and T.

9.3.7 The maximum static force FS, actually developed bythe jack, is the greatest of the values obtained for FCY for thevarious loading cases and calculated according to [9.3.3],[9.3.5] and [9.3.6].

9.3.8 Where the hopper well ends are partly fixed, the endmoments result in additional forces in the deck hinges,jacks, deck and bottom chocks, forward and aft of the well.

The distribution of these forces is to be determined by adirect calculation to be submitted to the Society for infor-mation.

9.3.9 The Designer is to give the value of the horizontallever arm b2 and the hull weight for the various loadingcases as stated in [9.3.3]. In each case, the value to be takeninto account is the most unfavourable one according to thedistribution of the compartments, considering the tendencyto open or to close.

However, the attention of the Owner and of the Designer isdrawn to the fact that side tank ballasting can noticeablyreduce the static forces necessary in the jacks to act againstopening of the two half-hulls in the above operating condi-tions.

9.4 Dynamic forces

9.4.1 The Designer is to give the dynamic forces applied onthe deck hinges and on the hydraulic jack attachments bymeans of a calculation to be submitted to the Society forinformation.

9.4.2 The dynamic forces are generally to be calculated bymeans of a long-term statistical analysis, under the condi-tions defined in Tab 16.

Table 16 : Probability for the determinationof dynamic forces

FBn1a3FCY M–

n2a4

------------------------------=

M Fha1– Fda212--- Δb1 Δ1b2– Qb3–( )+ +=

Condition Probability

Dredging and navigation with spoil, with sea state limited to HS = 3 m (1)

10−5 for jacks and hinges

Navigation without spoil, with-out limitation on sea state (2)

10−7 for jacks10−5 for hinges

(1) HS : Significant wave height, in m.(2) In sailing condition without spoil, a different probabil-

ity level may be adopted for the calculation of dynamicforces on the cylinders, subject to the Society's agree-ment, when a device intended to restore the pressure tothe cylinders after opening of the safety valves is fitted(see also [10.3.1]).

Note 1: Different calculation conditions are to be justifiedby the Designer.


Pt D, Ch 13, Sec 2

9.4.3 For each rule loading case, the results of the calcula-tion are to give:• the dynamic force FDCY in each jack, in kN

• the horizontal dynamic force FDHC in each hinge, in kN

• the vertical dynamic force FDVC in each hinge, in kN.

9.4.4 If loading cases other than those defined in [3] areconsidered, calculations for such additional cases are to bedefined in agreement with the Society on a case-by-casebasis.

9.4.5 In the case of dredgers with a capacity of less than700 m3, the dynamic forces in the jacks and hinges may betaken into account without long-term statistical calcula-tions. The calculations for jacks and hinges are to be justi-fied to the Society.

9.4.6 For ships with one of the navigation notations coastalarea or sheltered area, the dynamic forces in the cylindersand the hinges may be reduced by 10% in the case of navi-gation without spoil.

9.5 Scantlings

9.5.1 The maximum total force in the jack is to be takenequal to the greatest value, from all the loading cases fore-seen, obtained, in kN, from the following formula:Fm = FCY + FDCY

The jack is to be capable of developing a force at leastequal to Fm , at the setting pressure of the safety valve of thejack considered as isolated.

9.5.2 The scantlings of the jack lugs are to comply with[8.5] considering the force Fm as determined in [9.5.1].Cases where the force developed by the jack, at the settingpressure of the safety valve of the jack considered as iso-lated, is noticeably higher than Fm are to be examined bythe Society on a case-by-case basis.

9.5.3 The scantlings of the deck hinges are to comply with[8.5], considering the resultant of the total horizontal forceand the total vertical force, obtained, in kN, from the fol-lowing formula:

9.5.4 The scantling load of the transverse bottom chocks isto be defined in agreement with the Society.

9.5.5 The scantlings of the longitudinal bottom chocks pro-vided for in [9.3.2] are to be determined considering foreach chock the force obtained, in kN, from the followingformula:

where:Δm : Maximum displacement of the ship, in kN, with

the well loaded with spoiln3 : Total number of chocks (at deck and bottom).The scantlings of the longitudinal deck chocks mentioned in[9.3.2] are to be determined considering for each chock theforce obtained, in kN, from the following formula:

where:

Δn : Displacement of the ship with the well filledwith water up to the waterline

n4 : Number of longitudinal deck chocks.

The permissible shear stress for bottom and deck chocks isto be obtained, in N/mm2, from the following formula:

For the calculation of the shear stress in the deck chocks, areduced sectional area corresponding to the efficient sec-tional area of the chocks when the well is open is to be con-sidered.

9.5.6 The lugs of the jacks and the deck hinges may be cal-culated using a finite element model.

In such case, the finite element model and the applied load-ings are to be preliminarily agreed upon by the Society.

The permissible stress is to be defined in agreement with theSociety, depending on the finite element model and on thecharacteristics of the materials.

10 Split hopper dredgers and split hopper units: hydraulic jacks and associated piping systems

10.1 General

10.1.1 For ships with one of the service notations split hop-per dredger or split hopper unit, the check of hydraulicjacks and associated piping systems intended for closing thetwo half-hulls of the ship is to be carried out according to[10.1] to [10.6].

10.1.2 Hydraulic jack design and construction are to be inaccordance with the applicable requirements of Pt C, Ch 1,Sec 11, [2], while associated piping systems are generally tofulfil the relevant requirements of Pt C, Ch 1, Sec 10.

Materials used are to be in accordance with the applicablerequirements of NR216 Materials.

10.2 Definitions

10.2.1 For the checking of hydraulic jacks and associatedpiping systems, the following definitions are to be consid-ered:

Pm : Pressure on the rod side of the jack resultingfrom the extreme foreseen ambient conditionscorresponding to the maximum force Fm,defined in [9.5.1]

PC : Maximum pressure on the bottom side of thecylinder equal to the setting value of the safetyvalves protecting the bottom side of the cylinder

PP : Maximum pressure which can be deliveredthrough the pumps and their associated pres-sure limiting devices

FRes FCH FDCH+( )2 FDVC2+=

F 0 15Δm

n3

------,=

F 0 15Δn

n4

-----,=

τ 0 9ReH

3--------,=


Pt D, Ch 13, Sec 2

PS : Pressure on the rod side of the jack correspond-ing to the greatest of forces FS, defined in[9.3.7], and FP, defined in [9.3.3].

10.3 Arrangements

10.3.1 When large ships are concerned, the followingarrangements are generally to be provided:

• for each hydraulic jack, a measuring system of the pres-sure in the cylinder is to be supplied

• this system, in addition to the indication of the pressureat the bridge and at the dredging room, is to comprise avisual and audible alarm at the same locations, to beactivated when a certain limit is exceeded

• the measuring system, the alarm activating limit as wellas the instructions to be followed after the alarm occursare to be submitted to the Society for approval.

10.3.2 Special attention is to be paid to protection againstcorrosion.

10.4 Scantling of jacks

10.4.1 For the pressure parts of hydraulic jacks made ofsteel, the permissible stress related to the loading conditionsresulting in pressure PP or PS (whichever is the greater) act-ing on the cylinder rod side without pressure on the otherside is to be taken as the smaller of ReH / 1,8 and Rm / 2,7.

The allowable stress applicable to the cylindrical envelope,for the loading conditions resulting in pressure Pm , may betaken as the smaller of ReH / 1,5 and Rm / 2,25.

10.4.2 The scantlings of the jack end cover on the rod sideare to be determined using Pm as design pressure.

The scantlings of the jack end cover on the bottom side aswell as the mechanical connections (for example the boltsbetween the cover and the cylinder or between the pistonand the rod) are to be based on Fm.

The calculations justifying the proposed scantlings and, asthe case may be, the pre-stresses are to be submitted to theSociety for information.

10.4.3 The scantlings of the rod are to be based on Fm andon the smaller value of ReH / 2 and Rm / 2,4, for the meanpermissible stress in traction. A calculation proving the ade-quate buckling strength of the rod is to be submitted to theSociety for information.

10.4.4 The scantlings of the lugs and the pins at each endof the hydraulic cylinder are to be based on Fm.

10.5 Inspection and testing

10.5.1 In addition to inspections required in [10.1.2],where applicable, welded joints connecting parts subject tothe load Fm are to fulfil the requirements for class I pressurevessels or equivalent.

10.5.2 Completed cylinders and attached piping up to andincluding the first isolating valve are to undergo, at works, apressure test at the greater of the values 1,4 PS and 1,2 Pm

applied on the rod side and a pressure test at 1,4 PC on thebottom side for the fully extended position.

10.5.3 The completed hydraulic circuit is to be subjected,on board, to pressure tests at 1,4 times the relevant maxi-mum service pressure for normal conditions or static loads,for the part of the circuit considered.

10.6 Relief valve setting

10.6.1 At least one relief valve of appropriate capacity is toprotect each part of the circuit which may be subject tooverpressure due to external loads or due to pump action;in general, relief valves on the rod side of each cylinder orgroup of cylinders are to be set at Pm, while PC applies to thebottom side for relief valve setting purposes.

Parts of the circuit possibly subject to overpressure frompumps only are to be protected by relief valves set at pres-sure PP.

11 Rudders

11.1 General

11.1.1 The rudder stock diameter obtained from Pt B, Ch 9,Sec 1, [4] or NR600, Ch 5, Sec 2, as applicable, is to beincreased by 5%.

11.2 Additional requirements for split hopper dredgers and split hopper units

11.2.1 Each half-hull of ships with one of the service nota-tions split hopper unit or split hopper dredger is to be fittedwith a rudder complying with the requirements of Pt B, Ch9, Sec 1 or NR600, Ch 5, Sec 2, as applicable,.

11.2.2 An automatic system for synchronising the move-ment of both rudders is to be fitted.

12 Equipment

12.1 General

12.1.1 The requirements of this Article apply to ships hav-ing normal ship shape of the underwater part of the hull.

For ships having unusual ship shape of the underwater partof the hull, the equipment is to be considered by the Societyon a case-by-case basis.

12.1.2 The equipment obtained from [12.1.4] or [12.1.5] isindependent of anchors, chain cables and ropes which maybe needed for the dredging operations.

12.1.3 The Equipment Number EN is to be obtained fromthe following formula:

EN = 1,5 (L B D)2/3

When calculating EN, bucket ladders and gallows may notbe included.


Pt D, Ch 13, Sec 2

12.1.4 For ships equal to or greater than 80 m in length andfor ships with EN, calculated according to [12.1.3], equal toor greater than 795, the equipment is to be obtained from PtB, Ch 9, Sec 4, [3], with EN calculated according to Pt B,Ch 9, Sec 4, [2] and not being taken less than 795, consid-ering the following:• to apply the formula, the displacement considered is

that of the navigation draught, taking into account thecylinder housings and the free space between the twohalf-hulls

• the chain cable diameter is to be read off after movingto the next line below in the applicable Table.

12.1.5 For ships other than those defined in [12.1.4], theequipment is to be obtained from Tab 17.Where such ships are assigned one of the following naviga-tion notations:• summer zone• tropical zone• coastal area,

the equipment is to be obtained by consulting Tab 17 oneline higher.

Where such ships are assigned the navigation notation shel-tered area, the equipment is to be obtained by consultingTab 17 two lines higher.

12.2 Additional requirements for split hopper dredgers and split hopper units

12.2.1 Arrangements of ships with one of the service nota-tions split hopper dredger or split hopper unit are to be inaccordance with [12.2.2] to [12.2.5].

12.2.2 One chain locker and one complete mooring chaincable are generally to be provided for each half-hull.

12.2.3 If the mass of the anchor permits, only one windlassneeds to be provided on either of the half-hulls. In this case,in addition to the requirements in Pt B, Ch 9, Sec 4, [3], achain stopper is to be fitted on the half-hull which is notequipped with a windlass.

12.2.4 Fairleads or rollers are to be located in suitable placesbetween the windlass and the hawse pipe so that the drop-ping and the housing of the anchor are satisfactorily ensured.

12.2.5 Arrangements are to be made to avoid jamming ofthe cable during the opening and closing operations of thetwo half-hulls.

Table 17 : Ships for dredging activities - Equipment

Equipment number ENA< EN ≤ B

Stockless anchors Stud link chain cables for anchors

A B N Mass per anchor, in kg Total length, in m Diameter, in mm35 45 2 120 110,0 16,045 60 2 140 110,0 17,560 80 2 220 110,0 19,080 92 2 260 137,5 20,592 102 2 290 137,5 22

102 112 2 320 165,0 24112 130 2 350 165,0 24130 155 2 430 165,0 26155 185 2 500 165,0 28185 210 2 600 165,0 30210 250 2 700 165,0 32250 285 2 800 220,0 34285 315 2 900 220,0 36315 350 2 1000 220,0 38350 385 2 1100 220,0 38385 415 2 1200 220,0 40415 450 2 1300 220,0 40450 485 2 1400 220,0 42485 515 2 1500 220,0 44515 550 2 1600 220,0 46550 585 2 1700 220,0 48585 635 2 1800 275,0 48635 685 2 2000 275,0 50685 715 2 2100 275,0 52715 750 2 2200 275,0 54750 795 2 2300 275,0 54


Pt D, Ch 13, Sec 2

12.3 Towlines and mooring lines

12.3.1 The towline and the mooring lines are given as a guid-ance, but are not required as a condition of classification.

12.3.2 For ships equal to or greater than 80 m in length andships with EN, calculated according to [12.1.3], greaterthan 795, the characteristics of towlines and mooring linesmay be obtained from Pt B, Ch 9, Sec 4, [3] with EN calcu-

lated according to Pt B, Ch 9, Sec 4, [2], considering thedisplacement at navigation draught, taking into account thecylinder housings and the free space between the two half-hulls, the latter value of EN not being less than 795.

12.3.3 For ships other than those defined in [12.3.2], thecharacteristics of towlines and mooring lines may beobtained from Tab 18.

Table 18 : Ships for dredging activities - Towlines and mooring lines


Towline (1) Mooring lines (1)

A BMinimum length,

in mBreaking load,

in kNN

Length of each line, in m

Breaking load,in kN

35 45 120 88 2 90 5945 60 120 93 2 90 6460 80 120 98 2 90 6880 92 130 107 2 90 7392 102 130 117 2 110 78102 112 130 127 2 110 83112 130 140 137 2 110 88130 155 140 147 2 135 93155 185 140 156 2 135 98185 210 150 166 2 135 102210 250 150 176 2 135 107250 285 150 186 2 135 112285 315 150 196 2 135 117315 350 160 215 2 160 122350 385 160 240 2 160 127385 415 160 265 2 160 132415 450 160 295 2 160 137450 485 160 320 2 160 142485 515 160 340 3 160 147515 550 160 365 3 160 152550 585 160 390 3 160 157585 635 160 415 3 160 161635 685 160 440 4 160 166685 715 160 465 4 160 170715 750 160 490 4 160 175750 795 180 515 4 160 180

(1) The towline and the mooring lines are given as a guidance, but are not required as a condition of classification.


Pt D, Ch 13, Sec 3


SECTION 3 MACHINERY AND DREDGING SYSTEMS

1 General

1.1 Application

1.1.1 This Section provides requirements for ships havingthe service notation dredger, hopper dredger, hopper unit,split hopper unit and split hopper dredger. These require-ments are only applicable at the request of an Owner.

1.1.2 This Section does not cover the other aspects of thesystem and equipment design, in particular in respect oftheir performance.

1.1.3 The requirements for bottom doors and valves fittedon ships having the notation hopper dredger, hopper unit,split hopper unit and split hopper dredger are given in Ch13, Sec 2.

2 Dredging system

2.1 Attachment of dredging equipment to the hull

2.1.1 The scantlings of the structure for attachment of theequipment intended for dredging operations (e.g. connec-tion of the suction pipe to the hull, foundation of the suc-tion pipe davits) are to be based on the service load of suchequipment, as specified by the Designer.In determining the above service load, the Designer is totake account of additional loads imposed by ship move-ments (in particular pitch and heave) in the most unfavoura-ble sea and weather conditions expected during service.

3 Steering gear of split hopper dredgers and split hopper units

3.1 General

3.1.1 The rudder fitted to each half-hull of ships having theservice notations split hopper dredger or split hopper unit(see Ch 13, Sec 2, [11.2.1]) is to be served by its own steer-ing gear.

3.2 Design of the steering gear

3.2.1 The steering gear referred to in [3.1.1] is to consist ofa control system and a power actuating system capable tooperate the relevant rudder as required in Pt C, Ch 1, Sec11, [2.2.1] or Ch 20, Sec 4, [24.3.1], as appropriate.

3.2.2 An auxiliary steering gear or a duplicated poweractuating system need not be fitted.

3.3 Synchronisation

3.3.1 An automatic system for synchronising the movementof both rudders is to be fitted. It is to comply with the provi-sions of Pt C, Ch 1, Sec 11, [3.2.2].

4 Testing of dredging equipment

4.1 On board testing

4.1.1 Ship trials

a) Upon completion of construction, in addition to theconventional sea trials required in Pt C, Ch 1, Sec 15,specific tests may be required at the Society’s discretionin relation to the particular service for which the ship isintended or the specific characteristics of machineryand equipment fitted on board.

b) In particular, as regards propulsion and steering systems,tests may be required to check the manoeuvring capa-bility and the speed of the ship whilst operating.

4.1.2 Equipment trials

As far as the dredging system is concerned, tests are to becarried out to verify the proper operation of all relevantequipment in different sea and weather conditions, accord-ing to a specification submitted by the interested party.

Pt D, Ch 13, App 1

APPENDIX 1 GUIDANCE ON CALCULATION OF TRANSVERSE STRENGTH HOPPER WELL STRUCTURE

1 Hopper dredgers and hopper units: checking of hopper well structure

1.1 General

1.1.1 The requirements in [1] to [5] apply to ships with oneof the service notations hopper dredger or hopper unit.

2 Floors

2.1 General

2.1.1 The scantlings of floors of ships with open wells fittedwith bottom doors are to be obtained from a direct calcula-tion, according to Pt B, Ch 7, App 1 as applicable, and tak-ing into account the following assumptions:

• the span is equal to half the sum of the upper face platelength and the distance between lower ends of the hop-per well sloped bulkheads

• the floors have fixed ends

• the floors are subject to the uniform and concentratedloads detailed in [2.3]

• the central box (cellular keel) is supported by the floors

However, where this box has sufficient dimensions andscantlings to support a part of the loads, this may betaken into account if a relevant calculation of grid typeis submitted to the Society for information.

• In addition to the loads laid down in [2.3], the floor maysupport differential loads, for example when all thevalves are not simultaneously opened, or compressionloads when the well is empty

• the web cut-out section is deducted for the calculationsof shear stresses and normal stresses (tension or com-pression)

• for the calculation of normal stresses and bendingstresses, the face plate cross-section is taken intoaccount only if these face plates are correctly offset onthe adjacent structure

2.2 Different types of bottom and valves used

2.2.1 The different types of bottom doors and valves gener-ally used, as well as the relevant symbols, are defined in Fig1 to Fig 5.

Figure 1 : Bottom valve, centrally operated bya vertical shaft (Type 1)

Figure 2 : Single bottom door, with hinges at one side (either cellular keel side or lower wing tank side) and

operated by a vertical shaft at the other side(Type 2)

Figure 3 : Double bottom doors, with hinges at both sides and operated by one central vertical shaft con-

nected to the doors by means of two rods (Type 3)

a

C1

R1

cellularkeel

u

C1

a

R2 R2

R1

u u

a

C1

R2 R2


Pt D, Ch 13, App 1

Figure 4 : Longitudinal sliding bottom doors (Type 4)

Figure 5 : Transverse sliding bottom doors, guides being supported by floors (Type 5)

2.3 Load borne by floors

2.3.1 The loads borne by floors are a combination, accord-ing to the type of bottom doors, of the elementary loads [a],[b], [c], [d], [e] and [f], obtained, in kN, from the followingformulae:

[a] : Uniform load of spoils, to be taken equal to:

Q1 = g δ (D + hD) Sa

[b] : External hydrostatic pressure, to be taken equalto:

Q2 = g (TD − 0,5 h0) Sa

In the course of calculations, Pr is the reducedpressure, evenly distributed, to be taken equalto:

Pr = δ (D + hD) − (TD − 0,5 h0)

The resultant load is to be taken equal to:

Q = Q1 − Q2 = g Pr Sa

[c] : Load acting directly on a valve (to be deducted),to be taken equal to:

q = g Pr Abd

This load is assumed to be evenly distributedalong the length c1. It is to be cut off from theload Q.

In the case of type 5 bottom doors (see Fig 5), q= 0

[d] : Reactions R2 of the bottom doors on the floor (tobe added), the absolute values and abscissae ofwhich are indicated in Tab 1

Reactions R1 on the rods of the hydraulic jacksof bottom doors type 1 (see Fig 1), type 2 (seeFig 2) and type 3 (see Fig 3) are given in Tab 1for further calculations but they are not borneby the floors

[e] : Axial force due to the lack of spoils in the vol-ume occupied by the cellular keel (to bededucted), to be taken equal to:

F1 = g δ Sa A

[f] : Axial force due to a possible transmission of theresultant reaction R1 to the cellular keel,through a strong beam, an axial pillar orinclined pillars, to be taken equal to:

• with one axial pillar:

• with two inclined pillars:

F2 = 2 R1

For determination of the scantlings of strongbeams, girders and pillars, R1 is to bereplaced by FM, in kN, when calculating F2,if FM is higher than R1, FM being the maxi-mum force induced by the bottom doorhydraulic jack.

where:

hD : Distance, in m, from the highest weir level, cor-responding to the draught TD, to the deck-line(hD is to be counted negatively where the levelis located below the deck-line at side)

Sa : Transverse primary supporting ring spacing, in m

: Stiffener span, in m

In the case of floors, the span is equal to half thesum of the length of the upper flange plate andthe distance between the lower ends of thesloping sides of the hopper space.

h0 : Ship relative motion, in m, defined in Pt B, Ch5, Sec 3, [3.3] or NR600, Ch 3, Sec 3, as appli-cable

Abd : Whole sectional area, in m2, of the bottom doorwhatever its type may be

A : Area, in m2, enclosed by the contour of the cel-lular keel

v : Distance, in m, from the hydraulic jack cen-treline to the end of the strong beam span

0 : Span, in m, of the strong beam bearing the reac-tions of the hydraulic jacks

C1

R2

a

R2

C1

a

F2 4vR1

0

---------=


Pt D, Ch 13, App 1

Table 1 : Reactions R1 and R2 for elementary load [d]

2.4 Shear force diagrams

2.4.1 The shear force diagrams corresponding to each ele-mentary load defined in [2.3] are given in Fig 6 to Fig 11.

The total shear force, at abscissa X, equal to the algebraicalsum of the elementary shear forces corresponding to eachtype of bottom doors, is indicated in Tab 2.

Table 2 : Shear force values

Figure 6 : Shear force diagram forelementary load [a] - Load Q1

Figure 7 : Shear force diagram forelementary load [b] - Load Q2

Figure 8 : Shear force diagram forelementary load [c] - Load q

Figure 9 : Shear force diagram forelementary load [d] - Reactions R2

Bottom door type(see Fig 1 to Fig 5)

Reactions R2 Reactions R1

No. Value, in kN Abscissae Value, in kN

1 0 g Abd Pr

2 1 (a + 0,5 c1) or (a − 0,5 c1)

3 2 (a + 0,5 c1) and (a − 0,5 c1)

4 2 0,5 g Abd Pr (a + 0,5 c1) and (a − 0,5 c1) 0

5 0 0

Note 1:a : Distance, in m, from either end of the floor span to the centreline of the bottom door closest to that endc1 : Width of a bottom door, in mu : Distance, in m, from the fixing point of the hydraulic jack rod (or of the two rod hydraulic jack) to the centreline of the

bottom door.

gAbdPr2u

c1 2u+------------------ gAbdPr

c1

c1 2u+------------------

0 25g, AbdPrc1 4u–c1 2– u------------------ 0 5g, AbdPr

c1

c1 2– u----------------

Bottom door type(see Fig 1to Fig 5)

Total shear force T(x) at abscissa X, in kN

1 T0

2 T0 + R2

3 T0 + 2 R2

4 T0 + 2 R2

5 T0 + q − 0,5 F2

Note 1:X : Distance, in m, from the cross-section under

consideration to the end of the floor spanT0 : Total shear force, in kN, at the left end of the

span, to be taken equal to:

T012--- Q1 Q2– 2q– F1– F2+( )=

span �

Q1

spoil mass

externalhydrostaticpressure

Q2

load actingdirectly ona valve

q q

bottom door Type

1

2

R2

R = 02

3

4

5 R = 0(and q=0)2

reactionsof the valueon the floor

R2

R2R2 R2

R2

R2R2 R2

R2


Pt D, Ch 13, App 1

Figure 10 : Shear force diagram forelementary load [e] - Force F1

Figure 11 : Shear force diagram forelementary load [f] - Force F2

2.5 Bending moments for each elementary load

2.5.1 The bending moments for each elementary loaddefined in [2.3] are given in Tab 3, at span ends and at mid-span.

2.6 Resultant bending moment

2.6.1 The resultant bending moment is the sum of the ele-mentary moments for each type of valve.

The total moment value at abscissa X is determined bydeducting algebraically from the total moment value at thespan ends the value of the area bounded by the total shearforce curve.

2.7 Normal load

2.7.1 The normal load is to be obtained, in kN, from thefollowing formula:

FN = FN1 − FN2

where:

hV : Mean floor depth, in m.

Table 3 : Values of bending moments

F1

no spoilinsidecellular keel

R1

F2

�0v

F2 =�0

4vR1one axialpillar

F2 = 2R1two inclinedpillars

F2

R1

R1R1 FN1

3 3Saδ,2D hV–-------------------- D hD+( )2 2D hD–( )=

FN23 3Sa,

2D hV–-------------------- TD 0 5h0,–( )2 3D TD– 0 5h0,+( )=

Elementary load Bending moment, in kN.m, at span ends Bending moment, in kN.m, at mid-span

[a]

[b]

[c]

[d] • Types 1 or 5 bottom valves: 0

• Type 2 bottom valve (1):

• Type 3 or 4 bottom valves:

• Types 1 or 5 bottom valves:0

• Type 2 bottom valve:

• Type 3 or 4 bottom valves:

[e]

[f]

(1) Formula valid for a hinge on cellular keel. In the case of a hinge on lateral wing tank, replace (2 a + c1) with (2 a − c1)

Q1

12----------–

Q1

24----------

Q2

12---------- Q2

24----------–

qa a–( )

----------------------- qa2

---------–

R22a c1+( ) 2 2a– c1–( )

4----------------------------------------------------------–

R24a a–( ) c1

2–2

----------------------------------–

R22a c1+( )2

4-------------------------

R24a2 c1

2+2

--------------------

F1

8-------- F1

8--------–

F2

8--------–

F2

8--------


Pt D, Ch 13, App 1

2.8 Differential opening valves

2.8.1 In the case of a differential opening of the valves, thestresses induced by the bending moments and the shearforces are determined as follows:

• the upper flange is assumed to be simply supported atends; its span S is measured between the longitudinalbulkhead and the cellular keel

• the lower flange is assumed to have fixed ends and itsspan is taken equal to c1

• the transverse section moduli of the flanges are deter-mined with respect to a vertical axis located in theplane of the floor web

• for the upper flange, the transverse bending moment atmid-span is obtained, in kN.m, from the following for-mula:

• for the upper flange, the maximum shear force at endsof span S is obtained, in kN.m, from the following for-mula:

• for the lower flange, the maximum bending momentand shear force at span ends are obtained, in kN.m,from the following formulae:

2.9 Buckling of upper flange

2.9.1 When the ship is to navigate with empty hopperspace(s), the buckling of the upper flange is to be checked,using the formulae given in [3] for strong beams and assum-ing that:

where:

T2 : Maximum draught for navigation with emptyhopper space(s), in m

AS : Sectional area, in cm2, of the upper flange

AV : Sectional area, in cm2, of the floor, cut-outs inweb deducted

3 Strong beams at deck level

3.1 Forces acting on strong beams

3.1.1 Where strong beams are fitted at deck level, theforces acting on them are to be obtained, in kN, from thefollowing formulae:

• tension force due to the spoil pressure onto the longitu-dinal bulkheads of the well:

• compression force due to the external hydrostatic pres-sure:

• compression force due to moment at floor ends:

• compression force due to floor reaction at span ends:

where:

s : Spacing of strong beams, in m

d1 : Distance, in m, from the side plating to the lon-gitudinal bulkhead of the hopper well

b1 : Distance, in m, between the fixed end of thefloor and the hopper well longitudinal bulkheador its extension

M(0), T(0): Total bending moment and shear force at fixedends, determined, respectively, according to[2.5] and [2.4], for X = 0.

For strong beams with a large web depth, the upper flangeof which is located at deck level, the term D may bereplaced by (D − 0,5 hWS), where hWS is the web depth, inm, of strong beams.

The resultant of the forces is to be obtained, in kN, from thefollowing formula:

FR = FT − FC1 − FC2 − FC3

FR is a tension load when positive, a compression loadwhen negative.

3.2 Sectional area of strong beams

3.2.1 The sectional area of strong beams, after deduction ofpossible cut-outs, is to be obtained, in cm2, from Tab 4.

4 Brackets for trunks

4.1 General

4.1.1 Brackets for trunks are to be provided in way of thestrengthened transverse rings. They are to be securely fixedat their lower ends.

MS 0 05δhV2 3S

2S c1–( )2–[ ],=

TS 0 3δhV2S c1+( ),=

Mi 1 33c1

S

-----

2

MS,=

Ti 2c1

S

----- TS=

FR3 3Sa,–

2D hV–-------------------- T2 0 5h0,+( )2 3D T2– 0 5h0,–( ) AS

AV

------=

FT1 6δs D hD+( )2,

2D hV–--------------------------------------- 2 D hD+( ) 3hV–[ ]=

FC11 6s TD 0 5h0,–( )2,

2D hV–--------------------------------------------- 2TD h0– 3hV–( )=

FC22M 0( )2D hV–--------------------=

FC3d1 2b1+2D hV–---------------------T 0( )=


Pt D, Ch 13, App 1

Table 4 : Sectional area of strong beams

4.2

4.2.1 In order to check the stresses according to [4.3], thevalue of the bending moment at the lower end, in kN.m,and the value of the corresponding shear stress, in kN, maybe obtained, respectively, from the following formulae:

MP = 1,64 δ s hT3

TP = 4,9 δ s hT2

where:hT : Height, in m, of the trunk above the deck-line.

4.3

4.3.1 It is to be checked that the normal stress, in N/mm2,and the shear stress are, respectively, in compliance withthe following formulae:

σ ≤ 0,65 RY

τ ≤ 0,45 RY

5 Girders supporting the hydraulic cylinder in the hopper spaces (bottom door types 1, 2 and 3)

5.1

5.1.1 In order to check the stresses according to [5.2], thelocal bending stress due to the cylinder reaction and thecorresponding shear stress, in N/mm2, may be obtained,respectively, from the following formulae:

where:

F : Maximum value, in kN, of R1 and FM defined in[2.3]

w : Girder web modulus, in cm3

Aa : Girder web sectional area, in cm2, possible cut-outs deducted.

5.2

5.2.1 It is to be checked that the normal stress, in N/mm2,and the shear stress are, respectively, in compliance withthe following formulae:

σ ≤ 0,65 RY

τ ≤ 0,45 RY

Condition Sectional area AT, in cm2

FR ≥ 0 0,08 FR

FR < 0 • when F / r ≤ 1,15:

• when F / r > 1,15:

Note 1:F : Buckling length, in m, of the strong beam con-

sidered as fixed at ends, to be taken equal to0,50

r : Minimum gyration radius, in cm, to be takenequal to:

I : Moment of inertia, in cm4, equal to the mini-mum of IXX and IYY

IXX : Moment of inertia, in cm4, with respect to theaxis perpendicular to the plane of the web

IYY : Moment of inertia, in cm4, with respect to theaxis parallel to the plane of the web.

0 085 0 064F

r----

2

,+, FR

0 1F

r----

2

FR,

r IAT

------= σLX125F

w----------------=

τXY5FAa

------=


Pt D, Ch 13, App 1



Chapter 14

TUGS

SECTION 1 GENERAL


SECTION 3 INTEGRATED TUG/BARGE COMBINATION


Pt D, Ch 14, Sec 1


SECTION 1 GENERAL

1 General

1.1 Application

1.1.1 Ships complying with the requirements of this Chap-ter are eligible for the assignment of one of the followingservice notations:• tug• salvage tug

• escort tug

• anchor handling vessel.

as defined in Pt A, Ch 1, Sec 2, [4.7.2].







Ship arrangementL ≥ 90 m • Part B • NR566

L < 90 m • NR600 • NR566

Hull



L < 90 m• NR600• Ch 14, Sec 2

• NR600• Ch 14, Sec 2


• NR566• Ch 14, Sec 2

Machinery and cargo systems • Part C • NR566





Pt D, Ch 14, Sec 2


1 General

1.1 Application

1.1.1 The requirements of this Section apply to ships withone of the following service notations:

• tug, mainly intended for towing services, which are tocomply with the requirements in [2]

• salvage tug, having specific equipment for salvage serv-ices, which are to comply with the requirements in [2]and [3]

• escort tug, mainly intended for escort services such asfor steering, braking and otherwise controlling escortedships, which are to comply with the requirements in [2]and [4]

• anchor handling vessel, intended for towing vesselsand/or supply vessels equipped with winches for anchorhandling, having an open stern to allow the decking ofanchors and an appropriate thrust to perform theintended anchor handling operations, and complyingwith the requirements in [2] and [5].

Ships with the additional service feature barge combinedare to comply with the applicable requirements in Ch 14,Sec 3.

2 Tugs, salvage tugs, escort tugs and anchor handling vessels

2.1 General

2.1.1 In general, tugs are completely decked ships pro-vided with an ample drift surface and, where intended forservice outside sheltered areas, with a forecastle or halfforecastle, or at least with a large sheer forward.

Tugs of unusual design are to be considered by the Societyon a case-by-case basis.

2.2 Stability

2.2.1 Intact stability

The stability of the ship for the loading conditions in Pt B,Ch 3, App 2, [1.2.11] is to be in compliance with therequirements in Pt B, Ch 3, Sec 2.

2.2.2 Additional intact stability criteria

All the loading conditions reported in the trim and stabilitybooklet, with the exception of lightship, are also to bechecked in order to investigate the ship’s capability to sup-port the effect of the towing force in the beam direction.

A tug may be considered as having sufficient stability,according to the effect of the towing force in the beamdirection, if the following condition is complied with:

A ≥ 0,011

where:

A : Area, in m⋅rad, contained between the rightinglever and the heeling arm curves, measuredfrom the heeling angle θC to the heeling angle θD

θC : Heeling angle of equilibrium, corresponding tothe first intersection between heeling and right-ing arms

θD : Heeling angle, to be taken as the lowest of:

• the angle θM , corresponding to the positionof GZMAX (see Fig 1)

• the angle of downflooding

• 40°.

Figure 1 : Heeling and righting arms curves

The heeling arm curve is to be calculated as follows:

where:

bH : Heeling arm, in m

T : Maximum bollard pull, in kN

Where this force is unknown, it can be assumedequal to:

• T = 0,179 P for propellers not fitted withnozzles

• T = 0,228 P for propellers fitted with noz-zles

heeling angles�C

A

GZMAX

heeling and righting arm

�D �M

bHTHc

9 81, Δ---------------- θcos=


Pt D, Ch 14, Sec 2

P : Maximum continuous power, in kW, of the pro-pulsion engine

H : Vertical distance, in m, between the towinghook, or equivalent fitting, and half draught cor-responding to Δ

c : Coefficient to be taken equal to:

• c = 1,00 for ships with azimuth propulsion

• c = 0,65 for ships with non-azimuth propul-sion

Δ : Loading condition displacement, in t.

2.3 Structure design principles

2.3.1 Bollards

For tugs equipped for side towing, the relevant bollards areto be effectively fixed on the deck in way of side transversesand deck beams or bulkheads.

2.3.2 Fenders

A strong fender for the protection of the tug’s sides is to befitted at deck level.

Alternatively, loose side fenders may be fitted, provided thatthey are supported by vertical ordinary stiffeners extendingfrom the lightship waterline to the fenders themselves.

2.3.3 Floors

Floors are to be arranged with a welded face plate in themachinery space; elsewhere, floor flanging may be acceptedas an alternative to the fitting of welded face plates.

2.3.4 Shaft tunnels

For tugs having small depth, the shaft tunnel may be omit-ted. In this case, access to the shaft line is to be giventhrough the floor of the space above.

2.4 Hull scantlings

2.4.1 General

The net scantlings of plating, ordinary stiffeners and primarysupporting members are to be in accordance with Part B,Chapter 7 or NR600, as applicable, where the hull girderloads and the local loads are defined in Part B, Chapter 5 orNR600, as applicable, to be calculated for a mouldeddraught T not less than 0,85 D.

2.5 Other structures

2.5.1 Machinery casings

Exposed machinery casings are to be not less than 900 mmin height, measured from the upper surface of the deck, andprovided with weathertight means of closure.

In general, the longitudinal sides of the machinery casingsare to be extended downwards by a deck girder to whichthe deck beams are to be connected.

Side ordinary stiffeners are to be connected to the deck.Their spacing is to be not greater than 0,75 m.

2.5.2 Emergency exits from machinery spaceEmergency exits from the machinery space to the upperdeck are to be located as high as possible above the water-line and in way of the ship’s centreline, so that they may beused even at extreme angles of heel.

Escape hatch coaming heights are to be not less than600 mm above the upper surface of the deck.

Escape hatch covers are to have hinges fitted such that thepredominant direction of green sea will cause the cover toclose and are to be capable of being opened and closedwatertight from either side.

2.5.3 Height of hatchway coamingsThe height of the hatchway coamings is to be not less than300 mm. Hatch covers are to be fitted with efficient secur-ing devices.

2.6 Rudder and bulwarks

2.6.1 RudderFor tugs, the rudder stock diameter is to be increased by 5%with respect to that calculated according to Pt B, Ch 9, Sec 1,[4].

2.6.2 BulwarksThe bulwarks are to be sloped inboard to avoid distortionslikely to occur during contact. Their height may be reducedwhere required by operational necessities.

2.7 Equipment

2.7.1 GeneralThe mooring lines are given as a guidance, but are notrequired as a condition of classification.

2.7.2 Equipment numberThe equipment number EN is to be obtained from the fol-lowing formula:

EN = K (L B D)2/3

where:

K : • K = 1,30 for tugs with the navigation nota-tion unrestricted navigation

• K = 1,20 for tugs with the navigation nota-tion coastal area or sheltered area.

For tugs where the vertical extent of the superstructure ismuch greater than usual, the Society may require anincreased equipment number EN.

2.7.3 Anchors, chain cables and ropesTugs are to be provided with equipment in stocklessanchors, chain cables and ropes.

This equipment is to be obtained as a function of the Equip-ment Number EN, determined according to [2.7.2], from:

• Tab 1 and Tab 2 where EN ≤ 600

• Pt B, Ch 9, Sec 4 where EN > 600.

In that case, the value of EN to be used in Pt B, Ch 9,Sec 4 is the greater of the one calculated according to[2.7.2] and the one calculated according to Pt B, Ch 9,Sec 4, [2].


Pt D, Ch 14, Sec 2

Table 1 : Equipment for tugs

2.7.4 Fenders

Fenders are to be fitted at the deck level on the ship side,extending on the whole length of the ship.

2.8 Towing arrangements

2.8.1 General

In general, towing hooks and winches are to be arranged inway of the ship’s centreline, in such a position as to mini-mise heeling moments in normal working conditions.

2.8.2 Hooks and winches

The hook and the winch materials are to comply with theapplicable requirements of NR216 Materials and Welding.

The maximum bollard pull T, in kN, defined in [2.2.2], is tobe specified in the structural arrangement plans of the hookand the winch.

The hooks and the winches are to be subjected to a statictest, where the testing force CT is to be not less than thatobtained from Tab 3 as a function of T.

Winches may be equipped with a device for automaticadjustment of the tow.

Equipment number ENA < EN ≤ B

Stockless anchors Stud link chain cables for anchors

A B N Mass per anchor,

in kgTotal length,

in m (1)

Diameter, in mm

mild steel high strength steel

0435057647076839096105117130141158170192 208225 242258 275292308325 342358383416450483516

435057647076839096

105117130141158170192208225242258275292308325342358383416450483516600

22222222222222222222222222222222

10012014016018020022024026028030035040045050055060065070075080085090095010001050110012001300140015001600

100,0100,0110,0110,0110,0137,5137,5137,5137,5165,0192,5192,5192,5220,0220,0247,5275,0275,0275,0302,5302,5330,0330,0357,5357,5357,5385,0385,0385,0385,0385,0385,0

12,5 (2) 14,0 (2) 14,0 (2) 16,0 (2) 16,0 (2) 16,0 (2)

19,019,019,019,019,020,520,522,022,024,026,026,028,028,030,030,030,032,032,034,034,036,036,038,040,040,0

−12,512,514,014,014,017,517,517,517,517,517,517,519,019,020,522,022,024,024,026,026,026,028,028,030,030,032,032,034,034,034,0

(1) Where the total length required for chain cables is less than 220 m, one only of the two anchors may be linked with the chaincable and arranged in a hawse pipe. In this case, the second anchor is to be stowed such that it can be easily joined to the chaincable and dropped overboard in the event of loss of the first anchor.

(2) These diameters are applicable to studless chain cables.


Pt D, Ch 14, Sec 2

Table 2 : Mooring lines for tugs

Table 3 : Testing force CT

2.8.3 Hook quick-release device

The quick-release device is to be capable of being operatedfrom a remote control device on the bridge, or as near aspracticable, while the hook is under load. It is required that,in the case of a critical situation, the towline can be imme-diately released regardless of the angle of heel and thedirection of the towline.

The quick-release device is to be tested both at maximumbollard pull T and testing force CT, defined above. The forcenecessary to open the hook under load is to be not greaterthan 150 N.

After installation on board, an unhooking trial under load isto be carried out by means of the above remote controldevice. This trial may be performed with a test load lessthan the maximum bollard pull T.

2.8.4 Winch slip device

Winches are to be equipped with a suitable slip device,operable by remote control, allowing the rope to unwindwhen necessary.

2.8.5 Winch quick-release device

The unhooking of the rope from the winch drum is to beenabled by means of a suitable device or by using a ropewhose terminal is not fixed to the drum.

2.8.6 Connection with the hull structures

The structures intended to connect the towing arrangementsto the hull are to be suitably reinforced to withstand thetesting force CT obtained from Tab 3 and, in such condition,to meet the following strength criteria:

and

where:

τ : Shear stress, in N/mm2, to be obtained as aresult of direct calculations

σE : Von Mises equivalent stress, in N/mm2, to beobtained as a result of direct calculations

γR : Resistance partial safety factor, to be takenequal to 1,25

γm : Material partial safety factor, to be taken equalto 1,02

Ry : Minimum yield stress, in N/mm2, of the mate-rial, to be taken equal to 235/k N/mm2, unlessotherwise specified.

2.9 Construction and testing

2.9.1 Bollard pull test

At the request of the interested parties, tugs may be sub-jected to a bollard pull test. The value of the bollard pull isindicated in a declaration enclosed with the Certificate ofClassification.

Equipment number ENA < EN ≤ B

Mooring lines (1)Equipment number EN

A < EN ≤ BMooring lines (1)

A B NBreaking load,

in kNLength of each

line, in mA B N

Breaking load, in kN

Length of each line, in m

0435057647076839096105117130141158170

435057647076839096105117130141158170192

2222222222222222

55,057,059,061,063,065,065,566,066,567,067,368,571,573,575,577,0

808090909090110110110110110110110110110110

192 208225 242258 275292308325 342358383416450483516

208225242258275292308325342358383416450483516600

2222222222222223

7882848688909193949698

101104107112117

110110135135135135135135135135135160160160160160

(1) The mooring lines are given as a guidance, but are not required as a condition of classification.

Bollard pull T, in kN Testing force CT, in kN

T < 400 2 T

400 ≤ T ≤ 1200 T + 400

T > 1200 1,33 T τ 0 65RY

γRγm

----------,≤

σERY

γRγm

---------- ≤


Pt D, Ch 14, Sec 2

The bollard pull test is to be carried out, in the presence of aSurveyor of the Society, using suitable equipment (e.g. elec-trical load cell equipment) capable of providing, at any timeduring the test, a readout of the bollard pull developed bythe tug and a record, in numerical or graphical form, of thevalues measured. The test procedure location and condi-tions (environmental conditions, tug trim, etc.) are to beagreed with the Society.

In the case of sister ships, the Society may assign the bollardpull on the basis of the results obtained from the tests car-ried out on the prototype ship.

3 Additional requirements for salvage tugs

3.1 General

3.1.1 Application

The requirements of this Article apply to ships with the serv-ice notation salvage tug and specify the criteria these shipsare to satisfy in addition to those in [2].

Table 4 : Additional equipment for salvage tugs

Arrangement or equipment Number of items

Fixed or movable drainage pumps having approximately the same capacity (1) (2) (3) 2 or more pumps of total capacity ≥ 400 m3/h

Fire pumps each capable of throwing two simultaneous jets of water having a horizontal reach not less than 30 m (4)

2 pumps, each having acapacity ≥ 60 m3/h

Breathing apparatuses for divers 2

Gas masks with filter 2

Cargo boom 1, with service load ≥ 1 t

Power operated winch capable of producing an adequate pull 1

Water stops to stop leaks of approximately 1 x 2 m 4

Complete set of equipment for flame cutting with at least 25 metres of flexible piping 1

Drain hoses at least 20 m per pump

Fire hoses 10

Connections for fire main at least 3

Power operated diver’s compressor, with associated equipment (5) 1

Additional towline equipment 1

Lamps for underwater operation 2

Floodlight of power ≥ 500 W 1

Working lamps 2

Winding drums with wire ropes see (6)

Electrical cables, each not less than 100 metres long and capable of supplying at least 50 kW 3

Tackles with lifting capacity of 1 t 2

Tackles with lifting capacity of 3 t 2

Radar with a range not less than 24 nautical miles 1

Echo-sounding device with a range of 100 m 1

Hydraulic jackets with lifting capacity of 10 t 2

Hydraulic jackets with lifting capacity of 20 t 2

Portable electrical drill with a set of twist bits having diameters up to 20 mm 1

(1) For each pump fitted on board, a suction strainer and, in the case of non self-priming pumps, a foot valve, are also to be pro-vided.

(2) Where portable pumps are used, they are to be capable of effectively operating even with transverse and longitudinal inclina-tions up to 20°.

(3) These pumps are additional to the drain pumps intended for the drainage service of the ship.(4) These pumps may be the same required for drainage purposes provided they have an adequate head.(5) As an alternative, a compressor for recharging the oxygen tanks of divers may be provided together with two complete sets of

equipment for divers.(6) Winding drums fitted on board are to be capable of housing wire ropes of suitable size and length not normally less than

350 m.


Pt D, Ch 14, Sec 2

3.2 Equipment

3.2.1 Additional equipment

Ships with the navigation notation salvage tug are to be fit-ted with the additional equipment specified in Tab 4.

4 Additional requirements for escort tugs

4.1 General

4.1.1 Application

The requirements of this Article apply to ships with the serv-ice notation escort tug and specify the criteria these tugs areto satisfy in addition to those in [2].

4.1.2 Characteristics of escort tugs

For classification purposes, the following characteristics areto be specified by the Designer:

• the maximum steering force TY, in kN, applied by thetug on the stern of the escorted ship, which is the trans-verse component of the maximum bollard pull T withrespect to the longitudinal axis of the escorted ship. Thisforce is to be calculated at speeds V, to be defined bythe Designer (see Fig 2) and in general to be comprisedbetween 8 and 10 knots.

If the tug escort service is carried out within a certainspeed range, the maximum steering forces TY at the min-imum and maximum service speeds VMIN and VMAX,respectively, are to be calculated by the Designer.

• the manoeuvring time t, in s, used by the tug to passfrom the position which provides the maximum steeringforce TY on one side of the escorted ship to the mirrorposition on the other side, with respect to the longitudi-nal axis of the escorted ship (see Fig 2). The towlineangle α need not be taken greater than 60°, where α isdefined in Fig 2.

Figure 2 : Typical escort configuration

• the manoeuvrability coefficient M of the tug:M = m TY

where:m : Coefficient, to be taken as the lesser of:

• m = 31 / t• 1,0.

The above characteristics are to be obtained on the basis ofthe results of full scale tests, to be carried out at speed V or,as applicable, at speeds VMIN and VMAX, defined above (see[4.5]).

4.1.3 DocumentationIn addition to the documents defined in Pt B, Ch 1, Sec 3,the following plans are to be submitted to the Society forinformation:• towing arrangement plan, including towline compo-

nents with relevant minimum breaking loads• preliminary calculation of maximum steering forces TY

at speeds V or VMAX, as applicable according to [4.1.2],including the propulsion force which is needed forequilibrating hydrodynamic forces acting on the tug andthe towline pull

• preliminary stability calculation.

4.1.4 Propulsion forcesThe hydrodynamic forces acting on the tug, the towline pulland the tug propulsion force are to be so designed thatthese forces are in equilibrium thereby minimising therequired propulsion force itself.

However, the engine is to ensure a sufficient thrust formanoeuvring the tug quickly for any angular position β,where β is defined in Fig 2.

4.1.5 Loss of propulsionIn the case of propulsion loss, the heeling moment due tothe remaining forces is to lead to a safe equilibrium positionof the tug with reduced heel.

4.2 Stability

4.2.1 Intact stabilityThe two following intact stability criteria are to be compliedwith:

A ≥ 1,25 B

C ≥ 1,40 D

where:A : Righting lever curve area, in m⋅rad, measured

from the heeling angle θC to a heeling angle of20° (see Fig 3)

B : Heeling arm curve area, in m⋅rad, measuredfrom the heeling angle θC to a heeling angle of20° (see Fig 3)

C : Righting lever curve area, in m⋅rad, measuredfrom the angle 0° heel to the heeling angle θD

(see Fig 4)D : Heeling arm curve area, in m⋅rad, measured

from the angle 0° heel to the heeling angle θD

(see Fig 4)

Mirror p

osition

Escorted ship

TX

T TY

�

�Tug


Pt D, Ch 14, Sec 2

Figure 3 : Definition of the areas A and B

Figure 4 : Definition of the areas C and D

θC : Heeling angle of equilibrium, corresponding tothe first intersection between heeling and right-ing arms, to be obtained when the maximumsteering force TY , defined in [4.1.2], is appliedfrom the tug

θD : Heeling angle, to be taken as the lesser of:

• the angle of downflooding

• 40°.

The heeling arm curve is to be obtained from the full scaletests (see [4.5]), for the maximum steering force TY.

Moreover, the heeling arm is to be assumed constant fromthe angle of equilibrium θC to an angle equal to 20°.

4.3 Structural design principles

4.3.1 Hull shape

The hull shape is to be such as to provide adequate hydro-dynamic lift and drag forces and to avoid excessive trimangles for large heeling angles.

4.3.2 Bulwark

A bulwark is to be fitted all around the weather deck.

4.4 Equipment

4.4.1 Towline breaking load

The towline breaking load, in kN, is to be not less than SF⋅T,where:

T : Bollard pull, in kN, measured during the tests(see [4.5])

SF : Safety factor, to be taken equal to:

• SF = 3,0 for T ≤ 500

• SF = 4,0 − T/500 for 500 < T < 1000

• SF = 2,0 for T ≥ 1000

4.4.2 Towing winches

The towing winch is to be fitted with a system suitable toreduce the load in order to avoid overload due to dynamicoscillations of the towline. It is to be able to release the tow-line when the pull is greater than 50% of the towline break-ing load.

Normal escort services may not be based on use of the tow-ing winch brakes.

4.5 Construction and testing

4.5.1 Testing

Requirements [4.5.2] and [4.5.3] apply to full scale tests tobe carried out in order to obtain the values of the character-istics of the tug defined in [4.1.2].

If such full scale tests cannot be carried out, an equivalentmethod may be considered by the Society on a case by casebasis.

�c 20

A

Righting andheeling arms

Righting arm

Heeling arm

heelingangles

B

�c 20


Righting arm

Heeling arm

heelingangles


C

Righting arm

Heeling arm

heelinganglesD�


Righting arm

Heeling arm

D�

D

heelingangles


Pt D, Ch 14, Sec 2

4.5.2 Full scale tests

The following documentation is to be submitted to the Soci-ety for information prior to testing:

• test speed of the tug; the speed is to be intended as rela-tive speed with respect to the sea motions, therefore theeffects of any possible current are to be taken intoaccount

• main propulsion characteristics (power, maximum ori-entation angle of the rudder)

• preliminary calculation of the maximum steering forceTY at the test speed

• calculation of the route deviation of the escorted ship(for the tests, the escorted ship is to be selected so thatthe route deviation induced by the tug is not too large)

• preliminary stability calculation in the above conditions

• towing arrangement plan, including the load cell andthe specification of the breaking loads of the towlinecomponents

• documentation relevant to the bollard pull test (see[2.9.1]).

4.5.3 Data to be collected during tests

During the tests, all data needed to define the characteris-tics of the tug are to be collected, e.g. the relative positionship-tug, their heading and speed, the towline length, thetowline angle α (see Fig 2), the maximum bollard pull T, theship rudder position, the heeling angle of the tug and anyother parameter used in the preliminary calculation.

5 Additional requirements for anchor handling vessels

5.1 General

5.1.1 Application

The requirements of this Article apply to ships with the serv-ice notation anchor handling vessel and specify the criteriathese vessels are to satisfy in addition to those in [2] andPart D, Chapter 15, as applicable.

5.1.2 Procedures for unintended situations

Procedures for unintended situations are to be established,which describe, for each type of equipment, emergencyrelease methods, time delays and release speed in both nor-mal operating condition and dead ship condition.

These procedures are to be communicated to the ship'screw and vital information are to be displayed next to thecontrol desk or any other appropriate location on the bridgewhere the navigator on duty may see easily the informationfrom his usual command post.

5.1.3 Definitions

• Anchor handling winch: the dedicated winch used foranchor handling operation

• Wire: a dedicated line (wire rope or chain cable) usedfor the handling of anchors by means of the anchor han-dling winch

• Stern roller: a roller or similar equipment arranged at theaft boundary of the ship to launch and recover theanchors

The stern roller is designed to adequately support theworking line during the launching/recovering of anchors

• Wire stopper (i.e. shark jaw, karm fork): deck equipmentdesigned to temporary secure the inboard end of theworking line

• Guide pin: deck equipment guiding the working lines tothe intended sectors

• Bollard pull (BP): the maximum sustained towline forcethe vessel is capable of generating at zero forward speed

This force is to be initially specified by the Designer andis to be verified by a bollard pull test in accordance witha recognised standard.

• Safe working load (SWL): load to be specified by theapplicant of each shipboard fitting. Individual SWLs areto be marked on each concerned fitting.

• Loads on anchor handling winch:

- rated line pull (RP): maximum rope tension (includ-ing dynamic effects) that a winch is able to haulbefore stalling

- brake holding load (BHL): maximum rope tensionwith holding brake activated

- rendering load (RL): maximum rope tension at thedrum exit when the drum just starts rotating in theopposite direction of the applied driving torque witha first layer of rope wound on the drum.

5.2 Stability

5.2.1 General

During anchor handling, the wire comes from the anchorhandling winch and is controlled by the guide pins andconnected, over the stern roller, to the lifted item (see Fig 5).

For vessels used for anchor handling while their towingcapacity and/or the traction power of their winches is/arealready in action, calculations are to be made showing themaximum acceptable tension to which the vessel is able tobe exposed.


Pt D, Ch 14, Sec 2

Figure 5 : Schematic definition of equipment

5.2.2 Assumptions

All loading conditions are to be prepared with 10% and100% bunkers and all winches fully loaded with the heavi-est anticipated line type.

The tension TW in the wire, its vertical component TWz andits horizontal component TWy , as well as the angles α and βdefining the wire position are shown in Fig 6.

Figure 6 : Tension and position of wire

TW : Maximum wire tension, in t

TWz : Vertical component of the wire tension causing the

ship to trim: TWz = TW sinβ

TWy : Horizontal component of the wire tension causing the

ship to heel: TWy = TW sinα cosβ

β : Vertical angle, in degrees, between the waterline andthe wire, varying between 0 and +90

α : Horizontal angle, in degrees, between the longitudi-nal axis passing through the inner part of the guidepin and the wire, the ship being in the upright posi-tion, taken positive starboard and varying up to 90°.The angle α does not need to be taken less than:

• 15° for a vessel having a double pair of guide pins(PS and SB) (see Fig 7), and

• 25° in the case of a single pair of guide pinslocated at the vessel centreline (see Fig 8)

Figure 7 : Vessel with single pair of guide pins

Figure 8 : Vessel with double pair of guide pins

y0 : Transverse distance, in m, between the vessel cen-treline and the inner part of the guide pin

x : Longitudinal distance, in m, between the stern andthe guide pin or any physical restriction of the trans-verse wire movement

y : Torque arm, in m, of the vertical component TWz.

y is equal to the transverse distance from the vessel cen-treline to the outboard point at which the wire tension isapplied to the ship and is obtained by the formula:

y = y0 + x tanαy is not to be taken greater than B/2 and may be lim-ited to a physical restriction of the transverse wiremovement. Cargo rails, cranes, A-frames may be con-sidered as physical restrictions

Guide pins Wire

Wire stopperStern roller

Anchor handlingwinch

wire

TWy

TWz

TW

y

x

y0

y

x

y0


Pt D, Ch 14, Sec 2

5.2.3 Heeling moment

The most unfavourable conditions for transverse tension areto be considered for the calculations.

The maximum heeling moment occurs when α equals 90°.Even though practical experience shows that α normallydoes not exceed a maximum value of 45° during anchorhandling operations, the calculations are to be made up to90° in order to cover the complete range of angles.

Calculations are to be made for the maximum acceptablewire tension TW allowing the vessel to fulfil the require-ments of [5.2.4] during anchor handling operations.

The heeling arm bh , assumed to be constant, is to be calcu-lated, in m, as the total effect of the horizontal and verticaltransverse components TWy and TWz of wire tension TW , asfollows:

bh = TW (h sinα cosβ + y sinβ) / D = (TWy h + TWz y) / D

where:

h : Torque arm, in m, of the horizontal componentTWy.

h is equal to the vertical distance from theuppermost part of the guide pins to the centre ofthe main propulsion propeller or of the sternside propellers, whichever is deeper (see Fig 9).

In case of azimuth thrusters, h is to be taken asthe vertical distance from the uppermost part ofthe guide pins to the centre of the deepest drive(see Fig 10).

D : Displacement of the considered loading condi-tion, in t, including the vertical component TWz

of the towing force.


The stability of the vessel, for the loading conditionsincluded in Pt B, Ch 3, App 2, [1.2.11], is to be in compli-ance with the requirements of Pt B, Ch 3, Sec 2.

For all loading condition intended for anchor handlingoperations, the vessel is to comply with the following crite-ria, under the assumptions set out in [5.2.2]:

a) The maximum heeling angle is to be limited to one ofthe following angles, whichever occurs first (see Fig 11):

• heeling angle equivalent to GZ value equal to 50%of GZmax

• angle of deck immersion

• 15°.

b) Loading conditions other than the most unfavourableones and associated with anchor handling operationsneed to be calculated in the same way as described initem a), taking into account the prevailing practice withregards to loads on deck and winch reels.

Generally, when calculating the trim and the righting armcurve, the vertical component of the towing force is addedas a weight in the loading condition located at the cen-treline and at the stern of the vessel (normally the sternroller).

Alternatively, in case the vertical and horizontal compo-nents of the tension are both included in the loading condi-tion (e.g. by introducing a weight with offset), the rightingarm curve is to be corrected as follows before intact stabilitycalculations:

GZ = GZ0 + bh cosθ

with:

GZ : Righting arm curve after correction, so as toexclude the horizontal component of the tow-ing force

GZ0 : Righting arm curve including both vertical andhorizontal components of the towing force, var-ying with the heeling angle θ of the vessel.

Figure 9 : Vessel with stern side propellers and a fixed propulsion propeller

PS guide pin SB guide pin

h

y

TWy

TWz


Pt D, Ch 14, Sec 2

Figure 10 : Vessel with azimuth thrusters and a moveable propulsion propeller

Figure 11 : Heeling and righting arm curves

5.2.5 Information to be displayed

Information stating the maximum allowed tension in thewire, as well as the corresponding angles α and β, inaccordance with the calculations performed for each load-ing condition, are to be communicated to the vessel's crewand displayed next to the control desk or at any locationwhere the navigator on duty can easily see the informationfrom his command post.

The displayed information is to be under the form of curves,prepared so that the master can easily determine the maxi-mum tension that can be applied to the vessel, as a functionof the displacement (or draught) and of the vertical centre ofgravity (VCG), for a given value of trim, so as to satisfy thestability criteria (see Fig 12).

5.2.6 Stability booklet

The following information is to be included in the stabilitybooklet in addition to the information required in Pt B, Ch 3,App 2:

• Where ballasting or de-ballasting is applied beforeanchor handling operations, a sufficient number ofloading conditions representing this operation is to besubmitted, taking into account the relevant free surfaceeffects

• Calculation of the maximum heeling moment and cor-responding maximum tension is to be provided, forevery loading condition intended for anchor handlingoperations, satisfying the criteria of [5.2.4].

For all the possible combinations of angles α and β, theinterval between two angle values is not to exceed:

- for angle β: 5°

- for angle α: 5° when α is less than 50° and 10°when α is from 50° up to 90°.

The results are to be given in a table showing the maxi-mum tension (corresponding to the maximum accepta-ble heeling moment) as a function of angles α and β.

• Curves (or tables) of the maximum permissible tensionas a function of VCG (or GM) are to be provided for thedraught (or displacement) and trim values covering theintended anchor handling operations. For each trim, twosets of curves (or tables) are to be provided, correspond-ing to the following ranges of angle α:

- one set of curves (or tables) for 0 ≤ α ≤ 45°

- one set of curves (or tables) for α > 45°

The draught (or displacement), trim and VCG (or GM) tobe taken into consideration are those before applicationof the tension (see Fig 12).

In case a loading instrument performing direct stabilitycalculations for anchor handling is installed on board,the maximum permissible tension curves may be omit-ted from the stability booklet, see [5.2.7].

5.2.7 Loading instrumentTwo types of loading instrument may be used on board:

• either a software checking the intended or actual tensionon the basis of the maximum permissible tension curves,or

• a software performing direct stability calculations tocheck compliance with the criteria given in [5.2.4], for agiven loading condition (before application of the ten-sion force), a given tension and a given wire position(defined by angles α and β, see Fig 6).

PS guide pin SB guide pin

h

y

TWy

TWz

GZ m

ax

1/2

GZ m

ax

bh

Heelingangle Angle of deck

immersion

15°


Pt D, Ch 14, Sec 2

Figure 12 : Maximum permissible tension curves

Table 5 : Documents to be submitted

No. I / A (1) Document

1 I General arrangement showing:- detail arrangement of anchor handling deck equipment (wire stopper, guide pins, etc.)- typical arrangement of cargo on deck (anchors, wires, chain cables, etc.)- chain lockers used for mooring deployment- anchor handling/towing winch- tugger winches- stern roller, including lateral limits on both ends- lifting appliances, if any- typical paths of lines between winches and stern roller, showing the limit line sectors

2 I Design information of deck winches, including:- detailed drawing of winches- maximum rated line pull (RP), and the reeled layer for which the rated line pull is defined- brake holding load (BHL), and the reeled layer for which the rated line pull is defined- rendering load (RL)- specification of emergency quick release system including response time and intended remaining

holding force after release- strength calculation of the drum with flanges, shafts with coupling, framework and brakes- minimum guaranteed breaking strength of the wire

3 I Design information of wire stopper, including:- safe working load (SWL)- emergency release capabilities in normal and dead ship conditions

4 I Design information of guide pins, including:- safe working load (SWL)- emergency release capabilities in normal and dead ship conditions

5 I Safe working load (SWL) of stern roller

6 I Certified bollard pull (BP)

7 I Maximum weight of anchors on deck

8 I Maximum weight of wire/chain cable stored on deck

9 I Operational manual, including procedures mentioned in [1.2.1]

10 A Detailed drawing of wire stopper

11 A Detailed drawing of guide pins

12 A Detailed drawing of stern roller

13 A Deck reinforcements in way of deck equipment, including foundations and supports

14 I / A Loading manual, if relevant (see [5.3.3])

(1) A = for approval ; I = for information.

230225220215210205200195190185

4,8 5,0 5,2 5,4 5,6 5,8 6,0 6,2KG (m)

Per

mis

sibl

e te

nsio

n (t)

T = 4,2 T = 4,4

180170160150140130120110

1004,8 5,0 5,2 5,4 5,6 5,8 6,0 6,2

KG (m)

Per

mis

sibl

e te

nsio

n (t)


Pt D, Ch 14, Sec 2

5.3 Structural design principles

5.3.1 GeneralIt is the Designer's responsibility to check the consistency ofstrength capacity of the deck equipment (stern roller, wirestopper, guide pins) in relation to the performance of thewinch.

5.3.2 Documents to be submittedThe plans and documents listed in Tab 5 are to be submittedas applicable.

The listed plans are to be construction plans complete withall the dimensions and are to contain full indication on thetype of materials employed.

Plans of equipments which are type-approved by the Soci-ety need not be submitted, provided the types and modelnumbers are made available.

5.3.3 Hull girder strengthFor ships greater than 90 m in length, the loading manual isto include a loading condition corresponding to the chainlockers being fully loaded and winches fully loaded withthe heaviest anticipated line type.

5.3.4 Design loadsThe design loads DL defined below are to be taken not lessthan the maximum value of the tension in the wire (or chaincable) during anchor handling resulting from the stabilityanalysis.

Local strength of deck structure is to be based on the follow-ing design loads:

• in way of anchor handling winch:

DL = max (1,5 BP; 1,5 RP; BHL)

• in way of guide pins:

DL = max (2 SWL; 2 RP; BHL)

• in way of wire stopper:


• in way of stern roller:


Strength of anchor handling winch is to be based on the twofollowing design loads DL:

• case 1: DL = max (1,5 BP; 1,5 RP)

• case 2: DL = BHL as defined in [5.1.3].

Strength of deck equipment (guide pins, wire stopper, sternroller) is to be based on the same design loads as those con-sidered for the deck foundations.

5.3.5 Deck structureLocal reinforcements are to be provided in way of deckareas subjected to concentrated loads.

The strength checking required in [5.3.6], [5.3.7] and[5.3.8] are to be based on the following criteria:

• Stress level in the deck structure is not to exceed the fol-lowing permissible stresses:

- normal stress: σ ≤ 0,75 Ry

- shear stress: τ ≤ 0,47 Ry

- equivalent stress: σVM ≤ 0,85 Ry

• In case the yielding check of the structure is carried outby means of a three-dimensional finite element model,these permissible stress levels may be increased by 10per cent.

• Where necessary, buckling strength is to be checked.

Strength of the deck structure is to be checked considering:

• in way of anchor handling winch, including welds:

design load DL as defined in [5.3.4], with the followingassumptions:

- wire considered at the most unfavourable layer ofthe drum, in general

- direction of wire cable taken in the most unfavoura-ble direction allowed by the anchor handling equip-ment.

• in way of anchor handling deck equipment other thanwinches (i.e. guide pins, wire stopper), including welds:

design load DL as defined in [5.3.4], exerted in the mostunfavourable directions, with the most severe verticallocation.

• in way of stern roller, including welds:

design load DL as defined in [5.3.4], considering ananchor hanging underwater below the stern roller at anegative angle of 30° with respect to a vertical axis (seeFig 13).

• in way of handling and/or lifting appliances, if any,including welds:the maximum dynamic reactions exerted by liftingappliance pedestal, according to the lifting appliancecertification.

Figure 13 : Angle of hanged anchorwith respect to vertical axis

5.3.6 Anchor handling winchThe combined stress is not to exceed the following permis-sible stress depending on the design load, for both casesdefined in [5.3.4]:

• for case 1: σVM ≤ Re

• for case 2: σVM ≤ 0,9 Re

The emergency quick-release system is to be designed to:

• allow drum release in all operational modes, includingemergency mode, in the shortest possible delay

• be activated locally at the winch and from a position atthe bridge with full view and control of the operation

• operate even in dead ship condition

• be protected against unintentional operation.

Roller

Winch

30°


Pt D, Ch 14, Sec 2

A winch intended for functions of anchor handling and tow-ing is to meet both the requirements of [2.8] and therequirements above.

Strength is to be checked on the basis of the calculationssubmitted, in particular the components which are exposedto the tension in the towline, such as the winch drums,drum shafts, brakes and support frame.

5.3.7 Anchor handling deck equipment other than winches

Strength of the deck equipment used for anchor handling,including guide pins and wire stopper, is to be checkedunder the maximum load on the wire equal to design loadDL as defined in [5.3.4], exerted in the most unfavourabledirections, with the most severe vertical location.

Stress levels in the deck structure in way of anchor handlingdeck equipment are not to exceed the following permissiblestresses:

• normal stress: σ ≤ 0,75 Re

• shear stress: τ ≤ 0,47 Re

• equivalent stress: σVM ≤ 0,85 Re

In case the yielding check of the structures is carried out bymeans of a three-dimensional finite element model, thesepermissible stress levels may be increased by 10 per cent.

Where necessary, buckling strength is to be checked.

5.3.8 Stern roller

The structure of the stern roller is to be checked underdesign load DL as defined in [5.3.4], considering an anchorhanging underwater below the stern roller at a negativeangle of 30° with respect to a vertical axis (see Fig 13).

For strength purposes, design load DL as defined in [5.3.4]is to be considered in any transverse position on the sternroller, as allowed by the actual locations of the guide pinsand the anchor handling deck equipment.

The bending, shearing and combined stresses are not toexceed the following permissible stresses:

• normal stress: σ ≤ 0,75 Re

• shear stress: τ ≤ 0,47 Re

• equivalent stress: σVM ≤ 0,85 Re

Where necessary, buckling strength is to be checked.

5.3.9 Wire

The minimum breaking strength of the wire is not to be lessthan the design load DL defined in [5.3.4] for the anchorhandling winch.

The towline is to be protected from being damaged by chaf-ing and abrasion. To this end, cargo rails, bulwarks, and allthe elements supporting the towline are to be adequatelyrounded.

Strength of the wire attachment on the winch is to allowbreaking in case the line is to be run out. Under normaloperation, at least 3 turns of wire on the drum are consid-ered.

5.4 Testing

5.4.1 Load test

Load test is to be performed at the manufacturer workshop,for hoisting operation, and witnessed by the Society.

Winches are to be tested at design load DL, as defined in[5.3.4]. However, in case the winch is not of novel or par-ticular design, it is sufficient to perform load test at the bol-lard pull BP. In this case, it may be performed on boardduring commissioning trials and is to be witnessed by theSociety.

Bollard pull BP is to be verified by means of a bollard pulltest performed in accordance with a recognised standard.

5.4.2 Functional test

The proper functioning of the anchor handling equipment,including anchor handling winch, stern roller, guide pinsand wire stopper, is to be verified by on board test and wit-nessed by the Society, according to approved procedures.

The tests are performed to check the proper:

• operation of the equipment within the specified limita-tions

• arrangement of the towline sectors and the towlinepaths, as shown on the arrangement drawing

• functioning under the normal operation modes

• functioning under the emergency operation modes,including the emergency release and the dead shipoperations.

In particular, the emergency quick-release systems are to befunction tested at the bollard pull BP.

5.4.3 Operational tests

Prior to anchor handling operation, operational tests are tobe performed by the crew in order to ensure the satisfactoryoperation of the winches and deck equipment, in particularthe emergency quick-release system, as requested by theoperational manual.

Records of the operational tests are to be kept on board andmade available to the Society upon request.


Pt D, Ch 14, Sec 3

SECTION 3 INTEGRATED TUG/BARGE COMBINATION

Symbols

Ry : Minimum yield stress, in N/mm2, of the mate-rial, to be taken equal to 235/k N/mm2, unlessotherwise specified

k : Material factor for steel, defined in Pt B, Ch 4,Sec 1, [2.3]

ReH : Yield stress, in N/mm2, of the steel used, and notexceeding the lower of 0,7 Rm and 450 N/mm2

Rm : Minimum ultimate tensile stress, in N/mm2, ofthe steel used.

1 General

1.1 Application

1.1.1 GeneralThe requirements of this Section apply to the integratedtug/barge combinations constituted by:• a tug, to which the additional service feature barge

combined is assigned• a barge, to which the additional service feature tug

combined is assigned

and specify the criteria these combinations are to satisfy inaddition to those in:• Ch 14, Sec 2, [2], for the tug• Ch 19, Sec 2, for the barge.

1.1.2 When a series of barges may be operated in combi-nation with a specific tug, the identification numbers ofsuch barges are to be indicated in the tug class certificate.

1.1.3 When a series of tugs may be operated in combina-tion with a specific barge, the identification numbers ofsuch tugs are to be indicated in the barge Certificate ofClassification.

1.2 Permanent connections

1.2.1 An integrated tug/barge combination is connectedwith permanent connection if the tug and the barge cannotbe disconnected in open sea. The connection is such that norelative motion between the tug and the barge is permitted.

1.3 Removable connections

1.3.1 GeneralAn integrated tug/barge combination is connected withremovable connection if the tug and the barge can be dis-connected in open sea. The disconnecting procedure is tobe performed safely by one man and is to take less than5 min. After disconnection in open sea, the tug is to bearranged to tow the barge by hawser.

The procedure for disconnecting and reconnecting at seathe integrated tug/barge combination is to be made availa-ble for guidance to the Master.

1.3.2 Types of removable connections

The removable connection is classed in the two followingtypes:

• rigid connection, if no relative motion between the tugand the barge is permitted

• flexible connection, if relative motion between the tugand the barge is permitted (e.g. the tug is free to pitchwith respect to the barge).

1.3.3 Tug

The tug is to have the capability of separating from thebarge and shifting to tow it by hawser.

2 General arrangement design

2.1 Bulkhead arrangement

2.1.1 Number and disposition of tug transverse watertight bulkheads

The tug is to be fitted with transverse watertight bulkheadsaccording to Pt B, Ch 2, Sec 1.

2.1.2 Number and disposition of barge transverse watertight bulkheads

In applying the criteria in Pt B, Ch 2, Sec 1, [4], the barge isto be fitted at least with an aftermost transverse watertightbulkhead located forward of the connection area andextended from side to side.

The cargo spaces are to be separated from the other spacesnot used for cargo by watertight bulkheads.

2.1.3 Barge collision bulkhead

The collision bulkhead of the barge is to be located at a dis-tance, in m, from the fore end of L of not less than 0,05 LLLC

or 10 m, whichever is the lesser, and not more than 0,08LLLB, where:

LLLC : Ship’s length, in m, measured between the aftand fore ends of L of the integrated tug/bargecombination, taken at the fore and aft ends ofthe load line length

LLLB : Ship’s length, in m, measured between the aftand fore ends of L of the barge considered as anindividual ship, taken at the fore and aft ends ofthe load line length.


Pt D, Ch 14, Sec 3

3 Integrated tug/barge combinations with permanent connection: stability, freeboard, design loads, hull scantlings and equipment

3.1 Stability calculations

3.1.1 The integrated tug/barge combination is to complywith the applicable intact and, where additional notationSDS is requested, damage stability requirements in Part B,Chapter 3 considering the integrated tug/barge combinationas a ship of the size of the combination.

3.2 Freeboard calculation

3.2.1 The freeboard is to be taken as the greatest of:

• the freeboard of the tug, considered as an individual ship

• the freeboard of the barge, considered as an individualship

• the freeboard of the integrated tug/barge combination,considered as a ship of the size of the combination. Forthe freeboard calculation the barge is to be consideredas being manned.

3.3 Still water hull girder loads

3.3.1 The still water hull girder loads and the forces trans-mitted through the connection are to be calculated for eachloading condition considering the integrated tug/bargecombination as a ship of the size of the combination.

3.4 Wave hull girder loads

3.4.1 The wave hull girder loads and the forces transmittedthrough the connection are to be calculated according to PtB, Ch 5, Sec 2 considering the integrated tug/barge combi-nation as a ship of the size of the combination.

3.4.2 Direct calculationWhen deemed necessary by the Society, the wave hull girderloads and the forces transmitted through the connection areto be obtained from a complete analysis of the integratedtug/barge combination motion and acceleration in irregularwaves, unless such data are available from similar ships.

These loads are to be obtained as the most probable theintegrated tug/barge combination, considered as a ship ofthe size of the combination, may experience during itsoperating life for a probability level of 10-8. For this calcula-tion, the wave statistics relevant to the area of navigationand/or worst weather condition expressed by the navigationnotation assigned to the integrated tug/barge combinationare to be taken into account. For unrestricted navigation,the wave statistics relevant to the North Atlantic are to betaken into account.

When the difference between the tug and the barge depthsis not considered negligible by the Society, its effects are tobe considered in evaluating the buoyancy force distribu-tions and the corresponding hull girder loads on the tugstructures immediately aft of the connection section, for thedifferent wave encountering conditions.

3.5 Still water local loads

3.5.1 The still water local loads are to be calculated accord-ing to Pt B, Ch 5, Sec 5 for each loading condition anddraught of the integrated tug/barge combination. The draughtof the integrated tug/barge combination is to be taken notless than 0,85 D, where D is the greater of the tug and thebarge depths and not greater than the draught of the barge.

3.6 Wave local loads

3.6.1 The wave local loads are to be calculated accordingto Pt B, Ch 5, Sec 5, [2] considering the integrated tug/bargecombination as a ship of the size of the combination. Thedraught of the integrated tug/barge combination is to betaken not less than 0,85 D, where D is the greater of the tugand the barge depths and not greater than the draught of thebarge.

3.7 Hull girder strength

3.7.1 Strength check

The longitudinal strength is to comply with Part B, Chapter6, where the hull girder loads are those defined in [3.3] and[3.4].

3.7.2 Loading manual

The loading manual is to include the (cargo and ballast)loading conditions of the integrated tug/barge combinationat sea and in port conditions on the basis of which theapproval of its hull structural scantlings is based.

The manual is to indicate the still water bending momentand shear force along the length of the integrated tug/bargecombination as well as the permissible values at each hullsection.

Information on loading and unloading sequences is to beprovided for guidance to the Master.

3.8 Scantlings of plating, ordinary stiffeners and primary supporting members

3.8.1 The scantlings of plating, ordinary stiffeners and pri-mary supporting members are to be in accordance with PartB, Chapter 7 or NR600, as applicable, where the hull girderand local loads are those defined in [3.3] to [3.6].

In any case, the scantlings of plating, ordinary stiffeners andprimary supporting members of the tug and the barge are tobe not less than those obtained according to Ch 14, Sec 2and Ch 19, Sec 2 for the tug alone and the barge alone,respectively.

3.9 Equipment

3.9.1 The equipment is to be in accordance with therequirements in both

• Ch 14, Sec 2, for the tug, and

• Ch 19, Sec 2, for the barge, considering the barge as aship of the size of the integrated tug/barge combination.


Pt D, Ch 14, Sec 3

4 Integrated tug/barge combination with removable connection:stability, freeboard, design loads, hull scantlings and equipment

4.1 Stability calculations

4.1.1 The integrated tug/barge combination is to complywith the applicable intact stability requirement in Part B,Chapter 3, considering the integrated tug/barge combina-tion as a ship of the size of the combination.

4.2 Freeboard calculation

4.2.1 The freeboard is to be calculated for the tug and thebarge considered as individual ships.

4.3 Still water hull girder loads

4.3.1 General

The still water hull girder loads and the forces transmittedthrough the connection are to be calculated for each load-ing condition considering the integrated tug/barge combi-nation as a ship of the size of the combination.

4.3.2 Integrated tug/barge combination with removable flexible connection

For integrated tug/barge combinations with removable flexi-ble connection, the effect of the degrees of freedom of theconnection on the still water hull girder loads in the combi-nation may be taken into account (e.g. free pitch of the tugwith respect to the barge implies vertical bending momentequal to zero in the connection).

4.4 Wave hull girder loads

4.4.1 The wave hull girder loads and the forces transmittedthrough the connection are to be calculated according to[3.4].

4.4.2 Integrated tug/barge combination with removable flexible connection

For integrated tug/barge combinations with removable flexi-ble connection, the effect of the degrees of freedom of theconnection on the wave hull girder loads in the combina-tion may be taken into account (e.g. free pitch of the tugwith respect to the barge implies vertical bending momentequal to zero in the connection).

4.5 Still water local loads

4.5.1 The still water local loads are to be calculatedaccording to Pt B, Ch 5, Sec 5 for each loading conditionand draught of the integrated tug/barge combination. Thedraught of the integrated tug/barge combination is to betaken not less than 0,85 D, where D is the greater of the tugand the barge depths and not greater than the draught of thebarge.

4.6 Wave local loads

4.6.1 The wave local loads are to be calculated accordingto Pt B, Ch 5, Sec 5, [2] considering the integrated tug/bargecombination as a ship of the size of the combination. Thedraught of the integrated tug/barge combination is to betaken not less than 0,85 D, where D is the greater of the tugand the barge depths and not greater than the draught of thebarge.

4.7 Hull girder strength

4.7.1 The longitudinal strength is to comply with Part B,Chapter 6, where the hull girder loads are those defined in[4.3] and [4.4].

4.7.2 Loading manual

The loading manual is to include the items specified in[3.7.2].

4.8 Scantlings of plating, ordinary stiffeners and primary supporting members

4.8.1 Integrated tug/barge combinations with removable rigid connection

For integrated tug/barge combinations with removable rigidconnection, the scantlings of plating, ordinary stiffeners andprimary supporting members are to be in accordance withPart B, Chapter 7 or NR600, as applicable, where the hullgirder and local loads are those defined in [4.3] to [4.6].

In any case, the scantlings of plating, ordinary stiffeners andprimary supporting members of the tug and the barge are tobe not less than those obtained according to Ch 14, Sec 2and Ch 19, Sec 2 for the tug alone and the barge alone,respectively.

4.8.2 Integrated tug/barge combinations with removable flexible connection

For integrated tug/barge combinations with removable flexi-ble connection, the scantlings of plating, ordinary stiffenersand primary supporting members of the tug and the bargeare to be not less than those obtained according to Ch 14,Sec 2 and Ch 19, Sec 2 for the tug alone and the bargealone, respectively.

4.9 Equipment

4.9.1 The equipment is to be in accordance with [3.9.1].

5 Connection

5.1 General

5.1.1 The components of the connecting/disconnectingsystem are to be fitted on the tug.

Where the connecting system is located on a tug super-structure, this is to be checked according to Pt B, Ch 8, Sec4 or NR600, as applicable. The efficiency of the structuralconnection between this superstructure and the underlyinghull structures is to be ensured.


Pt D, Ch 14, Sec 3

5.1.2 The connecting system is to comply with the follow-ing requirements:

• it is to be permanently locked in position, at sea, withremote indication and control on the bridge

• it is to remain locked in the event of damage to the con-trol system. A local control is to be provided for ena-bling the disconnection from the coupler machineryroom.

5.2 Scantlings

5.2.1 General

The bow of the tug and the stern of the barge are to be rein-forced in order to withstand the connection forces.

The structure reinforcements are to be continued in aft andfore directions of the integrated tug/barge combination inorder to transmit the connection forces to the hull structureof the tug and the barge.

5.2.2 Calculation of stresses in the connection

The stresses in the connection are to be obtained by meansof direct calculations, where the connection forces are to beobtained according to [3.3] and [3.4] or [4.3] and [4.4], asapplicable, and the partial safety factors specified in Tab 1are to be applied.

When calculating the stresses in the connection, pre-load-ing from locking devices, if any, is to be taken into account.

For notch type connections, the analysis of the barge wingwalls is to take into account the effects of bending moment,shear force and torque.

5.2.3 Shear check of the structural elements of the connection

The shear stresses in the structural elements of the connec-tion are to comply with the following formula:

where:

τ : Shear stress, in N/mm2, to be obtained as aresult of direct calculations

γR : Resistance partial safety factor, defined in Tab 1

γm : Material partial safety factor, defined in Tab 1.

Table 1 : Partial safety factors

5.2.4 Yielding check of the structural elements of the connection

The Von Mises equivalent stresses in the structural elementsof the connection are to comply with the following formula:

where:


γR : Resistance partial safety factor, defined in Tab 1

γm : Material partial safety factor, defined in Tab 1.

5.2.5 Deflections

Deflections of the structural elements in the connection areto be obtained from direct calculations, to be carried out inaccordance with [5.2.2] and submitted to the Society forreview.

Deflection and pre-loading of the connection, if any, are tobe considered in order to avoid hammering in the connec-tion area.

6 Other structures

6.1 Tug fore part

6.1.1 General

For integrated tug/barge combinations with permanent con-nection or removable rigid connection, the tug fore struc-ture is to be aligned with the barge aft structure in way ofthe notch or the dock bottom.

6.1.2 Scantlings

The scantlings of the fore part of the tug are to be in accord-ance with Part B, Chapter 7 or NR600, as applicable, con-sidering the hull girder loads, the local loads and theconnection forces defined in [3.3] to [3.6] for integratedtug/barge combinations with permanent connection or [4.3]to [4.6] for integrated tug/barge combinations with remova-ble connection.

6.2 Tug aft part

6.2.1 Scantlings for integrated tug/barge combinations with permanent or removable rigid connections

The scantlings of the aft part of the tug are to be in accord-ance with Pt B, Ch 8, Sec 2 or NR600, as applicable, con-sidering this part as belonging to a ship of the size of theintegrated tug/barge combination.

6.2.2 Scantlings for integrated tug/barge combinations with removable flexible connections

The scantlings of the aft part of the tug are to be in accord-ance with Pt B, Ch 8, Sec 2 or NR600, as applicable, con-sidering the tug as an individual ship.

Partial safety factors covering uncertainties regarding

SymbolPartial safety factor value

Still water hull girder loads γS1 1,00

Wave hull girder loads γW1 1,15

Still water pressure γS2 1,00

Wave pressure γW2 1,20

Material γm 1,02

Resistance γR 1,25

τ 0 65RY

γRγm

----------,≤

σERY

γRγm

----------≤


Pt D, Ch 14, Sec 3

6.3 Barge fore part

6.3.1 Scantlings for integrated tug/barge combinations with permanent or removable rigid connections

The scantlings of the fore part of the barge are to be inaccordance with Pt B, Ch 8, Sec 1 or NR600, as applicable,considering this part as belonging to a ship of the size of theintegrated tug/barge combination.

6.3.2 Scantlings for integrated tug/barge combinations with removable flexible connections

The scantlings of the fore part of the barge are to be inaccordance with Pt B, Ch 8, Sec 1 or NR600, as applicable,considering the barge as an individual ship.

6.4 Barge aft part

6.4.1 GeneralFor integrated tug/barge combinations with permanent con-nection or removable rigid connection, the barge aft struc-ture is to be aligned with the tug fore structure in way of thenotch or the dock bottom.

6.4.2 ScantlingsThe scantlings of the aft part of the barge are to be inaccordance with Part B, Chapter 7 or NR600, as applicable,considering the hull girder loads, the local loads and theconnection forces defined in [3.3] to [3.6] for integratedtug/barge combinations with permanent connection or [4.3]to [4.6] for integrated tug/barge combinations with remova-ble connection.

7 Hull outfitting

7.1 Rudder and steering gear

7.1.1 The tug rudder and steering gear are to be in accord-ance with Pt B, Ch 9, Sec 1 and Pt C, Ch 1, Sec 11, respec-tively, considering the maximum service speed (in aheadand astern condition) of the tug as an individual ship andthe maximum service speed (in ahead and astern condition)of the integrated tug/barge combination.

The characteristics and performance of the rudder and thesteering gear are to ensure the manoeuvrability of the inte-grated tug/barge combination.

8 Construction and testing

8.1 Test of the disconnection procedure of removable connection

8.1.1 Tests are to be carried out in order to demonstrate thecapability of the tug to be safely disconnected from thebarge within 5 min by one man.

These tests may be performed in harbour. However, addi-tional information is to be submitted to the Society in orderto demonstrate the capability of the tug and the barge ofbeing safely disconnected and reconnected at sea. Theoperating procedure, indicating the maximum or pre-fixedsea states, is to be made available for guidance to the Mas-ter, as indicated in [1.3.1].



Chapter 15

SUPPLY VESSELS

SECTION 1 GENERAL


SECTION 3 MACHINERY AND CARGO SYSTEMS

SECTION 4 ELECTRICAL INSTALLATIONS

SECTION 5 FIRE PREVENTION, PROTECTION AND EXTINCTION


Pt D, Ch 15, Sec 1

SECTION 1 GENERAL

1 General

1.1 Application

1.1.1 Service notation supply vessel

Ships complying with the requirements of this Chapter areeligible for the assignment of the service notation supplyvessel, as defined in Pt A, Ch 1, Sec 2, [4.7.3].

The provisions in this Chapter do not regulate the transportof dangerous goods and marine pollutants in packagedform, including transport of dangerous goods in portabletanks.

1.1.2 Additional service feature oil product

For ships intended to carry oil products with any flashpointin bulk in its cargo spaces and having a maximum cargotank capacity as required in [1.2.1], the service notationsupply vessel is to be completed by the additional servicefeature oil product.

The additional service feature oil product may be com-pleted by the additional service feature FP>60°C when thesupply vessel is intended to carry only oil products having aflashpoint exceeding 60°C (closed cup test). This additionalservice feature is not to be assigned to units intended tocarry oil products heated within 15°C of their flash point.

Note 1: Supply vessels intended to carry less than 200m3 of oilproducts having a flashpoint exceeding 60°C need not have theadditional service feature oil product.

Note 2: The present Chapter is in compliance with MARPOLAnnex I, Regulation 2.2.

1.1.3 Additional service feature LHNS

For supply vessels, other than well stimulation vessels, car-rying amounts of hazardous and noxious liquid substancesin bulk not exceeding the maximum specified in [1.2.2], theservice notation supply vessel is to be completed by theadditional service feature LHNS.

The products which may be carried are hazardous and nox-ious liquids listed in Tab 1 and those other products whichmay be assigned to Tab 1 based on the following criteria:

a) products which for safety reasons may be assigned forcarriage on a type 3 ship as defined by the IBC Codeand which are not required to meet all the requirementsfor toxic products in section 15.12 of that Code, and

b) noxious liquid substances which would be permitted forcarriage on a type 3 ship.

1.1.4 Additional service feature WS

For well stimulation vessels, the service notation supply ves-sel may be completed by the additional service feature WS.

1.1.5 Applicable requirementsShips dealt with in this Chapter are to comply with:

• Part A of the Rules,

• NR216 Materials and Welding.


1.1.6 Assignment of different additional service features

A supply vessel may be assigned a combination of the addi-tional service features described above. In such a case, thespecific rule requirements applicable to each additionalservice feature are to be complied with.

1.1.7 Supply vessels intended to carry heated cargoes

For supply vessels intended to carry cargoes heated at atemperature of 90°C or more, design of the cargo tanks is tobe subjected to special consideration.

1.2 Maximum bulk liquid cargo capacity

1.2.1 Supply vessels with additional service feature oil product

The total capacity of cargo tanks designed to carry oil prod-uct having any flashpoint is to be less than 1000 m3.

1.2.2 Supply vessels with additional service feature LHNS

The aggregate quantity of bulk liquids identified in [1.1.3] isto be less than 800m3 and not to exceed a volume, in m3,equal to 40% of the unit’s deadweight calculated at a cargodensity of 1,0.

The Society may permit carriage of more than the maximumamount specified above, provided that the survival capabil-ity requirements of Chapter 2 of the IBC Code or IGC Codeare complied with.

1.2.3 Supply vessels with additional service feature WS

Well stimulation vessels are allowed to carry more than themaximum amount specified in [1.2.2].

1.3 Definitions

1.3.1 FlashpointFlashpoint is the temperature in degrees Celsius (closed cuptest) at which a product will give off enough flammablevapour to be ignited, as determined by an approved flash-point apparatus.

1.3.2 Flammable liquidA flammable liquid is any liquid having a flashpoint (closedcup test) not exceeding 60°C determined by an approvedflashpoint apparatus.


Pt D, Ch 15, Sec 1

1.3.3 Oil productOil product means petroleum in any form including crudeoil, sludge, oil refuse and refined products (other than thepetrochemicals which are subject to the provisions ofAnnex II of MARPOL 73/78, as amended) and excludes fueloil as defined in [1.3.4].

1.3.4 Fuel oilFuel oil means any oil used as fuel in connection with thepropulsion and auxiliary machinery of the ship on whichsuch oil is carried.

1.3.5 Safety hazard substancesThe safety hazard substances are those where "S" or "S/P"is assigned to column d) in Chapter 17 of the IBC Code.

1.3.6 Pollution hazard substancesThe pollution hazard substances are those where "P" or"S/P" is assigned to column d) in Chapter 17 of the IBCCode and substances of pollution category Z listed in Chap-ter 18 of the IBC Code.

1.3.7 Pollution hazard only substancesThe pollution hazard only substances are those where "P"only is assigned to column d) in Chapter 17 of the IBC Codeand substances of pollution category Z listed in Chapter 18of the IBC Code.

1.3.8 Well stimulation vesselA well stimulation vessel is a ship designed and equippedfor the stimulation of wells for production of oil and/or gas.

Table 1 : Hazardous and noxious permitted products

Name Flammability

Oil based mud containing mixtures of products listed in Chapters 17 and 18 of the IBC Code and the MEPC.2/Circular and permitted to be carried under [1.1.3]

No

Water based mud containing mixtures of products listed in Chapters 17 and 18 of the IBC Code and the MEPC.2/Circular and permitted to be carried under [1.1.3]

No

Drilling brines, including:• Sodium chloride solution• Calcium bromide solution• Calcium chloride solution

No

Calcium nitrate / Magnesium nitrate / Potassium chloride solution No

Calcium nitrate solution (50% or less) No

Drilling brines (containing zinc salts) No

Potassium formate solution No

Potassium chloride solution No

Ethyl alcohol Yes

Ethylene glycol No

Ethylene glycol monoalkyl ether Yes

Methyl alcohol Yes

Acetic acid Yes

Formic acid Yes

Hydrochloric acid No

Hydrochloric-hydrofluoric mixtures containing 3% or less Hydrofluoric acid No

Sodium silicate solution No

Sulfuric acid No

Triethylene Glycol No

Toluene Yes

Xylene Yes

Liquid carbon dioxide No

Liquid nitrogen No

Noxious liquid, NF, (7) n.o.s (trade name ..., contains ...) ST3, Cat. Y No

Noxious liquid, F, (8) n.o.s (trade name ..., contains ...) ST3, Cat. Y Yes

Noxious liquid, NF, (9) n.o.s (trade name ..., contains ...) ST3, Cat. Z No

Noxious liquid, F, (10) n.o.s (trade name ..., contains ...) ST3, Cat. Z Yes

Noxious liquid, F, (11) n.o.s (trade name ..., contains ...) Cat. Z No

Non-noxious liquid, F, (12) n.o.s (trade name ..., contains ...) Cat. OS No


Pt D, Ch 15, Sec 1


1.3.9 Cargo tank

Cargo tank is the envelope designed to contain the cargo.

1.3.10 Integral tank

Integral tank means a cargo containment envelope whichforms part of the ship's hull and which may be stressed inthe same manner and by the same loads which stress thecontiguous hull structure and which is normally essential tothe structural completeness of the ship's hull.

1.3.11 Independent tank

Independent tank means a cargo containment envelopewhich is not contiguous with, or part of, the hull structure.

An independent tank is built and installed so as to eliminatewhenever possible (or in any event to minimize) its stressingas a result of stressing or motion of the adjacent hull struc-ture. An independent tank is not essential to the structuralcompleteness of the ship’s hull.

1.3.12 Hold space

Hold space is the space enclosed by the ship's structure inwhich an independent cargo tank is situated.

1.3.13 Hazardous area

Hazardous area is an area in which an explosive atmos-phere is or may be expected to be present in quantities suchas to require special precautions for the construction, instal-lation and use of electrical apparatus.

1.3.14 Gas-safe area

Gas-safe area is an area which is not defined as hazardous.

1.3.15 Cargo areaCargo area is that part of the ship where cargo and cargovapours are likely to be present and includes cargo tanks,cargo pump-rooms, hold spaces in which independenttanks are located, cofferdams, ballast or void spaces sur-rounding integral cargo tanks and the following deck areas:• within 3 m of a cargo tank installed on deck• within 3 m of a cargo tank outlet in case of independent

tanks installed below deck• within 3 m of a cargo tank outlet in case of integral tanks

installed below deck and separated from the weatherdeck by a cofferdam

• the deck area above an integral tank without an overlay-ing cofferdam plus the deck area extending transverselyand longitudinally for a distance of 3 m beyond eachside of the tank

• within 3 m of any cargo liquid or vapour pipe, flange,cargo valve, gas or vapour outlet, or entrance or ventila-tion opening to a cargo pump-room.

Note 1: Cargo area definition is not applicable for supply vesselsintended to carry substances with FP>60°C.

1.3.16 Propeller shaft tunnelPropeller shaft tunnel is a compartment where the sterntube bulkhead seal is exposed to open sea.A propeller shaft tunnel is defined as a narrow enclosedspace/room with the primary purpose of containing the pro-peller shaft with associated equipment, but it could also con-tain limited amounts of other equipment. A full size room,e.g. where the propeller shaft is carried below the floor butabove the top of the tank, is not regarded as a propeller shafttunnel. In case of open sea water lubricated stern tube, thecompartment containing the stern tube bulkhead seal shouldalso be considered as a propeller shaft tunnel.


Ship arrangement

L ≥ 65 or 90 m (1)• Part B• Ch 15, Sec 2

• NR566• Ch 15, Sec 2

L < 65 or 90 m (1)• NR600• Ch 15, Sec 2

• NR566• Ch 15, Sec 2

Hull

L ≥ 65 or 90 m (1)• Part B• Ch 15, Sec 2


L < 65 or 90 m (1)• NR600• Ch 15, Sec 2

• NR600• Ch 15, Sec 2


• NR566• Ch 15, Sec 2


• NR566• Ch 15, Sec 3

Electrical installations• Part C• Ch 15, Sec 4

• NR566• Ch 15, Sec 4


Fire protection, detection and extinction • Ch 15, Sec 5 • Ch 15, Sec 5

(1) Refer to the scope of application of NR600.Note 1:NR566: Hull Arrangement, Stability and Systems for Ships less than 500 GTNR600: Hull Structure and Arrangement for the Classification of Cargo Ships less than 65 m and Non Cargo Ships less than 90 m.


Pt D, Ch 15, Sec 1

1.3.17 IndependentIndependent means that a piping or venting system, forexample, is in no way connected to another system and thatthere are not provisions available for the potential connec-tion to other systems.

1.3.18 SeparateSeparate means that a cargo piping system or cargo ventsystem, for example, is not connected to another cargo pip-ing or cargo vent system. The separation may be achievedby the use of design or operational methods. Operationalmethods are not to be used within a cargo tank and are toconsist of one of the following types:

• removing of spool pieces or valves and blanking of pipeends

• arrangement of two spectacle flanges in series, with pro-visions of detecting leakage into the pipe between thetwo spectacle flanges.

1.3.19 Noxious liquid substance

Noxious liquid substance means any substance indicated inthe Pollution category column of chapter 17 or 18 of theIBC Code or provisionally assessed under the provisions ofregulation 6.3 of MARPOL Annex II as falling into categoryX, Y or Z.


Pt D, Ch 15, Sec 2


Symbols

k : Material factor for steel, defined in Pt B, Ch 4,Sec 1, [2.3]

s : Length, in m, of the shorter side of the platepanel.

1 General

1.1 Application

1.1.1 This Section applies to ships having the followingservice notation and additional service features:• supply vessel• supply vessel oil product• supply vessel oil product FP>60°C• supply vessel LHNS• supply vessel WS


1.2.1 The documents listed in Tab 1 are to be submitted.



2.1 Compartment arrangement for all supply vessels

2.1.1 Watertight integrityThe machinery spaces and other working and living spacesin the hull should be separated from the other compart-ments by watertight bulkheads.

2.1.2 Afterpeak bulkheadAn afterpeak bulkhead should be fitted and made watertightup to the freebord deck. The afterpeak bulkhead may, how-ever, be stepped below the freebord deck, provided thedegree of safety of the supply vessel as regards subdivisionis not thereby diminished.

2.1.3 Location of cargo tanksAll cargo tanks are to be located aft of the collision bulk-head and forward of the aft peak.

2.1.4 Location of accommodation, service and machinery spaces and control stations

a) Accommodation, service and machinery spaces of cate-gory A and control stations should not be located withinthe cargo area except machinery spaces dedicated toWS equipment.

b) Unless they are spaced at least 7 m away from the cargoarea containing flammable products, entrances, airinlets and openings to accommodation, service andmachinery spaces and control stations should not facethe cargo area. Doors to spaces not having access toaccommodation, service and machinery spaces andcontrol stations, such as cargo control stations andstorerooms, may be permitted by the Society within the7 m zone specified above, provided the boundaries ofthe spaces are insulated to A-60 standard. Whenarranged within the 7 m zone specified above, windowsand sidescuttles facing the cargo area are to be of a fixedtype. Such sidescuttles in the first tier on the main deckare to be fitted with inside covers of steel or equivalentmaterial.

c) In order to guard against the danger of hazardousvapours, due consideration is to be given to the locationof air intakes and openings into accommodation, serv-ice and machinery spaces and control stations in rela-tion to cargo piping and cargo vent systems.

d) For supply vessels intended to carry pollution hazardonly substances having a flashpoint exceeding 60°C oroil products having a flashpoint exceeding 60°C, thearrangements referred to in a) to c) may be disregarded.

2.2 Compartment arrangement for supply vessels with additional service feature oil product

2.2.1 Cargo segregation

a) Cargo tanks or tanks containing residues of cargo are tobe segregated from machinery spaces, propeller shafttunnels, if fitted, dry cargo spaces, accommodation andservice spaces and from drinking water and stores forhuman consumption, by means of a cofferdam, voidspace, cargo pump-room, fuel oil tank, or other similarspace. On-deck stowage of independent tanks or instal-lation of independent tanks in otherwise empty holdspaces is to be considered as satisfactory.

Note 1: A cargo tank exclusively dedicated to the transport of pol-lution hazard only substances having a flashpoint exceeding60°C (closed cup test) may be considered as a "similar space".

Item N°

Description of the documentStatus of

the review

1 General arrangement I

2 Access arrangement A

3Arrangement of entrances, air inlets and openings to accommodation service, machinery spaces and control stations

A


Pt D, Ch 15, Sec 2

b) when the additional service feature FP>60°C isassigned, the supply vessel need not comply with itema), provided that:• the boundary bulkheads are fitted continuously

through joining structure to the top of the tank,where full penetration welding is to be carried out

• the boundary bulkheads are accessible for inspection• the segregation requirements for accommodation

spaces, drinking water and stores for human con-sumption are observed.

2.2.2 Length of cargo tanksThe length of each cargo tank may not exceed 10 metres orone of the values of Tab 2, as applicable, whichever is thegreater.

2.3 Compartment arrangement for supply vessels with additional service feature LHNS or WS

2.3.1 Location of cargo tanksCargo tanks containing products as listed in Ch 15, Sec 1,[1.1.3] are to be located at least 760 mm measured inboardfrom the side of the vessel perpendicular to the centreline atthe level of the summer load waterline.

2.3.2 Cargo segregationa) Tanks containing cargo or residues of cargo listed in Ch

15, Sec 1, [1.1.3] are to be segregated from machineryspaces, propeller shaft tunnels, if fitted, dry cargospaces, accommodation and service spaces and fromdrinking water and stores for human consumption, bymeans of a cofferdam, void space, cargo pump-room,fuel oil tank, or other similar space. On-deck stowage ofindependent tanks or installation of independent tanksin otherwise empty hold spaces is to be considered assatisfactory.

Note 1: A cargo tank only dedicated to the transport of oil productshaving a flashpoint exceeding 60°C (closed cup test) may beconsidered as a "similar space".

b) Cargoes which react in a hazardous manner with othercargoes or fuel oils are to be segregated from such othercargoes or fuel oils by means of a cofferdam, voidspace, cargo pump-room, pump-room, empty tank, ortank containing a mutually compatible cargo.

c) Except for cargo tanks intended to carry pollution haz-ard only substances having a flashpoint exceeding60°C, where not bounded by bottom shell plating, fueloil tanks, a cargo pump-room or a pump-room, thecargo tanks are to be surrounded by cofferdams. Tanksfor other purposes (except fresh water and lubricatingoils) may be accepted as cofferdams for these tanks.

d) Cargo tanks may extend to the deck plating, provideddry cargo is not handled in that area. Where dry cargo ishandled on the deck area above a cargo tank, the cargotank may not extend to the deck plating unless a contin-uous, permanent deck sheathing of wood or other suita-ble material of appropriate thickness and construction isfitted to the satisfaction of the Society.

e) For pollution hazard only substances having a flashpointexceeding 60°C (closed cup test), the Society maywaive the arrangements referred to in a), provided that:

- the segregation requirements for accommodationspaces, drinking water and stores for human con-sumption are observed

- the boundary bulkheads are fitted continuouslythrough joining structure to the top of the tank,where full penetration welding is to be carried out

- the boundary bulkheads are accessible for inspec-tion

Additionally, item c) need not be applied.

3 Access arrangement and access to spaces

3.1 Access arrangement for supply vessels with additional service feature oil product

3.1.1 Access to spaces

For access to all spaces, the minimum spacing betweencargo tank boundaries and adjacent ship's structures, otherthan the side shell, is to be 600 mm.

Note 1: For supply vessels intended to carry oil products having aflashpoint exceeding 60°C, this requirement need not be applied.

Table 2 : Length of cargo tanks

Longitudinal bulkhead Type of cargo tank bi /B (1) Centreline bulkhead Length (m)

No bulkhead − − − (0,5 bi /B + 0,1) L (2)

Centreline bulkhead − − − (0,25 bi /B + 0,15) L

Two or more bulkheads

Wing cargo tank − − 0,2 L

Centre cargo tank

if bi /B > 1/5 − 0,2 L

if bi /B < 1/5No (0,5 bi /B + 0,1) L

Yes (0,25 bi /B + 0,15) L

(1) Where bi is the minimum distance from the side of the supply vessel to the outer longitudinal bulkhead of the tank in question measured inboard at right angles to the centreline at the level corresponding to the assigned summer freeboard.

(2) Not to exceed 0,2 L.


Pt D, Ch 15, Sec 2

3.1.2 Access arrangement

a) Access to cofferdams, ballast tanks, cargo tanks (includ-ing double-bottom cargo tanks) and other spaces in thecargo area should be direct from the open deck andsuch as to ensure their complete inspection.

b) Access to double-bottom spaces (other than cargo tanks)may be through a cargo pump-room, pump-room, deepcofferdam, pipe tunnel or similar dry compartments,provided that the ventilation of these spaces complieswith Ch 15, Sec 3, [7.1.2].

c) For supply vessels intended to carry oil products havinga flashpoint exceeding 60°C, the following require-ments may apply instead of items a) and b):

• Access to cargo tanks should be direct from theopen deck and such as to ensure their completeinspection except for access to cargo tanks in dou-ble-bottoms that may be through a cargo pump-room, pump-room, deep cofferdam, pipe tunnel orsimilar dry compartments, provided that the ventila-tion of these spaces complies with Ch 15, Sec 3,[7.1.2].

• Access to cargo pumps does not need to be from theopen deck provided that the access is independentof watertight doors.

d) For access through horizontal openings, hatches ormanholes, the dimensions should be sufficient to allowa person wearing a self-contained air-breathing appara-tus and protective equipment to ascend or descend anyladder without obstruction and also to provide a clearopening to facilitate the hoisting of an injured personfrom the bottom of the space. The minimum clear open-ing should be not less than 600 mm by 600 mm.

e) For access through vertical openings, or manholes pro-viding passage through the length and breath of thespace, the minimum clear opening should be not lessthan 600 mm by 800 mm at a height of not more than600 mm from the bottom shell plating unless gratings orother footholds are provided.

f) Smaller dimensions may be approved by the Society inspecial circumstances, if the ability to traverse suchopenings or to remove an injured person can be provedto the satisfaction of the Society.

3.2 Access arrangement for supply vessels with additional service feature LHNS or WS

3.2.1 Access to spaces

For access to all spaces, the minimum spacing betweencargo tank boundaries and adjacent ship's structures, otherthan the side shell, is to be 600 mm.

Note 1: For supply vessels intended to carry pollution hazard onlysubstances having a flashpoint exceeding 60°C, this requirementneed not be applied.

3.2.2 Access to spaces in the cargo area

a) Access to cofferdams, ballast tanks, cargo tanks andother spaces in the cargo area should be direct from theopen deck and such as to ensure their complete inspec-tion.

Access to double-bottom spaces may be through acargo pump-room, pump-room, deep cofferdam, pipetunnel or similar dry compartments, subject to consider-ation of ventilation aspects.

Note 1: In case of access to double-bottom spaces through pump-rooms or cofferdam or pipe tunnel or similar spaces, thesespaces are to be capable of being ventilated as requested inCh 12.3 of the IBC Code.

b) For access through horizontal openings, hatches ormanholes, the dimensions should be sufficient to allow aperson wearing a self-contained air-breathing apparatusand protective equipment to ascend or descend any lad-der without obstruction and also to provide a clearopening to facilitate the hoisting of an injured personfrom the bottom of the space. The minimum clear open-ing should be not less than 600 mm by 600 mm.

c) For access through vertical openings, or manholes pro-viding passage through the length and breath of thespace, the minimum clear opening should be not lessthan 600 mm by 800 mm at a height of not more than600 mm from the bottom shell plating unless gratings orother footholds are provided.

d) Smaller dimensions may be approved by the Society inspecial circumstances, if the ability to traverse suchopenings or to remove an injured person can be provedto the satisfaction of the Society.

4 Stability

4.1 General

4.1.1 Application

Every decked offshore supply vessel of 24 metres and overbut not more than 100 metres in length is to comply withthe provisions of [4.2] and [4.4]. The intact and damage sta-bility of a supply vessel of more than 100 metres in lengthshould be to the satisfaction of the Society.

4.1.2 Relaxation

Relaxation in the requirements of [4.2] and [4.4] may bepermitted by the Society for supply vessels granted withnavigation notation coastal area provided the operatingconditions are such as to render compliance with [4.2] and[4.4] unreasonable or unnecessary.

4.2 Intact stability for all supply vessels

4.2.1 General stability criteria

The stability of the supply vessels, for the loading conditionsdefined in Pt B, Ch 3, App 2, [1.2.1] and Pt B, Ch 3, App 2,[1.2.12] with the assumptions in [4.2.5], is to be in compli-ance with the requirements of Pt B, Ch 3, Sec 2, [2.1] or, asan alternative, with the requirements of [4.2.2]. The addi-tional criteria of [4.2.3] are also to be complied with.


Pt D, Ch 15, Sec 2

4.2.2 Alternative stability criteria

The following equivalent criteria are recommended where asupply vessel's characteristics render compliance with Pt B,Ch 3, Sec 2, [2.1] impracticable:

• the area, in m⋅rad, under the curve of righting levers(GZ curve) may not be less than 0,070 up to an angle of15° when the maximum righting lever (GZ) occurs at15° and 0,055 up to an angle of 30° when the maxi-mum righting lever (GZ) occurs at 30° or above. Wherethe maximum righting lever (GZ) occurs at angles ofbetween 15° and 30°, the corresponding area “A”, inm⋅rad, under the righting lever curve is to be:

where θmax is the angle of heel, in degrees, at which therighting lever curve reaches its maximum

• the area, in m⋅rad, under the righting lever curve (GZcurve) between the angles of heel of 30° and 40°, orbetween 30° and θf if this angle is less than 40°, may notbe less than 0,03, where θf is defined in Pt B, Ch 3, Sec2, [2.1.2]

• the righting lever (GZ), in m, is to be at least 0,20 at anangle of heel equal to or greater than 30°

• the maximum righting lever (GZ) is to occur at an angleof heel not less than 15°

• the initial transverse metacentric height (GM), in m,may not be less than 0,15 m.

4.2.3 Additional criteria

A minimum freeboard at the stern of at least 0,005 L is to bemaintained in all operating conditions.

4.2.4 Factors of influence

The stability criteria mentioned in [4.2.1] and [4.2.2] are min-imum values; no maximum values are recommended. It isadvisable to avoid excessive values, since these might lead toacceleration forces which could be prejudicial to the vessel,its complement, its equipment and the safe carriage of cargo.

Where anti-rolling devices are installed, the stability criteriaindicated in [4.2.1] and [4.2.2] are to be maintained whenthe devices are in operation.

4.2.5 Assumptions for calculating loading conditions

If a vessel is fitted with cargo tanks, the fully loaded condi-tions of Pt B, Ch 3, App 2, [1.2.12] are to be modified,assuming first the cargo tanks full and then the cargo tanksempty.

If in any loading condition water ballast is necessary, addi-tional diagrams are to be calculated, taking into account thewater ballast, the quantity and disposition of which are tobe stated in the stability information.

In all cases when deck cargo is carried, a realistic stowageweight is to be assumed and stated in the stability informa-tion, including the height of the cargo and its centre of grav-ity.

Where pipes are carried on deck, a quantity of trappedwater equal to a certain percentage of the net volume of thepipe deck cargoes is to be assumed in and around thepipes. The net volume is to be taken as the internal volumeof the pipes, plus the volume between the pipes. This per-centage is 30 if the freeboard amidships is equal to or lessthan 0,015 L and 10 if the freeboard amidships is equal toor greater than 0,03 L. For intermediate values of the free-board amidships, the percentage may be obtained by linearinterpolation. In assessing the quantity of trapped water, theSociety may take into account positive or negative sheer aft,actual trim and area of operation.

If a vessel operates in zones where ice accretion is likely tooccur, allowance for icing should be made in accordancewith the provisions of Pt B, Ch 3, Sec 2, [6].

A vessel, when engaged in towing operations, may not carrydeck cargo, except that a limited amount, properly secured,which would neither endanger the safe working of the crewnor impede the proper functioning of the towing equip-ment, may be accepted.

4.3 Damage stability for all supply vessels where the additional class notation SDS has been requested

4.3.1 General

Taking into account, as initial conditions before flooding,the standard loading conditions as referred to in Pt B, Ch 3,App 2, [1.2.1] and Pt B, Ch 3, App 2, [1.2.12], the vessel isto comply with the damage stability criteria as specified in[4.3.8].

4.3.2 Damage dimensions

The assumed extent of damage of supply vessels is to be asindicated in Tab 3.

Table 3 : Extent of damage

A 0 055, 0 001, 30° θmax–( )⋅+=

Longitudinalextent

Transverseextent

Verticalextent

3L/100 + 3 for L>43 m 760 mm (1)

Full depth (2) L/10 for L≤43 m

(1) Measured inboard from the side of the vessel perpen-dicularly to the centreline at the level of the summerload waterline.

(2) From the underside of the cargo deck, or the continua-tion thereof.

Note 1: Anywhere in the vessel’s length between any trans-verse watertight bulkhead.


Pt D, Ch 15, Sec 2

4.3.3 Consideration of transverse watertight bulkheads for flooding

A transverse watertight bulkhead extending from the ves-sel's side to a distance inboard of 760 mm or more at thelevel of the summer load line joining longitudinal watertightbulkheads may be considered as a transverse watertightbulkhead for the purpose of the damage calculations.

Where a transverse watertight bulkhead is located withinthe transverse extent of assumed damage and is stepped inway of a double bottom or side tank by more than 3,05 m,the double bottom or side tank adjacent to the stepped por-tion of the bulkhead is to be considered as flooded simulta-neously.

If the distance between adjacent transverse watertight bulk-heads or the distance between the transverse planes passingthrough the nearest stepped portions of the bulkheads isless than the longitudinal extent of damage given in [4.3.2],only one of these bulkheads should be regarded as effectivefor the purpose of the damage assumptions described inTab 3, Note 1.

4.3.4 Progressive flooding

If pipes, ducts or tunnels are situated within the assumedextent of damage, arrangements are to be made to ensurethat progressive flooding cannot thereby extend to compart-ments other than those assumed to be floodable for eachcase of damage. The progressive flooding is to be consid-ered in accordance with Pt B, Ch 3, Sec 3, [3.3].

4.3.5 Minor damage

If damage of a lesser extent than that specified in [4.3.2]results in a more severe condition, such lesser extent is to beassumed.

4.3.6 Permeability

The permeability of spaces assumed to be damaged is to beas indicated in Tab 4.

Table 4 : Values of permeability

4.3.7 Survival requirements

Compliance with the requirements of [4.3.8] is to be con-firmed by calculations which take into consideration thedesign characteristics of the vessel, the arrangements, con-figuration and permeability of the damaged compartmentsand the distribution, specific gravities and free surface effectof liquids.

4.3.8 Damage stability criteria

a) The final waterline, taking into account sinkage, heeland trim, is to be below the lower edge of any openingthrough which progressive flooding may take place. Theprogressive flooding is to be considered in accordancewith Pt B, Ch 3, Sec 3, [3.3].

b) In the final stage of flooding, the angle of heel due tounsymmetrical flooding may not exceed 15°. This anglemay be increased up to 17° if no deck immersion occurs.

c) The stability in the final stage of flooding is to be investi-gated and may be regarded as sufficient if the rightinglever curve has at least a range of 20° beyond the posi-tion of equilibrium in association with a maximum resid-ual righting lever of at least 100 mm within this range.Unprotected openings may not become immersed at anangle of heel within the prescribed minimum range ofresidual stability unless the space in question has beenincluded as a floodable space in calculations for damagestability. Within this range, immersion of any of the open-ings referred to in item a) and any other openings capa-ble of being closed weathertight may be authorized.

d) The stability is to be sufficient during intermediate stagesof flooding. In this regard, the Society applies the samecriteria relevant to the final stage of flooding also duringthe intermediate stages of flooding.

4.4 Damage stability for supply vessels with additional service feature WS where the additional class notation SDS has been requested

4.4.1 GeneralSupply vessels with additional service feature WS carryingsubstances listed in Ch 15, Sec 1, [1.1.3] more than themaximum amounts specified in Ch 15, Sec 1, [1.2.2] are tocomply with the requirements of [4.3] considering the dam-age dimensions as specified in Tab 5.

Table 5 : Extent of damage


5.1 General

5.1.1 For supply vessels greater than 24 m in length, it isrecommended that a double skin is provided to reinforcethe protection of the main compartments in the event ofcontact with pontoons or platform piles.

Spaces Permeability

Appropriated for stores 0,60

Occupied by accommodation 0,95

Occupied by machinery 0,85

Void spaces, empty tanks 0,95

Intended for dry cargo 0,95

Intended for liquids (1)

(1) The permeability of tanks is to be consistent with theamount of liquid carried.

Longitudinalextent

Transverse extent

Verticalextent

3L/100 + 3 for L>43 m (1) L/10 for L≤43 m (1)

760 mm (2)

Full depth (3)

(1) Anywhere in the vessel’s length at any transverse water-tight bulkhead.

(2) Measured inboard from the side of the vessel perpen-dicularly to the centreline at the level of the summerload waterline.

(3) From the underside of the cargo deck, or the continua-tion thereof.


Pt D, Ch 15, Sec 2

5.2 Side structure exposed to bumping

5.2.1 Longitudinally framed side

In the whole area where the side of the supply vessel isexposed to bumping, distribution frames are to be providedat mid-span, consisting of an intercostal web of the sameheight as the ordinary stiffeners, with a continuous faceplate.

Within reinforced areas, scallop welding for all side ordi-nary stiffeners is forbidden.

5.2.2 Transversely framed side

In the whole area where the side of the supply vessel isexposed to bumping, a distribution stringer is to be fitted atmid-span, consisting of an intercostal web of the sameheight as the ordinary stiffeners, with a continuous faceplate.

Side frames are to be fitted with brackets at ends.

Within reinforced areas, scallop welding for all side ordi-nary stiffeners is forbidden.

5.2.3 Fenders

Efficient fenders, adequately supported by structural mem-bers, are to be fitted on the side, including the forecastle, onthe full length of the areas exposed to contact.

5.3 Deck structure

5.3.1 Local reinforcements are to be fitted in way of spe-cific areas which are subject to concentrated loads.

5.3.2 Exposed decks carrying heavy cargoes or pipes are toprovide protection and means of fastening for the cargo,e.g. inside bulwarks, guide members, lashing points, etc.

5.4 Structure of cement tanks and mud compartments

5.4.1 Cargo tanks and hoppers intended to carry mud orcement are to be supported by structures which distributethe acting forces as evenly as possible on several primarysupporting members.

5.5 Acid spill protection for supply vessels with additional service feature LHNS or WS

5.5.1 Floors and decks under acid storage tanks and pumpsand piping for acid should have a lining or coating of corro-sion-resistant material extending up to a minimum height of500 mm on the bounding bulkheads or coamings. Hatchesor other openings in such floors or decks should be raised toa minimum height of 500 mm; where the Society deter-mines that this height is not practicable, a lesser height maybe required.

6 Design loads

6.1 Dry uniform cargoes

6.1.1 Still water and inertial pressuresThe still water and inertial pressures transmitted to the struc-ture of the upper deck intended to carry loads are to beobtained, in kN/m2, as specified in Pt B, Ch 5, Sec 6, [4],where the value of pS is to be taken not less than 24 kN/m2.

7 Hull scantlings

7.1 Plating

7.1.1 Minimum net thicknessesThe net thickness of the side and upper deck plating is to benot less than the values given in Tab 6.

Table 6 : Minimum net thickness ofthe side and upper deck plating

7.1.2 Strength deck platingWithin the cargo area, the thickness of strength deck platingis to be increased by 1,5 mm with respect to that deter-mined according to Pt B, Ch 7, Sec 1 or NR600, as applica-ble.

However, the above increase in thickness by 1.5mm maybeommitted provided all the following conditions are fulfilled:

a) Wooden planking provide an efficient protection of thedeck at the satisfaction of the society.

b) The welding of the steel fittings securing the wood pro-tection is performed before coating application.

c) Full coating application is applied after item b) above.

7.2 Ordinary stiffeners

7.2.1 Longitudinally framed side exposed to bumpingIn the whole area where the side of the supply vessel isexposed to bumping, the section modulus of ordinary stiff-eners is to be increased by 15% with respect to that deter-mined according to Pt B, Ch 7, Sec 2 or NR600, asapplicable.

7.2.2 Transversely framed side exposed to bumpingIn the whole area where the side of the supply vessel isexposed to bumping, the section modulus of ordinary stiff-eners, i.e. side, ‘tweendeck and superstructure frames, is tobe increased by 25% with respect to that determinedaccording to Pt B, Ch 7, Sec 2 or NR600, as applicable.

Plating Minimum net thickness, in mm

Side below freeboard deck

The greater of:• 2,1 + 0,031 L k0,5 + 4,5 s• 8 k0,5

Side between freeboard deck and strength deck

The greater of:• 2,1 + 0,013 L k0,5 + 4,5 s• 8 k0,5

Upper deck 7,0


Pt D, Ch 15, Sec 2

7.3 Primary supporting members

7.3.1 Distribution stringers The section modulus of the distribution stringer required in[5.2.2] is to be at least twice that calculated in [7.2.2] forordinary stiffeners.

7.3.2 Cement tanks and mud compartmentsThe net scantlings of the primary supporting members ofcement tanks and mud compartments are to be calculatedtaking into account high stresses resulting from vertical andhorizontal accelerations due to rolling and pitching.

Secondary moments due to the tendency of materials to tipover are to be considered by the Society on a case-by-casebasis.

8 Other structure

8.1 Aft part

8.1.1 RollersAt the transom, local reinforcements are to be fitted in wayof rollers and other special equipment intended for cargohandling.

8.1.2 Structures in way of rollersThe structures in way of the stern rollers and those of theadjacent deck are considered by the Society on a case-by-case basis, taking into account the relevant loads which areto be specified by the Designer.

8.1.3 Propeller protectionIt is recommended that devices should be fitted to protectthe propellers from submerged cables.

8.2 Superstructures and deckhouses

8.2.1 ForecastleThe forecastle length may not exceed 0,3 to 0,4 times thelength L.

8.2.2 Deckhouses Due to their location at the forward end of the supply ves-sel, deckhouses are to be reduced to essentials and specialcare is to be taken so that their scantlings and connectionsare sufficient to support wave loads.

8.2.3 Minimum net thicknessesThe net thickness of forecastle aft end plating and of platingof deckhouses located on the forecastle deck is to be notless than the values given in Tab 7.

Table 7 : Plating of forecastle aft end andof deckhouses located on the forecastle deck

8.2.4 Ordinary stiffenersThe net section modulus of ordinary stiffeners of the fore-castle aft end and of deckhouses located on the forecastledeck is to be not less than the values obtained from Tab 8.

Table 8 : Ordinary stiffeners of forecastle aft end and of deckhouses located on the forecastle deck

Ordinary stiffeners of the front of deckhouses located on theforecastle deck are to be fitted with brackets at their ends.Those of side and aft end bulkheads of deckhouses locatedon the forecastle deck are to be welded to decks at theirends.

8.3 Arrangement for hull and forecastle openings

8.3.1 Sidescuttles and windowsSidescuttles and windows of opening type are, in general,accepted only in unexposed areas of the deckhouseslocated immediately above the forecastle and the areasabove.

8.3.2 Sidescuttles of gas-safe areas facing hazardous areas

Sidescuttles of gas-safe areas facing hazardous areas,excluding those of non-opening type, are to be capable ofensuring an efficient gas-tight closure.

Warning plates are to be fitted on access doors to accom-modation and service spaces facing the cargo area indicat-ing that the doors and sidescuttles mentioned above are tobe kept closed during cargo handling operations.

8.3.3 Freeing portsThe area of freeing ports is to be increased by 50% withrespect to that determined according to Pt B, Ch 8, Sec 10,[6] or NR600, as applicable.

For ships operating in areas where icing is likely to occur,shutters may not be fitted.

8.3.4 Freeing ports through box-bulwarksWhere box-bulwarks the upper level of which extends tothe forecastle deck are fitted in way of the loading area, thefreeing ports are to pass through these box-bulwarks andtheir area is to be increased to take account of the height ofthe bulwarks.

8.3.5 MiscellaneousAir pipes, ventilators, small hatchways, fans and controlvalves are to be located outside the loading area and pro-tected from possible shifting of the deck cargo.

Structure PlatingMinimum net thickness,

in mm

Forecastle aft end 1,04 (5 + 0,01 L)

Deckhouses locatedon the forecastledeck

front 1,44 (4 + 0,01 L)

sides 1,31 (4 + 0,01 L)

aft end 1,22 (4 + 0,01 L)

StructureOrdinary

stiffeners onNet section modulus,

in cm3

Forecastle aft end plating 3 times the value cal-culated according to Pt B, Ch 8, Sec 4, [4] or NR600, as applica-ble

Deckhouses located on the forecastle deck

front plating

sides plating 0,75 times that of the forecastle ‘tweendeck framesaft end plating


Pt D, Ch 15, Sec 2

8.4 Structure of cargo tanks

8.4.1 Scantling of cargo tanks is to be in compliance withthe provisions of Pt B, Ch 5, Sec 6 and Part B, Chapter 7 orNR600, as applicable.Refer to Ch 15, Sec 3, [4] to Ch 15, Sec 3, [7] for designdetails.

9 Hull outfitting

9.1 Rudders

9.1.1 Rudder stock scantlingsThe rudder stock diameter is to be increased by 5% withrespect to that determined according to Pt B, Ch 9, Sec 1,[4].

9.2 Bulwarks

9.2.1 Plating In the case of a high bulwark, fitted with a face plate of largecross-sectional area, which contributes to the longitudinalstrength, the thickness of the plating contributing to the lon-gitudinal strength is to be not less than the value obtainedaccording to Pt B, Ch 7, Sec 1 or NR600, as applicable.

9.2.2 Stays

The bulwark stays are to be strongly built with an attach-ment to the deck reinforced to take account of accidentalshifting of deck cargo (e.g. pipes).

9.3 Equipment

9.3.1 Mooring lines

The mooring lines are given as a guidance, but are notrequired as a condition of classification.

The length of mooring lines may be calculated according toPt B, Ch 9, Sec 4, [5.2].

However, in the case of supply vessels provided withdevices enabling ample manoeuvring characteristics (e.g.supply vessels provided with two or more propellers,athwartship thrust propellers, etc.), the length of mooringlines, in m, may be reduced to (L + 20).

9.3.2 Chain locker

Chain lockers are to be arranged as gas-safe areas. Hullpenetrations for chain cables and mooring lines are to bearranged outside the hazardous areas specified in Ch 15,Sec 1, [1.3.13].


Pt D, Ch 15, Sec 3

SECTION 3 MACHINERY AND CARGO SYSTEMS

1 General

1.1 Application

1.1.1 This Section provides, for ships having the servicenotation supply vessel, requirements for:

• machinery systems

• cargo tanks and piping systems, in particular where theadditional service features oil product, LHNS or WS areassigned.


1.2.1 The documents listed in Tab 1 are to be submitted forapproval.

2 Machinery systems for supply vessels with additional service feature oil product, LHNS or WS

2.1 Bilge system

2.1.1 Bilge system serving spaces within the cargo area areto be independent from systems serving spaces outside thecargo area and are to be entirely situated within the cargoarea. Bilge systems serving spaces outside the cargo areaare to be located outside the cargo area.

For supply vessels intended to carry pollution hazard onlysubstances having a flashpoint above 60°C or oil productshaving a flashpoint above 60°C this requirement does notneed to be applied.

2.2 Ballast system

2.2.1 Pumps, ballast lines, vent lines and other similarequipment serving permanent ballast tanks shall be inde-pendent of similar equipment serving cargo tanks and ofcargo tanks themselves.

2.2.2 Discharge arrangement for permanent ballast tankssited immediately adjacent to cargo tanks shall be outsidemachinery spaces and accommodation spaces. Fillingarrangements may be in the machinery spaces provided thatsuch arrangements ensure filling from the tank deck leveland non-return valves are fitted.

2.2.3 Filling of ballast in cargo tanks may be arranged fromdeck level by pumps serving permanent ballast tanks, pro-vided that the filling line has no permanent connection tocargo tanks or piping and that non-return valves are fitted.

2.2.4 For ships intended to carry pollution hazard only sub-stances having a flashpoint above 60°C or oil products hav-ing a flashpoint above 60°C, the requirements [2.2.1],[2.2.2] and [2.2.3] do not need to be applied.


Item N°

Description of the document (1)Status of

the review

1 Capacity plan where the following tanks need to be clearly indicated as such:• cargo tanks (for oil products and/or for LHNS) • fuel oil tanks

I

2 Diagram of cargo piping system A

3 Diagram of cargo tank venting system A

4 Diagram of the cargo tank level gauging with overfill safety arrangement A

5 Diagram of the bilge and ballast system serving spaces within the cargo area A

6 Diagram of the bilge and ballast system serving spaces outside the cargo area A

7 General layout of the cargo pump room with details of:• Bulkhead penetrations• Flammable vapors detections system• Bilge level monitoring devices• Ventilation

A

8 Diagram of the cargo heating system, if any A

9 Diagram of inert gas system with details of the inert gas plant, if any A

(1) Diagrams are also to include, where applicable, the (local and remote) control and monitoring systems and automation systems.


Pt D, Ch 15, Sec 3

2.3 Cargo heating systems

2.3.1 When provided, any cargo tank heating system is tocomply with the following provisions:

• for supply vessels having the additional service featureoil product FP>60°C: Ch 7, Sec 4, [2.6]

• for supply vessels having the additional service featureLHNS or WS: Ch 8, Sec 7 and Chapter 7 of the IBCCode.

With reference to Ch 15, Sec 1, [1.1.2], particular attentionto be provided to the maximum heating temperature ofcargo tanks on supply vessels having the additional servicefeature oil product FP>60°C.

2.4 Exhaust pipes

2.4.1 Exhaust outlets from diesel engines are to be pro-vided with spark arresters.

Exhaust outlets from engines are to be fitted as high as prac-ticable above the upper deck, except for supply vesselsintended to carry pollution hazard only substances having aflashpoint above 60°C or oil products having a flashpointabove 60°C.

2.5 Inert gas system

2.5.1 When provided, nitrogen/inert gas systems fitted on asupply vessel are to comply with the provision of Ch 7, Sec6, [5.5.1], except items a) to c) and g).

Where connections to the cargo tanks, to the hold spaces orto the cargo piping are not permanent, the non-returndevices required by item l) of Ch 7, Sec 6, [5.5.1] may bereplaced by two non-return valves.

2.6 Other machinery systems

2.6.1 Fuel oil, lubricating oil tanks, foam forming liquidtanks, oil dispersant tanks and similar tanks which arelocated inside the cargo area may be served by pumpslocated outside the cargo area, provided that the piping isdirectly connected to the associated pump and does not runthrough cargo tanks.

3 Cargo piping design for supply vessels with additional service feature oil product, LHNS or WS

3.1 Cargo separation

3.1.1 For cargo handling, a pumping and piping systemindependent from the other pumping and piping systems onboard is to be provided.

3.1.2 For supply vessels having the additional service fea-ture oil product FP>60°C, the piping system serving the oilproduct cargo tanks may be connected to the fuel oil pump-ing system in engine room, provided that:

• there are suitable means of separation between thebranches serving the tanks dedicated for the cargo oilproduct tanks and the branches serving the fuel oil tanks

• mixing the two different kinds of oils does not jeopard-ize the intended use of neither the fuel oil nor the cargo.

3.1.3 When carrying cargoes which react in a hazardousmanner with other cargoes, supply vessels having the addi-tional service feature LHNS or WS are to have separatepumping and piping systems which may not pass throughother cargo tanks containing such cargoes, unless encasedin a tunnel.

3.2 Design and Materials

3.2.1 Unless otherwise specified, materials for construction oftanks, piping, fittings and pumps are to be in accordance with:

• for supply vessels having the additional service featureoil product: Ch 7, Sec 4, [3.3.2]

• for supply vessels having the additional service featureLHNS or WS:

• Ch 8, Sec 5 and Chapter 6 of the IBC Code, or

• Ch 9, Sec 6 and Chapter 6 of the IGC Code,

as applicable.

3.2.2 Unless otherwise specified, cargo piping is to bedesigned and constructed according to:

• for supply vessels having the additional service featureoil product: Ch 7, Sec 4, [3.3.1]

• for supply vessels having the additional service featureLHNS or WS:

• Ch 8, Sec 5, [1.2.1] and Chapter 5 of the IBC Code,or

• Ch 9, Sec 5, [2.1.1] and Chapter 6 of the IGC Code,

as applicable.

3.3 Piping arrangement

3.3.1

a) Except for the tank connections to cargo pump-rooms,all tank openings and connections to the tank are to ter-minate above the weather deck and are to be located inthe tops of the tanks. Where cofferdams are providedover integral tanks, small trunks may be used to pene-trate the cofferdam.

Note 1: This requirement need not be applied for supply vesselsintended to carry pollution hazard only substances having aflashpoint above 60°C or oil products having a flashpointabove 60°C.

b) Cargo piping is to be located entirely within the cargo areaexcept cargo piping conveying pollution hazard only sub-stances having a flashpoint above 60°C or oil productshaving a flashpoint above 60°C provided that the separa-tion requirements for accommodation spaces, drinkingwater and stores for human consumption are observed.

c) Where cargo piping necessarily has to run outside acargo area in order to be connected to a cargo manifold,a shut-off valve is to be provided in the piping leaving thecargo area, except cargo piping conveying pollution haz-ard only substances having a flashpoint above 60°C or oilproducts having a flashpoint above 60°C.


Pt D, Ch 15, Sec 3

d) Cargo piping may run from the tank it serves and pene-trate cargo tanks, ballast tanks, void spaces, pump-rooms or cargo pump-rooms provided that inside thetank it serves it is fitted with a stop-valve operable fromabove the weather deck. As an exception, where acargo tank is adjacent to the cargo pump-room, thestop-valve operable from above the weather deck maybe situated on the tank bulkhead on the cargo pump-room side, provided an additional valve is fittedbetween the bulkhead valve and the cargo pump.

e) Where a cargo pump serves more than one tank, a stop-valve is to be fitted in the line of each tank.

f) Where necessary, cargo piping is to be provided withjoints or expansion bends.

g) In order to prevent any generation of static electricity,the outlets of filling lines are to be led as low as possiblein the tanks, except for supply vessels intended to carrypollution hazard only substances having a flashpointabove 60°C or oil products having a flashpoint above60°C.

4 Cargo tanks

4.1 Supply vessels with additional service feature LHNS or WS

4.1.1 Generala) Cargo tanks are to be of the type required by the IBC

Code or IGC Code, as applicable.

b) The design of the tanks is to comply with standardsacceptable to the Society taking into account the car-riage temperature and relative density of cargo. Dueconsideration is also to be given to dynamic forces andany vacuum pressure to which the tanks may be sub-jected.

4.1.2 Independent tanksa) The greatest of the following design pressures (gauge) is

to be used for determining scantlings of independentpressure tanks:• 0,7 bar• the vapour pressure of the cargo at 45°C• the vapour pressure of the cargo at 15°C above the

temperature at which it is normally carried, or• the pressure which occurs in the tank during the

loading or unloading.

b) When independent tanks are fitted on the weather deck:

• they are to be securely fastened to the hull structure

• in the zone on the weather deck where these tanksare arranged, a suitable possibly removable contain-ment coaming is to be fitted such as to prevent anyspillage and/or leakages from flowing to gas-safeareas

• a space is to be left between tanks and ship sides,sufficient to allow easy passage of ship personneland transfer of fire-fighting arrangements

• the cargo handling system serving these tanks is tobe such that liquid heads higher than those allowa-ble for cargo tanks, if any, served by the same systemcannot occur

• they are to be provided with appropriate accesshatches allowing the use of portable gas-freeingequipment

• provisions are to be made such that any of thesetanks is easily identifiable by means of markings orsuitable plates.

c) Scantling of independent cargo tanks is to be in compli-ance with the provisions of Pt B, Ch 5, Sec 6 and Part B,Chapter 7, except that the thickness is not to be lessthan 5 mm.

4.2 Supply vessels with additional service feature oil product

4.2.1 Integral and independent gravity tanks are to be con-structed and tested according to recognised standards tak-ing into account the carriage temperature and the cargorelative density.

5 Cargo pumping system

5.1

5.1.1 The delivery side of cargo pumps is to be fitted withrelief valves discharging back to the suction side of thepumps (bypass) in closed circuit. Such relief valves may beomitted in the case of centrifugal pumps with a maximumdelivery pressure not exceeding the design pressure of thepiping, with the delivery valve closed.

5.1.2 Cargo pumps are to be monitored as required in Tab 2.

Table 2 : Monitoring of cargo pumps

Equipment - parameter Alarm Indication Comments

Pump - discharge pressure L Local • on the pump (1), or• next to the unloading control station

Pump casing - temperature (2) H visual and audible, in cargo control room or pump control station

Bearings - temperature (2) H visual and audible, in cargo control room or pump control station

Bulkhead shaft gland - temperature (2) H visual and audible, in cargo control room or pump control station

(1) and next to the driving machine if located in a separate compartment.(2) not required for supply vessels intended to carry pollution hazard only substances having a flashpoint above 60°C or oil prod-

ucts having a flashpoint above 60°C.


Pt D, Ch 15, Sec 3

6 Cargo tank fittings for supply vessels with additional service feature oil product, LHNS or WS

6.1 Level gauging systems and overflow control

6.1.1 Supply vessels with additional service feature LHNS or WS

a) Each cargo tank is to have a level gauging system. Typesof gauging for individual products are shown in columnj in the table of IBC Code chapter 17.

b) For tanks intended to carry individual products wherespecific reference is made in column o in the table ofIBC Code Chapter 17, an overflow control system com-plying with IBC Code chapter 15.19 is to be fitted.

Note 1: Requirement 15.19.6 of the IBC Code for a visual andaudible high-level alarm may be waived by the Society takinginto account the cargo carriage arrangements and cargo load-

ing procedures.

c) Provision shall be made to ensure that the liquid head inany tank does not exceed the design head of the tank.Suitable high-level alarms, overflow control systems orspill valves, together with gauging and tank filling pro-cedures, may be accepted for this purpose. Where themeans of limiting cargo tank overpressure includes anautomatic closing valve, the valve shall comply with theappropriate provision of IBC Code, 15.19

d) Level gauging systems for process tanks on board ofsupply vessels having the additional service feature WSare to be to the satisfaction of the Society.


Each cargo tank is to be fitted with a level gauging system incompliance with Ch 7, Sec 4, [4.4] and an overflow controlsystem in compliance with with Ch 7, Sec 4, [4.5].

For the cargo tanks intended to carry oil products having aflash point above 60°C, the gauging systems may be of theopen type provided that the relevant provisions of Pt C, Ch 1,Sec 10, [9] and Pt C, Ch 1 Sec 10, [11] are complied with.

6.2 Cargo tank venting systems

6.2.1 General

Cargo tanks are to be provided with a venting system appro-priate to the cargo being carried and these systems shall beindependent of the air pipes and venting systems of all othercompartments of the ship.


a) Independent pressure tanks are to be fitted with pres-sure relief devices which are so designed as to direct thedischarge away from personnel and have a set pressureand capacity which is in accordance with standardsacceptable to the Society taking into account the designpressure referred to in [4.1.2].

b) Cargo tank vent systems of integral or independent grav-ity tanks are to meet the requirements of the IBC Code,except that the height specified in 8.3.4 of the IBC Codemay be reduced to 2 m.

c) Cargoes which react in a hazardous manner with othercargoes are to have separate tank venting systems.

d) The location of cargo tank vent outlets for independentpressure tanks and for cargo tanks used to carry pollu-tion hazard only substances with a flashpoint exceeding60°C (closed cup test) is to be to the satisfaction of theSociety.

e) Cargo tank vent systems of independent tanks allowedunder [4.1.2] are to be to the satisfaction of the Society,taking into account the provisions of this requirement.


• Except for supply vessels with additional service featureoil product FP>60°C, cargo tanks are to be fitted withcargo tank venting systems complying with the provi-sions of Ch 7, Sec 4, [4.2], except that the height speci-fied in Ch 7, Sec 4, [4.2.7], item c) may be reduced to 2m.

• For supply vessels with additional service feature oilproduct FP>60°C, the following requirements mayapply:

• general provisions of Pt C, Ch 1, Sec 10, [9] and Pt C,Ch 1, Sec 10, [11] are to be complied with

• tank venting systems are to open to the atmosphereat a height of at least 760 mm above the weatherdeck

• tanks may be fitted with venting systems of the opentype provided with a flame screen.

6.3 Cargo tank purging and/or gas freeing


Where considered appropriate by the Society, the provi-sions of Chapter 8 of the IBC Code related to cargo tankpurging and/or gas freeing are to be applied.


At least portable means are to be provided onboard for gasfreeing. Such arrangement should comply with the require-ments of Ch 7, Sec 4, [4.3].

This requirement is not applicable to supply vessels withadditional service feature oil product FP>60°C.


Pt D, Ch 15, Sec 3

7 Arrangement of cargo pump-rooms

7.1 Cargo pump-room ventilation


a) The requirements of Chapter 12 of the IBC Code apply.The Society may, however, grant relaxation concerningthe distances required in Section 12.1.5 of the IBC Code.

b) For certain products where the specific reference ismade in column o (in the table of IBC Code Ch 17) to15.17, the ventilation system shall have a minimumcapacity of at least 45 changes of air per hour, basedupon the total volume of the space.


a) Cargo pump rooms are to be mechanically ventilated.The number of changes of air is to be at least 20 perhour, based upon the gross volume of the space.

b) Ventilation exhaust ducts are to discharge upwards inlocations at least 3 m from the ventilation intakes andopenings to gas-safe spaces.

c) Ventilation intakes are to be so arranged as to minimizethe possibility of recycling hazardous vapours from ven-tilation discharge openings.

d) Ventilation ducts are not to be led through gas-safespaces, cargo tanks or slop tanks.

Note 1: Supply vessels assigned with the additional service featureFP>60°C need not comply with item b).

7.2 Measures to prevent explosions

7.2.1

a) Lighting in the cargo pump-room is to be interlockedwith the ventilation system so the ventilation is to be inoperation to energize the lighting.

b) A system for continuously monitoring the concentrationof flammable vapors shall be fitted in the cargo pumprooms except for ships intended to carry pollution haz-ard only substances having a flashpoint above 60°C oroil products having a flashpoint above 60°C. Samplingpoints or detector heads shall be located in suitablepositions in order that potentially dangerous leakagesare readily detected. When the flammable gas concen-tration reaches a preset level, which shall not be higherthan 10% of the lower flammable limit, a continuousaudible and visual alarm signal shall be automaticallyeffected in the cargo pump room, engine control room,cargo control room and navigation bridge to alert thepersonnel to the potential hazard.

c) Cargo pumps rooms shall be provided with bilge levelmonitoring devices together with appropriately locatedalarms.

d) Surface temperatures shall not exceed those required forthe temperature class of the electrical equipment.

8 Cargo transfer system for supply vessels with additional service feature oil product, LHNS or WS

8.1

8.1.1

a) The cargo transfer system is to comply with the require-ments of Chapter 5 of the IBC Code or Chapter 5 of theIGC Code, when applicable.

b) The remote shutdown devices for all cargo pumps andsimilar equipment, required by 5.6.1.3 of the IBC Code,are to be capable of being activated from a dedicatedcargo control location which is manned at the time ofcargo transfer and from at least one other location out-side the cargo area and at a safe distance from it.

c) In the case of transfer operations involving pressures inexcess of 50 bar gauge, arrangements for emergencydepressurizing and disconnection of the transfer hoseare to be provided. The controls for activating emer-gency depressurization and disconnection of the trans-fer hose are to meet the provisions of item b) above.

9 Special requirements for supply vessels with additional service feature LHNS or WS

9.1 Prevention of pollution

9.1.1 Discharge into the sea of residues of noxious liquidsubstances permitted for carriage in Ship Type 3, or prod-ucts listed in Ch 15, Sec 1, Tab 1 or ballast water, tankwashings, or other residues or mixtures containing suchsubstances, is prohibited. Any discharges of residues andmixtures containing noxious liquid substances should be tothe reception facilities in port.

9.2 Special requirements for acids

9.2.1 Piping systems intended for acids are to comply withthe following provisions:

a) Flanges and other detachable connections are to becovered by spray shields.

b) Portable shield covers protecting the connecting flangesof the loading manifold are to be provided. Drip trays ofcorrosion-resistant material are to be provided underloading manifolds for acids.

9.2.2 Spaces for acid storage tanks and acid pumping andpiping are to be provided with drainage arrangements ofcorrosion-resistant materials.

9.2.3 Deck spills should be kept away from accommoda-tion and service spaces by mean of a permanent coamingheight and extension.


Pt D, Ch 15, Sec 3

9.3 Special requirements for the carriage of liquefied gases

9.3.1 a) Each enclosed space used for handling or storage of a liq-

uefied gas should be fitted with a sensor continuouslymonitoring the oxygen content of the space and an alarmindicating low oxygen concentration. For semi-enclosedspaces, portable equipment may be also acceptable.

b) Drip trays resistant to cryogenic temperatures should beprovided at manifolds transferring liquefied gases or atother flanged connections in the liquefied gas system.

c) For the carriage of liquid nitrogen the requirements of17.19 of the IGC Code should apply.

d) The construction of cargo tanks and cargo piping sys-tems for liquefied nitrogen and liquid carbon dioxideshould be to the satisfaction of the Society.

e) Emergency shutoff valves should be provided in liquidoutlet lines from each liquefied gas tank. The controlsfor the emergency shutoff valves should meet therequirements given in [8.1.1], item b).


Pt D, Ch 15, Sec 4



1 General

1.1 Application

1.1.1 This Section applies to ships having the followingservice notation and additional service features:

• supply vessel oil product

• supply vessel oil product FP>60°C

• supply vessel LHNS

• supply vessel WS.

1.2 Documentation to be submitted

1.2.1 In addition to the documentation requested in Pt C,Ch 2, Sec 1, Tab 1, the following are to be submitted:

a) plan of hazardous area including location of all electri-cal equipment

b) document giving details of types of cables and safetycharacteristics of the electrical equipment installed inhazardous area.

2 Hazardous location and types of equipment

2.1 Supply vessels with additional service feature oil product

2.1.1 Supply vessels having the additional service featureoil product are to comply with the requirements of Ch 7,Sec 5. For supply vessels having the additional service fea-ture oil product FP>60°C, Ch 7, Sec 5, [2.2] applies insteadof Ch 7, Sec 5, [2.1].

2.1.2 Electrical equipment, cables and wiring shall not beinstalled in the hazardous location unless it conforms to IEC60095-502:1999.

2.2 Supply vessels with additional service feature LHNS or WS

2.2.1 Supply vessels having the additional service featureLHNS or WS are to comply with the requirements of:• Ch 8, Sec 10• IBC Code, Chapter 10.

2.2.2 Electrical equipment, cables and wiring shall not beinstalled in the hazardous location unless it conforms to IEC60095-502:1999.

Pt D, Ch 15, Sec 5

SECTION 5 FIRE PREVENTION, PROTECTION AND EXTINCTION

1 General

1.1 Application

1.1.1 Unless otherwise specified, this Section applies, irre-spective of their tonnage, to supply vessels having the fol-lowing additional service features:

• oil product

• LHNS, except for ships intended to carry substanceshaving a flashpoint exceeding 60°C

• WS, except for ships intended to carry substances hav-ing a flashpoint exceeding 60°C.

1.1.2 For vessels intended to carry only liquid identified asnon-flammable, the fire-fighting requirements are to be tothe satisfaction of the Society.




2 Fire prevention and protection

2.1 Structure, bulkheads within accommodation and service spaces and details of construction

2.1.1 The method of protection adopted in accommoda-tion and service spaces is to be method IC (see Pt C, Ch 4,Sec 5, [1.4.1]). The Society may permit use of anothermethod where considered appropriate.

2.1.2 Unless they are located at least 7,0 m from the near-est cargo area, exterior boundaries of the superstructuresand deckhouses enclosing accommodations and includingany overhanging decks which support such accommoda-tions are to be insulated to A-60 standard for the whole ofthe portions which face the cargo areas up to the undersideof the navigation bridge deck and for a distance of 3,0 mfrom the end of the boundary facing the cargo area.

2.1.3 Windows and sidescuttles fitted within 7,0 m fromthe nearest cargo area are to have the same integrity as thebulkhead in which they are fitted.

2.1.4 For supply vessels intended to carry pollution hazardonly substances having a flashpoint exceeding 60°C or oilproducts having a flashpoint exceeding 60°C, the arrange-ments referred to in [2.1.2] and [2.1.3] may be disregarded.

2.1.5 Skylights to cargo pump-rooms are to be made ofsteel and are to be capable of being closed from outside thepump-room.

2.2 Fire integrity of bulkheads and decks

2.2.1 Fire integrity of bulkheads and decks is to complywith the requirements of Pt C, Ch 4, Sec 5, [1.5.2] or, whereconsidered appropriate by the Society, with the require-ments of Pt C, Ch 4, Sec 5, [1.4.3].

2.3 Vapour detection system


a) Vapour detection for the cargoes carried is to be pro-vided in accordance with the requirements contained inthe IBC Code.

b) For certain products where compliance to IBC Code,15.11.7 is required, enclosed and semi-enclosed spacescontaining installations for acid are to be fitted withfixed vapour detection and alarm systems which providevisual and audible indication. The vapour detection sys-tems are to be capable of detecting hydrogen exceptthat, in the case where only hydrochloric acid is carried,a hydrogen chloride vapour detection system is to beprovided.

c) At least two portable instruments for detecting flamma-ble vapour concentrations are to be provided.

d) At least two portable instruments suitable for measuringthe concentration of oxygen in atmospheric air are to beprovided.


Every supply vessel having the additional service feature oilproduct is to be provided with at least two portable gasdetectors capable of measuring flammable vapour concen-trations in air and at least two portable O2 analysers. Forsupply vessels fitted with inert gas system, at least two port-able gas detectors are to be capable of measuring concen-trations of flammable vapours in inerted atmosphere.

Item N°

Description of the documentStatus of

the review

1 Fire extinguishing system in cargo area A

2 Specification of fixed means of vapordetection

A


Pt D, Ch 15, Sec 5

3 Fire fighting

3.1 General

3.1.1 Irrespective of their tonnage, the requirements in PartC, Chapter 4 are to be complied with except that the fol-lowing requirements• Pt C, Ch 4, Sec 6, [1]• Pt C, Ch 4, Sec 6, [3.4]• Pt C, Ch 4, Sec 6, [4.2] to Pt C, Ch 4, Sec 6, [4.5],

apply as they would apply to cargo ships of 2000 tons grosstonnage and over.

3.2 Protection of the deck area


A fixed deck foam system complying with the requirementsof Ch 7, Sec 6, [3] shall be provided.


a) Either a fixed deck foam system or a fixed fire-extinguish-ing system of the dry chemical type complying with thefollowing is to be provided:

1) the system is to be located to protect the deck withinthe cargo area

2) the system is to be capable of covering the deckwithin the cargo area without being moved

3) when a fixed deck foam system is provided, it is tocomply with the requirements of 11.3.3 to 11.3.12of the IBC Code. Only foam suitable for the productscarried is to be used

4) the Society may approve a fixed fire-extinguishingsystem, provided that:

• on a deck area of 45 m2 or less, there are two ormore dry chemical extinguishers whose totalcapacity is not less than 135 kg

• on a deck area of more than 45 m2, there arethree or more dry chemical extinguishers whosetotal capacity of extinguishing agent is not lessthan:C = 3⋅A kg

where A is the deck area, in m2

• the minimum rate of supply of the extinguishingagent is not less than 3 kg/min per m2.

b) An alternative to the systems required in item a) may beallowed, provided the Society is satisfied that such sys-tem is not less effective.

3.3 Special requirements for supply vessels with additional service feature LHNS or WS

3.3.1 Fire main and fire hoses

a) During cargo transfer, water pressure is to be main-tained on the fire main system.

b) Fire hoses, fitted with approved dual-purpose nozzles(i.e. spray/jet type with a shut-off), are to be attached toeach fire hydrant in the vicinity of the flammable liquidto be carried.

3.4 Fire-extinguishing systems for cargo pump-rooms


The cargo pump-room is to be provided with a fixed fire-extinguishing system in accordance with Ch 7, Sec 6,[4.2.2].


The cargo pump-room where flammable liquids are han-dled is to be provided with a fixed fire-extinguishing systemin accordance with 11.2 of the IBC Code.

4 Personnel protection for supply vessels with the additional service feature LHNS or WS

4.1 Decontamination showers and eyewashes

4.1.1 Except in the case of pollution hazard only sub-stances, a suitable marked decontamination shower andeyewash should be available on deck in a convenient loca-tion. The shower and eyewash should be operable in allambient conditions.

4.2 Protective and safety equipment

4.2.1 Protective and safety equipment should be kept onboard in suitable locations as required by Chapter 14 of theIBC Code or the IGC Code for products to be carried.


Pt D, Ch 15, Sec 5



Chapter 16

FIRE FIGHTING SHIPS

SECTION 1 GENERAL


SECTION 3 MACHINERY AND SYSTEMS

SECTION 4 FIRE PROTECTION AND EXTINCTION


Pt D, Ch 16, Sec 1


SECTION 1 GENERAL

1 General

1.1 Application

1.1.1 Ships complying with the requirements of this Chap-ter are eligible for the assignment of the service notationfire-fighting ship, as defined in Pt A, Ch 1, Sec 2, [4.7.4].



• NR216 Materials and Welding.




Ship arrangementL ≥ 90 m • Part B • NR566

L < 90 m • NR600 • NR566

Hull



L < 90 m• NR600• Ch 16, Sec 2

• NR600• Ch 16, Sec 2


• NR566• Ch 16, Sec 2


• NR566• Ch 16, Sec 3



Fire protection, detection and extinction• Part C• Ch 16, Sec 4

• NR566• Ch 16, Sec 4


Pt D, Ch 16, Sec 2


1 Stability


1.1.1 General

The stability of the ship for the loading conditions definedin Pt B, Ch 3, App 2, [1.2.11] is to be in compliance withthe requirements in Pt B, Ch 3, Sec 2.

1.1.2 Additional criteria

The loading conditions reported in the trim and stabilitybooklet, with the exception of lightship, are also to bechecked in order to investigate the ship’s capability to sup-port the effect of the reaction force of the water jet in thebeam direction due to the monitors fitted on board.

A fire-fighting ship may be considered as having sufficientstability, according to the effect of the reaction force of thewater jet in the beam direction due to the monitors fitted onboard, if the heeling angle of static equilibrium θ0, corre-sponding to the first intersection between heeling and right-ing arms (see Fig 1), is less than 5°.

The heeling arm may be calculated as follows:

where:

bh : Heeling arm, in m, relevant to the reaction forceof the water jet of the monitors fitted on board,and to the effect of transversal manoeuvring

thrusters. The monitors are assumed to be ori-ented in beam direction parallel to the sea sur-face, so as to consider the most severe situation

Ri : Reaction force, in kN, of the water jet of eachmonitor fitted on board (see Fig 2)

hi : Vertical distance, in m, between the location ofeach monitor and half draught (see Fig 2)

S : Thrust, in kN, relevant to manoeuvringthruster(s), if applicable (see Fig 2)

e : Vertical distance, in m, between the manoeu-vring thruster axis and keel (see Fig 2)

Δ : Displacement, in t, relevant to the loading con-dition under consideration

T : Draught, in m, corresponding to Δ (see Fig 2).

Figure 1 : Heeling and righting arm curves

Figure 2 : Reaction force of water jet in the beam direction due to monitors

bhΣ Ri hi⋅ ⋅ S T 2⁄ e–( )⋅+

9 81, Δ⋅------------------------------------------------------------ θcos⋅=

heeling andrighting arms

GZ

bh

�o heelingangle

S

e

R1

h 1

T


Pt D, Ch 16, Sec 2


2.1 Hull structure

2.1.1 The strengthening of the structure of the ships, wherenecessary to withstand the forces imposed by the fire-extin-guishing systems when operating at their maximum capac-ity in all possible directions of use, are to be considered bythe Society on a case-by-case basis.

2.2 Water and foam monitors

2.2.1 The seatings of the monitors are to be of adequatestrength for all modes of operation.

3 Other structures


3.1.1 On ships which are not fitted with a water-sprayingsystem complying with Ch 16, Sec 4, [3], all windows andport lights are to be fitted with efficient deadlights or exter-nal steel shutters, except for the wheelhouse.


Pt D, Ch 16, Sec 3


1 General

1.1 Application

1.1.1

a) This Section provides, for ships having the service nota-tions fire-fighting ship E, fire-fighting ship 1, fire-fight-ing ship 2, and fire-fighting ship 3, specific requirementsfor:


• fire-fighting systems installed on board the ship andintended for fighting of external fires.

b) The requirements related to the self-protection water-spraying systems fitted to fire-fighting ships having theadditional service feature water spray are given in Ch 16,Sec 4.



2 Design of machinery systems

2.1 Manoeuvrability

2.1.1 Generala) The ratios between the main ship dimensions and the

power of propulsion engines and of engines driving sidethrusters are to be adequate and such as to ensure aneffective manoeuvrability during fire-fighting operations.

b) The side thrusters and the main propulsion system are tobe capable of maintaining the ship in position in stillwater and of withstanding the reaction forces of thewater monitors even in the most unfavourable combina-tion of operating conditions of such monitors, withoutrequiring more than 80% of the above propulsivepower, to prevent engine overload.

2.1.2 Power control systemAn operating control system of the power supplied by theengines is to be provided, including:• an alarm device operating at 80% of the maximum pro-

pulsive power available in free navigation, and • an automatic reduction of power on reaching 100% of

the above propulsive power,

to prevent engine overload.Note 1: Such operating control system may not be required, at thediscretion of the Society, in cases where the installed power isredundant.


Item N° Description of the document (1) Status of the review

1 General arrangement showing the disposition of all fire-fighting equipment I

2 Details of all fire-fighting equipment such as pumps and monitors, including their capacity, range and trajectory of delivery

A

3 Schematic diagram of the water fire-fighting system A

4 Plan of the water monitor seating arrangements A

5 Diagram of local control and remote control system for water monitors A

6 Schematic diagram of the fixed foam fire-extinguishing system A

7 Plan of the foam monitor seating arrangements (2) A

8 Diagram of local control and remote control system for foam monitors (2) A

9 Specification and plan showing the location of firemen’s outfits A

10 Particulars of the means of keeping the ship in position during fire-fighting operations A

11 Calculation of the required fuel oil capacity according to [2.2.1] (3) I

12 Operating manual I

(1) Diagrams are also to include, where applicable:• the (local and remote) control and monitoring systems and automation systems• the instructions for the operation and maintenance of the piping system concerned (for information).

(2) for ships having the service notation fire-fighting ship 3.(3) for ships having one of the following service notations: fire-fighting ship 1, fire-fighting ship 2, fire-fighting ship 3.


Pt D, Ch 16, Sec 3

2.2 Fuel oil capacity

2.2.1 All ships are to have fuel oil tanks whose capacity isto be sufficient for continuous fighting of fires whilst all thewater monitors are operating for a period of time not lessthan:

• 24 hours in the case of ships having the service notationfire-fighting ship 1

• 96 hours in the case of ships having the service notationfire-fighting ship 2 or fire-fighting ship 3.

This capacity is to be additional to that provided for the nor-mal operation of the ship (propulsion, etc.). Note 1: The determination of such required capacity is the respon-sibility of the Designer.

2.3 Scuppers

2.3.1 When the ship is protected by a water-spraying sys-tem, suitable scuppers or freeing ports are to be provided toensure efficient drainage of water accumulating on decksurfaces when such system is in operation.

3 General requirements for fire-fighting systems

3.1 General

3.1.1 This Article applies to both water fire-extinguishingsystems and fixed foam fire-extinguishing systems.

3.2 Independence of pumping and piping systems

3.2.1 The piping system serving the water and foam moni-tors are not to be used for other services except for thewater-spraying system referred to in Section 7.

3.2.2 Where the water monitor pumps are also used for thewater-spraying system referred to in Section 7, it is to bepossible to segregate the two systems by means of a valve.

3.2.3 The piping system from the pumps to the water mon-itors is to be separate from the piping system to the hoseconnections required for the portable fire-fighting equip-ment referred to in [6.2].

3.3 Design and construction of piping sys-tems

3.3.1 General

a) Fire-fighting piping systems are to comply with the pro-visions of Pt C, Ch 1, Sec 10.

b) The maximum design water velocity is not normally toexceed 2 m/s in the suction line.

3.3.2 Sea suctions

a) Sea suctions for fire-fighting pumps are not to be usedfor other purposes.

b) Sea suctions and associated sea chests are to be soarranged as to ensure a continuous and sufficient watersupply to the fire-fighting pumps, not adversely affectedby the ship motion or by water flow to or from bowthrusters, side thrusters, azimuth thrusters or main pro-pellers.

c) Sea suctions are to be located as low as practicable toavoid:

• clogging due to debris or ice

• oil intake from the surface of the sea.

d) Sea water inlets are to be fitted with strainers having afree passage area of at least twice that of the sea suctionvalve. Efficient means are to be provided for clearing thestrainers.

3.3.3 Pumps

a) Means are to be provided to avoid overheating of thefire-fighting pumps when they operate at low deliveryrates.

b) The starting of fire-fighting pumps when sea water inletvalves are closed is either to be prevented by an inter-lock system or to trigger an audible and visual alarm.

3.3.4 Valves

a) A sea water suction valve and water delivery valve witha nominal diameter exceeding 450 mm are to be pro-vided with a power actuation system as well as a man-ual operation device.

b) The sea water suction valve and water delivery valveand pump prime movers are to be operable from thesame position.

3.3.5 Protection against corrosionMeans are to be provided to ensure adequate protectionagainst:

• internal corrosion, for all piping from sea water inlets towater monitors

• external corrosion, for the lengths of piping exposed tothe weather.

3.3.6 Piping arrangementSuction lines are to be as short and straight as practicable.

3.4 Monitors

3.4.1 Design of monitors

a) Monitors are to be of an approved type.

b) Monitors are to be of robust construction and capable ofwithstanding the reaction forces of the water jet.

3.5 Monitor control

3.5.1 GeneralWater monitors and foam monitors are to be operated andcontrolled with a remote control system located in a com-mon control station having adequate overall visibility.


Pt D, Ch 16, Sec 3

3.5.2 Manual controlIn addition to the remote control system, a local manualcontrol is to be arranged for each monitor. It is to be possi-ble to:

• disconnect the local manual control from the controlstation

• disconnect the remote control system, from a positionclose to each monitor, to allow the operation with thelocal manual control.

3.5.3 Valve controlThe valve control is to be designed so as to prevent pressurehammering.

3.5.4 Control system

a) The control system is to comply with the relevant provi-sions of Pt C, Ch 3, Sec 1 and Pt C, Ch 3, Sec 2.

b) The control system is to be designed with a redundancylevel such that lost function can be restored within 10minutes.

c) In the case of a hydraulic or pneumatic control system,the control power units are to be duplicated.

3.5.5 MarkingAll control and shut-off devices are to be clearly marked,both locally and in the control station.

4 Water fire-fighting system

4.1 Characteristics

4.1.1

a) For ships having the service notation fire-fighting ship 1,fire-fighting ship 2 or fire-fighting ship 3, the number ofpumps and monitors and their characteristics are to bein accordance with the requirements given in Tab 2.

b) For ships having the service notation fire-fighting ship E,the characteristics of the water fire-fighting system willbe given special consideration by the Society.

4.2 Monitors

4.2.1 Monitors are to be so arranged as to allow an easyhorizontal movement of at least 90° equally divided aboutthe centreline of the ship. The allowed vertical angularmovement is to be such that the height of throw required inTab 2 can be achieved.

4.2.2 The monitors are to be located such that the water jetis free from obstacles, including ship’s structure and equip-ment.

4.2.3 The monitors are to be capable of throwing a contin-uous full water jet without significant pulsations and com-pacted in such a way as to be concentrated on a limitedsurface.

4.2.4 At least two monitors are to be equipped with adevice to make the dispersion of the water jet (spray jet)possible.

4.3 Piping

4.3.1 The maximum design water velocity is not normallyto exceed 4 m/s in the piping between pumps and watermonitors.

Table 2 : Number of pumps and monitors and their characteristics

Required characteristicsService notations

fire-fighting ship 1 fire-fighting ship 2 fire-fighting ship 3

minimum number of water monitors 2 3 4 4

minimum discharge rate per monitor (m3/h) 1200 2400 1800 2400

minimum number of fire-fighting pumps 1 2 2

minimum total pump capacity (m3/h) (1) 2400 7200 9600

length of throw of each monitor (m) (2) (4) 120 150 150

height of throw of each monitor (m) (3) (4) 45 70 70

(1) Where the water monitor pumps are also used for the self-protection water-spraying system, their capacity is to be sufficient toensure the simultaneous operation of both systems at the required performances.

(2) Measured horizontally from the monitor outlet to the mean impact area.(3) Measured vertically from the sea level, the mean impact area being at a distance of at least 70 m from the nearest part of the

ship.(4) The length and height of throw are to be capable of being achieved with the required number of monitors operating simultane-

ously in the same direction.


Pt D, Ch 16, Sec 3

5 Fixed foam fire-extinguishing system

5.1 General

5.1.1

a) Only ships having the service notation fire-fighting ship3 are to be equipped with a fixed low expansion foammonitor system complying with the provisions of Pt C,Ch 4, Sec 14, [5] and with those of this Article.

b) For ships having the service notation fire-fighting ship E,some relaxation in the provisions of this Section may beaccepted by the Society.

5.2 Characteristics

5.2.1 Foam expansion ratioThe foam expansion ratio is not to exceed 12.

5.2.2 Foam monitorsa) The ship is to be fitted with two foam monitors, each

having a foam solution capacity not less than 300 m3/h.

b) The height of throw is to be at least 50 m above the sealevel, when both monitors are in operation at the maxi-mum foam production rate.

5.2.3 Foam concentrate capacitySufficient foam concentrate is to be available for at least 30min of simultaneous operation of both monitors at maxi-mum capacity.Note 1: When determining the necessary quantity of foam concen-trate, the concentration rate is assumed to be 5%.

5.3 Arrangement

5.3.1 Foam generating systemThe foam generating system is to be of a fixed type with sep-arate foam concentrate tank, foam-mixing units and pipingto the monitors.

5.3.2 PumpsThe pumps of the water monitor system may be used forsupplying water to the foam monitor system. In such case, itmay be necessary to reduce the pump water delivery pres-sure to ensure correct water pressure for maximum foamgeneration.

6 Portable fire-fighting equipment

6.1 Portable high expansion foam generator

6.1.1 Ships having the service notation fire-fighting ship 2or fire-fighting ship 3 are to be equipped with a portablehigh expansion foam generator having a foam capacity notless than 100 m3/min for fighting of external fires.

6.1.2 The total capacity of foam concentrate is to be suffi-cient for 30 min of continuous foam production. The foamconcentrate is to be stored in portable tanks of about 20litres capacity.

6.2 Hydrants and fire hoses

6.2.1 Hydrants

a) Hydrants are to be provided in accordance with Tab 3.

b) At least half of the required hydrants are to be arrangedon the main weather deck.

c) Where hydrants are fed by the pumps serving the moni-tor supply lines, provision is to be made to reduce thewater pressure at the hydrants to a value permitting safehandling of the hose and the nozzle by one man.

Table 3 : Number of hydrants

6.2.2 Fire hose boxes

a) At least one box containing fire hoses is to be providedfor every two hydrants.

b) Each box is to contain two fire hoses complete withdual-purpose (spray/jet) nozzles.

6.2.3 Fire hoses

a) Fire hoses and associated nozzles are to be of a typeapproved by the Society.

b) Fire hoses are to be of 45 to 70 mm in diameter andgenerally are to be 20 m in length.

7 Firemen’s outfits

7.1 Number and characteristics

7.1.1 The ship is to be fitted with firemen’s outfits inaccordance with Tab 4.

Table 4 : Number of firemen’s outfits

7.1.2 The air breathing apparatuses, protective clothingand electric safety lamps constituting parts of firemen’s out-fits are to be of a type approved by the Society.

7.1.3 Breathing apparatuses are to be of the self-containedtype. They are to have a capacity of at least 1200 litres offree air.

At least one spare air bottle is to be provided for each appa-ratus.

7.1.4 The firemen’s outfits are to be stored in a safe positionreadily accessible from the open deck.

fire-fighting ship E

fire-fighting ship 1



4at each side

4at each side

8at each side

8 ateach side (1)

(1) May be increased to 10 hydrants at each side, depend-ing on the ship’s length.

fire-fighting ship E




4 4 8 8


Pt D, Ch 16, Sec 3

7.2 Compressed air system for breathing apparatuses

7.2.1 General

Ships are to be equipped with a high pressure air compres-sor complete with all fittings necessary for refilling the bot-tles of air breathing apparatuses. The compressor is to belocated in a suitable sheltered location.

7.2.2 Capacity

The capacity of the compressor is to be sufficient to allowthe refilling of the bottles of air breathing apparatuses in nomore than 30 min. This capacity is not to be less than75 l/min.

7.2.3 Accessories

a) The compressor is to be fitted on the air suction with asuitable filter.

b) The compressor is to be fitted on the delivery with oilseparators and filters capable of preventing passage ofoil droplets or vapours to the air bottles.

8 Testing

8.1 General

8.1.1 The provisions of this Article are related to the work-shop and on board tests to be carried out for:


• fire-fighting systems.

They supplement those required in Part C, Chapter 1 formachinery systems.

8.2 Workshop tests

8.2.1 Tests for materiala) Materials used for the housing of fire-fighting pumps are

to be subjected to a tensile test at ambient temperatureaccording to the relevant provisions of NR216 Materialsand Welding.

b) Materials used for pipes, valves and other accessoriesare to be tested in accordance with the provisions of PtC, Ch 1, Sec 10, [20.3].

8.2.2 Hydrostatic testing After completion of manufacture and before installation onboard, pipes, valves, accessories and pump housings are tobe submitted to a hydrostatic test in accordance with theprovisions of Pt C, Ch 1, Sec 10, [20.4].

8.3 On board tests

8.3.1 Fixed fire-fighting systemsa) After assembly on board, the water fire-fighting system

and the fixed foam fire-extinguishing system are to bechecked for leakage at normal operating pressure.

b) The water fire-fighting system and fixed foam fire-extin-guishing system are to undergo an operational test onboard the ship, to check their characteristics and per-formances.

8.3.2 Propulsion and manoeuvring systemsa) A test is to be performed to check the manoeuvring

capability of the ship.

b) The capability of the side thrusters and of the main pro-pulsion system to maintain the ship in position with allwater monitors in service without requiring more than80% of the propulsive power is to be demonstrated.


Pt D, Ch 16, Sec 4

SECTION 4 FIRE PROTECTION AND EXTINCTION

1 General

1.1 Application

1.1.1 This Section provides, for ships having the servicenotations fire-fighting ship 1, fire-fighting ship 2 and fire-fighting ship 3, specific requirements for:

• fire protection

• self-protection water-spraying system.

These requirements supplement those given in Part C, Chap-ter 4.

1.1.2 For ships having the service notation fire-fightingship E, fire protection arrangements will be given specialconsideration by the Society.



2 Fire protection of exposed surfaces

2.1 Structural fire protection

2.1.1

a) On ships having the service notation fire-fighting ship 1,all exterior boundaries above the lightest operatingwaterline, including superstructures and exposed decks,are to be of steel and are to be internally insulated so asto form A-60 class divisions.

This need not apply to ships granted with the additionalservice feature water spray.

b) On ships having the service notation fire-fighting ship 2or fire-fighting ship 3, all exterior boundaries are to beof steel but they need not be insulated.

c) On all ships, other boundaries may be constructed ofmaterials other than steel, subject to special considera-tion by the Society.

2.2 Deadlights and shutters

2.2.1 On ships for which the additional service featurewater spray is not assigned, steel deadlights or external steelshutters are to be provided on all windows, sidescuttles andnavigation lights, except for the windows of the navigatingbridge.

3 Self-protection water-spraying system

3.1 General

3.1.1 The provisions of this Article apply to the self-protec-tion water-spraying systems fitted to ships having the addi-tional service feature water spray. They supplement thosegiven in Pt C, Ch 4, Sec 14, [6].

3.2 Capacity

3.2.1 The capacity of the self-protection water-spraying sys-tem is to be not less than 10 l/min for each square metre ofprotected area. In the case of surfaces which are internallyinsulated, such as to constitute A-60 class divisions, a lowercapacity may be accepted, provided it is not less than 5l/min for each square metre of protected area.

3.3 Arrangement

3.3.1 Areas to be protectedThe fixed self-protection water-spraying system is to provideprotection for all vertical areas of the hull and superstruc-tures as well as monitor foundations and other fire-fightingarrangements, and is to be fitted in such a way as not toimpair the necessary visibility from the wheelhouse andfrom the station for remote control of water monitors, alsoduring operation of spray nozzles.

3.3.2 SectionsThe fixed self-protection water-spraying system may bedivided into sections so that it is possible to isolate sectionscovering surfaces which are not exposed to radiant heat.


Item N° Description of the document Status of the review

1 Plan showing the structural fire division, including doors and other closing devices of openingsin A and B class divisions

A

2 Fire test reports for insulating materials I

3 Schematic diagram of the fixed self-protection water-spraying system A


Pt D, Ch 16, Sec 4

3.3.3 Spray nozzlesThe number and location of spray nozzles are to be suitableto spread the sprayed water uniformly on areas to be pro-tected.

3.4 Pumps

3.4.1 Use of pumps serving other systemsThe following pumps may be used for the self-protectionwater-spraying system:

• fire pumps referred to in Pt C, Ch 4, Sec 6, [1.3]

• water monitor system pumps referred to in Sec 4, [4].

In this case, a shut-off valve is to be provided to segregatethe systems concerned.

3.4.2 Capacity of the pumps

a) The pumps of the self-protection water-spraying systemare to have a capacity sufficient to spray water at therequired pressure from all spray nozzles of the system.

b) Where the pumps serving the self-protection water-spraying systems are also used for another service, theircapacity is to be sufficient to ensure the simultaneousoperation of both systems at the required performances.

3.5 Piping system and spray nozzles

3.5.1 GeneralPipes are to be designed and manufactured according to therequirements of Pt C, Ch 1, Sec 10.

3.5.2 Protection against corrosionSteel pipes are to be protected against corrosion, both inter-nally and externally, by means of galvanising or equivalentmethod.

3.5.3 Drainage cocksSuitable drainage cocks are to be arranged and precautionsare to be taken in order to prevent clogging of spray nozzlesby impurities contained in pipes, nozzles, valves andpumps.



Chapter 17

OIL RECOVERY SHIPS

SECTION 1 GENERAL




SECTION 5 FIRE PROTECTION, DETECTION AND EXTINCTION


Pt D, Ch 17, Sec 1

SECTION 1 GENERAL

1 General

1.1 Application

1.1.1 Ships complying with the requirements of this RuleNote are eligible for the assignment of service notation oilrecovery ship as defined in Pt A, Ch 1, Sec 2, [4.7.5].

1.1.2 Ships dealt with in this Chapter with:




1.1.3 Additional service feature OILTREAT

The additional service feature OILTREAT may be assignedto the ships designed and equipped to recover pollutedwater which is subjected to a chemical and/or a physicaltreatment, in order to separate the oil from the pollutedwater. The separated oil is to be stored and transported indedicated tanks.

1.1.4 Additional service feature SECOND-LINEThe additional service feature SECOND-LINE may beassigned to the ships designed and equipped to recover pol-luted water in the event of spills of oils which have, at thetime of recovery, a flash point exceeding 60°C (closed cuptest).This service feature is not to be assigned to oil recoveryships carrying heated recovered oils within 15°C of theirflash point.

1.2 Definitions

1.2.1 Oil recovery shipAn oil recovery ship is a ship specially equipped with afixed installation and/or a mobile equipment for theremoval of oil from the sea surface and its retention onboard, carriage and subsequent unloading.

1.2.2 Recovered oilRecovered oil is the top layers of polluted water collectedby means of skimmers, rotating disk, floating pumps orequivalent systems together with sweeping arms, booms orsimilar devices.


Item Greater than or equal to 500 GT Ships less than 500 GT

Ship arrangement

L ≥ 65 or 90 m (1)• Part B• Ch 17, Sec 2

• NR566• Ch 17, Sec 2

L < 65 or 90 m (1)• NR600• Ch 17, Sec 2

• NR566• Ch 17, Sec 2

Hull

L ≥ 65 or 90 m (1)• Part B• Ch 17, Sec 2


L < 65 or 90 m (1)• NR600• Ch 17, Sec 2

• NR600• Ch 17, Sec 2


• NR566• Ch 17, Sec 2


• NR566• Ch 17, Sec 3

Electrical installations• Part C• Ch 17, Sec 4

• NR566• Ch 17, Sec 4



• NR566• Ch 17, Sec 5



Pt D, Ch 17, Sec 1

1.2.3 Oil recovery tankAn oil recovery tank is a tank intended for the retention andthe transportation of recovered oil.

For ships assigned with the additional service feature OIL-TREAT, the oil recovery tanks may be classified in two dif-ferent categories:• those intended for the retention of oil removed and sep-

arated from sea water, also named accumulation tanks• those intended for the retention of polluted water only,

also named settling tanks.

1.2.4 Oil recovery pump roomAn oil recovery pump room is a space containing the pumpsand their accessories for the handling of recovered oil.

1.2.5 Oil recovery areaThe oil recovery area is the part of the ship that contains theoil recovery tanks, oil recovery pumps rooms, cofferdams,ballast or void spaces surrounding the integral tanks and

hold spaces in which independent tanks are located, andthe following deck areas:• the deck area above the oil recovery tanks• the deck area extending transversely and longitudinally

from the oil recovery tanks over a distance of 3 m, whenthe rule length is greater than 50 m.

Note 1: Oil recovery area definition is not applicable to oil recov-ery ships assigned with the additional service feature SECOND-LINE.

1.2.6 Hazardous areasThe hazardous areas are the areas in which an explosiveatmosphere is, or may be, expected to be present in quanti-ties such as to require special precautions for the construc-tion, installation and use of electrical apparatus.

1.2.7 Gas-safe areasThe gas-safe areas are the gas areas which are not definedas hazardous.


Pt D, Ch 17, Sec 2


1 General



1.2 General arrangement

1.2.1 Tank arrangement

a) Oil recovery tanks are to be separated from machineryspaces category A, propeller shaft tunnels, dry cargospaces, accommodations, control stations and servicespaces and from drinking water and stores for humanconsumption by means of a cofferdam or equivalentspace. Fuel oil tanks, tanks for ballast water, tanks forliquids used for oil treatment, tanks for anti-pollutionliquids, storerooms for oil removal equipment andpump-rooms are considered as spaces equivalent to acofferdam.

When this cofferdam is impracticable, oil recoverytanks adjacent to the engine room may be accepted pro-vided that:

• boundary bulkheads are accessible for inspection

• the boundary bulkheads are fitted continuouslythrough joining structure to the top of the tank,where full penetration welding is to be carried out

• the tanks are to be pressure tested at each renewalsurvey.

b) Oil recovery tanks are to be located abaft the collisionbulkhead.

c) For ships non-exclusively dedicated to oil recoveryoperations, the ship may use the following tanks as oilrecovery tanks:

• tanks covered by the service notation supply vesselwith additional service feature oil product, LHNS orWS, if designed for a cargo mass density of, at least,1,025 t/m3

• water ballast tanks

• fuel oil tanks

• hoppers spaces.

In all cases, the tanks and their associated equipmentand piping are to comply with all the requirements foroil recovery tanks.

Fresh water tanks and tanks with a complex inner struc-ture that can lead to obstruction can not be part of theoil recovery tanks.

d) Oil recovery ships assigned with the additional servicefeature SECOND-LINE do no need to comply with thearrangements referred to in item a), provided that thesegregation requirements for accommodations, controlstations, drinking water and stores for human consump-tion are observed.

1.2.2 Accommodation, control station, service and machinery spaces

a) Accommodation or service spaces, control stations ormachinery spaces category A are to be located outsidethe oil recovery area.

Note 1: When, instead of a cofferdam, boundaries between oilrecovery tanks and machinery spaces of category A are built asdescribed in the second paragraph of [1.2.1], item a), themachinery spaces of category A may be located within the oilrecovery area.

b) Unless they are spaced at least 7 m away from the oilrecovery area entrances, air inlets and openings toaccommodation, service and machinery spaces cate-gory A and control stations should not face the oilrecovery area. Doors to spaces not having access toaccommodation, service and machinery spaces andcontrol stations, such as oil recovery control stations,storerooms or equipment rooms, may be permitted bythe Society within the 7 m zone specified above, pro-vided the boundaries of the spaces are insulated to A-60standard.

c) When the additional service feature SECOND-LINE isassigned, the arrangement referred to in items a) and b)may be disregarded.


Item N° Description of the document Status of the review (1)

1 General arrangement A

2 General arrangement of access and openings A

3 Procedure and limiting conditions for recovering oil, oil recovery transfer, tank cleaning, gas freeing and ballasting

I

4 Specification of the oil removal operational test I

(1) A = for approval, I = for information.


Pt D, Ch 17, Sec 2

1.2.3 Access

a) Access hatches (at least 600 mm x 600 mm of clearopening) within the oil recovery area are to be directfrom the open deck. Such access should be suitable forcleaning and gas-freeing.

b) For ships assigned with the additional service featureSECOND-LINE, the following requirements may applyinstead of item a):

• Access to oil recovery tanks is to be direct from theopen deck and such as to ensure their completeinspection, except for access to cargo tanks in dou-ble bottoms that may be through a cargo pump-room, pump-room, deep cofferdam, pipe tunnel orsimilar dry compartment, provided the ventilation ofthese spaces complies with Ch 17, Sec 5, [2.2]

• Access to oil recovery pump rooms does not need tobe from the open deck, provided the access is inde-pendent of watertight doors.

1.2.4 Oil recovery tank construction

a) A cargo density of 1,025 t/m3 is to be considered for cal-culating the internal pressures and forces in cargo tanksaccording to Pt B, Ch 5, Sec 6 or NR600 as applicable.

b) All tank openings and connections to the tank are to ter-minate above the weather deck and should be locatedin the tops of the tanks.

c) The structural design of the tanks should take intoaccount the carriage temperature, and additionalstrength calculation may be required in case of risk ofsloshing induced loads.

2 Stability


2.1.1 General

In addition to the standard loading conditions specified inPt B, Ch 3, App 2, [1.2.1], the following loading cases are to

be included in the trim and stability booklet for shipsassigned with the service notation oil recovery ship:• ship in the fully loaded departure to the oil recovery

spot having all the oil recovery equipment installed onboard

• ship in the worst anticipated operating during oil recov-ery operation; the worst operating condition regardingfree surface effects when the equipment is fitted in themost unfavourable condition (for example, swiping armextended).

3 Hull scantlings

3.1 Additional loads

3.1.1 For the checking of structures supporting oil recoveryequipment, the reactions induced by this equipment duringoil recovery operations may be calculated assuming that theoil recovery operations take place in moderate sea condi-tions (accelerations reduced by 10%).

3.1.2 If cranes are used during oil recovery operations, thescantling of their supporting structures is to be checkedaccording to NR526 Rules for the Certification of LiftingAppliances, Sec 3 and Sec 4. Environmental conditionsdefined in NR526, Sec 3, [3.3] may be based on curve 5.

3.1.3 In case of oil collected in movable tanks fitted on theweather deck, the resulting reactions to be considered fordeck scantling are to be calculated, as a rule, according toPt B, Ch 5, Sec 6 or NR600 as applicable.

4 Construction and testing

4.1 Testing

4.1.1 Oil removal equipmentTests are to be carried out according to a specification sub-mitted by the interested Party, in order to check the properoperation of the oil recovery equipment.

These tests may be performed during dock and sea trials.


Pt D, Ch 17, Sec 3


1 General



2 Machinery installation and piping system other than oil recovery system

2.1 Sea water cooling system

2.1.1 One of the suctions serving the sea water cooling sys-tem (see Pt C, Ch 1, Sec 10, [10.7.1]) is to be located in thelower part of the hull.

2.2 Water fire-extinguishing system

2.2.1 Sea suctions serving the fire water pumps are to belocated as low as possible.

2.3 Exhaust gas systems

2.3.1

a) Exhaust lines from engines, gas turbines, boilers andincinerators are to be led outside any hazardous area (asdefined in Ch 17, Sec 4) above the deck and are to befitted with a spark arrester. The spark arrester is notrequired if the ship is assigned with the additional serv-ice feature SECOND-LINE.

b) Where the distance between the exhaust lines ofengines and the hazardous areas is less than 3 m, theducts are to be fitted in a position:

• near the waterline, if cooled by water injection, or

• below the waterline, in the other cases.

3 Pumping system, piping system and pump-rooms intended for recovered oil

3.1 Design of pumping and piping systems

3.1.1 General

The provisions of Ch 7, Sec 4, [3] and Pt C, Ch 1, Sec 10 areto be complied with, as far as applicable.

3.2 Arrangement of piping systems

3.2.1

a) Piping systems for handling recovered oil are not to passthrough:• accommodation spaces• service spaces• control stations• machinery spaces of category A except for ship

assigned with the additional service feature SEC-OND-LINE.

b) Pumping and piping systems intended for recovered oilare to be independent from the other pumping and pip-ing systems of the ship, except in the following cases:• If sections of the cargo system covered by the serv-

ice notation supply vessel (with the additional serv-ice feature oil product, LHNS or WS) or if fuel oiltanks are used, means are to be provided to isolatethe oil recovery system from any other system fromwhich it may be connected. The connectionbetween the cargo system and the recovered oiltransfer piping may consist of movable pipe sec-tions.

• If water ballast tanks are used as oil recovery tankswhen the ship is in oil recovery mode, the water bal-last piping is to be blanked-off at the nearest posi-tion at the tank before starting the oil recoveryoperation. The connection between the oil recoverypiping and the water ballast tanks is to be done bymeans of detachable spool pieces.

c) Piping intended for recovered oil and located below themain deck may run from the tank it serves and penetratetank bulkheads or boundaries common to longitudinallyor transversely adjacent oil recovery tanks, ballast tanks,empty tanks, pump-rooms or oil recovery pump-rooms,provided that inside the tank it serves it is fitted with astop-valve operable from the weather deck.As an alternative, where an oil recovery tank is adjacentto an oil recovery pump-room, the stop valve operablefrom the weather deck may be situated on the tank bulk-head on the oil recovery pump-room side, provided anadditional valve is fitted between the bulkhead valveand the oil recovery pump.A totally enclosed hydraulically operated valve locatedoutside the oil recovery tank may also be accepted, pro-vided that the valve is:- fitted on the bulkhead of the oil recovery tank it

serves- suitably protected against mechanical damage- fitted at a distance from the shell as required for

damage protection, and- operable from the weather deck.


Pt D, Ch 17, Sec 3

d) Transfer of recovered oil through hatches (by means offlexible hoses or movable piping) is not permittedexcept if the additional service feature SECOND-LINE isassigned.

3.3 Oil recovery pumps

3.3.1

a) Oil recovery pumps are to comply with the require-ments of cargo pumps for oil tanker, flash point > 60°C(see Ch 7, Sec 4, [3.2]).

b) Oil recovery pumps are to be capable of being remotelyshutdown from a location which is manned during oilrecovery operations and from at least one other locationoutside the oil recovery area.

c) If an oil recovery pump serves more than one tank, astop valve is to be fitted in the line of each tank.

d) For ships non exclusively dedicated to oil recoveryoperation, the use of portable pumps or pumps servingcargo systems may be permitted, subject to special con-sideration by the Society.

3.4 Oil recovery pump-rooms

3.4.1

a) Pump-rooms containing the pumps for handling therecovered oil are to be provided with a fixed fire-extin-guishing system suitable for machinery spaces of cate-gory A except if the ship is assigned with the additionalservice feature SECOND-LINE.

b) Means are to be provided to deal with drainage and anypossible leakage from oil recovery pumps and valves inthe oil recovery pump-room. Bilge pumping arrange-ment is to be situated entirely within the oil recoveryarea. The bilge system is to be operable from outside theoil recovery pump-room. Oil recovery pumps may alsobe used provided they are connected to the oil recoverypump-room bilge piping through a shut-off valve and anon-return valve arranged in series.

c) For ventilation of oil recovery transfer pump-rooms, seeCh 17, Sec 5, [2].

d) Oil recovery pump-rooms are to have no direct commu-nication with machinery spaces of category A, exceptwhen the ship is assigned with the additional servicefeature SECOND-LINE.

4 Oil recovery tank fittings

4.1 Vent pipes

4.1.1

a) Vent pipes of oil recovery tanks are to lead to the openat least 2,4 m above the weather deck.

b) Vent pipes are to be located at a distance of at least5,0 m measured horizontally from the nearest air intakeor opening to accommodations, control stations, serviceand machinery spaces of category A and other gas-safespaces and from ignition sources.

c) Openings of vent pipes are to be directed to open deckand fitted with:

• flameproof wire gauze made of corrosion resistantmaterial easily removable for cleaning, and

• closing appliances complying with the provisions ofPt C, Ch 1, Sec 10, [9.1]

d) For ships non exclusively dedicated to oil recoveryoperations, portable vent pipes may be accepted.

4.2 Level gauging and overfilling control

4.2.1 Level gauging

Oil recovery tanks are to be fitted with sounding pipes orother level gauging devices of a type approved by the Soci-ety.

4.2.2 Overfilling control

a) Oil recovery tanks are to be fitted with a high levelalarm or an overflow control system except if the oilrecovery tank is an open hopper space.

b) The high level alarm is to be of a type approved by theSociety and is to give an audible and visual alarm.


Item N° Description of the document (1)Status of the review (2)

1 General plan of the system for oil recovery and specification of all relevant apparatuses I2 Schematic arrangement of recovered oil piping and pumping systems A3 Tank venting arrangement A4 Diagram of the bilge and ballast systems serving the spaces located in the oil recovery area A5 Specification of the anti-explosion devices (crankcase explosion relief valves, spark arresters)

provided for diesel enginesA

6 Location and arrangement of sea chests for engine cooling and fire-fighting purposes A7 Diagram of the oil recovery cargo tank level gauging system with overfilling safety arrangement A8 Diagram of the cargo heating system, where applicable A

(1) Diagrams are also to include, where applicable, the (local and remote) control and monitoring systems and automation systems.(2) A = for approval, I = for information.


Pt D, Ch 17, Sec 3

5 Heating systems

5.1

5.1.1 Heating systems fitted to oil recovery tanks are tocomply with the provisions of Ch 7, Sec 4, [2.6].

6 Additional requirements

6.1 Ships assigned with the additional service feature OILTREAT

6.1.1 When the separating system designed to reduce theoil content in the water being discharged into the sea is of agravity type (single or in series):

• means for locating the oil/water interface in the oilrecovery tanks are to be provided

• discharges of processed water from the separating proc-ess are to take place above waterline for visual control

• if chemical additives are added, the coating of the oilrecovery tanks is to be compatible. The Shipyard isresponsible for providing compatibility information tothe ship operator and/or the master

• adequate means are to be provided for cleaning the oilrecovery tanks.

6.1.2 Other types of separating system (e.g. gravity typecoalescing, centrifugal separator, …) are to be reviewed ona case-by-case basis.


Pt D, Ch 17, Sec 4


1 General

1.1 Application

1.1.1 The requirements in this Section apply, in addition tothose contained in Part C, Chapter 2.

1.2 Documentation to be submitted

1.2.1 In addition to the documentation requested in Pt C,Ch 2, Sec 1, [2.1.1], the documents listed in Tab 1 are to besubmitted.

2 Design requirements

2.1 System of supply

2.1.1 The following systems of generation and distributionof electrical energy are acceptable:

a) direct current:

• two-wire insulated

b) alternating current:

• single-phase, two-wire insulated

• three-phase, three-wire insulated.

2.1.2 Earthed systems with hull return are not permitted, withthe following exceptions to the satisfaction of the Society:

a) impressed current cathodic protective systems

b) limited and locally earthed systems, such as starting andignition systems of internal combustion engines, pro-vided that any possible resulting current does not flowdirectly through any hazardous area

c) insulation level monitoring devices, provided that thecirculation current of the devices does not exceed30 mA under the most unfavourable conditions.

2.1.3 Earthed systems without hull return are not permitted,with the following exceptions:

a) earthed intrinsically safe circuits and the following othersystems to the satisfaction of the Society;

b) power supplies, control circuits and instrumentation cir-cuits in non-hazardous areas where technical or safetyreasons preclude the use of a system with no connec-tion to earth, provided the current in the hull is limitedto not more than 5 A in both normal and fault condi-tions; or

c) earthed systems, provided that any possible resultinghull current does not flow directly through any hazard-ous area; or

d) isolating transformers or other adequate means, to beprovided if the distribution system is extended to areasremote from the machinery space.

2.1.4 In insulated distribution systems, no current carryingpart is to be earthed, other than:

a) through an insulation level monitoring device

b) through components used for the suppression of inter-ference in radio circuits.

2.2 Earth detection

2.2.1 The devices intended to continuously monitor theinsulation level of all distribution systems are also to moni-tor all circuits, other than intrinsically safe circuits, con-nected to apparatus in hazardous areas or passing throughsuch areas. An audible and visual alarm is to be given, at amanned position, in the event of an abnormally low level ofinsulation.

3 Hazardous locations and types of equipment

3.1 Electrical equipment permitted in hazardous areas

3.1.1 In order to facilitate the selection of appropriate elec-trical apparatus and the design of suitable electrical installa-tion, hazardous areas are classified in zones (zone 0, zone 1and zone 2), according to Pt C, Ch 2, Sec 1, [3.24.3]. Thedifferent spaces are to be classified according to Tab 2 orTab 3, as applicable.

The types of electrical equipment permitted, depending onthe zone where they are installed, are specified in Pt C, Ch2, Sec 3, [10].

3.1.2 The explosion group and temperature class of electri-cal equipment of a certified safe type are to be at least IIAand T3.

3.2 Additional requirements for machinery installations in hazardous areas

3.2.1 Hazardous areas are not to contain:

• internal combustion engines

• steam turbines and steam piping with a steam tempera-ture in excess of 200°C

• other piping systems and heat exchangers with a surfacetemperature exceeding 200°

• any other source of ignition.


Pt D, Ch 17, Sec 4

3.3 Openings, access and ventilation conditions affecting the extent of hazardous areas

3.3.1 There are normally not to be access doors or otheropenings between a safe space, such as accommodation orservice spaces, machinery spaces, control stations and simi-lar spaces, and a hazardous area.Access (other than access between oil recovery pump-rooms and machinery spaces category A) may, however, beaccepted between such spaces and hazardous areas, pro-vided that:

a) safe spaces are fitted with forced ventilation in order tomaintain an overpressure therein

b) access doors are:

1) of a self-closing type and arranged to swing into thesafer space, so that they are kept closed by the over-pressure, with the self-closing device capable ofshutting the doors against an inclination of 3,5°opposing closure, without hold-back hooks keepingthem in an open position, or

2) gas-tight, kept closed during oil recovery operationuntil gas freeing is carried out, and provided with awarning plate (suitable instructions are given in theoil recovery manual).


Table 2 : Oil recovery ships - Space descriptions and hazardous area zones

Table 3 : Oil recovery ships, second-line - Space descriptions and hazardous area zones

Item N° Description of the document Status of the review (1)

1 Plan of hazardous areas and location of electrical equipment A

2 Document giving details of types of cables and safety characteristics of the equipment installed in hazardous areas

A

(1) A = for approval, I = for information.

Hazardous areaSpaces

N° Description

Zone 0 1 Oil recovery tanks, pipes and equipment containing the recovered oil

Zone 1 2 Areas on open deck or semi-enclosed spaces on open deck within 3 m of any oil recovery tank outlet,oil recovery manifold valve, oil recovery valve, oil recovery pipe flange, oil recovery hatches

Zone 1 3 Cofferdams and enclosed or semi-enclosed spaces adjacent to or immediately above oil recovery tankwhich do not contain pipes, valves or other equipment for the handling of recovered oil unless sepa-rated by gas-tight boundaries and fitted with forced ventilation capable of giving at least 20 air changesper hour. An alarm on the navigation bridge is to be provided to indicate any loss of the required venti-lation capacity. The alarm is to be initiated by fall-out of starter relay fan motor

Zone 1 4 For open hopper dredgers operating as oil recovery ships: the area above the hopper extended to themaximum breath of the ship with an unlimited height

Zone 1 5 Oil recovery pump-rooms

Zone 2 6 Enclosed or semi-enclosed spaces for the storage of floating pumps, associated hoses and equipmentfor the handling of recovered oil unless acceptable means are provided to drain or empty the equip-ment after completion of oil recovery operation

Zone 2 7 Double bottoms or duct keels located under oil recovery tanks unless separated by gas-tight bounda-ries and fitted with forced ventilation capable of giving at least 20 air changes per hour. An alarm onthe navigation bridge is be provided to indicate any loss of the required ventilation capacity. Thealarm is to be initiated by fall-out of starter relay fan motor

Zone 2 8 Enclosed or semi-enclosed spaces containing pipes, valves or other equipment for the handling ofrecovered oil unless made of entirely welded construction except for necessary flanged connectionsto valves, expansion joints, spool pieces and similar fittings or where required for coating, lining, fab-rication, inspection or maintenance

Zone 2 9 Enclosed or semi-enclosed spaces containing pipes, valves or other equipment for the handling ofrecovered oil unless separated by gas-tight boundaries and fitted with forced ventilation capable of giv-ing at least 20 air changes per hour. An alarm on the navigation bridge is to be provided to indicate anyloss of the required ventilation capacity. The alarm is to be initiated by fall-out of starter relay fan motor.

Zone 2 10 Areas on open deck over all oil recovery tanks up to a height of 2,4 m above the deck

Hazardous areaSpaces

N° Description

Zone 2 1 Oil recovery tanks, any pipe work of pressure relief or other venting system for oil recovery tanks, pipes and equipment containing recovered oil


Pt D, Ch 17, Sec 5

SECTION 5 FIRE PROTECTION, DETECTION AND EXTINCTION

1 General



2 Mechanical ventilation in the oil recovery area

2.1 General

2.1.1 Spaces considered as hazardous are to have a ventila-tion system independent from those serving gas-safe spaces.

2.2 Ventilation of recovered oil pump rooms

2.2.1 Oil recovery pump rooms are to be provided with amechanical ventilation system of the extraction type capa-ble of giving at least 20 air changes per hour.

2.2.2 Ventilation intakes are to be so arranged as to mini-mise the possibility of recycling hazardous vapours fromventilation discharge openings.

2.2.3 Ventilation exhaust ducts are to discharge upwards toa safe area on the weather deck in locations at least 3,0 mfrom any ventilation intake and opening to accommoda-tions, service and machinery spaces, control stations andother spaces outside the oil recovery area.

2.2.4 Protection screens of not more than 13 mm squaremesh are to be fitted on ventilation duct intakes and outlets.

2.2.5 Ventilation fans are to be of non-sparking construc-tion as per Ch 7, Sec 1, [1.2.10].

2.2.6 The ventilation system is to be capable of being con-trolled from outside the oil recovery pump-room.

2.2.7 Provision is to be made to ventilate such spaces priorto entering the compartment and operating the equipmentand a warning notice requiring the use of such a ventilationis to be placed outside the compartment.

2.2.8 Ventilation ducts are not to lead through accommo-dations, service and machinery spaces or other similarspaces.

2.3 Ventilation of enclosed spaces normally entered during oil recovery operation other than recovery oil pump rooms

2.3.1 Enclosed spaces normally entered within the oilrecovery area are to be provided with a mechanical ventila-tion system of the extraction type capable of giving at least8 air changes per hour.

2.3.2 Ventilation intakes are to be located at a distance ofnot less than 3,0 m from the ventilation outlets of oil recov-ery pump-rooms.

3 Fire protection and fighting

3.1 Vapor detector

3.1.1 At least one portable gas detection instrument capa-ble of measuring flammable vapour concentrations in airand an equipment for oil flashpoint measurements are to beprovided on board.

Alternatively, instead of a portable gas detection instrument,a fixed system may be accepted provided that the sample isdrawn from a point within 6,0 m from the waterline.


Item N° Description of the document (1)Status of the

review

1 Diagram of mechanical and natural ventilation with indication of inlets and outlets serving:• spaces within the oil recovery area• machinery spaces• accommodation spaces

A

2 Specification of flammable gas detectors and flash point measurement equipment A

3 Drawing and specification of the fixed, if any, or movable fire-fighting system A



Pt D, Ch 17, Sec 5

3.2 Structural fire protection

3.2.1 Unless they are located at least 7,0 m from the near-est oil recovery area, exterior boundaries of the superstruc-tures and deckhouses enclosing accommodations andincluding any overhanging decks which support suchaccommodations are to be insulated to A-60 standard forthe whole of the portions which face the oil recovery areasup to the underside of the navigation bridge deck and for adistance of 3,0 m aft or forward of such areas.Alternatively to A-60 insulation, a fixed water-spraying sys-tem capable of delivering water at a rate of 10 l/m2/min maybe accepted. This system is to comply with the require-ments listed in Ch 16, Sec 4, [3], except that the only pro-tected area is to be the exterior boundaries of thesuperstructures and deckhouses enclosing accommodationsand including any overhanging decks which support suchaccommodations facing the oil recovery area.

3.2.2 Windows and sidescuttles fitted within 7,0 m fromthe nearest oil recovery area are to have the same fire integ-rity as the bulkhead in which they are fitted. If they have a

lower fire rating because they are protected by the fixedwater-spraying system mentioned in [3.2.1], windows andsidescuttles are to be fitted with inside covers of steel orother equivalent material having a thickness equal to thebulkhead in which they are fitted. Where they are not of thefixed type, they are to be such as to ensure an efficient gas-tight closure.

3.2.3 Ships assigned with the additional service featureSECOND-LINE do not need to comply with [3.2.1] and[3.2.2].

3.3 Fire-fighting

3.3.1 For the protection of the oil recovery area, the follow-ing fire-fighting equipment is to be provided near the work-ing area:

• two dry powder fire extinguishers, each with a capacityof at least 50 kg or equivalent

• at least one portable foam extinguishing applicatorcomplying with Pt C, Ch 4, Sec 14, [3.2.2].


Pt D, Ch 17, Sec 5



Chapter 18

CABLE-LAYING SHIPS

SECTION 1 GENERAL



SECTION 4 FIRE PROTECTION


Pt D, Ch 18, Sec 1


SECTION 1 GENERAL

1 General

1.1 Application

1.1.1 Ships complying with the requirements of this Chap-ter are eligible for the assignment of the service notationcable laying ship, as defined in Pt A, Ch 1, Sec 2, [4.7.7].







Ship arrangementL ≥ 65 or 90 m (1) • Part B • NR566

L < 65 or 90 m (1) • NR600 • NR566

Hull

L ≥ 65 or 90 m (1)• Part B• Ch 18, Sec 2


L < 65 or 90 m (1)• NR600• Ch 18, Sec 2

• NR600• Ch 18, Sec 2


• NR566• Ch 18, Sec 2


• NR566• Ch 18, Sec 3




• NR566• Ch 18, Sec 4


Pt D, Ch 18, Sec 2


1 General

1.1 Application

1.1.1 The requirements of this Section apply to ships fitted,in general, with one or more continuous decks, suitableholds for the carriage of cables and superstructures extend-ing for most of the ship’s length.

The main characteristics of the ship may vary according tothe service primarily performed which may be as follows:

• laying (and possibly burying) submarine cables on thesea bed

• hauling and repairing submarine cables.

2 Stability


2.1.1 General

The stability, the freeboard and the metacentric radius orroll period are to be such as to ensure:

• satisfactory seakeeping performance in working condi-tions

• a steady working platform in order to facilitate the per-formance of cable laying and/or repair operations.

Anti-roll tanks or bilge keels of adequate size may be fittedto meet the above requirements.

2.1.2 Tanks intended for liquid consumable

Special attention is to be paid to the arrangement of tanksintended to contain liquid consumables in order to preventweight variations during service resulting in excessivechanges in the ship’s trim.


The stability of the ship for the loading conditions in Pt B, Ch3, App 2, [1.2.1] and for the (departure and arrival) loadingconditions corresponding to the maximum draught is to bein compliance with the requirements in Pt B, Ch 3, Sec 2.

2.2 Damage stability for ships where the notation SDS has been required

2.2.1 Application

The requirements of this item apply to cable laying shipscarrying less than 240 persons.

Damage stability criteria for cable laying ships carrying 240persons and more are to be considered by the Society on acase-by-case basis.

2.2.2 General

Cable laying ships are to comply with the survival require-ments specified in Pt B, Ch 3, App 3, where the requiredindex R is to be considered as follows inTab 1 and calcu-lated according to [2.2.3].

Table 1 : Index R

2.2.3 Calculation of the required index

where:

N1 : Number of persons for whom lifeboats are pro-vided

N2 : Number of persons the ship is permittted tocarry in excess of N1.

Where the conditions of service are such that compliancewith R on the basis of N = N1 + 2 N2 is inpracticable andwhere the society considers that a suitable reduced degreeof hazard exists, a lesser value of N may be taken, but in nocase less than N = N1 + N2. The reduced value of N is alsoto be subject to the agreement of the flag administration.

3 Hull scantlings

3.1 Cable tanks

3.1.1 The net scantlings of cable tanks are to be obtainedthrough direct calculations to be carried out according to PtB, Ch 7, App 1, where the still water and wave loads are tobe calculated for the most severe condition of use.

3.2 Connection of the machinery and equip-ment with the hull structure

3.2.1 The net scantlings of the structures in way of the con-nection between the hull structure and the machinery andequipment, constituting the laying or hauling line for sub-marine cables, are to be obtained through direct calculationto be carried out according to Pt B, Ch 7, App 1, based onthe service loads of such machinery and equipment, asspecified by the Designer.

Number of persons: Nb Index R

Nb ≤ 60 0,8 R

60 < Nb < 240 Linear interpolation between 0,8 R and R (1)

(1) The required index is equal to R for Nb = 240

R 1 5000LS 2 5N, 15225+ +-------------------------------------------------–=

N N1 2N2+=


Pt D, Ch 18, Sec 2

In calculating these above service loads, the Designer is totake into account the inertial loads induced by ship motionsin the most severe condition of use.

4 Other structures

4.1 Fore part

4.1.1 In general, a high freeboard is needed in the forwardarea, where most repair work is carried out, in order to pro-vide adequate safety and protection against sea waves.

5 Hull outfitting

5.1 Equipment

5.1.1 Hawse pipesHawse pipes are to be integrated into the hull structure insuch a way that anchors do not interfere with the cable lay-ing.

5.1.2 SheavesWhere there is a risk that, in rough sea conditions, sheavesare subjected to wave impact loads, special solutions suchas the provision of retractable type sheaves may be adopted.


Pt D, Ch 18, Sec 3


1 General

1.1 Propulsion and manoeuvrability

1.1.1 The main propulsion systems of cable laying and/orrepair ships are to be capable of:

a) maintaining an adequate speed during the transit condi-tion

b) ensuring a satisfactory manoeuvrability at the speedassumed by the Designer for the performance of cablelaying and/or repair operations.


1.2.1 Table 1 lists the documents which are to be submittedfor information in duplicate.


2 Arrangements for cable laying, hauling and repair

2.1 Typical machinery and equipment of cable laying ships

2.1.1 Cable laying ships, in relation to the special service tobe performed, are generally to be provided with the follow-ing machinery and equipment:

a) a main windlass for cable hauling or laying, which gen-erally consists of a drum with a horizontal axis (the sur-face of which is formed by a series of timed conveyorswhich fleet the cable axially across the face of the drum)housing the repeaters fitted throughout the cable lengthwithout damaging them (see Fig 1 (a))

b) a linear tensioner working in conjunction with the mainwindlass and fitted between it and the cable tank, whichmaintains the due tension of the cable in relation to thecable type so as to allow effective cable hauling or lay-ing. In order to permit the passage of repeaters, the ten-sioner may be of the type having either a series ofdouble opposed rubber tyres (see Fig 1 (b)) or pressure-compensated opposed tracks (see Fig 1 (c)).

c) a dynamometer, normally fitted between the main wind-lass and the bow and stern sheaves, which continuouslymeasures the force required to displace the cable undertension

d) one or more cable transporters, used to move the cablefrom the tank(s) and the tensioner.

All the above machinery and equipment form the "cablelaying or hauling line". More than one line may be fitted onboard in the case of special service requirements.

Figure 1 : Cable handling machinery

No Document

1 General arrangement of the cable laying equipment

2 Design loads on all components of the cable layingequipment transferred to the ship structure

3 Structural plans of seating components of the cablelaying equipment, including gears, pressure vessels,hydraulic systems, etc., as applicable, includingdetails of the deck connection

4 Specification of the cable-laying equipment opera-tion test

(a)Fleeting cable drum

(b)Rubber tyre tensioner

(c)Track linear tensioner


Pt D, Ch 18, Sec 3

2.2 Design of cable handling machinery and equipment

2.2.1 The scantlings of components of machinery andequipment listed in [2.1] and, more generally, of any othermachinery and/or equipment to be used for the laying,hauling or repair of submarine cables are outside the scopeof classification.

2.3 Safety

2.3.1 The requirements of this Chapter are based on theassumption that during cable handling all necessary safetymeasures are taken, due consideration being given to risksconnected with the use of machinery and equipment dealtwith in [2.1] and that such machinery and equipment areproperly used by skilled personnel.

2.4 Testing of cable handling machinery and equipment

2.4.1 General

Machinery covered by [2.1] is to be tested in compliancewith the following requirements, with the exception ofprime movers and "hydraulic accumulator" type pressurevessels, which are to be tested in compliance with theapplicable requirements of the various Sections of theRules.

2.4.2 Testing of materials and components of the machinery

a) In general, testing is required for materials intended forshafts, gearing, pressure parts of pumps and hydraulicmotors, and plates of foundations of welded construc-tion.

b) As far as mechanical tests of materials are concerned,internal shop testing certificates submitted by the Manu-facturer may be accepted by the Society at its discretion;in such cases, testing operations witnessed by the Sur-veyor may be limited to visual external inspection asso-ciated, where necessary, with non-destructiveexaminations and hardness tests.

2.4.3 Hydrostatic tests

Pressure parts are to be subjected to hydrostatic tests inaccordance with the applicable requirements.

2.4.4 Tests on electrical components

The tests required in Part C, Chapter 2 of the Rules are to becarried out as applicable.

2.4.5 Running testsa) Running tests of each individual piece of equipment are

to be carried out whenever possible at the Manufac-turer’s works; as an alternative, the above tests may beperformed on board during the trials required afterinstallation of machinery.

b) On completion and subject to the result of the abovetests, the inspection of components may be required,with dismantling where deemed necessary by the Sur-veyor in charge of the testing.

3 On board trials

3.1 Ship trials

3.1.1

a) Upon completion of construction, in addition to con-ventional sea trials, specific tests may be required at theSociety’s discretion in relation to the particular servicefor which the ship is intended or the particular charac-teristics of machinery and equipment fitted on boardand according to a test specification submitted by theinterested party.

b) In particular, as far as propulsion and steering systemsare concerned, tests may be required to check themanoeuvring capability and the speed of the ship whilstoperating with only directional propellers or active rud-ders or a combination thereof.

c) In the case of ships mainly intended for repair of subma-rine cables, a check of manoeuvring capability whilstrunning astern or a complete overturning trial may berequired to be carried out using the rudder, active rud-ders or side thrusters only.

d) In the case of ships provided with a dynamic positioningsystem, tests to check the capability of holding thedesired position or heading are requested.

3.2 Equipment trials

3.2.1

a) As far as arrangements for the cable laying, haulingand/or repair lines are concerned, tests are to be carriedout to verify the proper operation of all relevant machin-ery and equipment, by means of the actual hauling andlaying of submarine cables, plain or with repeaters, atdifferent ship speeds and, if necessary, in different seaand weather conditions.

b) Special attention is to be paid during such tests so as toprevent cables being forced to reach their minimumallowed bending radius, both inside and outside theship.


Pt D, Ch 18, Sec 4



1 Cable tanks

1.1 Means for fire fighting

1.1.1 Depending on any special requirements of the Manu-facturers of cables, cable tanks may also be required to beprotected by a fixed pressure water-spraying or automaticsprinkler fire-extinguishing system.


Chapter 19

NON-PROPELLED UNITS

SECTION 1 GENERAL


SECTION 3 MACHINERY SYSTEMS


Pt D, Ch 19, Sec 1


SECTION 1 GENERAL

1 General

1.1 Application

1.1.1 Ships complying with the requirements of this Chap-ter are eligible for the assignment of one of the followingnotations applicable to non propelled units, as defined inPt A, Ch 1, Sec 2, [4.8]:• service notations:

- barge- pontoon- pontoon-crane

• additional service feature:

- non propelled.





1.1.3 For ships dealing with in this Chapter and intended tocarry only one type of cargo, the Society reserves the rightto establish requirements and/or conditions additional tothose contained in these Rules.



Ship arrangementL ≥ 65 or 90 m (1) • Part B • NR566

L < 65 or 90 m (1) • NR600 • NR566

Hull

L ≥ 65 or 90 m (1)• Part B• Ch 19, Sec 2


L < 65 or 90 m (1)• NR600• Ch 19, Sec 2

• NR600• Ch 19, Sec 2


• NR566• Ch 19, Sec 2


• NR566• Ch 19, Sec 3





Pt D, Ch 19, Sec 2


Symbols

s : Spacing, in m, of ordinary stiffeners.

1 General

1.1 Application

1.1.1 GeneralUnless otherwise specified, the requirements of this Sectionapply to ships with one of the service notations barge, pon-toon and pontoon - crane.

Specific requirements which apply only to ships with theservice notation barge or ships with the service notationpontoon or pontoon- crane are indicated.

Barges with the additional service feature tug combined arealso to comply with the applicable additional requirementsin Ch 14, Sec 3.

1.1.2 Main characteristics of non-propelled unitsThe requirements of this Section are based on the followingassumptions, relevant to the main characteristics of non-propelled units:

• the structural configuration and proportions of non-pro-pelled units are similar to those of propelled ships

• the cargo is homogeneously distributed.

The scantlings of non-propelled units with unusual shapesand proportions or carrying cargoes which are not homoge-neously distributed, such as containers or heavy loads con-centrated in limited areas, are to be considered by theSociety on a case-by-case basis, taking into account theresults of direct calculations, to be carried out according toPt B, Ch 7, App 1.

1.2 Additional class notations for lifting appliances of ships with service notation pontoon - crane

1.2.1 For ships with service notation pontoon - crane, oneof the following additional class notations, defined in Pt A,Ch 1, Sec 2, [6.12], is generally to be granted:

• ALP or (ALP) for lifting appliances intended to be usedin harbours or similary sheltered areas

• ALM or (ALM) for lifting appliances intended to be usedin offshore conditions.

Note 1: when the lifting appliance is provided to be used essen-tially in harbour conditions or similarly sheltered areas and excep-tionally in offshore conditions, the additional class notation ALP or(ALP) is generally assigned. For the exceptional using in offshoreconditions, the lifting capacity is reduced to a value in accordancewith the considered sea conditions.

2 Stability

2.1 Intact stability for ships with service notation pontoon or pontoon - crane

2.1.1 Application

The requirements of this item apply to seagoing ships withone of the service notations pontoon and pontoon - cranewith the following characteristics:

• unmanned

• having a block coefficient not less than 0,9

• having a breadth/depth ratio greater than 3,0

• having no hatchways in the deck except small manholesclosed with gasketed covers.

2.1.2 Trim and stability booklet

In addition to the information to be included in the trim andstability booklet specified in Pt B, Ch 3, App 2, [1.1], simpli-fied stability guidance, such as a loading diagram, is to besubmitted to the Society for approval, so that pontoons maybe loaded in compliance with the stability criteria.

2.1.3 Stability calculations

Stability calculations may be carried out according to thefollowing criteria:

• no account is to be taken of the buoyancy of deck cargo(except buoyancy credit for adequately secured timber)

• consideration is to be given to such factors as waterabsorption (e.g. timber), trapped water in cargo (e.g.pipes) and ice accretion

• in carrying out wind heel calculations:

- the wind pressure is to be constant and for generaloperations considered to act on a solid mass extend-ing over the length of the cargo deck and to anassumed height above the deck

- the centre of gravity of the cargo is to be assumed ata point mid-height of the cargo

- the wind lever arm is to be taken from the centre ofthe deck cargo to a point at one half the draught

• calculations are to be carried out covering the full rangeof operating draughts

• the downflooding angle is to be taken as the angle atwhich an opening through which progressive floodingmay take place is immersed. This would not be an open-ing closed by a watertight manhole cover or a vent fittedwith an automatic closure.


Pt D, Ch 19, Sec 2


The following intact stability criteria are to be compliedwith, for the loading conditions specified in Pt B, Ch 3, App2, [1.2.1] and Pt B, Ch 3, App 2, [1.2.2]:

• the area under the righting lever curve up to the angle ofmaximum righting lever is to be not less than 0,08 m.rad

• the static angle of heel due to a uniformly distributedwind load of 0,54 kPa (wind speed 30 m/s) may notexceed a heeling angle corresponding to half the free-board for the relevant loading condition, where thelever of wind heeling moment is measured from the cen-troid of the windage area to half the draught

• The minimum range of stability is to be:

- 20° for L < 100 m

- 20° − 0,1° (L − 100) for 100 ≤ L ≤ 150 m

- 15° for L > 150 m.

2.2 Additional intact stability criteria for ships with service notation pontoon - crane

2.2.1 Application

The requirements of this sub-article apply to ships with theservice notation pontoon - crane and specify the criteriathese ships are to satisfy during cargo lifting in addition tothose in [2.1].

2.2.2 Intact stability criteria during cargo lifting

The following intact stability criteria are to be compliedwith:

• θC ≤ 15°

• GZC ≤ 0,6 GZMAX

• A1 ≥ 0,4 Atot

where:

θC : Heeling angle of equilibrium, corresponding tothe first intersection between heeling and right-ing arms (see Fig 1)

GZC, GZMAX: Defined in Fig 1

A1 : Area, in m.rad, contained between the rightinglever and the heeling arm curves, measuredfrom the heeling angle θC to the heeling angleequal to the lesser of:

• heeling angle θR of loss of stability, corre-sponding to the second intersection betweenheeling and righting arms (see Fig 1)

• heeling angle θF, corresponding to floodingof unprotected openings as defined in Pt B,Ch 3, Sec 3, [3.3.2] (see Fig 1)

ATOT : Total area, in m.rad, below the righting levercurve.

In the above formula, the heeling arm, corresponding to thecargo lifting, is to be obtained, in m, from the following formula:

where:

P : Cargo lifting weight, in t

d : Transversal distance, in m, of lifting cargo to thelongitudinal plane (see Fig 1)

Z : Weight, in t, of ballast used for righting the pon-toon, if applicable (see Fig 1)

z : Transversal distance, in m, of the centre of grav-ity of Z to the longitudinal plane (see Fig 1)

Δ : Displacement, in t, at the loading conditionconsidered.

The above check is to be carried out considering the mostunfavourable situations of cargo lifting combined with thelesser initial metacentric height GM, corrected according tothe requirements in Pt B, Ch 3, Sec 2, [4].

Figure 1 : Cargo lifting

b P d⋅ Z z⋅–Δ

----------------------------=

righting andheeling arms

GZMAX

bGZC

A1

�C�F �R ��

��

��

�d

Z

z


Pt D, Ch 19, Sec 2

The residual freeboard of the unit during lifting operationsin the most unfavourable stability condition is to be not lessthan 0,30 m. However, the heeling of the unit is not to pro-duce in the lifting devices higher loads than those envis-aged by the Manufacturer, generally expected to be 5° inthe boom plane and 2° transversally in the case of a crane.

The vertical position of the centre of gravity of cargo liftingis to be assumed in correspondence of the suspensionpoint.

2.2.3 Intact stability criteria in the event of sudden loss of cargo during lifting

This additional requirement is compulsory when counter-weights or ballasting of the ship are necessary or whendeemed necessary by the Society taking into account theship dimensions and the weights lifted.

The case of a hypothetical loss of cargo during lifting due toa break of the lifting cable is to be considered.

In this case, the following intact stability criteria are to becomplied with:

•

• θ2 − θ3 ≥ 20°

where:

A1 : Area, in m.rad, contained between the rightinglever and the heeling arm curves, measuredfrom the heeling angle θ1 to the heeling angle θC

(see Fig 2)

A2 : Area, in m.rad, contained between the rightinglever and the heeling arm curves, measuredfrom the heeling angle θC to the heeling angle θ2

(see Fig 2)

A3 : Area, in m.rad, contained between the rightinglever and the heeling arm curves, measuredfrom the heeling angle θC to the heeling angle θ3

(see Fig 2)

θ1 : Heeling angle of equilibrium during lifting (seeFig 2)

Figure 2 : Cargo loss

A1 : Area between θ1 and θC

A2 : Area between θC and θ2 (in the Figure, θ2 = θF)

A3 : Area between θC and θ3

A3 = A1

A2

A1

------ 1≥

heeling andrighting arms

heelingangles

�C

2�

1�

P

�1

A1

�3 30˚ �F �R

A3A2


Pt D, Ch 19, Sec 2

θC : Heeling angle of equilibrium, corresponding tothe first intersection between heeling and right-ing arms (see Fig 2)

θ2 : Heeling angle corresponding to the lesser of θR

and θF

θ3 : Maximum heeling angle due to roll, at whichA3 = A1, to be taken not greater than 30° (anglein correspondence of which the loaded cargoon deck is assumed to shift (see Fig 2)

θR : Heeling angle of loss of stability, correspondingto the second intersection between heeling andrighting arms (see Fig 2)

θF : Heeling angle at which progressive floodingmay occur (see Fig 2).

In the above formulae, the heeling arm, induced on the shipby the cargo loss, is to be obtained, in m, from the followingformula:

where Z, z and Δ are defined in [2.2.2].


3.1 Hull structure

3.1.1 Framing of ships with one of the service notations pontoon and pontoon - crane

In general, ships with one of the service notations pontoonand pontoon - crane are to be longitudinally framed.

3.1.2 Supports for docked non-propelled units

Adequate supports are to be fitted on the longitudinal cen-treline in order to carry loads acting on the structure whenthe non-propelled units are in dry dock.

3.1.3 Truss arrangement supporting deck loads

Where truss arrangements are used as supports of the deckloads, including top and bottom girders in association withpillars and diagonal bracing, the diagonal members aregenerally to have angles of inclination with the horizontalof about 45° and cross-sectional area of about 50% that ofthe adjacent pillars.

3.2 Lifting appliances

3.2.1 Crane or derrick position during navigation

For ships with the service notation pontoon - crane, it is tobe possible to lower the crane boom or the derrick structureand to secure them to the pontoon during the voyage.

4 Hull girder strength

4.1 Yielding check

4.1.1 Non-propelled units lifted by crane

For non-propelled units intended to be lifted on board shipby crane, the hull girder strength is to be checked, in the

condition of fully-loaded barge lifted by crane, through cri-teria to be agreed with the Society on a case-by-case basis.

In general, the normal stress σ and the shear stress τinduced in the hull girder when lifted by crane are to com-ply with the following formulae:

σ ≤ 150/k N/mm2

τ ≤ 100/k N/mm2.

4.1.2 Ships with service notation pontoon carrying special cargoes

For ships with the service notation pontoon intended for thecarriage of special cargoes, such as parts of offshore units,the hull girder strength is to be checked through criteria tobe agreed with the Society on a case-by-case basis.

Moreover, where these ships are fitted with arrangementsfor launching the above structures, additional calculationsare to be carried out in order to evaluate the stresses duringthe various stages of launching. The Society may acceptstresses higher than those in [4.1.1], to be considered on acase-by-case basis, taking into account favourable sea andweather conditions during launching.

4.1.3 Ships with service notation pontoon - crane

For ships with the service notation pontoon - crane havinglength greater than 65 m, the hull girder strength is to bechecked when the lifting appliance, such as a crane or der-rick, is operated, taking into account the various loadingconditions considered, through criteria to be agreed withthe Society.

5 Hull scantlings

5.1 General

5.1.1 Minimum net thicknesses of ships with service notation barge carrying liquids

For ships with the service notation barge carrying liquidcargo inside tanks, the net thicknesses of cargo tank platingsare to be not less than the values given in Tab 1.

For other structures or transverse bulkheads not formingboundaries of cargo tanks, the above minimum thicknessesmay be reduced by 1 mm.

In pump rooms, the net thicknesses of plating of exposeddecks, longitudinal bulkheads and associated ordinary stiff-eners and primary supporting members are to be not lessthan the values given in Tab 1.

5.1.2 Minimum net thicknesses of decks forming tank top

Where the decks of non-propelled units form a tank top, theminimum net thicknesses of plating are to be not less thanthose obtained from Tab 1.

5.1.3 Net thickness of strength deck plating

Within the cargo area, the thickness of strength deck platingis to be increased by 1,5 mm with respect to that calculatedaccording to Pt B, Ch 7, Sec 1 or NR600, as applicable.

b ZzΔ------- θcos=


Pt D, Ch 19, Sec 2

Table 1 : Minimum net thickness of plating

5.2 Hull scantlings of non-propelled units with the service notation pontoon fitted with arrangements and systems for launching operations

5.2.1 Additional information

In addition to the documentation specified in Pt B, Ch 1,Sec 3, the following information is to be submitted to theSociety:

• maximum draught of the ship during the different stagesof the launching operations

• operating loads and their distribution

• launching cradle location.

5.2.2 Scantlings of plating, ordinary stiffeners and primary supporting members

In applying the formulae in Part B, Chapter 7 or NR600, asapplicable, T is to be taken equal to the maximum draughtduring the different stages of launching and taking intoaccount, where appropriate, the differential static pressure.

5.2.3 Deck scantlingsThe scantlings of decks are to be in accordance with Part B,Chapter 7 or NR600, as applicable, considering the maxi-mum loads acting on the launching cradle.

The thickness of deck plating in way of launch ground waysis to be suitably increased if the cradle may be placed in dif-ferent positions.

The scantlings of decks in way of pivoting and end areas ofthe cradle are to be obtained through direct calculations, tobe carried out according to the criteria in Pt B, Ch 7, App 1.

5.2.4 Launching cradlesThe launching cradles are to be adequately connected todeck structures and arranged, as far as possible, in way oflongitudinal bulkheads or at least of girders.

5.3 Hull scantlings of non-propelled units with service notation pontoon - crane

5.3.1 Loads transmitted by the lifting appliancesThe forces and moments transmitted by the lifting appli-ances to the ship’s structures, during both lifting service andnavigation, are to be submitted to the Society in the initialstage of the design.

5.3.2 Ship’s structuresThe ship’s structures, subjected to the forces transmitted bythe lifting appliances, are to be reinforced to the Society’ssatisfaction.

5.3.3 Lifting appliancesThe check of the behaviour of the lifting appliances at sea isoutside the scope of the classification and is under theresponsibility of the Designer. However, where the require-ments in [3.2.1] may not be complied with (i.e. sailing withboom or derrick up) or where, exceptionally, trips with sus-pended load are envisaged, the Designer is to submit thecheck of the lifting appliances during navigation to the Soci-ety for information.

6 Other structures

6.1 Reinforcement of the flat bottom forward area of ships with one of the service notations pontoon and pontoon - crane

6.1.1 Area to be reinforcedThe structures of the flat bottom forward area are to be ableto sustain the dynamic pressure due to the bottom impact.

The flat bottom forward area is:

• longitudinally, over the bottom located from the foreend to 0,15 L aft of the fore end

• transversely, over the whole flat bottom, and the adja-cent zones up to a height, from the base line, not lessthan 2L, in mm. In any case, this height need not begreater than 300 mm.

Note 1: The requirements of this sub article [6.1] are not applica-ble to non-propelled units having the navigation notation shelteredarea.

Plating Minimum net thickness, in mm

Decks, sides,bottom,inner bottom,bulkheads,primary supporting members in the cargo area

For L ≤ 45 m, the greater of:• (4,1 + 0,060 L) k0,5

• 2,8 + 0,060 LFor 45 m < L ≤ 200 m, the greater of:• (5,9 + 0,023 L) k0,5

• 4,5 + 0,023 LFor L > 200 m, the greater of:• (8,6 + 0,009 L) k0,5

• 7,2 + 0,009 L

Weather deck, within cargo area outside 0,4 Lamidships

For L ≤ 200 m, the greater of:• 11,3 s k0,5

• 11,3 s − 1,4For 200 m < L < 250 m, the greater of:• (11,3 s + 0,026 (L − 200)) k0,5

• 11,3 s + 0,026 s (L − 200) − 1,4For L ≥ 250 m, the greater of:• 12,6 s k0,5

• 12,6 s − 1,4

Web of ordinary stiffenersandother structuresof cargo tanks

For L ≤ 45 m, the greater of:• (4,1 + 0,060 L) k0,5

• 2,8 + 0,060 LFor 45 m < L ≤ 200 m, the greater of:• (5,9 + 0,023 L) k0,5

• 4,5 + 0,023 LFor L > 200 m, the greater of:• 10,0 k0,5

• 8,6

Note 1:k : Material factor for steel, defined in Pt B, Ch 4,

Sec 1, [2.3].


Pt D, Ch 19, Sec 2

6.1.2 Bottom impact

The bottom dynamic impact pressure is to be considered if:

TF < 0,04 L,

where TF is the minimum forward draught, in m, amongthose foreseen in operation in ballast conditions or condi-tions of partial loading.

If TF is less than 0,025 L, strengthening of the flat bottomforward is to be considered by the Society on a case-by-case basis.

6.1.3 Partial safety factors

The partial safety factors to be considered for checking thereinforcements of the flat bottom forward area are specifiedin Tab 2.

6.1.4 Scantlings of plating and ordinary stiffeners

Where TF is less than 0,03 L, the net scantlings of platingand ordinary stiffeners of the flat bottom forward area, asdefined in [6.1.1], are to be not less than those obtainedaccording to Pt B, Ch 8, Sec 1, [3] or NR600, as applicable,and those obtained from Tab 3.

Where TF is between 0,03 L and 0,04 L, the net scantlings ofplating and ordinary stiffeners are to be obtained by linearinterpolation between those obtained according to Pt B, Ch8, Sec 1, [2] or NR600, as applicable, and those obtainedfrom Tab 3.

6.1.5 TaperingOutside the flat bottom forward area, scantlings are to begradually tapered so as to reach the values required for theareas considered.

6.1.6 Floor spacingIn the area to be reinforced, defined in [6.1.1], the floorspacing is to be not greater than 0,68 L1/4.

Table 2 : Reinforcements of the flat bottom forward area - Partial safety factors

Table 3 : Reinforcements of plating and ordinary stiffeners of the flat bottom forward area

Partial safety factors covering uncertainties

regarding:

Partial safety factors

Symbol PlatingOrdinary stiffeners

Still water pressure γS2 1,00 1,00

Wave pressure γW2 1,10 1,10

Material γm 1,02 1,02

Resistance γR 1,30 1,15

Element Formula Minimum value

Plating Net thickness, in mm: Net minimum thickness, to be taken, in mm, not less than:t = 0,03 L + 5,5 − cE

nor than the lesser of:• t = 16• t = 6,3 (s − 0,228 L1/4) + 0,063 L + 3,5where s is to be taken not less than 0,182 L1/4

Ordinary stiffeners

Net section modulus, in cm3: Web net minimum thickness, in mm, to be not less than the lesser of:• t = 1,5 L2

1/3

• the thickness of the attached plating.

Net shear sectional area, in cm2:

Note 1:cE : Coefficient, to be taken equal to:

cE = 1 for L ≤ 65 mcE = 3 − L / 32,5 for 65 m < L < 90 mcE = 0 for L ≥ 90 m

cP : Ratio of the plastic section modulus to the elastic section modulus of the ordinary stiffeners with an attached shell plat-ing, to be taken equal to 1,16 in the absence of more precise evaluation

γR, γm, γS2, γW2: Partial safety factors defined in Tab 2βb, βS : Coefficients defined in Pt B, Ch 7, Sec 2, [3.7.3]pBI : Bottom dynamic impact pressure:

pBI = 12 L0,6 kN/m2

t 14 9ca, crs γRγmγW2pBI

Ry

---------------=

w γRγmβbγS2T6Ry

----------s2104=

ASh 10γRγmβsγW2pBI

Ry---------------- 1 s

2------–

s=


Pt D, Ch 19, Sec 2

7 Hull outfitting

7.1 Equipment

7.1.1 Manned non-propelled unitsThe equipment of anchors, chain cables and ropes to be fit-ted on board manned non-propelled units is to comply withPt B, Ch 9, Sec 4 or NR600, as applicable.

Chain cables for anchors may be replaced by steel ropeshaving the same breaking load. The ropes are to be con-nected to the anchors by approximately 10 m of chain cablecomplying with Pt B, Ch 9, Sec 4 or NR600, as applicable.

Non-propelled units continuously assisted by a tug mayhave only one anchor, complying with Pt B, Ch 9, Sec 4 orNR600, as applicable, and a chain rope having length nei-ther less than 75% of the length obtained according to Pt B,Ch 9, Sec 4 or NR600, as applicable, nor less than 220 m.

7.1.2 Unmanned non-propelled units

For unmanned non-propelled units, the equipment is notrequired for classification purposes. The scantlings ofanchors, chain cables and ropes to be fitted on board arethe responsibility of the Designer.

7.1.3 Towing arrangements

Non-propelled units are to be fitted with suitable arrange-ments for towing, with scantlings under the responsibility ofthe Designer.

The Society may, at the specific request of the interestedparties, check the above arrangements and the associatedhull strengthening; to this end, the maximum pull for whichthe arrangements are to be checked is to be specified on theplans.


Pt D, Ch 19, Sec 3

SECTION 3 MACHINERY SYSTEMS

1 General

1.1 Application

1.1.1 This Section provides requirements for bilge systemsof non propelled units.



2 Bilge system

2.1 Bilge system in ships having no source of electrical power

2.1.1 General

Where there is no source of electrical power on board,hand pumps are to be provided, in sufficient number and sopositioned as to permit an adequate drainage of all thecompartments of the ship.

2.1.2 Arrangement of the bilge system

The bilge system is to comply with one of the followingarrangements:

a) at least one pump is to be provided for each compart-ment

b) at least two pumps connected to a bilge main are to beprovided. The main is to have branch pipes allowing thedraining of each compartment through at least one suc-tion.

2.1.3 Hand pumps

a) Hand pumps are to be capable of being operated frompositions above the load waterline and are to be readilyaccessible at any time.

b) Hand pumps are to have a maximum suction height notexceeding 7,30 m.

2.1.4 Size of bilge pipes

a) The internal diameter, in mm, of suction pipes is not tobe less than the diameter given by the following for-mula:

where:

T : Underdeck tonnage, in t.

b) When the ship is subdivided into small watertight com-partments, the diameter of these suctions need notexceed 50 mm.

2.2 Bilge system in ships having a source of electrical power

2.2.1 General

On board ships having no propelling machinery but havinga source of electrical power, mechanical pumps are to beprovided for draining the various compartments of the ship.

2.2.2 Arrangement of the bilge system

The bilge system is to comply with the provisions of Pt C,Ch 1, Sec 10, [6.3] to Pt C, Ch 1, Sec 10, [6.6] applicable tothe spaces concerned, except that direct suctions need notbe provided.

2.2.3 Bilge pumps

The number and capacity of the bilge pumps are to complywith the relevant requirements of Pt C, Ch 1, Sec 10, [6.7].

2.2.4 Size of bilge pipes

The size of bilge pipes is to comply with the relevantrequirements of Pt C, Ch 1, Sec 10, [6.8].


d1T

100---------- 50+=

Item N° Description of the document (1) Status of the review

1 Diagram of the bilge system A

2 Diagram of the central priming system intended for the bilge pumps, where provided A

3 Capacity, prime mover and location of the bilge pumps A



Pt D, Ch 19, Sec 3



Chapter 20

FISHING VESSELS

SECTION 1 GENERAL

SECTION 2 SHIP ARRANGEMENT


SECTION 4 MACHINERY




Pt D, Ch 20, Sec 1


SECTION 1 GENERAL

1 General

1.1 Application

1.1.1 Ships complying with the requirements of this Chap-ter are eligible for the assignment of the service notationFishing vessel, as defined in Pt A, Ch 1, Sec 2, [4.9].

1.1.2 Ships dealt with in this Chapter are to comply with:• Part A of the Rules• NR216 Materials and Welding• applicable requirements according to Tab 1.

Table 1 :

Item Reference

Ship arrangement

L ≥ 65 or 90 m (1)• Pt B• Ch 20, Sec 2

L < 65 or 90 m (1)• NR600• Ch 20, Sec 2

Hull

L ≥ 65 or 90 m (1)• Pt B• Ch 20, Sec 3

L < 65 or 90 m (1)• NR600• Ch 20, Sec 3

Stability• Pt B• Ch 20, Sec 3

Machinery and cargo system• Pt C• Ch 20, Sec 4

Electrical installations• Pt C• Ch 20, Sec 5

Automation • Pt C

Fire protection, detection and extinc-tion

• Pt C• Ch 20, Sec 6 (2)

(1) Refer to the scope of application of NR600.(2) Articles Ch 20, Sec 6, [5], Ch 20, Sec 6, [6], Ch 20, Sec

6, [7], Ch 20, Sec 6, [8], Ch 20, Sec 6, [9] and Ch 20,Sec 6, [10] apply only to ships assigned with the addi-tional service feature F.

Note 1:NR600: Hull Structure and Arrangement for the Classificationof Cargo Ships less than 65 m and Non Cargo Ships less than90 m.

Pt D, Ch 20, Sec 2


SECTION 2 SHIP ARRANGEMENT


1.1 Subdivision arrangement

1.1.1 General

Fishing vessels are to be fitted with at least the followingtransverse watertight bulkheads:

• one collision bulkhead

• one after peak bulkhead

• two bulkheads forming the boundaries of the machineryspace in ships with machinery amidships, and a bulk-head forward of the machinery space in ships withmachinery aft.

1.1.2 Disposition of collision bulkhead

For vessels equal to or greater than 45 m in length, the colli-sion bulkhead is to be located at a distance from the for-ward perpendicular FPLL of not less than 5% and no morethan 8% of the length LLL of the ship.

For vessels less than 45 m in length, the collision bulkheadis to be located at a distance from the forward perpendicu-lar FPLL of not less than 5% of the length LLL of the ship andnot more than 5% of the length LLL + 1,35 m. For shipsgreater than 24 m in length, this distance is not to be lessthan 2 m.

Where any part of the ship below the waterline extends for-ward of the forward perpendicular, e.g a bulbous bow, theabove distances, in m, are to be measured from a pointeither:

• at the mid-length of such extension, or

• at a distance 1,5% of the length LLL of the ship forwardof the forward perpendicular, where this distance islesser.

1.1.3 Height of transverse watertight bulkheads

The bulkheads in [1.1.1] are to be watertight up to theworking deck.

Where a long forward superstructure is fitted, the collisionbulkhead is to be extended weathertight to the next deckabove the freeboard deck. The extension need not be fitteddirectly above the bulkhead below provided it is locatedwithin the limits prescribed in [1.1.2] and the part of thedeck which forms the step is made effectively watertight.

1.1.4 Openings in collision bulkhead

Openings in the collision bulkhead below the working deckare not allowed.

Where penetration of the collision bulkhead is necessary forpiping, arrangements are to be fitted to maintain the water-tight integrity and strength, with suitable valves operablefrom above the freeboard deck, whose valve chest is to besecured at the bulkhead inside the fore peak.

Where the collision bulkhead extends above the workingdeck, openings above the working deck are allowed pro-vided that they are supplied with weathertight means of clo-sure.

1.1.5 Openings in watertight bulkheads

The number of openings in watertight bulkheads is to bekept to a minimum compatible with the design and properworking of the ship.

Where penetration of watertight bulkheads and internaldecks is necessary for access, piping, ventilation, electricalcables, etc., arrangements are to be fitted to maintain thewatertight integrity and strength.

1.2 Cofferdams

1.2.1 Cofferdams are to be provided between compart-ments intended for liquid hydrocarbons (fuel oil, lubricatingoil) and those intended for fresh water or boiler feed water.

1.2.2 Cofferdams separating fuel oil tanks from lubricatingoil tanks and such tanks from those intended for the car-riage of fresh water or boiler feed water may not be requiredwhen deemed impracticable or unreasonable by the Societyin relation to the characteristics and dimensions of suchtanks, provided that:

• the thickness of common boundary plates of adjacenttanks is increased by 1 mm with respect to that obtainedaccording to Ch 20, Sec 3

• the tank structural test is carried out with a headincreased by 1 m with respect to that specified in Pt B,Ch 11, Sec 3, [1.4] or NR600, as applicable.

1.2.3 Spaces intended for the carriage of flammable liquidsare to be separated from accommodation and servicespaces by means of a cofferdam. Where accommodationand service spaces are arranged immediately above suchspaces, the cofferdam may be omitted only where the deckis not provided with access openings and is coated with alayer of material recognised as suitable by the Society.

The cofferdam may also be omitted where such spaces areadjacent to a passageway, subject to the conditions in[1.2.2] for the avoidance of cofferdams between fuel oil andlubricating oil tanks.

Pt D, Ch 20, Sec 3


Symbols

x, y, z : X, Y and Z co-ordinates, in m, of the calculationpoint with respect to the reference co-ordinatesystem defined in Pt B, Ch 1, Sec 2, [4]

p0 : Reference pressure, in kN/m2:

p0 = 10 if L ≤ 50

p0 = 0,2 L if L > 50

zTOP : Z co-ordinate, in m, of the highest point of thetank or of the hold

hTD : ‘Tween deck height at side, in m

1 Stability


1.1.1 Application

The stability of the ship for the loading conditions in Pt B,Ch 3, App 2, [1.2.13], with the assumptions in [1.1.2], is tobe in compliance with the requirements in [1.1.3].

1.1.2 Assumptions for calculating loading conditions

The assumptions for calculating the loading conditions in PtB, Ch 3, App 2, [1.2.13] are as follows:

• allowance is to be made for the weight of the wet fishingnets and tackle, etc., on deck

• allowance for icing, where this is anticipated to occur, isto be made in accordance with Pt B, Ch 3, Sec 2, [6]

• in all cases the cargo is to be assumed to be homoge-nous unless this is inconsistent with practice

• deck cargo is to be included if such a practice is antici-pated

• water ballast is normally to be included only if carried intanks which are specially provided for this purpose.


• The general intact stability criteria in Pt B, Ch 3, Sec 2,[2] are to be applied to fishing vessels equal to or greaterthan 24 m in length, except for the requirements below.

• The initial metacentric height GM0 is to be not less than0,35 m for single deck vessels.

• The metacentric height GM0 may be reduced to the sat-isfaction of the Society but in no case is GM0 to be lessthan 0,15 m for vessels with complete superstructure orvessels equal to or greater than 70 m in length.

Where arrangements other than bilge keels are provided tolimit the angle of roll, the above stability criteria are to bemaintained in all operating conditions.

1.1.4 Severe wind and rolling criterion (weather criterion)

The requirements in Pt B, Ch 3, Sec 2, [3] are to be com-plied with by:• fishing vessels equal to or greater than 45 m in length• fishing vessels in the length range between 24 m and

45 m, with the values of wind pressure defined in Tab 1,depending on the vertical distance h, in m, measuredfrom the centre of the projected vertical area of the shipabove the waterline to the waterline.

Table 1 : Values of wind pressure

1.1.5 IcingFor vessels operating in areas where ice accretion isexpected, the requirements in Pt B, Ch 3, Sec 2, [6] are tobe complied with.

2 Hull scantlings

2.1 Design loads

2.1.1 Fish holdThe design pressure pF, in kN/m2, to be considered for thescantling of fish holds, is to be obtained from the followingformula:

where:z0 : Z co-ordinate of the lowest point of the fish

hold.In all cases, this pressure is to be taken not less than10 kN/m2.

2.1.2 Cargo weather deckThe design pressure pWD , in kN/m2, to be considered for thescantling of cargo weather decks is to be obtained from thefollowing formula:

pWD = 0,4 pD + 12 pC

where:

Vertical distance h, in m Wind pressure, in kN/m2

1 0,316

2 0,386

3 0,429

4 0,460

5 0,485

6 and over 0,504

pF 7zTOP z–zTOP z0–---------------------- hTD=


Pt D, Ch 20, Sec 3

pD : Sea pressure defined in Tab 2

pC : Cargo load, in t/m².

Table 2 : Weather decks sea pressure

2.1.3 Lower deck

The design pressure pLD , in kN/m2, to be considered for thescantling of lower decks is to be obtained from the follow-ing formulae:

• for working deck:

pLD = 8,5

• for cargo tweendeck:

pLD = 7 hTD , to be taken not less than 10 kN/m2.

2.1.4 Dry uniform cargoes on decks

The design pressure transmitted to the deck structures is ingeneral defined by the designer; in any case, it may not betaken less than 10 kN/m2.

When the design pressure is not defined by the designer, itmay be taken, in kN/m2, equal to 7hTD.

2.2 Bottom, side and decks plating

2.2.1 The thickness of bottom, side and decks plating is tobe increased by 0,5 mm with respect to that calculatedaccording to Pt B, Ch 7, Sec 1 or NR600, as applicable.

2.3 Aft ramp

2.3.1 Plating of the aft ramp and the lower part of the aft ramp side

The thickness of plating of the aft ramp and the lower part ofthe aft ramp side is to be increased by 2 mm with respect tothat calculated according to Pt B, Ch 8, Sec 2, [3] orNR600, as applicable, for side plating with the same platepanel dimensions.

The gross thickness of plating of the aft ramp and the lowerpart of the aft ramp side is to be not less than 12 mm.

2.3.2 Plating of the upper part of the aft ramp side

The thickness of plating of the upper part of the aft rampside is to be not less than the value calculated according toPt B, Ch 8, Sec 2, [3] or NR600, as applicable, for side plat-ing with the same plate panel dimensions.

2.4 Machinery casings

2.4.1 Arrangements

The machinery casings are to be arranged in accordancewith Pt B, Ch 8, Sec 3, [7.1] or NR600, as applicable.

2.4.2 Engine room skylight coamings

If the engine room skylights are fitted with opening-typecovers providing light and air, the height of coamings is tobe not less than:

• 900 mm, for skylights located on working decks

• 300 mm, for skylights located on superstructure decks.

The thickness of engine room skylight coamings is to be notless than 6 mm.

Where the height of engine room skylight coamings isgreater than 900 mm, the section modulus of vertical ordi-nary stiffeners with spacing not greater than 760 mm is tobe increased by 10% with respect to that obtained for verti-cal ordinary stiffeners of deckhouses.

2.4.3 Scantlings

The scantlings of plating and ordinary stiffeners are to benot less than those of plating and ordinary stiffeners ofsupersrtuctures and deckhouses. In any case, the thicknessof protected or unprotected casing bulkheads is to be notless than 5 mm.

2.5 Hatch covers

2.5.1 Direct calculations

Where direct calculations are carried out, the followinginformation is to be submitted for review by the Society:

• structure model

• boundary conditions

• loading cases

• main results.

Permissible stresses for the calculation of hatch supportingstructure are given in Tab 3.


2.6.1 Sidescuttles

Sidescuttles may not be fitted in such a position that theirsills are below a line drawn parallel to the sheer at side andhaving its lowest point 0,5 m above the summer load water-line.

No sidescuttles may be fitted in any spaces which areappropriated exclusively for the carriage of cargo.

Weather deckSea pressure pD , in kN/m2

Midship region End regions

Strength deck of single deck ship

pD = p0 pD = 1,5 p0

Multideck ships:- freeboard deck- strength deck

pD = p0

pD = 0,7 p0

pD = 1,5 p0

pD = 1,05 p0

Forecastle deck pD = 0,7 p0

Poop deck pD = 0,6 p0

Long superstructures pD = 0,6 p0 pD = 0,6 p0

Short superstructuresFirst deck of deckhouses

pD = 0,4 p0 pD = 0,4 p0

Second deck of deckhouses pD = 0,3 p0 pD = 0,3 p0

Other decks of deckhouses pD = 3,0 pD = 3,0


Pt D, Ch 20, Sec 3

Table 3 : Permissible stress for direct calculation of hatch supporting structure

Table 4 : Navigation coefficients

2.6.2 Freeing portsThe freeing port area in bulwarks is to be not less than thevalue obtained from the formulae in Pt B, Ch 8, Sec 10, [6]or NR600, as applicable.

For ships with L < 24 m and the navigation notation coastalarea, the freeing port area in bulwarks on each side of theship may be not less than the value obtained from the fol-lowing formula:

A = 0,035 B + AC

where:

B : Length, in m, of bulwark in the well, to be takennot greater than 0,7 L

AC : Area, in m2, to be taken, with its sign, equal to:

AC = 0,04 B (hB − 1,2) for hB > 1,2

AC = 0 for 0,9 ≤ hB ≤ 1,2

AC = 0,04 B (hB − 0,9) for hB < 0,9

hB : Mean height, in m, of bulwark in the well oflength B .

2.6.3 Openings in bulkheads of enclosed superstructures and other outer structures

All access openings in bulkheads of enclosed superstruc-tures and other outer structures (e.g. machinery casings)through which water can enter and endanger the ship are tobe fitted with doors of steel or other equivalent material,

permanently and strongly attached to the bulkhead, andframed, stiffened and fitted so that the whole structure is ofequivalent strength to the unpierced bulkhead and weather-tight when closed. The doors are to be capable of beingoperated from both sides and generally to open outwards togive additional protection against wave impact.

These doors are to be fitted with gaskets and clampingdevices or other equivalent means permanently attached tothe bulkhead or to the door themselves.

Other openings are to be fitted with equivalent covers, per-manently attached in their proper position.

2.6.4 Door sillsThe height of the sill of the doors is to be not less than:

• 600 mm above the working deck

• 300 mm above the deck of the lower tier of superstruc-tures.

For doors protected from the direct impact of waves, exceptfor those giving direct access to machinery spaces, theheight of the sill may be taken not less than:

• 380 mm above the working deck

• 150 mm above the deck of the lower tier of superstruc-tures.

2.6.5 Ventilator coamingsThe height of ventilator coamings is to be not less than thevalue obtained from Tab 45.

The thickness of ventilator coaming plating is to be not lessthan both the thickness obtained for the ship’s deck and thethickness obtained for a deckhouse in the same position asthe ventilator.

Ventilator coamings are to be provided with weathertightclosing appliances to be used in rough weather. Theseappliances may be omitted when the ventilator height isgreater than the minimum value specified in Tab 45.

Table 5 : Ventilator coamings

Element Bending stress, in N/mm2 Shear stress, in N/mm2 Combined stress, in N/mm2

Hatch side girders:

• strength deck• other decks

125 / n2

150 / n2

90 / n2

100 / n2

150 / n2

175 / n2

Hatch end beams 150 / n2 100 / n2 175 / n2

Note 1:n2 : Navigation coefficient as defined in Tab 4

Navigation notation Navigation coefficient n2

Unrestricted navigation 1,0

Summer zone 0,95

Tropical zoneCoastal area

0,90

Sheltered area 0,85

Ship’s length, in m

Coaming height, in mm Minimum height of ventilators, in m

Ventilator openings on working decks

Ventilator openings on decksof lower tier of superstructure

Ventilator openings on working decks

Ventilator openings on decksof lower tier of superstructure

L > 45 900 760 4,5 2,3

24 ≤ L ≤ 45 760 450 3,4 1,7

12 ≤ L < 24 760 450 2,5 1,0

L < 12 300 300 2,5 1,0


Pt D, Ch 20, Sec 3

3 Lifting appliances and fishing devices

3.1 General

3.1.1 The limits of application to lifting appliances aredefined in Pt B, Ch 1, Sec 1, [1.2].

3.1.2 The requirements in [3] apply to the reinforcementsunder decks supporting fishing devices, and to the strengthcheck of fishing devices and masts if welded to the deck.

3.2 Design loads

3.2.1 The design loads to be considered for the strengthcheck of masts, fishing devices and reinforcements underdecks are:

• the weights of booms and net hauling fittings

• the cargo loads, to be taken equal to the maximum trac-tion loads of the different lifting appliances, consideringthe rolling-up diameters defined in [4.2.2].

3.2.2 The rolling-up diameters to be taken for the maxi-mum traction loads of the lifting appliances are:

• for the fishing winches: the mid rolling-up diameter

• for the net winches: the maximum rolling-up diameter

• for the winding-tackles: the minimum rolling-up diame-ter.

3.3 Strength check

3.3.1 Calculation of stresses in the structural elements

The stresses in the structural elements of masts, fishingdevices and reinforcements under decks are to be obtainedby means of direct calculations, using the design loadsspecified in [3.2].

3.3.2 Yielding check

The Von Mises equivalent stresses in the structural elementsof masts, fishing devices and reinforcements under decksare to comply with the following formula:

σE ≤ 0,5 ReH

where:


ReH : Minimum yield stress, in N/mm2, of the mate-rial, defined in Pt B, Ch 4, Sec 1, [2].

3.3.3 Buckling check

The buckling strength of the structural elements of mastsand fishing devices is to be checked in compliance withPart B, Chapter 7 or NR600, as applicable.

4 Hull outfitting

4.1 Rudder stock scantlings

4.1.1 The rudder stock diameter is to be increased by 5%with respect to that obtained from the formula in Pt B, Ch 9,Sec 1, [4] or NR600, as applicable.

4.2 Equipment

4.2.1 GeneralAnchors referred to in this section are bower anchors.

Fishing vessels are to be provided with equipment inanchors, chain cables and ropes to be obtained from Tab46, based on their Equipment Number EN, to be calculatedaccording to Pt B, Ch 9, Sec 4, [2].

The equipment in anchors, chain cables and ropes of fishingvessels with the navigation notation coastal area may beobtained from Tab 46 based on the Equipment Number ENcorresponding to the row above that relevant to the Equip-ment Number calculated for the ship considered.

In general, stockless anchors are to be adopted.

For ships with EN greater than 720, the determination of theequipment is to be considered by the Society on a case-by-case basis.

The mooring lines are given as a guidance, but are notrequired as a condition of classification.

4.2.2 AnchorsThe required mass for each anchor is to be obtained fromTab 46.

The individual mass of a main anchor may differ by ±7%from the mass required for each anchor, provided that thetotal mass of anchors is not less than the total mass requiredin Tab 46.

The mass of the head of an ordinary stockless anchor,including pins and accessories, is to be not less than 60% ofthe total mass of the anchor.

Where a stock anchor is provided, the mass of the anchor,excluding the stock, is to be not less than 80% of the massrequired in Tab 46 for a stockless anchor. The mass of thestock is to be not less than 25% of the mass of the anchorwithout the stock but including the connecting shackle.

4.2.3 Scantlings of stud link chain cablesThe mass and geometry of stud link chain cables, includingthe links, are to be in compliance with the requirements inNR 216 Materials, Ch 4, Sec 1, [2].

The diameter of stud link chain cables is to be not less thanthe value in Tab 46.

4.2.4 Chain cable arrangementChain cables are to be made by lengths of 27,5 m each,joined together by Dee or lugless shackles.

The total length of chain cables, as required in Tab 46, is tobe divided into approximately equal parts between the twoanchors ready for use.

Where different arrangements are provided, they are to beconsidered by the Society on a case-by-case basis.


Pt D, Ch 20, Sec 3

Table 6 : Equipment

4.2.5 Wire ropes

As an alternative to the stud link chain cables mentioned,wire ropes may be used in the following cases:

• wire ropes for both the anchors, for ship’s length lessthan 30 m

• wire rope for one of the two anchors, for ship’s lengthbetween 30 m and 40 m.

The wire ropes above are to have a total length equal to 1,5times the corresponding required length of stud link chaincables, obtained from Tab 6, and a minimum breaking load

equal to that given for the corresponding stud link chaincable (see [4.2.3]).

A short length of chain cable is to be fitted between the wirerope and the anchor, having a length equal to 12,5 m or thedistance from the anchor in the stowed position to thewinch, whichever is the lesser.

When chain cables are replaced by trawl warps, the anchoris to be positioned on the forecastle deck so that it may bereadily cast after it has been shackled to the trawl warp.Chocks or rollers are to be fitted at suitable locations, alongthe path of the trawl warps, between the winch and themooring chocks.


Stockless bower anchors Stud link chain cables for bower anchors Mooring lines (1)

A B N Mass per anchor, in kg

Total length,in m

Diameter, in mmN

Length of each line,

in m

Breaking load, in kNmild steel high strength

steel

10 15 2 30 110 11 11

15 20 2 40 110 11 11

20 25 2 50 165 11 11

25 30 2 60 165 11 11

30 40 2 80 165 11 11 2 50 29

40 50 2 100 192,5 11 11 2 60 29

50 60 2 120 192,5 12,5 11 2 60 29

60 70 2 140 192,5 12,5 11 2 80 29

70 80 2 160 220 14 12,5 2 100 34

80 90 2 180 220 14 12,5 2 100 37

90 100 2 210 220 16 14 2 110 37

100 110 2 240 220 16 14 2 110 39

110 120 2 270 247,5 17,5 16 2 110 39

120 130 2 300 247,5 17,5 16 2 110 44

130 140 2 340 275 19 17,5 2 120 44

140 150 2 390 275 19 17,5 2 120 49

150 175 2 480 275 22 19 2 120 54

175 205 2 570 302,5 24 20,5 2 120 59

205 240 2 660 302,5 26 22 2 120 64

240 280 2 780 330 28 24 3 120 71

280 320 2 900 357,5 30 26 3 140 78

320 360 2 1020 357,5 32 28 3 140 86

360 400 2 1140 385 34 30 3 140 93

400 450 2 1290 385 36 32 3 140 101

450 500 2 1440 412,5 38 34 3 140 108

500 550 2 1590 412,5 40 34 4 160 113

550 600 2 1740 440 42 36 4 160 118

600 660 2 1920 440 44 38 4 160 123

660 720 2 2100 440 46 40 4 160 127

(1) The mooring lines are given as a guidance, but are not required as a condition of classification.


Pt D, Ch 20, Sec 3

5 Protection of hull metallic structures

5.1 Protection of deck by wood sheathing

5.1.1 Protection of deck by wood sheathing is to complywith Pt B, Ch 11, Sec 1, [4.2].

5.2 Protection of cargo sides by battens

5.2.1 In cargo spaces, where thermal insulation is fitted,battens formed by spaced planks are generally to be fittedlongitudinally.

5.3 Deck composition

5.3.1 The deck composition is to be of such a material as toprevent corrosion as far as possible and is to be effectivelysecured to the steel structures underneath by means of suit-able connections.


Pt D, Ch 20, Sec 4

SECTION 4 MACHINERY

1 General

1.1 Application

1.1.1 Machinery systems fitted on board ships having thenotation fishing vessel are to comply with the relevant sec-tions of Part C, Chapter 1, with the exception of tests andthe following systems:• bilge system• scuppers and sanitary discharges• air pipes and sounding devices• ventilation• oil fuel systems• cooling systems• lubricating oil systems• compressed air systems• hydraulic systems• exhaust gas system• refrigerating installations• propelling and auxiliary machinery• steering gear,

for which substitutive requirements are provided in this Sec-tion.

1.1.2 This Section does not cover the design and perform-ances of the fishing equipment. However, the piping sys-tems and pressure vessels serving the fishing equipment arerequired to comply with the relevant Sections of Part C.


1.2.1 In addition to the documents listed in Tab 1 and Tab2, the diagram of the piping systems (hydraulic system, etc.)serving the fishing equipment is to be submitted forapproval.

1.3 Tests - Trials in ships L ≥ 24 m

1.3.1 See Part C, Chapter 1.

1.4 Tests - Trials in ships L < 24 m

1.4.1 GeneralThe building and fitting of fluid systems, pumps, pipes andtheir accessories, as well as other installations referred to inthis Chapter are to be attended by a Society's Surveyor, atthe Builder's request.

Pneumatic tests are to be avoided whenever possible. Whensuch testing is essential in lieu of hydraulic pressure test,procedure for testing is to be submitted to the Society foracceptance prior to testing.


1.4.2 Testing on board

After assembly onboard, all fittings and accessories beingfitted, a hydraulic pressure test is to be carried out for com-pressed air and oil fuel pipes.

As a rule, the test pressure is not to be less than 1,5 timesthe service pressure.

1.4.3 Hydraulic tests of oil fuel bunkers, tanks and accessories

The oil fuel bunkers and tanks not forming part of the ship'sstructure are to be submitted to a hydraulic test under apressure corresponding to the maximum liquid level inthese spaces or in the air or overflow pipes, subject to aminimum of 2,40 m above the top. This minimum height isto be 3,60 m for tanks intended to contain oil fuel having aflash point below 60°C.

Non metallic or metallic flexible pipes and expansion jointsare to be tested in accordance with the requirements statedin [1.10.4] item e) and [1.11.7] item a), as appropriate.

Item No Document (1)

1 Drawing showing the arrangement of the sea chestsand ship side valves

2 Diagram of the bilge and ballast systems (in and out-side machinery spaces)

3 Specification of the central priming system intendedfor bilge pumps, when provided

4 Diagram of the scuppers and sanitary discharge sys-tems

5 Diagram of the air, sounding and overflow systems

6 Diagram of cooling systems (sea and fresh waters)

7 Diagram of fuel oil system

8 Drawings of the fuel oil tanks not forming part of theship's structure

9 Diagram of the lubricating oil system

10 Diagram of the thermal oil system

11 Diagram of the hydraulic systems intended for essen-tial services or located in machinery spaces

12 Diagram of the compressed air system

13 Diagram of the hydraulic and pneumatic remotecontrol systems

14 Diagram of the exhaust gas system

15 Diagram of drip trays and gutterway draining system

16 Arrangement of the ventilation system

(1) To be submitted for approval, in four copies.Diagrams are also to include, where applicable, the(local and remote) control and monitoring systems andautomation systems.


Pt D, Ch 20, Sec 4

Table 2 : Information to be submitted

1.5 General requirements applicable to all piping systems in ship L ≥ 24 m

1.5.1 See relevant requirements of Pt C, Ch 1, Sec 10, [1]and Pt C, Ch 1, Sec 10, [5].

1.6 General requirements applicable to all piping systems in ship L < 24 m

1.6.1 Materials

The manufacturer's test certificate for materials for valvesand fittings can be accepted in lieu of the Society's materi-als certificate where the maximum conditions are notbeyond those shown in Tab 3.

Table 3 : Maximum conditions for acceptance ofmanufacturer's test certificate

1.6.2 Fixing and arrangement of the pipes

a) Except where otherwise permitted, piping and pumpingsystems covered by this Chapter are to be permanentlyfixed onboard ship.

b) Unless otherwise specified, the fluid lines referred to inthis Chapter are to consist of pipes connected to theship's structure by means of collars or similar devices.

c) As far as possible, pipes are not to pass near switch-boards or other electrical apparatuses. If this require-ment is impossible to satisfy, gutterways or masks are tobe provided wherever deemed necessary to prevent pro-jections of liquid on live parts.

d) These provisions also apply to the exhaust pipes of inter-nal combustion engines.

1.6.3 Protection of pipes

Pipes are to be efficiently protected against corrosion partic-ularly in their most exposed parts, either by selection oftheir constituent materials, or by an appropriate coating ortreatment.

1.6.4 Accessories

Locks, valves and other accessories are generally to be soplaced that they are easily visible and accessible formanoeuvring, control and maintenance.

1.7 Sea inlets and overboard discharges in ships L ≥ 24 m

1.7.1 See Pt C, Ch 1, Sec 10, [2.8].

1.8 Sea inlets and ship side valves in ships L < 24 m

1.8.1 Valves

All sea inlet and outlet pipes are to be provided with valvesfixed:

• directly on the plating, or

• on steel chests built on the plating, or

• on strong distance pieces as short as possible whichmay be welded to the plating.

1.8.2 Strainers

Sea inlets are to be fitted with strainers. The flow sectionthrough each strainer is not to be less than twice the totalsection of the suction pipes connected to the said inlet.

1.8.3 Materials

The valves on sea inlets and overboard discharges are to beof steel or appropriate non-brittle material.

Similar provisions apply to distance pieces connecting thevalves to the shell plating.

1.8.4 Protection against corrosion

Efficient arrangements such as the fitting of zinc anodes areto be made in order to protect the steel parts of sea inletsand discharges against corrosion.

1.9 Non-metallic rigid pipes in ships L ≥ 24m

1.9.1 See Pt C, Ch 1, App 3.

Item No

I/A (1)

Document

1 I Nature, service temperature and pressure ofthe fluids

2 A Material, external diameter and wall thicknessof the pipes

3 A Type of the connections between pipe lengths,including details of the weldings, where pro-vided

4 A Material, type and size of the accessories

5 A For plastic pipes:• the chemical composition• the physical and mechanical characteris-

tics in function of temperature• the characteristics of inflammability and

fire resistance• the resistance to the products intended to

be conveyed

(1) A = to be submitted for approval, in four copiesI = to be submitted for information, in duplicate.

Material Maximum conditions

Spheroidal ornodular cast iron

DN < 50 and PxDN < 2500

Carbon and low alloy steel

−10°C < t < 300°C and DN < 50, or−10°C < t < 300°C and PxDN < 2500

Cupreous alloy (1) t < 200°C and DN < 50, ort < 200°C and PxDN < 1500

(1) See Pt C, Ch 1, Sec 10, [2.1].Note 1: DN = nominal diameter, P = working pressure,t = working temperature.


Pt D, Ch 20, Sec 4

1.10 Non-metallic rigid pipes in ships L < 24m

1.10.1 General

a) The Society may permit the use of rigid pipes made ofplastics in lieu of metallic pipes in the conditions speci-fied in [1.10.2], [1.10.3] and [1.10.4].

b) These requirements apply to thermoplastic materialsbut, where appropriate, may also be applied to pipesmanufactured in fibre reinforced thermosetting resins.

c) For every application, characteristics of the proposedplastics are to be given to the Society, namely:

• the chemical composition

• the physical and mechanical characteristics in func-tion of the temperature

• the fire properties

• eventually, the resistance to the various productslikely to come into contact with those plastics.

1.10.2 Use of plastic pipes

a) Pipes made of plastics are permitted, as a general rule,for:

• scupper and sanitary discharge pipes

• ballast pipes except for the parts passing throughengine rooms, dangerous spaces and oil fuel bun-kers or located between pumps and their suctionsand discharges

• individual bilge pipes for small compartments suchas chain lockers.

b) For other pipes such as air and sounding pipes of com-partments not intended to contain oil fuel, the Societymay accept the use of plastics subject to an examinationof the relevant drawings.

c) Pipes made of plastics may be used for fluid systems notcovered by the classification provided the requirementsgiven in [1.10.3] are complied with.

d) Pipes made of plastics are not to be used where they aresubject to temperatures above 60°C or below 0°C.

The use at a higher temperature for particular applica-tions is subject to special examination.

e) Any proposed service for plastic pipes not mentionedabove is to be submitted to the Society for special con-sideration.

1.10.3 Intactness of watertight subdivision and fire divisions

a) As a rule, pipes made of plastics cannot pass throughwatertight bulkheads.

b) If, however, such a passage cannot be avoided, arrange-ments are to be made in order to ensure the integrity ofthe subdivision in case of pipe breakage. Such arrange-ments are to be submitted to the Society.

c) The use of pipes made of plastics is generally to beavoided wherever the destruction of these pipes in caseof fire would compromise the intactness of subdivisionor the safety of the ship.

d) Where pipes made of plastics are to pass through firedivisions, the arrangements taken to ensure the fireintegrity of these divisions are to be submitted to theSociety.

1.10.4 Design and construction

a) Pipes and fittings are to be of a robust construction andare to comply with the requirements of such nationalstandards as may be consistent with their intended use.

Particulars of scantlings and joints are to be submittedfor examination.

b) All pipes are to be adequately but freely supported. Suit-able provision for expansion and contraction is to bemade in each range of pipes to allow for importantclearance between pipes made of plastics and steelstructures, in consideration of the difference betweentheir individual coefficients of thermal expansion.

c) All fittings and branches are to be suitable for theintended service and are to have joints of cemented,flanged or other approved types.

d) The bursting pressure of pipes, fittings and joints madeof plastics, at their service temperature, is not to be lessthan 4 times their maximum service pressure, with aminimum of 5 bar.

e) After completion, pipes and fittings are to be subjectedto a hydraulic pressure test, to be applied during at least5 minutes under a pressure not less than 1,5 times theservice pressure.

1.11 Flexible hoses and expansion joints

1.11.1 General

a) The Society may permit the use of flexible hoses andexpansion joints, both in metallic and non-metallicmaterials, provided they are approved for the intendedservice.

b) Flexible hoses and expansion joints are to be of a typeapproved by the Society, designed in accordance with[1.11.3] and tested in accordance with [1.11.6].

c) Flexible hoses and expansion joints are to be installed inaccordance with the requirements stated in [1.11.5].

d) Flexible hoses and expansion joints intended for pipingsystems with a design temperature below the ambienttemperature will be given special consideration by theSociety.

1.11.2 Documentation

The information, drawings and documentation listed in[1.2.1], Tab 1 and Tab 2 are to be submitted to the Societyfor each type of flexible hose or expansion joint intended tobe used.

1.11.3 Design of flexible hoses and expansion joints

a) Flexible pipes and expansion joints are to be made ofmaterials resistant to the marine environment and to thefluid they are to convey. Metallic materials are to com-ply with Pt C, Ch 1, Sec 10, [2.1.2].


Pt D, Ch 20, Sec 4

b) Flexible pipes and expansion joints are to be designedso as to withstand:

• external contact with hydrocarbons

• internal pressure

• vibrations

• pressure impulses.

c) Flexible pipes intended to convey fuel oil or lubricatingoil and end attachments are to be of fire-resisting mate-rials of adequate strength and are to be constructed tothe satisfaction of the Society.

d) Where a protective lining is provided for this purpose, itis to be impervious to hydrocarbons and to hydrocarbonvapours.

e) Flexible pipes intended to convey:

• gaseous fluid at a pressure higher than 1 MPa

• fuel oil or lubricating oil,

are to be fitted with a metallic braid.

f) As a general rule, flexible hoses are to be fitted with crimpedconnections or equivalent. For water pipes subject to a pres-sure not exceeding 0,5 MPa, as well as for scavenge air andsupercharge air lines of internal combustion engines, clipsmade of galvanised steel or corrosion-resistant material withthickness not less than 0,4 mm may be used.

g) Flexible pipes and expansion joints are to be sodesigned that their bursting pressure at the service tem-perature is not less than 4 times their maximum servicepressure, with a minimum of 2 MPa. Exemptions fromthis requirement may be granted for expansion joints oflarge diameter used on sea water lines.

h) The junctions of flexible hoses and expansion joints totheir couplings are to withstand a pressure at least equalto the bursting pressure defined in item f).

1.11.4 Conditions of use of flexible hoses and expansion joints

a) The use of flexible hoses and expansion joints is to belimited as far as practicable.

b) The position of flexible hoses and expansion joints is tobe clearly shown on the piping drawings submitted tothe Society.

c) The use of non-metallic expansion joints on pipes con-nected to sea inlets and overboard discharges is to be givenspecial consideration by the Society. As a rule, the fitting ofsuch joints between the ship side and the valves mentionedin Pt C, Ch 1, Sec 10, [2.8.3] or [1.8.1], as applicable, isnot permitted. Furthermore, unless the above-mentionedvalves are fitted with remote controls operable from placeslocated above the freeboard deck, efficient means are to beprovided, wherever necessary, to limit the flooding of theship in the event of rupture of the expansion joints.

d) Expansion joints may be fitted in sea water lines, pro-vided they are arranged with guards which effectivelyenclose, but do not interfere with, the action of theexpansion joints and reduce to the minimum practica-ble any flow of water into the machinery spaces in theevent of failure of the flexible elements.

e) Use of expansion joints in water lines for other services,including ballast lines in machinery spaces, in ductkeels and inside double bottom water ballast tanks, andbilge lines inside double bottom tanks and deep tanks,is to be given special consideration by the Society.

1.11.5 Arrangement of flexible hoses and expansion joints

a) Flexible hoses and expansion joints are to be soarranged as to be accessible at all times.

b) Flexible hoses and expansion joints are to be as short aspossible.

c) The radius of curvature of flexible hoses is not to be lessthan the minimum recommended by the manufacturer.

d) The adjoining pipes are to be suitably aligned, sup-ported, guided and anchored.

e) Isolating valves are to be provided permitting the isola-tion of flexible hoses intended to convey flammable oilor compressed air.

f) Expansion joints are to be protected against over exten-sion or over compression.

g) Where they are likely to suffer external damage, flexiblehoses and expansion joints of the bellows type are to beprovided with adequate protection.

Table 4 : Type tests to be performed forflexible hoses and expansion joints

1.11.6 Type tests of flexible hoses and expansion joints

a) Type approval tests are to be carried out on a flexiblehose or an expansion joint of each type and each size,in accordance with Tab 4.

b) The flexible pipes or expansion joints subjected to thetests are to be fitted with their connections.

c) The fire-resistance test is to be carried out in the condi-tions hereafter; other test methods may be applied afterspecial examination.

Type test Required

Bursting Yes

Fire-resistance Yes (1)

Vibration Yes (2)

Pressure impulse Yes

Flexibility Yes (3)

Cyclic expansion Yes (4)

Resistance Yes (5)

(1) Only for flexible hoses and expansion joints used inflammable oil and sea water systems.

(2) Only for flexible hoses and expansion joints fitted toengines, pumps, compressors or other sources of highvibrations.

(3) Only for flexible hoses conveying low temperature fluids.(4) Only for piping systems subjected to expansion cycles.(5) Internal to the conveyed fluid and external to UV.


Pt D, Ch 20, Sec 4

The flexible pipe is to be subjected to fire for 30 minutesat a temperature of 800°C, while water at the maximumservice pressure is circulated inside the pipe; the tem-perature of the water at the outlets is not to be less than80°C. No leak is to be recorded during and after the test.

d) Flexible pipes or expansion joints granted with a typeapproval certificate issued by the Society for theintended conditions of use are exempted from type-tests.

1.11.7 Hydraulic tests

a) Each flexible pipe or expansion joint, together with itsconnections, is to undergo a hydraulic test under a pres-sure at least equal to twice the maximum service pres-sure, subject to a minimum of 10 bar.

b) During the test, the pipe or expansion joint is to berepeatedly deformed from its geometrical axis.

1.11.8 Marking

Each flexible pipe or expansion joint is to be stencilled orotherwise marked with its specified maximum service pres-sure and, when used in other than ambient temperature, itsmaximum or minimum service temperature or both.

1.11.9 Periodical replacement - Spare parts

a) Flexible pipes or expansion joints are to be periodicallyreplaced according to the periodicity depending ontheir types.

b) A spare is recommended for each type of flexible pipeor expansion joint the failure of which could impair theoperation of main engines, that of auxiliary engines foressential services or the safety of the ship.

1.12 Metallic flexible pipes and joints

1.12.1 Metallic flexible pipes and joints are to comply withthe requirements stated in [1.11], as far as applicable.

Fire-resistance tests need not be carried out.

2 Bilge system in ships L ≥ 24 m

2.1 General

2.1.1 Application

The following provisions supersede those given in Pt C, Ch1, Sec 10, [6].

2.1.2 Principle

a) Fishing vessels are to be provided with an efficient bilgepumping system capable of pumping from and draining,under all practical conditions, any watertight compart-ment other than spaces exclusively intended for the car-riage of fresh water, water ballast or fuel oil, for whichother efficient means of pumping are to be provided.

b) In fishing vessels where fishing handling or processingmay cause quantities of water to accumulate inenclosed spaces, adequate drainage is to be provided.

c) The bilge pumping system is to consist of pumps con-nected to a bilge main line so arranged as to allow thedraining of all spaces mentioned in item a).

d) Bilge pumping arrangement may be dispensed with inparticular compartments where no equipment nor open-ings are likely to leak.

e) Where expressly permitted, some small compartmentsmay be drained by means of hand pumps.

f) Bilge and ballast systems are to be so designed as to pre-vent the possibility of water passing from the sea andfrom water ballast spaces into the cargo and machineryspaces, or from one compartment to another. Provisionsare to be made to prevent any space having bilge andballast connections being inadvertently flooded fromthe sea when containing cargo, or being dischargedthrough the bilge system when containing water ballast.

g) Where there are common valves between bilge and firefighting lines, they are to have a locked device on hishandwheels in order to avoid the discharge of bilgewater into the fighting circuit.

2.2 Design of the bilge system

2.2.1 General

a) All suction pipes up to the connection with the bilgepumps are to be independent from any other piping sys-tem of the ship.

b) Non-return valves are to be fitted on:

• direct and emergency suctions in machinery spaces

• the pipe connections to bilge distribution boxes

• the suctions of pumps having also connections fromthe sea or from compartments normally intended tocontain liquid

• the direct suctions connected to independent bilgepumps, where required.

c) All compartments are to be provided with at least onesuction on each side. However, in the case of short andnarrow compartments, a single suction ensuring an effi-cient draining may be accepted.

2.2.2 Draining of machinery spaces

a) Machinery spaces of ships with double bottom, orwhere the rise of floor is less than 5°, are to be providedon each side with one bilge suction connected to thebilge main.

b) Machinery spaces of ships without double bottom, orwhere the rise of floor exceeds 5°, may be providedwith only one bilge suction located in the centrelineand connected to the bilge main.

c) In addition to the bilge suctions required in items a) andb), machinery spaces are to be provided with a directsuction, which is to be led direct to an independentpower bilge pump and so arranged that it can be usedindependently of the bilge main.


Pt D, Ch 20, Sec 4

2.2.3 Emergency bilge suction

a) The emergency bilge suction is to be led directly fromthe drainage level of the machinery space to the greatercapacity sea water pump. Its capacity is to be at leastequal to the required capacity of each bilge pump asdetermined in [2.3.4].

b) The emergency bilge suction is to be located at the low-est possible level in the machinery spaces.

c) The diameter of emergency bilge suction pipes is to beat least the diameter of the suction connected to of thesea water pump in normal operation.

d) The high of the hand-wheels of the non-return valvescontrolling emergency bilge suctions are to rise at least450 mm above the manoeuvring floor.

e) If the requirement mentioned in d) can not be verified,the height of the hand-wheels of the non-return valves isto be the minimum height to permit the easy operationof the valve.

2.2.4 Draining of holds

a) Holds of ships with double bottom, or where the rise offloor is less than 5°, are to be provided on each sidewith one bilge suction connected to the bilge main.

b) Holds of ships without double bottom, or where the riseof floor exceeds 5°, may be provided with only onebilge suction located in the centreline and connected tothe bilge main.

c) Holds greater than 30 m in length, bilge suctions are tobe provided in the fore and aft ends and connected tothe bilge main.

2.2.5 Draining of refrigerated spacesRefrigerated spaces are to be provided with drainagearrangement allowing the continuous drainage of conden-sates.

2.2.6 Draining of fore and aft peaks

a) Fore and aft peaks, where not used as tanks, are to befitted with a bilge suction connected to the bilge main.Passage through the collision bulkhead is to complywith [2.5.2].

b) Peaks of small dimensions may be drained by means ofa hand pump provided that the suction lift is well withinthe capacity of the pump and in no case exceeds7,30 m.

2.2.7 Draining of double bottom compartmentsDouble bottom compartments, where not used as tanks, areto be provided with bilge suctions. Their number and loca-tion are to comply with the provisions of [2.2.4]. However,if deemed acceptable by the Society, the cofferdams fittedbetween two different compartments of the double bottommay be provided with one bilge suction only.

2.2.8 Draining of other compartments

a) Provision is to be made for the drainage of chain lockersand other fore spaces by means of hand or power pumpsuctions or hydraulic ejectors.

b) Provision is to be made for the drainage of the steeringgear compartment and other spaces located above theaft peak by means of suctions connected to the bilgemain or by means of hand pumps or hydraulic ejectors.

c) These spaces may, however, be drained by means ofscuppers discharging to the shaft tunnel, provided thatthe discharge pipes are fitted with self-closing valves sit-uated in easily visible and accessible positions.

d) Fish processing spaces are to be fitted with drainagemeans, the capacity of which is four times the normalfeedwater flow in the space.

2.3 Bilge pumps

2.3.1 Number and arrangement of pumps

a) Fishing vessels are to be provided with at least twopower bilge pumps of the self-priming type connectedto the bilge main and having the capacity required in[2.3.4]. One of these pumps may be driven by the pro-pulsion machinery.

b) Each bilge pump may be replaced by two or morepumps, provided that they are connected to the bilgemain and that their total capacity is not less than thatrequired in [2.3.4].

c) One of the bilge pumps required in item a) may bereplaced by a hydraulic ejector having the capacityrequired in [2.3.4] and connected to a high pressurewater pump.

d) Where permitted, hand pumps are to be operable froman easily accessible position above the load waterline.

2.3.2 Location of bilge pumpsBilge pumps are to be located on the aft side of the collisionbulkhead. This may not apply to those pumps only used forthe draining of the spaces located on the fore side of thecollision bulkhead.

2.3.3 Use of pumps intended for other duties

a) Pumps used for sanitary service, general service or bal-last may be considered as independent bilge pumpsprovided that:

• they have the capacity required in [2.3.4]

• they are of the self-priming type

• they are connected to the bilge system.

b) Non-return valves are to be provided in accordancewith [2.2.1], item b).

2.3.4 Bilge pump capacity

a) The water speed V in the bilge main and the capacity Qof each bilge pump are to be not less than the valuesgiven in Tab 5.

b) If the capacity of one of the pumps is less than the rulecapacity, the deficiency may be compensated by anexcess capacity of the other pumps. Such deficiency is,however, not to exceed 30% of the rule capacity.


Pt D, Ch 20, Sec 4

Table 5 : Water speed and pump capacity

2.4 Size of bilge pipes

2.4.1 Bilge main line

a) The diameter of the bilge main is to be calculatedaccording to the following formula:

without being less than 50 mm,

where:

d : Internal diameter of the bilge main, in mm

L : Length of the ship between perpendiculars,in m

B : Breadth of the ship, in m

D : Depth of the ship, measured up to the bulk-head deck, in m.

b) The actual internal diameter may be rounded off. Thenearest standard size is in no case to be more than5 mm smaller than that obtained from the formula givenin item a).

2.4.2 Branch bilge suction pipes

a) The diameter of the pipes situated between the distribu-tion boxes and the suctions in the various spaces (holds,machinery space, etc) is to be calculated according tothe following formulae:


where:

d1 : Internal diameter of the suction pipe, in mm

L1 : Length of the space considered, in m

L, B, D : Length, breadth and depth of the ship asdefined in [2.4.1].

b) The actual internal diameter may be rounded off. Thenearest standard size is in no case to be more than5 mm smaller than that obtained from the formula givenin item a).

2.5 Bilge piping arrangement

2.5.1 Passage through double bottom compartments and tanks

Bilge pipes are not to pass through double bottom compart-ments or tanks unless they are enclosed in appropriate pipetunnels. Where this is not practicable, pipes are to be of

reinforced thickness as per Pt C, Ch 1, Sec 10, Tab 6 andmade of either one piece or several pieces assembled bywelding or by reinforced flanges.

2.5.2 Passage through the collision bulkhead

a) A maximum of two pipes may pass through the collisionbulkhead below the freeboard deck, unless otherwisejustified. Such pipes are to be fitted with suitable valvesoperable from above the freeboard deck and the valvechest is to be secured at the bulkhead inside the forepeak. Such valves may be fitted on the after side of thecollision bulkhead provided that they are readily acces-sible under all service conditions and the space inwhich they are located is not a cargo space. All valvesare to be of steel, bronze or other approved ductilematerial. Valves of ordinary cast iron or similar materialare not acceptable.

b) The remote operation device of the valve referred to ina) is to include an indicator to show whether the valve isopen or shut.

2.5.3 Bilge suctions in machinery spaces and shaft tunnels

In machinery spaces and shaft tunnels, the terminationpipes of the bilge suctions are to be straight and vertical andare to be led to mud boxes so arranged as to be easilyinspected and cleaned. The lower end of the terminationpipe is not to be fitted with a strum box.

2.5.4 Bilge suctions in other compartments

In compartments other than machinery spaces and shafttunnels, the open ends of bilge suction pipes are to be fittedwith strum boxes or strainers having holes not more than10 mm in diameter. The total area of such holes is not to beless than twice the required cross-section of the suctionpipe.

2.5.5 Bilge alarms

Propulsion machinery spaces are to be fitted with a bilgelevel sensor capable of indicating water ingress in thosespaces at the bridge by means of a visual and audiblealarm.

2.6 Materials

2.6.1 All bilge pipes used in fuel storage tanks or in boileror machinery spaces, including spaces in which oil-settingtanks or fuel oil pumping units are situated, are to be ofsteel or other suitable material non-sensitive to heat.

3 Bilge system in ships L < 24 m

3.1 General

3.1.1 Principle

All ships are to be provided with efficient means for pump-ing and draining any watertight space with at least one suc-tion pipe when the ship is on an even keel and either isupright or has a list of up to 5°.

Ship’s length L < 35 L ≥ 35

Water speed V = 1,22 V = 2,00

Pump capacity Q = 0,00345 d2 Q = 0,00565 d2

L : Length of the ship, in mV : Minimum water speed in the bilge main, in m/sQ : Minimum capacity of each pump, in m3/hd : Internal diameter of the bilge main, in mm, as

defined in [2.4.1].

d 25 1 68 L B D+( ),+=

d1 25 2 16 L1 B D+( ),+=


Pt D, Ch 20, Sec 4

3.1.2 Independence of the linesAs a general rule, bilge lines are to be distinct from theother lines of the ship.

However, this requirement need not be applied to pipeslocated between collecting boxes and pump suctions orbetween pumps and overboard discharges.

3.1.3 Intactness of watertight subdivisionThe lines and accessories are to be so arranged as to pre-vent intercommunication of compartments which are toremain segregated from each other or the accidental con-nection of these compartments directly to the sea.

3.1.4 Bilge mainA bilge main is to be provided for draining the differentcompartments for ships the length of which is greater than,or equal to, 12 m.

3.1.5 Number and distribution of suctionsAt least two bilge suctions are to be provided for drainingthe propulsion engine room. At least one of these suctions isto be connected directly to a bilge pump.

The suctions are to be located at the lowest points of thecompartment.

Additional suctions may be required if the flow of watertowards the suctions is disturbed by irregularities of the bot-tom.

At least one bilge suction is to be provided in each compart-ment located between two watertight bulkheads.

3.2 Pumps and ejectors

3.2.1 Pumps

a) At least two power bilge pumps are to be provided; oneof these pumps may be driven by a main propulsiveengine.

b) The Society may permit, after special consideration, thatone of the pumps be replaced by an ejector.

c) For ships the length of which is greater than, or equal to,12 m, the bilge pumps are to be connected to the bilgemain mentioned in [3.1.4].

d) For ships having the navigation notation coastal area,the Society may permit, after special consideration, thatone of bilge pumps be a fixed hand pump.

e) Small compartments may be drained by means of porta-ble or fixed hand pumps.

3.2.2 EjectorsWhere an ejector is used in lieu of a driven pump, its suc-tion capacity is not to be less than the required capacity ofthe pump it replaces.

3.2.3 Capacity of the pumpsThe capacity of the bilge pumps is to be such that a speed ofwater not less than 1,22 m/s may be obtained in the bilgemain, the diameter of which is given in [3.3.1]. The capac-ity of each pump is therefore not to be less than:

Q = 0,00345 d12

where:

Q : Minimum capacity of each pump, in m3/h

d1 : Internal diameter, in mm, of the bilge main asdefined in [3.3.1].

3.3 Size of bilge pipes

3.3.1 Bilge mainThe internal diameter, in mm, of the bilge main, is to be ofthe commercial size nearest to the diameter given in the fol-lowing formula:


where:

L, B : Rule length and breadth, respectively, of theship, in m, defined in Pt B, Ch 1, Sec 2

C : Moulded depth of the ship, in m, at the free-board deck.

3.3.2 Suctions in holds and machinery spacesThe internal diameter, in mm, of bilge pipes situatedbetween collecting boxes and suctions in holds andmachinery spaces, is to be of the commercial size nearest tothe diameter given by the following formula:


where:

B, C : Dimensions having the same meaning as in[3.3.1]

L1 : Length of the compartment, in m.

3.4 Arrangement of bilge lines and their accessories

3.4.1 Passage of pipes through certain compartments

If not contained in pipe tunnels, the part of bilge pipes pass-ing through compartments intended to contain oil fuel areto have reinforced thickness and are to consist of a singlepiece. These pipes are to be provided with non-returnvalves at their ends in the holds.

3.4.2 Passage through watertight bulkheads No bilge cock or similar device is to be fitted on the colli-sion bulkhead.

The fitting of bilge cocks or similar devices on other water-tight bulkheads is to be avoided as far as possible. However,where such accessories are provided, they are to be accessi-ble at any time and capable of being closed from positionsabove the deck. An indication is to be provided to showwhether these valves are open or close.

3.4.3 Non-return valvesAccessories are to be provided to prevent intercommunica-tion of compartments or lines which are to remain segre-gated from each other. For this purpose, non-return valvesor similar devices are to be fitted, namely on the pipe con-nections to bilge distribution boxes or to the alternativecocks, if any.

d1 25 1 68 L B C+( ),+=

d2 25 2 16 L1 B C+( ),+=


Pt D, Ch 20, Sec 4

3.4.4 Strainers and mud boxes Strainers and mud boxes are to be fitted on bilge lines wher-ever they are necessary.

4 Scuppers and sanitary discharges

4.1 Principle

4.1.1 Scuppers, sufficient in number and suitable in size,are to be provided to permit the drainage of water likely toaccumulate in the spaces which are not located in the ship’sbottom.

4.1.2 The number of scuppers and sanitary discharge open-ings in the shell plating is to be reduced to a minimum,either by making each discharge serve as many as possibleof the sanitary and other pipes, or in any other satisfactorymanner.

4.2 General

4.2.1 Discharges led through the shell either from spacesbelow the working deck or from within enclosed super-structures or deckhouses on the working deck fitted withweathertight doors are to be fitted with accessible means forpreventing water from passing inboard.

4.2.2 Each separate discharge is to have an automatic non-return valve with a positive means of closing it from anaccessible position, except when:

• satisfactory analysis is submitted to the Society, demon-strating that the entry of water into the vessel throughthe opening is not likely to lead to dangerous flooding,and

• the piping is of reinforced thickness as per Pt C, Ch 1,Sec 10, Tab 6.

4.2.3 The means for operating the positive action valve is tobe provided with an indicator showing whether the valve isopen or closed.

4.3 Discharges through manned machinery spaces

4.3.1 In manned machinery spaces, main and auxiliary dis-charges essential for the operation of machinery may becontrolled locally. The controls are to be accessible and areto be provided with indicators showing whether the valvesare open or closed.

4.4 Materials

4.4.1 Fittings attached to the shell and the valves requiredin [4.2.2] are to be of steel, bronze or other ductile material.

4.4.2 All pipes between the shell and the valves are to be ofsteel. However, in spaces other than machinery spaces ofvessels constructed of material other than steel, the use ofother materials may be permitted, subject to special consid-eration by the Society.

5 Air pipes and sounding devices in ships L ≥ 24 m

5.1 Air pipes

5.1.1 GeneralAir pipes are to be fitted to all spaces which are not fittedwith alternative ventilation arrangements.

Air pipes are to be so arranged and the upper part of com-partments so designed that air or gas likely to accumulate inthe said compartments can freely evacuate.

When only one air pipe is provided, it is not to be used asfilling pipe.

5.1.2 Exposed parts of air pipesWhere air pipes to tanks and void spaces below deckextend above the working or the superstructure decks, theexposed parts of the pipes are to be of strength equivalent tothe adjacent structures and fitted with the appropriate pro-tection.

5.1.3 Means of closingOpenings of air pipes are to be provided with means ofclosing, permanently attached to the pipe or adjacent struc-ture.

5.1.4 Height of air pipesThe height of air pipes above deck to the point where watermay have access below is to be at least:• 760 mm on the working deck, and• 450 mm on the superstructure deck.

The Society may accept reduction of the height of an airpipe to avoid interference with the fishing operations.

5.1.5 Special arrangements for air pipes of flammable oil tanks

a) Air pipes from fuel oil and thermal oil tanks are to dis-charge to a safe position on the open deck where nodanger will be incurred from issuing oil or gases.Where fitted, wire gauze diaphragms are to be of corro-sion resistant material and readily removable for clean-ing and replacement. The clear area of such diaphragmsis not to be less than the cross-sectional area of the pipe.

b) Air pipes of lubricating or hydraulic oil storage tanks notsubject to flooding in the event of hull damage may beled to machinery spaces, provided that in the case ofoverflowing the oil cannot come into contact with elec-trical equipment, hot surfaces or other sources of igni-tion.

c) The location and arrangement of vent pipes for fuel oilservice, settling and lubrication oil tanks are to be suchthat, in the event of a broken vent pipe, there is no riskof ingress of seawater or rainwater.

d) Where seawater or rainwater may enter fuel oil service,settling and lubrication oil tanks through broken airpipes, arrangements such as water traps with:• automatic draining, or• alarm for water accumulation,are to be provided.


Pt D, Ch 20, Sec 4

5.1.6 Construction of air pipes

a) Where air pipes to ballast and other tanks extend abovethe freeboard deck or superstructure deck, the exposedparts of the pipes are to be of substantial construction,with a minimum wall thickness of at least:

• 6,0 mm for pipes of 80 mm or smaller externaldiameter,

• 8,5 mm for pipes of 165 mm or greater externaldiameter.

Intermediate minimum thicknesses may be determinedby linear interpolation.

b) Air pipes with height exceeding 900 mm are to be addi-tionally supported.

c) In each compartment likely to be pumped up, andwhere no overflow pipe is provided, the total cross-sec-tional area of air pipes is not to be less than 1,25 timesthe cross-sectional area of the corresponding fillingpipes.

d) The internal diameter of air pipes is not to be less than50 mm, except for tanks of less than 2 m3.

5.2 Sounding and level gauging devices

5.2.1 GeneralSounding devices are to be fitted:

• to the bilges of those compartments which are not read-ily accessible at all times during voyages, and

• to all tanks and cofferdams.

5.2.2 Termination of sounding pipesWhere sounding pipes are fitted, their upper ends are toextend to a readily accessible position and, where practica-ble, above the working deck.

5.2.3 Means of closingThe openings of the sounding pipes are to be provided withpermanently attached means of closing. Sounding pipeswhich are not extended above the working deck are to befitted with automatic self-closing devices.

5.2.4 Special arrangements for sounding pipes of flammable oil tanks

Where tanks containing fuel oil or hydraulic oil are fittedwith sounding pipes, their upper ends are to terminate insafe positions and are to be fitted with suitable means ofclosure.

Gauges made of heat-resistant glass of substantial thicknessand protected with a metal case may be used, provided thatautomatic closing valves are fitted. The level gauge is to beof an approved type. Other means of ascertaining theamount of oil contained in the tank may be permitted pro-vided their failure or overfilling will not permit release offuel.

5.2.5 Construction of sounding pipes

a) Sounding pipes are normally to be straight. If it is neces-sary to provide bends in such pipes, the curvature is tobe as small as possible to permit the ready passage ofthe sounding apparatus.

b) Bent portions of sounding pipes are to have reinforcedthickness and be suitably supported.

c) The internal diameter of sounding pipes is not to be lessthan 32 mm. Where sounding pipes pass through refrig-erated spaces, or through the insulation of refrigeratedspaces in which the temperature may be below 0°C,their internal diameter is to be at least 60 mm.

d) Doubling plates are to be placed under the lower endsof sounding pipes in order to prevent damage to thehull. When sounding pipes with closed lower ends areused, the closing plate is to have reinforced scantlings.

6 Air pipes and sounding devices in ships L < 24 m

6.1 Air pipes

6.1.1 General

Air pipes are to be fitted to all compartments intended tocontain liquid or which are not fitted with alternative venti-lation arrangements.

These air pipes are to be so arranged as to be self-drainingwhen the ship is on an even keel.

6.1.2 Number and position of air pipes

Air pipes are to be so arranged and the upper part of com-partments so designed that air or gas likely to accumulate inthe said compartments can freely evacuate.

When only one air pipe is provided, it is not to be used asfilling pipe.

6.1.3 Tank air pipes

Air pipes of compartments likely to contain liquid hydrocar-bons, cofferdams or any capacity likely to be pumped upare to be led out, at a sufficient height above the deck.

Air pipes of all compartments which can be run up from thesea are to be led to above the deck.

Moreover, air pipes of compartments containing liquidhydrocarbons are not to be led to a place where dangercould be the consequence of the evacuation of hydrocar-bons or hydrocarbon vapours through these openings.

Air pipes of lubricating oil tanks and bunkers may be led tothe machinery spaces, provided that in case of overflow theoil cannot come into contact with electrical apparatus orwith surfaces likely to be at a high temperature.

6.1.4 Open ends of air pipes

Efficient, permanently attached devices are to be providedpermitting, should the necessity arise, to close the upperopenings of air pipes in order to prevent any accidentalentry of water into the spaces concerned.

Where the tank venting system is not of an automatic typeapproved by the Society, provision is to be made for reliev-ing vacuum when the tanks are being pumped out, and forthis purpose a hole of about 10 mm in diameter in the bendof the air pipe, or at a suitable position in the closingdevice, is acceptable.


Pt D, Ch 20, Sec 4

6.1.5 ConstructionIn each compartment likely to be pumped up, and whereno overflow pipe is provided, the total cross-sectional areaof air pipes is not to be less than the cross-sectional area ofthe corresponding filling pipes.

6.2 Sounding and level gauging devices

6.2.1 GeneralArrangements are to be made for sounding the tanksintended to contain liquid as well as all the compartmentswhich are not readily accessible at all times.

6.2.2 Upper ends of sounding pipesAs a general rule, the sounding pipes are to end above thedeck in easily accessible places and are to be fitted withefficient closing appliances.

However, in machinery spaces, when this requirement can-not be met, short sounding pipes may be used which are tolead to readily accessible positions above the floor and fit-ted with efficient closing appliances. When such soundingpipes are used for oil fuel or lubricating oil tanks, they arenot to end close to electric motors or switchboards and areto be fitted with automatic closing devices.

6.2.3 Constructiona) Internal diameter of sounding pipes is not to be less than

30 mm.

b) Doubling plates are to be placed under the lower endsof sounding pipes in order to prevent damage to thehull.

6.2.4 Level-indicator systemsa) Level-indicator systems are to be of robust construction

and suitably protected.

b) When used on fuel tanks or bunkers, level-indicator sys-tems are to meet the requirements stated in [12.1.4].

7 Ventilation in ships ≥ 24 m

7.1

7.1.1 See Pt C, Ch 1, Sec 1, [3.1.1] and Pt C, Ch 1, Sec 1,[3.6.1].See also Pt C, Ch 4, Sec 2, [2.1] and Pt C, Ch 4, Sec 6, [4].

8 Ventilation in ships < 24 m

8.1

8.1.1 Adequate ventilation is to be provided for spacescontaining engines, boilers or other heat generating appara-tuses, as well as for spaces where flammable vapours arelikely to accumulate.

8.2

8.2.1 Ventilators serving the machinery spaces are to becapable of being closed in case of fire, from outside the saidspaces. Skylights and other openings serving these spacesare to meet the following requirements:

• The skylights containing wire-reinforced glass panels areto be fitted with external shutters of steel or other equiv-alent material permanently attached

• Insulating materials in accommodation spaces, servicespaces, control stations and machinery spaces except inrefrigerated compartments are to be non-combustible.The surface of insulation fitted on the internal bounda-ries of machinery spaces is to be impervious to oil or oilvapours.

8.3

8.3.1 Ventilation of spaces containing propulsive plant andits auxiliaries is to be mechanical.

8.4

8.4.1 Mechanical ventilating fans are to be capable ofbeing stopped from outside the space supplied by theseventilating fans.

9 Engine cooling systems in ships L ≥ 24 m

9.1

9.1.1 See Pt C, Ch 1, Sec 10, [10].

10 Engine cooling systems in ships L < 24 m

10.1 Principle

10.1.1

a) Provision is to be made so that the cooling of mainengines and of lubricating oil or fresh water coolers forthese engines can be suitably ensured in all normaloperating conditions.

b) Generally, cooling water to propulsion engines and tolubricating oil or fresh water coolers is to be capable ofbeing supplied by two separate means.

c) Engine cooling systems in ships having several propul-sion engines are to be given special consideration by theSociety.

10.2 Motorships

10.2.1

a) The second means stated in [10.1.1] item b) for enginecooling may consist of a satisfactory connection to ageneral service pump of sufficient capacity.

b) Where the power per engine does not exceed 370 kWor when the ratio of the power per engine expressed inkW to the rotating speed in revolutions per minute doesnot exceed 0,75, the Society may permit that the secondmeans be a spare pump ready to be connected to thecooling system. Provision is to be made for the corre-sponding disassembling and reassembling operations tobe carried out on board in a time as short as possible.


Pt D, Ch 20, Sec 4

10.3 Fresh water cooling system

10.3.1 Where the engines are cooled by fresh water, thesecond means stated in [10.1.1] item b) may be omitted if aconnection is fitted from the fresh water system to a suitablesalt water system.

10.4 Cooling pumps

10.4.1 The pumps which may be connected to cooling sys-tems may be either independent or driven by the machinethey serve.

Relief valves are to be fitted on the discharge of coolingpumps driven by main engines, except for centrifugal typepumps.

10.5 Sea inlets

10.5.1

a) Not less than two sea inlets are to be provided for theengine cooling system. These sea inlets are to be distinctfor the two means of cooling given in [10.1.1] item b),but they may be cross connected by a cross pipe.

b) These sea inlets are to be low inlets and one of themmay be that of the ballast pump or of the general servicepump. A sea-inlet is considered as low provided itremains submerged under all normal navigating condi-tions.

10.6 Filters

10.6.1 Where propulsive engines are directly cooled by seawater, either in normal service or in emergency, filters are tobe fitted on the suction of cooling pumps.

10.7 Operating control

10.7.1 Means are to be provided for controlling the tem-perature and the water circulation of each engine.

10.8 Materials

10.8.1 The materials used for cooling systems are to besuch as to limit the effects of galvanic corrosion and ero-sion, considering the circulation speeds adopted.

11 Oil fuel systems in ships L ≥ 24m

11.1

11.1.1 See Pt C, Ch 1, Sec 10, [11].

12 Oil fuel systems in ships L < 24m

12.1 General

12.1.1 ScopeThe requirements stated in [12.1] and [12.2] are applicableto oil fuel systems for the service of propulsion engines and

auxiliary machines. The flash point of the oil fuel used,determined by means of closed cup test, is not to be lowerthan 60°C.

The use for propulsion engines and auxiliary machine of oilfuel having a flash point lower than 60°C is subject to a spe-cial examination by the Society.

12.1.2 Pump controls

The power supply to oil fuel transfer pumps and to otherpumps of the oil fuel system as well as to oil fuel separatorsis to be capable of being stopped from an always accessibleplace in the event of fire within the compartment where thisequipment is located.

12.1.3 Drip-trays and gutterways

Drip-trays or gutterways with appropriate discharge devicesare to be fitted:

• under pumps, valves and filters

• under oil fuel tanks and bunkers which are not part ofthe ship's structure, as well as

• under all the accessories subject to oil fuel leakage.

12.1.4 Level indicators

a) Gauge cocks for checking the level in the tanks are notto be used.

The glasses of any level indicator fitted on such tanksare to be made of heat-resistant material and are to beefficiently protected against shock. Such level indicatorsare to be fitted with self-closing cocks at their lower endas well as at their upper end if the latter is below themaximum liquid level.

b) Where the fuel transfer system does not include powerpumps but only hand pumps, the valves to be providedat the lower end of level-indicators for fuel tanks, withthe exception of daily service tanks, need not to be ofthe self-closing type. These valves are however to bereadily accessible and instruction plates are to be fittednear these valves specifying that they are to be main-tained closed except during transfer operations.

12.2 Oil fuel tanks and bunkers

12.2.1 Scantlings

The scantlings of oil fuel bunkers and tanks are to complywith the requirements stated in Ch 20, Sec 3.

12.2.2 Location of oil fuel tanks and bunkers

a) Location of oil fuel tanks and bunkers is to be chosen ina way to avoid any abnormal rise in temperature inthese capacities.

b) The use of free standing oil fuel tanks is not permitted inhigh fire risk areas.


Pt D, Ch 20, Sec 4

12.2.3 Suctions and discharges to oil fuel tanks and bunkers

a) All suction pipes to oil fuel tanks and bunkers, includingthose in double bottom, are to be provided with valves.

In the case of bunkers and oil fuel storage, settling ordaily service tanks other than those in the double bot-tom, the valves are to be fitted directly on the plating ofthese bunkers and tanks and are to be so arranged thatthey can always be remotely closed in the event of firetaking place in the compartment where they are located.

b) Where the oil fuel transfer installation does not includepower pumps but only hand pumps, the suction valvesto oil fuel tanks and bunkers, with the exception of dailyservice tanks, need not to be provided with remote con-trols. These valves are however to be readily accessibleand instruction plates are to be fitted in their vicinityspecifying that they are to be maintained closed exceptduring transfer operations.

c) Where the discharge pipes to oil fuel bunkers and tanksare not led to the upper part of the said bunkers andtanks, they are to be provided with non-return valves attheir ends.

12.2.4 DrainsDaily service tanks are to be provided with drains permit-ting the evacuation of water and impurities likely to accu-mulate in the lower part of these tanks. These drains are tobe fitted with self-closing valves or cocks.

12.2.5 Materials - Tests

a) The use of materials other than steel for fuel bunkersand tanks which are not part of the ship's structure isspecially examined.

b) Oil fuel tanks and bunkers are to be tested under theconditions specified in [1.4.3].

12.3 Transfer pipes

12.3.1 Arrangement of the transfer systemThe transfer system together with its accessories are to be soarranged that oil fuel cannot enter compartments the struc-ture of which does not allow them to be filled with oil fuelor compartments intended to contain drinking water.

12.3.2 Transfer pumpsWhere oil fuel is transferred by means of a power pump,arrangements are to be made so that oil fuel may bepumped, in the event of damage to this pump, by means ofa stand-by pump, which can be a hand pump.

12.3.3 Passage through particular compartmentsNo fuel pipes are to pass through fresh water tanks and nofresh water pipes are to pass through fuel oil tanks.

12.4 Oil fuel supply to engines

12.4.1 The suctions of engine fuel pumps are to be soarranged as to prevent the suction of gathered water andsludge likely to accumulate after decanting at the lower partof service tanks.

12.4.2 Two filters, or similar devices, are to be providedand so arranged that one of the filters can be overhauledwhile the other is in use.

12.5 Materials - Construction

12.5.1 Low-pressure oil fuel pipes are generally to be madeof steel. Where the internal diameter of these pipes does notexceed 25 mm, they may be of seamless copper or copper-alloy unless they pass through oil fuel tanks.

12.5.2 Transfer oil fuel pipes may be of non metallic hosesin the conditions stated in [1.10].

12.5.3 The pipes are to be connected by means of close-fit-ting flanges or other devices deemed equivalent for theapplication considered. The materials of the joints are to beimpervious to liquid hydrocarbons.

13 Lubricating oil systems in ships L ≥ 24 m

13.1

13.1.1 See Pt C, Ch 1, Sec 10, [12].

14 Lubricating oil systems in ships L < 24 m

14.1 General

14.1.1 The lubricating oil systems are to be so arranged asto operate satisfactorily when the ship is inclined from thenormal position to angles of up to 15° transversely or 5°longitudinally, or when rolling to angles of up to 22°30' orpitching up to 7°30'.

Lubricating oil pipes are to be independent of any otherfluid system.

14.2 Lubricating pumps

14.2.1

a) Main engines are normally to be provided with at leasttwo power lubricating pumps. Where the installationincludes at least two propulsive units, the Society maypermit that only one pump be provided for each propul-sive unit.

b) Where the power per engine does not exceed 370 kWor when the ratio of the power per engine expressed inkW to the rotating speed in revolutions per minute doesnot exceed 0,75, the Society may permit that one of thepumps mentioned in item a) be a spare pump ready tobe connected to the lubricating oil system. Provision isto be made for the corresponding disassembling andreassembling operations to be carried out on board in atime as short as possible.


Pt D, Ch 20, Sec 4

14.3 Filters

14.3.1 In forced lubrication systems, a device is to be fittedwhich efficiently filters the lubricating oil in the circuit. Thefilters provided for this purpose are to be so arranged thatthey can be easily cleaned without stopping the lubricationof the machines.

14.4 Safety devices

14.4.1 Lubricating oil systems for propulsive engines are tobe provided with an alarm device giving audible warning inthe event of an appreciable reduction of the oil pressure.

15 Hydraulic systems in ships L ≥ 24 m

15.1

15.1.1 See Pt C, Ch 1, Sec 10, [14].

16 Hydraulic systems in ships L < 24 m

16.1 General

16.1.1 Installations using flammable oils are to be givenspecial consideration by the Society.

16.2 Safety and monitoring devices

16.2.1 Whenever practicable, the hydraulic power unitsare to be located outside the main engine or boiler rooms.Shields or similar devices are to be provided around thehydraulic power units in order to avoid accidental oil sprayor oil mist on heated surfaces which may ignite oil.

17 Compressed air systems in ships L ≥ 24 m

17.1

17.1.1 See Pt C, Ch 1, Sec 10, [17].

18 Compressed air systems in ships L < 24 m

18.1

18.1.1 Starting compressed air systems

a) The compressed air system for starting main engines isto be so arranged that it is possible to ensure the initialcharge of the air receiver(s). A hand compressor may beused for this purpose. Alternatively a compressor with ahand started prime mover may be used.

b) The prescription a) can be considered as fulfilled whenthe starting of the main engines is conducted, normallyor under emergency, by starting devices such as fuses,inertia starters or other means deemed equivalent.

c) When only one air compressor is used for filling the airreceivers, there are to be at least two air receivers.

d) The main engine air receivers are to have a total capac-ity sufficient to provide, without replenishment:

• 12 consecutive starts of the reversible type engines

• 6 consecutive starts of the non-reversible typeengines.

18.2 Accessories for compressed air sys-tems

18.2.1 The receivers, compressors, pipes and other acces-sories of the compressed air systems are to be fitted withadequate devices to avoid any appreciable overpressure inany point of the system.

18.3 Arrangement of compressed air sys-tems

18.3.1

a) Efficient oil and water separators are to be provided onthe discharge of compressors.

b) Non-return valves or other safety devices are to be pro-vided on the starting air mains of each engine.

18.4 Construction - Material

18.4.1

a) The construction and scantlings of compressed air pipesand of their accessories are to comply with the require-ments of Pt C, Ch 1, Sec 10.

b) Air receivers are to be constructed in accordance withthe relevant requirements of Pt C, Ch 1, Sec 3.

19 Exhaust gas systems in ships L ≥ 24 m

19.1

19.1.1 See Pt C, Ch 1, Sec 10, [17].

20 Exhaust gas systems in ships L < 24 m

20.1 Hull outlet

20.1.1 Where exhaust gas pipes are led overboard close tothe load water line, arrangements are to be made to preventany entry of water in the ship or in the engines while in nor-mal operation.

20.2 Cooling and lagging

20.2.1 The exhaust gas pipes and silencers which passthrough spaces of the ship where a temperature rise mightbe dangerous are to be efficiently cooled or lagged.


Pt D, Ch 20, Sec 4

20.3 Water-cooled exhaust gas pipes

20.3.1 When water-cooled exhaust gas pipes are used, ahigh temperature alarm must be fitted after the water injec-tion device. Alternatively, a low sea water flow rate may befitted.

21 Refrigeration systems for the preservation of the catch

21.1 General

21.1.1 Refrigeration systems are to be so designed, con-structed, tested and installed as to take account of the safetyof the system and also the emission of chlorofluorocarbons(CFCs) or any other ozone-depleting substances from therefrigerant held in quantities or concentrations which arehazardous to human health or to the environment.

21.1.2 Methylchloride or CFCs whose ozone-depletingpotential is higher than 5% of CFC-11 are not to be used asrefrigerants.

21.1.3 Adequate guidance for the safe operation of therefrigeration system and emergency procedures are to beprovided by means of suitable notices displayed on boardthe vessel.

21.2 Design of refrigeration systems

21.2.1 Refrigeration systems are to be adequately protectedagainst vibration, shock, expansion, shrinkage, etc. and areto be provided with an automatic safety control device toprevent a dangerous rise in temperature and pressure.

21.2.2 Refrigeration systems in which toxic or flammablerefrigerants are used are to be provided with drainagedevices leading to a place where the refrigerant presents nodanger to the vessel or to persons on board.

21.3 Arrangement of the refrigerating machinery spaces and refrigerating rooms

21.3.1 Separation of spaces

a) Any space containing refrigerating machinery, includingcondensers and gas tanks utilising toxic refrigerants, isto be separated from any adjacent space by gas-tightbulkheads. Any space containing refrigerating machin-ery, including condensers and gas tanks utilizing toxicrefrigerants, is to be fitted with a leak detection systemhaving an indicator outside the space adjacent to theentrance and is to be provided with an independentventilation system and a water-spraying system.

b) When such containment is not practicable due to thesize of the vessel, the refrigeration system may beinstalled in the machinery space provided that the quan-tity of refrigerant used will not cause danger to personsin the machinery space, should all the gas escape, andprovided that an alarm is fitted to give warning of a dan-gerous concentration of gas should any leakage occur inthe compartment.

21.3.2 Exits from spaces

In refrigerating machinery spaces and refrigerating rooms,alarms are to be connected to the wheelhouse or control sta-tions or escape exits to prevent persons being trapped. Atleast one exit from each such space is to be capable of beingopened from the inside. Where practicable, exits from spacescontaining refrigerating machinery using toxic or flammablegas are not to lead directly into accommodation spaces.

21.4 Breathing apparatus

21.4.1 Where any refrigerant harmful to persons is used ina refrigeration system, at least two sets of breathing appara-tus are to be provided, one of which is to be placed in aposition not likely to become inaccessible in the event ofleakage of refrigerant. Breathing apparatus provided as partof the vessel’s fire-fighting equipment may be considered asmeeting all or part of this provision provided its locationmeets both purposes. Where self-contained breathing appa-ratus is used, spare cylinders are to be provided. Alternativearrangement authorized by the administration concernedmay be accepted.

22 Propelling and auxiliary machinery in ships L ≥ 24 m

22.1

22.1.1 See Pt C, Ch 1, Sec 7.

23 Propelling and auxiliary machinery in ships L < 24 m

23.1 Shafting

23.1.1 Propeller shaft diameter

The diameter of the shaft going through the stern tube is notto be less than the diameter d, in mm, given by the follow-ing formula:

where:

P : Maximum continuous power of the propulsionmachinery, in kW

N : Shaft revolutions per minute

d 126 PN---- 560

Rm 160+-----------------------⋅

1 3⁄

⋅=


Pt D, Ch 20, Sec 4

Rm : Minimum tensile strength of the shaft material,in N/mm2. In the above formula, Rm is not to betaken greater than:

• 600 N/mm2 for intermediate shaft in carbonand carbon manganese steels

• 800 N/mm2 for intermediate shaft in alloysteels

• 600 N/mm2 for propeller shaft in carbon,carbon manganese and alloy steels.

In case of stainless steels and in other particularcases, at the discretion of the Society, the valueof Rm to be introduced in the above formula isto be specially considered.

Furthermore, the shaft diameter is not to be less than 25 mmfor carbon steel or carbon manganese steel, and 20 mm forthe other materials.

23.1.2 Intermediate shaft diameter

The diameter, in mm, of the intermediate shafts is not to beless than:

d’ = 0,87 d

23.2 Shaft accessories

23.2.1 Coupling bolts

The diameter of coupling bolts at the joining faces of thecouplings is to be not less than the diameter Db given, inmm, by the following formula, for intermediate, propellerand thrust shafts:

where:

d’ : Intermediate shaft diameter defined in [23.1.2]

n : Number of bolts in the coupling

DC : Pitch circle diameter of the coupling bolts, inmm

Rb : Ultimate tensile strength of the bolt metal, inN/mm2.

23.2.2 Shaft liners

The thickness of bronze shaft liners in way of the bushesand sterngland is to be not less than the thickness e, in mm,given by the following formula:

where:

d : Actual diameter of the propeller shaft, in mm.

23.2.3 Stern bearing

a) Water lubrication

The length of the after bearing of the propeller shaft isnot to be less than 4 times the rule diameter of the pro-peller shaft; furthermore the bearing is to be made of atype approved synthetic material.

For a bearing design substantiated by experimental datato the satisfaction of the Society, consideration may begiven to a bearing length less than 4 times, but in nocase less than 2 times, the rule diameter of the shaft inway of the bearing.

b) Oil lubrication

The length of the after bearing of the propeller shaft isnot to be less than 2 times the rule diameter of the pro-peller shaft; furthermore:

• the bearing material is to be of the antifrictional type

• the oil gland is to be type approved.

c) Other arrangements

The other arrangements beside those defined in items a)and b) are to be given special consideration. The lengthof the after bearing of the propeller shaft is not to be lessthan 3,5 times the rule diameter of the propeller shaft.

23.2.4 Sealing gland

a) The sealing glands must be readily accessible, forinspection or replacement

b) The sealing glands are to be periodically inspected.

The temporary actions to be taken in case of accidental fail-ure of a main component, as well as the inspection perio-dicity and the replacement schedule of parts subject towear or deterioration, are to be specified.

The wear strength of non-metallic parts is to be established,either by satisfactory operations, or by relevant tests.

An easy to fit emergency device may be accepted.

24 Steering gear

24.1 Application

24.1.1 The provisions of this Article apply in addition tothose of Pt C, Ch 1, Sec 11. with the exception of Sub-Arti-cles Pt C, Ch 1, Sec 11, [2.1] to Pt C, Ch 1, Sec 11, [2.4].

24.2 General

24.2.1 Unless expressly provided otherwise, every ship isto be provided with main steering gear and auxiliary steer-ing gear to the satisfaction of the Society.

Db 0 65, d′3 Rm 160+( )⋅n DC Rb⋅ ⋅

--------------------------------------- ⋅

1 2⁄

=

e d 230+32

-------------------=


Pt D, Ch 20, Sec 4

24.3 Strength, performance and power operation of the steering gear

24.3.1 Main steering gear

The main steering gear and rudder stock are to be:

a) of adequate strength and capable of steering the ship atmaximum ahead service speed, which is to be demon-strated

b) capable of putting the rudder over from 35° on one side to35° on the other side with the ship at its deepest seagoingdraught and running ahead at maximum ahead servicespeed and, under the same conditions, from 35° on eitherside to 30° on the other side in not more than 28s

c) operated by power where necessary to fulfil the require-ments of b), and

d) so designed that they will not be damaged at maximumastern speed; however, this design requirement need notbe proved by trials at maximum astern speed and maxi-mum rudder angle.

24.3.2 Auxiliary steering gear

The auxiliary steering gear is to be:

a) of adequate strength and sufficient to steer the ship atnavigable speed and capable of being brought speedilyinto action in an emergency,

b) capable of putting the rudder over from 15° on one sideto 15° on the other side in not more than 60s with theship at its deepest seagoing draught and running aheadat one half of the maximum ahead service speed or 7knots, whichever is the greater, and

c) operated by power where necessary to meet the require-ments of b).

24.3.3 Hand operation

Hand operation of steering gear is permitted when itrequires an effort less than 160 N.

24.4 Control of the steering gear

24.4.1 Control of the main steering geara) Control of the main steering gear is to be provided on

the navigation bridge.

b) Where the main steering gear is arranged in accordancewith [24.5.2], two independent control systems are tobe provided, both operable from the navigation bridge.This does not require duplication of the steering wheelor steering lever.

24.4.2 Control of the auxiliary steering geara) Control of the auxiliary steering gear is to be provided

on the navigation bridge, in the steering gear compart-ment or in another suitable position.

b) If the auxiliary steering gear is power operated, its con-trol system is also to be independent of that of the mainsteering gear.

24.5 Availability

24.5.1 Arrangement of main and auxiliary means for actuating the rudder

The main steering gear and the auxiliary means for actuat-ing the rudder are to be arranged so that a single failure inone will not render the other inoperative.

24.5.2 Omission of the auxiliary steering gearWhere the main steering gear comprises two or more iden-tical power units, auxiliary steering gear need not be fitted,provided that the main steering gear is capable of operatingthe rudder:

a) as required in [24.3.1], item b), while operating with allpower units

b) as required in [24.3.2], item b), while any one of thepower units is out of operation.

24.5.3 Hydraulic power supplyHydraulic power installations supplying steering gear mayalso supply other equipment at the same time provided thatthe operation of the steering gear is not affected:

a) by the operation of this equipment, or

b) by any failure of this equipment or of its hydraulic sup-ply piping.


Pt D, Ch 20, Sec 5


1 General

1.1 Application

1.1.1 The requirements contained in Part C, Chapter 2apply to fishing vessels, except for those contained in Pt C,Ch 2, Sec 1, [2], Pt C, Ch 2, Sec 15, [2], Pt C, Ch 2, Sec 3,[2], Pt C, Ch 2, Sec 3, [3], Pt C, Ch 2, Sec 11, [1], Pt C, Ch2, Sec 11, [2], Pt C, Ch 2, Sec 11, [3], Pt C, Ch 2, Sec 11,[4], and Pt C, Ch 2, Sec 11, [5], which are replaced by allthose contained in this Section.

2 Documentation to be submitted

2.1


The list of documents requested is to be intended as guid-ance for the complete set of information to be submitted,rather than an actual list of titles.

The Society reserves the right to request the submission ofadditional documents regarding unconventional design orwhere deemed necessary for the evaluation of the system,equipment or components.

Unless otherwise agreed with the Society, documents forapproval are to be sent in triplicate if submitted by the ship-yard and in four copies if submitted by the equipment sup-plier. Documents requested for information are to be sent induplicate.

In any case, the Society reserves the right to require addi-tional copies when deemed necessary.

Where the length is less than 24 m, the Society may giveexemptions to the documents to be submitted.

3 Type approved components

3.1

3.1.1 The following components are to be type approvedcase-by-case based on submission of adequate documenta-tion and execution of tests:

• electrical cables

• switching devices (circuit-breakers, contactors, discon-nectors, etc.) and overcurrent protective devices

• electronic components used for tasks essential to safety.

4 General requirements for system design, location and installation

4.1 Design and construction

4.1.1 The design and construction of electrical installationsare to be such as to provide:

a) the services necessary to maintain the vessel in normaloperational and habitable conditions without havingrecourse to an emergency source of power,

b) the services listed in [4.4.2] when failure of the mainsource of electrical power occurs, and

c) protection of the crew and vessel from electrical haz-ards.


N° I/A (1) Documents to be submitted

1 A Single line diagram of main and emergency power and lighting systems

2 I Electrical power balance (main and emergency supply)

3 A Calculation of short-circuit currents for each installation in which the sum of rated power of the energy sources which may be connected contemporaneously to the network is greater than 500 kW

4 A List of circuits including, for each supply and distribution circuit, data concerning the nominal current, the cable type, length and cross-section, the nominal and setting values of the protective and control devices

5 A Single line diagram and detailed diagram of the main switchboard

6 A Single line diagram and detailed diagram of the emergency switchboard

7 A Diagram of the most important section boards and motor control centres (above 100 kW)

8 A Detailed diagram of the navigation-light switchboard

(1) A: to be submitted for approvalI: to be submitted for information.


Pt D, Ch 20, Sec 5

4.2 Distribution

4.2.1 Supply systems

Distribution systems given in Pt C, Ch 2, Sec 3, [1] may beused on board of fishing vessels. Where length is less than24 m, on d.c. installations, two-wire systems with one poleearthed may be used.

4.2.2 General requirements given in Pt C, Ch 2, Sec 3,[1.1.3] and Pt C, Ch 2, Sec 3, [1.1.4] are applicable to fish-ing vessels. In addition, where length is less than 24 m,every conductor carrying the current from a circuit to thehull is to have the same cross section as the correspondinginsulated conductor. In d.c. installations, one pole of gener-ator and of supplied appliances is to be earthed in readilyaccessible places.

4.2.3 The hull return system of distribution is not to be usedfor power, heating or lighting in vessels of 75 m of lengthand over.

4.2.4 The requirement in [4.2.3] does not preclude, underconditions approved by the Society, the use of:

a) impressed current cathodic protective systems

b) limited and locally earthed systems, or

c) insulation level monitoring devices provided the circu-lation current does not exceed 30 mA under the mostunfavourable conditions.

4.2.5 Where the hull return system is used, all final subcir-cuits (all circuits fitted after the last protective device) are tobe two-wire and special precautions are to be taken to thesatisfaction of the Society.

4.3 Main source of electrical power

4.3.1 Where the electrical power constitutes the onlymeans of maintaining auxiliary services essential for thepropulsion and safety of the vessel, a main source of electri-cal power is to be provided which is to include at least twogenerating sets, one of which may be driven by the mainengine. The Society may accept other arrangements havingequivalent electrical capability.

4.3.2 The power of these sets is to be such as to ensure thefunctioning of the services referred to in [4.1.1] a), exclud-ing the power required in fishing activities, processing andpreservation of the catch, in the event of any one of the gen-erating sets being stopped. However, in vessels of less than45 m, in the event of any one of the generating sets beingstopped, it is only necessary to ensure the functioning of theservices essential for the propulsion and safety of the vessel.

4.3.3 The arrangement of the vessel's main source of elec-trical power is to be such that the services referred to in[4.1.1] a) can be maintained regardless of the number ofrevolutions and direction of the main propelling engines orshafting.

4.3.4 Where transformers constitute an essential part of thesupply system required by this item, the system is to be soarranged as to ensure continuity of the supply.

4.3.5 The arrangement of the main electric lighting systemis to be such that a fire or other casualty in spaces contain-ing the main source of electrical power, including trans-formers, if any, will not render the emergency lightingsystem inoperative.

4.3.6 The arrangement of the emergency electric lightingsystem is to be such that a fire or other casualty in spacescontaining the emergency source of electrical power,including transformers, if any, will not render the mainlighting system inoperative.

4.3.7 Navigation lights, if solely electrical, are to be sup-plied through their own separate switchboard and adequatemeans for the monitoring of such lights are to be provided.

4.3.8 For fishing vessels propelled by electrical power andhaving two or more constant voltage propulsion generatingsets which constitute the source of electrical energy for theship's auxiliary services, see Pt C, Ch 2, Sec 14.

4.3.9 Load shedding or other equivalent arrangementsshould be provided to protect the generators required in thepresent Article against sustained overload.

The load shedding should be automatic.

The non-essential services, services for habitability and, ifnecessary, the secondary essential services may be shed inorder to make sure that the connected generator set(s) is/arenot overloaded.

4.3.10 Where paralleling operation of the generators isneeded, necessary instruments for this operation are to beprovided.

4.3.11 Where the length is greater than 24 m, the measure-ment devices are to be in accordance with the generalrequirements given in Pt C, Ch 2, Sec 8, [1.6.1] to Pt C, Ch2, Sec 8, [1.6.8].

Where the length is less than 24 m.

a) The following instruments are to be normally provided:

• for each generator:

- one ammeter with mark indicating the normalfull load value (for installations where the ratedvoltage is below 24 V and fitted with a loadlimit, only a charge control lamp can be pro-vided)

- one voltmeter

- one lamp indicator to indicate the generatorvoltage

- one battery charging control lamp

• for each battery:

- one ammeter with two-sided deviation

• for busbars:

- one voltmeter


Pt D, Ch 20, Sec 5

• for three-phase system, it is to be provided, in addi-tion:

- one ammeter per phase or one ammeter withcommutator permitting to measure the current ineach phase

- one frequency meter

- one synchronising device if alternators arearranged to run in parallel

- one wattmeter for alternators over 50 kVA.

b) Protection:

Measuring instruments connected to the network andindicator lamps are to be protected by a fuse. Where ameasuring instrument and an indicator lamp correspondto the same indication, each one is to be provided witha fuse.

Requirements given in Pt C, Ch 2, Sec 8, [1.6.13], Pt C, Ch2, Sec 8, [1.6.14] and Pt C, Ch 2, Sec 8, [1.6.15], are appli-cable to all fishing vessels.

4.3.12 The main switchboards are to be placed far awayfrom flammable gas, vapour accumulation, acid gas orother liquid. Their location is to be such that there is nopipe carrying liquids above, beside or near them. When thiscannot be avoided, pipes are to be built joint less or pro-vided with protections.

4.4 Emergency source of electrical power

4.4.1 A self-contained emergency source of electricalpower located, to the satisfaction of the Society, outsidemachinery spaces is to be provided and so arranged as toensure its functioning in the event of fire or other causes offailure of the main electrical installations.

4.4.2 The emergency source of electrical power is to becapable, having regard to starting currents and the transitorynature of certain loads, of serving simultaneously for aperiod of at least three hours:

a) the VHF radio installation and, if applicable:

1) the MF radio installation

2) the ship earth station and

3) the MF/HF radio installation

b) internal communication equipment, fire detection sys-tems and signals which may be required in an emer-gency

c) the navigation lights if solely electrical and the emer-gency lights:

1) of launching stations and overside of the vessel

2) in all alleyways, stairways and exits

3) in spaces containing machinery or the emergencysource of power

4) in control stations, and

5) in fishing handling and fish processing spaces, and

d) the operation of the emergency fire pump, if any.

4.4.3 The emergency source of electrical power may beeither a generator or an accumulator battery.

4.4.4 Where the emergency source of electrical power is agenerator, it is to be provided both with an independent fuelsupply and with efficient starting arrangements to the satis-faction of the Society. Unless a second independent meansof starting the emergency generator is provided, the singlesource of stored energy is to be protected to preclude itscomplete depletion by the automatic starting system.

4.4.5 Where the emergency source of electrical power isan accumulator battery, it is to be capable of carrying theemergency load without recharging whilst maintaining thevoltage of the battery throughout the discharge periodwithin plus or minus 12% of its nominal voltage. In theevent of failure of the main power supply, this accumulatorbattery is to be automatically connected to the emergencyswitchboard and is to immediately supply at least thoseservices specified in [4.4.2], items b) and c). The emergencyswitchboard is to be provided with an auxiliary switchallowing the battery to be connected manually, in case offailure of the automatic connection system.

4.4.6 When the length is less than 24 m, the start of themain engine of the ship is carried out by electrical starterand where the emergency source of power is a storage bat-tery, the emergency source of power can be considered asthe second required starting power source for the mainengine. Then:

• The starting system cables are to be designed to permitthe necessary commutation with a change over switchand fixed connections.

• The available power of the emergency battery is to beadequate to supply the emergency services during thetime specified in above paragraphs, and, in principle,have the capacity of six consecutive starts of the mainengine.

4.4.7 The emergency switchboard is to be installed as nearas is practicable to the emergency source of power and is tobe located in accordance with [4.4.1]. Where the emer-gency source of power is a generator, the emergencyswitchboard is to be located in the same place unless theoperation of the emergency switchboard would thereby beimpaired.

4.4.8 An accumulator battery, other than batteries fitted forthe radio transmitter and receiver in vessels of less than 45m in length, is to be installed in a well ventilated spacewhich is not to be the space containing the emergencyswitchboard. An indicator is to be mounted in a suitableplace on the main switchboard or in the machinery controlroom to indicate when the battery constituting the emer-gency source of power is being discharged.

4.4.9 The emergency switchboard is to be supplied in nor-mal operation from the main switchboard by an intercon-nector feeder which is to be protected at the mainswitchboard against overload and short-circuit and which isto be disconnected automatically at the emergency switch-board upon failure of the main source of electrical power.


Pt D, Ch 20, Sec 5

Where the system is arranged for feedback operation, theinterconnector feeder is also to be protected at the emer-gency switchboard at least against short-circuit.

For ships whose length is equal to or greater than 45 m, thearrangement at the emergency switchboard is to be suchthat in the event of failure of the main power supply anautomatic connection of the emergency supply will be pro-vided.

4.4.10 The emergency generator and its prime mover andany emergency accumulator battery are to be so arrangedas to ensure that they will function at full rated power whenthe vessel is upright and when rolling up to an angle of22,5° either way and simultaneously pitching 10° by bowor stern, or in any combination of angles within those limits.

4.4.11 The emergency source of electrical power and auto-mation starting equipment is to be so constructed andarranged as to enable adequate testing to be carried out bythe crew while the vessel is in operating condition.

4.4.12 When the length is less than 24 m, the Society mayexempt Owners from the installation of the emergencysource of electrical power.

4.4.13 Where emergency generator is used in port, therequirements stated in Pt C, Ch 2, Sec 3, [2.4] are applica-ble.

4.5 Precaution against shock, fire and other hazards of electrical origin

4.5.1 Exposed permanently fixed metal parts of electricalmachines or equipment which are not intended to be livebut which are liable under fault conditions to become liveare to be earthed (grounded) unless:

a) they are supplied at a voltage not exceeding 50 V directcurrent or 50 V, root mean square between conductors;auto-transformers are not to be used for the purpose ofachieving this alternative current voltage, or

b) they are supplied at a voltage not exceeding 250 V bysafety isolating transformers supplying one consumingdevice only, or

c) they are constructed in accordance with the principle ofdouble insulation.

4.5.2 Electrical apparatus is to be so constructed andinstalled that it will not cause injury when handled ortouched in the normal manner.

4.5.3 Main and emergency switchboards are to be soarranged as to afford easy access as may be needed to appa-ratus and equipment, without danger to attendants. Thesides, backs and, where necessary, the fronts of switch-boards are to be suitably guarded. Exposed live parts havingvoltages to earth exceeding a voltage to be specified by theSociety are not to be installed on the front of the switch-boards. There are to be non-conducting mats or gratings atthe front and rear, where necessary.

4.5.4 When a distribution system, whether primary or sec-ondary, for power, heating or lighting, with no connectionto earth is used, a device capable of monitoring the insula-tion level to earth is to be provided.

4.5.5 When a distribution system is in accordance with[4.5.4] and a voltage exceeding 50 V direct current or 50 V,root mean square, between conductors, is used, a devicecapable of continuously monitoring the insulation level toearth and of giving an audible or visual indication of abnor-mally low insulation values is to be provided.

4.5.6 Distribution systems which are supplied at a voltagenot exceeding 250 V direct current or 250 V, root meansquare, between conductors, and which are limited inextent, may comply with [4.5.4], subject to the satisfactionof the Society.

4.5.7 Except as permitted by the Society in exceptional cir-cumstances, all metal sheaths and armour of cables are tobe electrically continuous and to be earthed.

4.5.8 All electrical cables are to be at least of a flame-retardant type and are to be so installed as not to impairtheir original flame-retarding properties. The Society maypermit the use of special types of cables where necessaryfor specific applications, such as radio frequency cables,which do not comply with the foregoing.

4.5.9 Cables and wiring serving essential or emergencypower, lighting, internal communications or signals are asfar as practicable to be routed clear of galleys, machineryspaces of category A and other high fire risk areas and laun-dries, fish handling and fish processing spaces and otherspaces where there is a high moisture content. Cables con-necting fire pumps to the emergency switchboard are to beof a fire-resistant type where they pass through high fire riskareas. Where practicable, all such cables are to be run insuch a manner as to preclude their being rendered unserv-iceable by heating of the bulkheads which may be causedby a fire in an adjacent space.

4.5.10 Where cables which are installed in spaces wherethe risk of fire or explosion exists in the event of an electri-cal fault, special precautions against such risk are to betaken to the satisfaction of the Society. When fitted in placeswhere flammable gases or vapours may accumulate, or inrooms intended to mainly contain accumulators, paint orsimilar material, the equipment is to be of a safety typeapproved by the Society.

4.5.11 Wiring is to be supported in such a manner as toavoid chafing or other damage.

4.5.12 Terminations and joints in all conductors are to bemade such that they retain the original electrical, mechani-cal, flame-retarding and, where necessary, fire-resistingproperties of the cable.

4.5.13 Cables installed in refrigerated compartments are tobe suitable for low temperatures and high humidity.


Pt D, Ch 20, Sec 5

4.5.14 Circuits are to be protected against short-circuit. Cir-cuits are also to be protected against overload, unless other-wise specified in these Rules or where the Society mayexceptionally otherwise permit.

4.5.15 The rating or appropriate setting of the overload pro-tective device for each circuit is to be permanently indi-cated at the location of the protective device.

4.5.16 Lighting fittings are to be so arranged as to preventtemperature rises which could damage the wiring and toprevent surrounding material from becoming excessivelyhot.

4.5.17 Lighting or power circuits terminating in a spacewhere the risk of fire or explosion exists are to be providedwith isolating switches outside the space.

4.5.18 The housing of accumulator batteries is to be con-structed and ventilated to the satisfaction of the Society.

4.5.19 Electrical or other equipment which may constitutea source of ignition of flammable vapours is not permittedin these compartments except as provided for in [4.5.21].

4.5.20 An accumulator battery is not to be located inaccommodation spaces unless installed in a hermeticallysealed container.

4.5.21 In spaces where flammable mixtures are liable tocollect and in any compartments assigned principally to thecontainment of an accumulator battery, no electrical equip-ment is to be installed unless the Society is satisfied that itis:

a) essential for operational purposes

b) of a type which will not ignite the mixture concerned

c) appropriate for the space concerned, and

d) appropriately certified for safe usage in the dusts,vapours or gases likely to be encountered.

4.5.22 Where shore supply is provided, requirementsstated in Pt C, Ch 2, Sec 3, [3.7] are applicable. The socket-outlets used for the supply of the ship from the shore net-work and when the voltage exceeds 50 V, are to be pro-vided with a built-in earth connection provided to beconnected to the earth.

4.5.23 On board of ship with non-metallic hull, bonding isto be provided between the frame of generators, the bedplate of the pumps, the bed plate of the motors and theearth plate, if fitted. All the elements of the fuel installationare to be electrically bonded and connected to the abovebonding.

4.5.24 If the protection of cables against overload current ismade by fuses, their rating is to be selected according to themaximum permissible current in the cable.

4.5.25 Particular attention is to be paid to the fixing ofequipment made of cast brass or other copper alloys on alu-minium decks or bulkheads.

4.5.26 Heaters

Electric heaters are to be permanently installed.

They are to be constructed and installed in such a way thatclothing or other combustible objects cannot be left there orbe hung above these heaters.

4.6 Engineers’ alarm

4.6.1 In vessels of 75 m in length and over, an engineers’alarm is to be provided to be operated from the engine con-trol room or at the manoeuvring platform as appropriate,and is to be clearly audible in the engineers’ accommoda-tion.

4.7 Steering gear

4.7.1 For the steering gear, general requirements includedin Ch 20, Sec 4, [24] are applicable. Where length of thefishing vessel is less than 24 m, the Society may giveexemptions to these requirements.

4.8 Fire detection and fire alarm

4.8.1 The fire detection and fire alarm system are to be sup-plied from the main source and an emergency source.

4.9 Alarm - Communication

4.9.1 For the crew muster, an alarm system operated fromthe bridge is to be provided. This system may be part of thegeneral alarm system.

4.9.2 Ships of 12 m or more in length are to be equippedwith a system enabling the general broadcast of alarm andmessages in case of damage or ship escape.

4.9.3 The bridge operating compartment is to be fitted withthe internal communication and control means as quotedhereunder:

• An engine room telegraph with repeater, or equivalentsystem, is to be provided and duplicated by anotherindependent system, enabling the communication withthe engine control position. If the size and arrangementof the ship make useless the equipment mentionedabove, only a dual calling system such as telephone,megaphone or bell may be fitted.

• If the propelling machinery is remote-controlled fromthe bridge-operating compartment, at least one ordertelegraph, reversible or with repeater, is to be fitted atthe local direct engine control position.

• Furthermore, unless the size and arrangement of theship make useless this equipment, the bridge operatingcompartment is to be connected by means of a reversi-ble voice communication system to the local control ofsteering gear, propelling machinery and the serviceaccommodation.


Pt D, Ch 20, Sec 5

4.10 Final sub-circuits

4.10.1 Every final sub-circuit connected to a distributionpanel is to be protected, unless otherwise specified, by afuse or a maximum current circuit breaker on each insu-lated pole. These circuits can be controlled by single poleswitches in dry spaces of the accommodation.

A separate final sub-circuit is to be provided for every appa-ratus assuming an essential service and for each motor rated1 kW or more.

4.11 Electric cables

4.11.1 General requirements given in Pt C, Ch 2, Sec 3, [9]are applicable for all fishing vessels.

4.11.2 Choice of runs

a) Cable runs are to be as straight and accessible as possi-ble.

b) Cable runs are to be fitted away from source of water.Cables exposed to the risk of mechanical damage, if notarmoured or enclosed in steel conduits, are to be pro-tected by a casing.

c) The cable runs are to be so designed that the internalradius of bend does not exceed at any point the permis-sible value for the cable concerned. In the absence ofvalues specified by the manufacturer, the following val-ues are to be adopted as minima for the internal radiusof bend:

• 4 d for rubber-like insulated cables without metalliccovering (6 d if d > 25 mm)

• 6 d for rubber-like insulated cables with metalliccovering or for silicone asbestos cables.

4.11.3 Cable fixing

a) Cables are to be bunched as regularly as possible.

b) Cables are to be so arranged as to avoid any friction; ifneeded, fastening parts are to be used. The distancebetween fastening parts is to be defined according to thecable nature and the special installation provisions. Thedistance between two fastening parts is generally not toexceed 0,50 m.

4.12 Switchboard

4.12.1 Installation

When the voltage exceeds 50 volts, AC or DC, an insulatedmat, grating or impregnated wood surface is to be providedin front of switchboards and also at the rear if access to therear is provided. The insulated mat, grating or surface is tobe oil-resistant and non-slippery.

4.12.2 Design - Construction

Generally, switchboards or enclosures containing switch-boards are to be constructed of durable, flame retardant andnon-hygroscopic materials. In addition, mechanical featuresof the materials are to be suitable for the service conditions.

Live parts normally submitted to a voltage exceeding50 volts are not to be installed without protection on thefront of switchboards.

The switchboard frame or enclosures containing switch-boards are to be earthed.

Air clearances between live parts are to be suitable for therated voltage or protected by means of insulating and fire-proof shields.

Every switchboard part, including the connections, is to beeasily accessible.

4.13 Rotating electrical machines

4.13.1 Location - Installation

Machines and their gears are to be located in spaces suita-bly ventilated where flammable dusts, vapours or gases can-not accumulate. Where this condition, in the case ofmotors, cannot be fulfilled, the Society is to be advisedaccordingly and a special consideration will be given, afterexamination, of the proposed arrangements.

4.13.2 Earthing

Bed plates and framework of machines or generating setsare to be efficiently earthed; no insulating material is to beplaced between the prime movers and the alternators andgenerally between the prime movers and the drivenmachines, unless there is one efficient earthing of each part.

4.13.3 Generators speed control

Prime movers for driving generators are to be fitted with aspeed regulator in such a way that at all loads between noload and rated power the permanent speed variations can-not exceed 5% of the rated speed. For Diesel generatingsets, when the rated power is suddenly thrown off, the tran-sient speed variations are not to exceed 10%.

The generators driven by the propulsion engine, by a gearedshaft or by an auxiliary set intended for another purpose,are to be designed with consideration that the variation ofspeed may occur in service.

4.13.4 Particular provisions for the motor control device - Starters

a) DC and AC motors of more than 0,5 kW are to be fittedwith a under-voltage protection and a protection againstoverload. Under-voltage protection may not be pro-vided for steering gear motor or any other motor thecontinuous running of, which is essential.

b) When the starter, the selector switch or all other equip-ment used to cut off completely the supply of the motoris at a distance from it, it is recommended that one ofthe following measures be applied:

• locking of the disconnecting switch of the circuit inopen position, or removable fuses

• installation near to the motor of a second discon-necting switch.

4.14 Batteries

4.14.1 As general, Pt C, Ch 2, Sec 11, [6] is applicable.


Pt D, Ch 20, Sec 5

4.14.2 Where the length is less than 24 m, the following isalso applicable:

• Batteries which can be charged by a power exceeding2 kW (calculated from the maximum charging currentof the charging apparatus and from the nominal voltageof the battery) are to be installed in a ventilated suitablespace or in a locker protected from dangerous gas accu-mulation.

4.14.3 For all fishing vessels:

a) All spaces especially reserved for batteries, includinglockers or chests, boxes, shelves are to be protectedagainst the deleterious effects of the electrolyte. The bat-teries are to be so manufactured and installed that noelectrolyte discharge may occur under 22°5 inclination.

b) Deck boxes are to be provided with exhaust ducts ontop and air inlets at lower part. The assembly is to besuitably weatherproof. For battery of low capacity, onlyopenings on the top of the battery box are required.

5 Lightning protection

5.1 Application

5.1.1 A lightning protection system is to be fitted for:

a) ships with wooden hull or of composite constructionwith wooden masts

b) ships with wooden hull or of composite constructionwith steel masts

c) ships with steel hull with wooden masts.

5.1.2 Lightning conductors are to be fitted to all woodenmasts or topmasts. In vessels constructed of non-conductivematerials, the lightning conductors are to be connected to acopper plate fixed to the vessel's hull well below the water-line.

5.1.3 Lightning fittings exposed to risks of mechanicaldamage are to be suitably protected or strongly built.


Pt D, Ch 20, Sec 6


1 General

1.1 Application

1.1.1 This Section provides requirements for the fire safetyof ships having the service notation fishing vessel and alength of 65 m or less.

Type approval of materials and products listed in a) to h) of[1.2.1] and Articles [5], [6], [7], [8], [9] and [10] of this Sec-tion apply only to ships assigned with the additional servicefeature F.

The fire safety of fishing vessels having a length of morethan 65 m is to comply with the provisions of Part C, Chap-ter 4.

1.2 Type approved products

1.2.1 The following materials, equipment, systems or prod-ucts in general used for fire protection are be type approvedby the Society, except for special cases for which theacceptance may be given for individual ships on the basis ofsuitable documentation and/or tests:

a) fire-resisting and fire-retarding divisions (bulkheads ordecks) and associated doors

b) automatic closing devices of fire doors

c) materials for pipes penetrating A or B class divisions(where they are not of steel or other equivalent material)

d) materials for oil or fuel oil pipes (where they are not ofsteel or copper and its alloys)

e) bulkhead or deck penetrations for electrical cables pass-ing through A or B class divisions

f) materials with low flame spread characteristics includ-ing paints, varnishes and similar, when they are requiredto have such characteristics

g) non-combustible materials

h) non-readily igniting materials for primary deck coverings

i) fixed foam fire-extinguishing systems and portable foamfire-extinguishing units

j) sensing heads for automatic fire alarm and fire detectionsystems

k) portable fire extinguishers

l) extinguishing media substitute for the foam in fire extin-guishers

m) fire hoses

n) fire hydrants and nozzles, including dual-purpose noz-zles, for fire hoses.

As regards the type approval, the requirements of Part Aapply.

1.3 Definitions

1.3.1 ForewordFor the purpose of this Section, unless otherwise stated, thedefinitions given in [1.3.2] to [1.3.13] below apply.

1.3.2 Non-combustible materialNon-combustible material is a material which neither burnsnor gives off flammable vapours in sufficient quantity forself-ignition when heated to approximately 750°C. Suchproperty is to be demonstrated by means of a test performedin accordance with a procedure accepted by the Society.

Any other material is to be considered as a combustiblematerial.

1.3.3 Standard fire test - A class divisions - B class divisions

Refer to the definitions given in Pt C, Ch 4, Sec 1, [3.2.1]and Pt C, Ch 4, Sec 1, [3.4.1].

The Society may require a test of a prototype bulkhead of Aor B class to ensure that it meets the requirements for integ-rity or temperature rise.

1.3.4 Steel or other equivalent materialWhere the words "steel or other equivalent material" occur,"equivalent material" means any non-combustible materialwhich, by itself or due to insulation provided, has structuraland integrity properties equivalent to steel at the end of theapplicable exposure to the standard fire test (e.g. aluminiumalloy with appropriate insulation).

1.3.5 Low flame spread“Low flame spread” means that the surface thus describedoffers an adequate resistance to the spread of flame. Such aproperty is to be demonstrated by a test procedure deemedacceptable by the Society.

1.3.6 Accommodation spaces“Accommodation spaces” are those spaces normally usedby the crew such as corridors, lavatories, cabins, offices,lounges, dining rooms and other similar spaces.

1.3.7 Service spaces“Service spaces” are those spaces used for galleys, pantriescontaining cooking appliances, lockers, storerooms, work-shops other than those forming part of machinery spaces,and similar spaces and trunks to such spaces. They alsoinclude the spaces used for the storage of the fishing nets.

1.3.8 Cargo spaces“Cargo spaces” are all spaces used for the storage of the fishand the trunks to such spaces.


Pt D, Ch 20, Sec 6

1.3.9 Machinery spaces of category A

“Machinery spaces of category A” are those spaces whichcontain internal combustion type machinery, used for:

• either main propulsion, or

• other purposes where such machinery has in the aggre-gate a total power output of not less than 750 kW,

or which contain any oil-fired boiler or fuel unit.

1.3.10 Machinery spaces

“Machinery spaces” are those machinery spaces of categoryA and all other spaces containing the propulsion machinery,boilers, fuel oil units, steam and internal combustionengines, generators and major electric motors, steering gear,oil filling stations, ventilation and air conditioning machin-ery, refrigerating machinery, stabilisers and similar spaces ortrunks to such spaces.

1.3.11 Control stations

“Control stations” are those spaces containing the mainnavigating equipment, the ship’s radio, the emergencysource of power, or where the fire recording and fire controlequipment is centralised.

1.3.12 Continuous B-class ceilings or linings

“Continuous B-class ceilings or linings” are those B-classceilings or linings which terminate only at a “A” or “B” classdivision.

1.3.13 Materials which do not readily ignite

“Materials which do not readily ignite“ are materials havingapproved characteristics of ignitability. These characteristicsare to be obtained from a test procedure deemed accepta-ble by the Society.

2 Water fire-fighting system

2.1 General

2.1.1

a) Every ship is to be provided with a water fire-fightingsystem consisting of fire pumps, fire main, hydrants andhoses complying as applicable with the provisions ofthis Article, depending on the length of the ship.

b) The water fire-fighting system is to be independent ofany other system of the ship. A connection with thewashing system is permitted, however.

2.2 Number and type of fire pumps

2.2.1 Ships with L ≥ 45 m

All ships having a length of 45 m or more are to be providedwith:

• at least two main fire pumps; one is to be independentlydriven and power operated and the other may be drivenby the propulsion engine

• one emergency fire pump complying with [2.3.2], if afire in any compartment could put all the fire pumps outof action.

Note 1: In the case of ships having a restricted navigation notation,the emergency fire pump may be omitted.

2.2.2 Ships with 24 m ≤ L < 45 m

Ships having a length of 24 m and above but less than 45 mare to be provided with:

• at least one main fire pump, independently driven andpower-operated

• one emergency fire pump, except when the main firepump, its source of power and its sea connection arelocated outside the spaces containing the propulsionmachinery or oil fired boilers.

Note 1: In the case of ships having a restricted navigation notation,the emergency fire pump may be omitted.

2.2.3 Ships with 15 m ≤ L < 24 m

Ships having a length of 15 m and above but less than 24 mare to be provided with:

• at least one pump for the fire fighting service, power-operated

• one hand pump complying with [2.3.3], except whenthe power-operated pump is independently driven.

2.2.4 Ships with L < 15 m

Ships having a length less than 15 m are to be providedwith at least one hand pump complying with [2.3.3].

2.3 Characteristics and arrangement of fire pumps

2.3.1 Main fire pumps

a) When delivering together for fire-fighting purposes atthe pressure specified in [2.4.1], item b), the requiredfire pumps, other than hand pumps and the emergencyfire pump, are to have a total capacity Q, in m3/h, notless than that determined from the following formula:

where:

L : Length of the ship between perpendiculars,in m

B : Breadth of the ship, in m

D : Depth of the ship, measured up to the bulk-head deck, in m.

However, the total capacity of the main fire pumps neednot exceed 180 m3/h.

Q 0 15 L B D+( ), 2 25,+( )2=


Pt D, Ch 20, Sec 6

b) When several power-operated fire pumps other than thefire emergency pump are required, each pump is tohave a capacity not less than 80% of the total requiredcapacity divided by the minimum number of requiredfire pumps. Each such pump is, in any event, to be capa-ble of delivering at least the two jets of water required in[2.4.1], item b). These fire pumps are to be capable ofsupplying the fire main system under the required con-ditions. Where more than the minimum number ofrequired pumps are installed, the capacity of such addi-tional pumps may be less than that required above, pro-vided it is deemed satisfactory by the Society.

c) Sanitary, ballast, bilge or general service pumps may beaccepted as fire pumps, provided they are not normallyused for pumping oil and that, if they are subject tooccasional duty for the transfer or pumping of fuel oil,suitable change-over arrangements are fitted.

2.3.2 Emergency fire pumps

The emergency fire pump and its location are to complywith the following requirements:

a) The capacity of the pump is not to be less than 40% ofthe total capacity of the main fire pumps and in anycase not less than:

• 25 m3/h for ships having a length of 45 m or more

• 15 m3/h for ships having a length less than 45 m.

b) When the pump is delivering the quantity of waterrequired by clause a) above, the pressure at any hydrantis not to be less than the minimum pressures required in[2.4.1], item b).

c) Any diesel driven power source for the emergency firepump is to be capable of being readily started in all thetemperature conditions likely to be encountered, takinginto account the navigation assigned to the ship.

d) Any service fuel tank is to contain a sufficient quantityof fuel to enable the emergency fire pump to run on fullload for at least 3 h and sufficient reserves of fuel are tobe available outside machinery spaces to enable thepump to run on full load for an additional 15 h.

e) The emergency fire pump is to be of the self-primingtype and capable of operating under all conditions ofimmersion, list, trim, roll and pitch likely to be encoun-tered in service. The sea suction valve is to be capableof being operated from a position close to the pump.

f) The emergency fire pump and its source of power are tobe installed in a safe and readily accessible positionlocated in a separate compartment as far as possiblefrom the compartment containing the main fire pumpsand their source of power.

When this is not practicable, the emergency fire pumpmay be located in a compartment adjacent to the onecontaining the main fire pumps, provided that the bulk-heads and decks forming the boundaries of both com-partments are insulated to A-60 standard.

Note 1: For ships having a length less than 45 m and a restrictednavigation notation, the emergency fire pump may also beportable and located in a space other than the one containingthe main fire pump.

2.3.3 Hand pumps

Hand pumps are to have a capacity of at least two thirds ofthat required for the bilge pump and a total suction head toproject a sufficient jet of water to the satisfaction of theSociety.

2.4 Fire main, hydrants and hoses

2.4.1 Diameter of, and pressure in, the fire main

a) The diameter of the fire main and water service pipes isto be sufficient for the effective distribution of the maxi-mum required discharge from all the main fire pumpsoperating simultaneously. However, this diameter needonly be sufficient for the discharge of 140 m3/h.

b) When main power fire pumps are delivering the quan-tity of water required in [2.3.1] item a) through the firemain, fire hoses and nozzles, the pressure maintained atany hydrant is not to be less than 0,25 N/mm2.

2.4.2 Pipes and hydrants

a) Materials readily rendered ineffective by heat are not tobe used for the fire main and hydrants unless adequatelyprotected. The pipes and hydrants are to be so placedthat the fire hoses may be easily coupled to them. Thearrangement of pipes and hydrants is to be such as toavoid the possibility of freezing.

b) A valve is to be fitted to serve each fire hose so that anyhose may be removed while the fire pumps are at work.

c) Isolating valves to separate the section of the fire mainwithin the machinery space containing the main firepump or pumps from the rest of the fire main are to befitted in easily accessible and safe positions outside themachinery space. The fire main is to be so arranged that,when the isolating valves are shut, all the hydrants of theship except those in the machinery space referred toabove can be supplied with water by a fire pump notlocated in this machinery space through pipes which donot enter this space. Exceptionally, the Society may per-mit short lengths of the emergency fire pump suctionand discharge piping to penetrate the machinery spaceif it is impracticable to route it externally provided thatthe integrity of the fire main is maintained by the enclo-sure of the piping in a substantial steel casing.

2.4.3 Number and position of hydrants

a) Fire hydrants should be positioned so as to allow easyand quick connection of fire hoses and so that at leastone jet can be directed into any part of the ship which isnormally accessible during navigation.

b) The jet required in item a) should be from a singlelength of fire hose.

c) In addition to the requirements of item a), machineryspaces of category A should be provided with at leastone fire hydrant complete with fire hose and dual-pur-pose nozzle. This fire hydrant should be located outsidethe space and near the entrance.


Pt D, Ch 20, Sec 6

d) For every required fire hydrant there should be one firehose. At least one spare fire hose should be provided inaddition to this requirement.

e) Single lengths of fire hose should not exceed 20 m.

f) Fire hoses should be of an approved material. Each firehose should be provided with couplings and a dual-pur-pose nozzle.

g) Except where fire hoses are permanently attached to thefire main, the couplings of fire hoses and nozzles shouldbe completely interchangeable.

h) The nozzles as required by item f) should be appropriateto the delivery capacity of the fire pumps fitted, but inany case should have a diameter of not less than 12 mm.

3 Fire-extinguishing appliances in machinery spaces

3.1

3.1.1

a) Spaces containing oil-fired boilers, fuel oil units or inter-nal combustion machinery having a total power outputof not less than 750 kW should be provided with one ofthe following fixed fire extinguishing systems, to the sat-isfaction of the Society:

• a pressure water-spraying installation

• a fire-smothering gas installation

• a fire-extinguishing installation using vapours fromlow toxicity vapourizing liquids, or

• a fire-extinguishing installation using high expan-sion foam.

b) New installations of halogenated hydrocarbon systemsused as fire-extinguishing media should be prohibitedon new and existing ships.

c) Where the engine and boiler rooms are not entirely sep-arated from each other or if fuel oil can drain from theboiler room into the engine room, the combined engineand boiler rooms should be considered as one compart-ment.

3.2

3.2.1 Installations listed in [3.1.1] item a) should be con-trolled from readily accessible positions outside suchspaces not likely to be cut off by a fire in the protectedspace. Arrangements should be made to ensure the supplyof power and water necessary for the operation of the sys-tem in the event of fire in the protected space.

3.3

3.3.1 In all machinery spaces of category A at least twoportable extinguishers should be provided, of a type suita-ble for extinguishing fires involving fuel oil. Where suchspaces contain machinery, which has a total power outputof not less than 250 kW, at least three such extinguishersshould be provided. One of the extinguishers should bestowed near the entrance to the space.

3.4

3.4.1 Ships having machinery spaces not protected by afixed fire extinguishing system should be provided with atleast a 45 l foam extinguisher or its equivalent, suitable forfighting oil fires. Where the size of the machinery spacesmakes this provision impracticable, the Society can acceptan additional number of portable fire extinguishers.

4 Fire extinguishers

4.1 Design and installation of fire extin-guishers

4.1.1 General

All fire extinguishers are to be of a type and characteristicsapproved by the Society.

4.1.2 Equivalences

a) The Society reserves the right to establish equivalencesbetween the various types of extinguishers.

b) Foam extinguishers may be replaced by equivalentextinguishers deemed appropriate by the Society.

4.1.3 Spare chargesA sufficient number of spare charges is to be provided. Ingeneral, spare charges are to be provided for 10% of theportable water or foam extinguishers on the ship, with aminimum of 5 spare charges of each type. However, thenumber of spare charges need not exceed the number ofwater or foam extinguishers on board.

4.1.4 Capacity of portable fire extinguishersThe capacity of required portable fluid extinguishers is notto be more than 13,5 l and not less than 9 l. Other extin-guishers are to be at least as portable as the 13,5 l fluidextinguishers and are to have a fire-extinguishing capabilityat least equivalent to a 9 l fluid extinguisher.

4.1.5 Extinguishing mediumFire extinguishers containing an extinguishing mediumwhich, in the opinion of the Society, either by itself or underexpected conditions of use gives off toxic gases in suchquantities as to endanger persons are not permitted.

4.1.6 Installation One of the portable fire extinguishers intended for use inany space is to be stowed near the entrance to that space.

4.2 Arrangement of fire extinguishers in accommodation and service spaces

4.2.1 General All ships are to be provided with a sufficient number ofportable fire extinguishers such that, in any accommodationor service spaces, a fire extinguisher is readily available incase of need. The type of the extinguisher is to be suitablefor the type of fire which is likely to break out in the spaceconcerned.


Pt D, Ch 20, Sec 6

4.2.2 Number and type of extinguishers in the various spaces

a) Accommodation spaces are to be provided with at least:

• 5 water or foam extinguishers, with a minimum ofone such extinguisher for each ‘tweendeck, for shipshaving a length of 45 m or more

• 3 water or foam extinguishers, with a minimum ofone such extinguisher for each ‘tweendeck, for shipshaving a length of 24 m or more but less than 45 m

• 1 water or foam extinguisher for each ‘tweendeck,for ships having a length less than 24 m.

b) In the vicinity of switchboards or section boards havinga power of 20 kW or more, at least one carbon dioxideor powder extinguisher is to be provided.

c) Spaces containing a galley are to be provided with atleast one foam or powder extinguisher.

d) Stores containing paint or other easily flammable prod-ucts used on board are to be provided with at least onefoam or carbon dioxide or powder extinguisher.

e) The navigation bridge is to be provided with at least onefoam or carbon dioxide extinguisher.

f) The spaces containing the ship’s radio equipment are tobe provided with at least two carbon dioxide extinguish-ers.

Note 1: In small ships where the sole electric switchboard and/orthe sole radio station is/are located on the navigation bridge orin the same position as the wheelhouse, only two extinguishersneed be provided, one of the water type, the other of the car-bon dioxide type or equivalent.

5 Structural fire protection

5.1

5.1.1 Hull, superstructures, structural bulkheads, decks anddeckhouses are to be of steel. However, in special cases, theSociety may accept the use of other equivalent materials(such as aluminium alloys) when the fire risk has been takeninto account and provided that such material is so insulatedthat, in the event of fire, the structure cannot collapse.

5.2 Ships of 45 m in length and over

5.2.1 The decks and bulkheads separating machineryspaces of category A from accommodation spaces, servicespaces or control stations should be constructed to "A-60"Class standard where the machinery space of category A isnot provided with a fixed fire-extinguishing system and to"A-30" Class standard where such a system is fitted. Decksand bulkheads separating other machinery spaces fromaccommodation, service spaces and control stations shouldbe constructed to "A-0" Class standard. Decks and bulk-heads separating control stations from accommodation andservice spaces should be constructed to "A" Class standard,insulated to the satisfaction of the Society, except that theSociety may permit the fitting of "B-15" Class divisions forseparating such spaces as skipper's cabin from the wheel-house.

5.2.2

a) The bulkheads of corridors serving accommodationspaces, service spaces and control stations should be of"B-15" Class divisions.

b) Any bulkhead required by item a) should extend fromdeck to deck unless a continuous ceiling of the sameClass as the bulkhead is fitted on both sides of the bulk-head, in which case the bulkhead can terminate at thecontinuous ceiling.

5.2.3 Interior stairways serving accommodation spaces,service spaces or control stations should be of steel or otherequivalent material. Such stairways should be within enclo-sures constructed of "B-15" Class divisions, provided thatwhere a stairway penetrates only one deck, it need beenclosed at one level only.

5.2.4 Doors and other closures of openings in bulkheadsand decks referred to in [5.2.1] and [5.2.2], doors fitted tostairway enclosures referred to in [5.2.3] and doors fitted inengine and boiler casings, should be as far as practicableequivalent in resisting fire to the divisions in which they arefitted. Doors to machinery spaces of category A should beself-closing.

5.2.5 Lift trunks, which pass through the accommodationand service spaces, should be constructed of steel or equiv-alent material and should be provided with means of clos-ing which will permit control of draught and smoke.

5.2.6

a) The boundary bulkheads and decks of spaces contain-ing any emergency source of power and bulkheads anddecks between galleys, paint rooms, lamp rooms or anystore-rooms which contain appreciable quantities ofhighly flammable materials, and accommodationspaces, service spaces or control stations should be of"A" Class divisions insulated to the satisfaction of theSociety, having in mind the risk of fire, except that theSociety can accept "B-15" Class divisions between gal-ley and accommodation spaces, service spaces andcontrol stations when the galley contains electricallyheated furnaces, electrically heated hot water appli-ances or other electrically heated appliances only.

b) Highly flammable products should be carried in suitablysealed containers.

5.2.7 Where bulkheads or decks, required by [5.2.1],[5.2.2], [5.2.4] or [5.2.6] to be of "A" Class or "B" Class divi-sions, are penetrated for the passage of electrical cables,pipes, trunks, ducts, etc., arrangements should be made toensure that the fire integrity of the division is not impaired.

5.2.8 Air spaces enclosed behind ceilings, panellings orlinings in accommodation spaces, service spaces and con-trol stations should be divided by close-fitting draught stopsspaced not more than 7 m apart.


Pt D, Ch 20, Sec 6

5.2.9 Windows and skylights to machinery spaces shouldbe as follows:

a) Where skylights can be opened they should be capableof being closed from outside the space. Skylights con-taining glass panels should be fitted with external shut-ters of steel or other equivalent material permanentlyattached.

b) Glass or similar materials should not be fitted inmachinery space boundaries. This does not preclude theuse of wire-reinforced glass for skylights and glass incontrol rooms within the machinery spaces; and

c) In skylights referred to in item a) wire-reinforced glassshould be used.

5.2.10 Insulating materials in accommodation spaces, serv-ice spaces except domestic refrigerating compartments,control stations and machinery space should be non-com-bustible. The surface of insulation fitted on the internalboundaries of machinery spaces of category A should beimpervious to oil or oil vapours.

5.2.11 Within compartments used for stowage of fish, com-bustible insulation should be protected by close-fitting clad-ding.

5.2.12 Notwithstanding the requirements of this sub-arti-cle, the Society can accept "A-0" class divisions in lieu of"B-15" class divisions, having regard to the amount of com-bustible materials used in adjacent spaces.

5.3 Ships of 24 m in length and over but less than 45 m

5.3.1 The decks and bulkheads separating machineryspaces of category A from accommodation spaces, servicespaces or control stations should be constructed to "A-60"Class standard where the machinery space of category A isnot provided with a fixed fire-extinguishing system and to"A-0" Class standard where such a system is fitted. Decksand bulkheads separating other machinery spaces fromaccommodation, service spaces and control stations shouldbe constructed to "A-0" Class standard. Decks and bulk-heads separating control stations from accommodation andservice spaces should be constructed to "B" Class standard,insulated to the satisfaction of the Society.

5.3.2

a) The bulkheads of corridors serving accommodationspaces, service spaces or control stations should be of"B-0" Class divisions.

b) Any bulkhead of corridors serving accommodationspaces, services and central stations should extend fromdeck to deck unless a continuous ceiling of the sameClass as the bulkhead is fitted on both sides of the bulk-head, in which case the bulkhead can terminate at thecontinuous ceiling.

5.3.3 Interior stairways serving accommodation spaces,service spaces or control stations should be of steel or otherequivalent material. Such stairways connecting more thantwo decks should be within enclosures constructed of "B-15" Class divisions.

5.3.4 Doors and other closures of openings in bulkheadsand decks referred to in [5.3.1] and [5.3.2], doors fitted tostairway enclosures referred to in [5.3.3] and doors fitted inengine and boiler casings, should be as far as practicableequivalent in resisting fire to the divisions in which they arefitted. Doors to machinery spaces of category A should beself-closing.

5.3.5 Lift trunks, which pass through the accommodationand service spaces, should be constructed of steel or equiv-alent material and should be provided with means of clos-ing which will permit control of draught and smoke.

5.3.6

a) The boundary bulkheads and decks of spaces contain-ing any emergency source of power and bulkheads anddecks between galleys, paint rooms, lamp rooms or anystore-rooms which contain appreciable quantities ofhighly flammable materials, and accommodationspaces, service spaces or control stations should be of"A" Class divisions insulated to the satisfaction of theSociety, having in mind the risk of fire, except that theSociety can accept "B-15" Class divisions between gal-ley and accommodation spaces, service spaces andcontrol stations when the galley contains electricallyheated furnaces, electrically heated hot water appli-ances or other electrically heated appliances only.

b) Highly flammable products should be carried in suitablysealed containers.

5.3.7 Where bulkheads or decks, required by [5.3.1],[5.3.2], [5.3.4] or [5.3.6] to be of "A" Class or "B" Class divi-sions, are penetrated for the passage of electrical cables,pipes, trunks, ducts, etc., arrangements should be made toensure that the fire integrity of the division is not impaired.

5.3.8 Air spaces enclosed behind ceilings, panellings orlinings in accommodation spaces, service spaces and con-trol stations should be divided by close-fitting draught stopsspaced not more than 7 m apart.

5.3.9 Windows and skylights to machinery spaces shouldbe as follows:

a) Where skylights can be opened they should be capableof being closed from outside the space. Skylights con-taining glass panels should be fitted with external shut-ters of steel or other equivalent material permanentlyattached.

b) Glass or similar materials should not be fitted inmachinery space boundaries. This does not preclude theuse of wire-reinforced glass for skylights and glass incontrol rooms within the machinery spaces; and

c) In skylights referred to item a) wire-reinforced glassshould be used.

5.3.10 Insulating materials in accommodation spaces, serv-ice spaces except domestic refrigerating compartments,control stations and machinery space should be non-com-bustible. The surface of insulation fitted on the internalboundaries of machinery spaces of category A should beimpervious to oil or oil vapours.


Pt D, Ch 20, Sec 6

5.3.11 Within compartments used for stowage of fish, com-bustible insulation should be protected by close-fitting clad-ding.

5.3.12 Notwithstanding the requirements of this sub-arti-cle, the Society can accept "A-0" class divisions in lieu of"B-15" class divisions, having regard to the amount of com-bustible materials used in adjacent spaces.

5.4 Ships of less than 24 m in length

5.4.1 If steel decks or steel bulkheads in accommodationform the top or side of a fuel oil tank, they should be coatedwith a non-combustible material of thickness and density tothe satisfaction of the Society. Manholes or other openingsto fuel oil tanks should not be positioned in the accommo-dation.

5.4.2 External bulkheads and ship’s sides, which delimitthe accommodation spaces, should be insulated with anappropriate insulating material. Bulkheads between accom-modation spaces and machinery spaces or cargo spacesshould be insulated with a non-combustible material ofthickness and density to the satisfaction of the Society. Thesurface of insulation fitted on the internal boundaries of themachinery spaces of category A and in spaces into whichoil products may penetrate should be impervious to oil oroil vapours.

5.4.3 All insulation in accommodation spaces and thewheelhouse should be made of non-combustible materials.Combustible insulation fitted in spaces used for the storageor processing of fish should be protected by a tight non-combustible covering.

5.4.4 Where there is a door between the accommodationspace and the machinery space, this should be a self-closingdoor of steel or equivalent. Doors between galley rooms anddining rooms might be permitted, provided they are made offire-retardant material; the same applies to a serving hatch.Where only electric cooking appliances are used in the gal-ley, the galley and the mess room could be seen as onecommon room, divided into two appropriate compartments.

6 Ventilation systems

6.1

6.1.1 Means should be provided to stop fans and closemain openings to ventilation systems from outside thespaces served.

6.1.2 Means should be provided for closing, from a safeposition, the annular spaces around funnels.

6.1.3 Ventilation openings can be permitted in and under thedoors in corridor bulkheads except that such openings shouldnot be permitted in and under stairway enclosure doors. Theopenings should be provided only in the lower half of a door.Where such opening is in or under a door the total net area ofany such opening or openings should not exceed 0,05 m2.When such opening is cut in a door it should be fitted with agrill made of non-combustible material.

6.1.4 Ventilation ducts for machinery spaces of category Aor galleys should not in general pass through accommoda-tion spaces, service spaces or control stations. Where theSociety permits this arrangement, the ducts should be con-structed of steel or equivalent material and arranged to pre-serve the integrity of the divisions.

6.1.5 Ventilation ducts of accommodation spaces, servicespaces or control stations should not in general passthrough machinery spaces of category A or through galleys.Where the Society permits this arrangement the ductsshould be constructed of steel or equivalent material andarranged to preserve the integrity of the divisions.

6.1.6 Storerooms containing appreciable quantities of highlyflammable products should be provided with ventilationarrangements, which are separate from other ventilation sys-tems. Ventilation should be arranged at high and low levelsand the inlets and outlets of ventilators should be positionedin safe areas. Suitable wire mesh guards to arrest sparksshould be fitted over inlet and outlet ventilation openings.

6.1.7 Ventilation systems serving machinery spaces shouldbe independent of systems serving other spaces.

6.1.8 Where ducts serve spaces on both sides of "A" Classbulkheads or decks dampers should be fitted so as to preventthe spread of smoke between compartments. Manual damp-ers should be operable from both sides of the bulkhead orthe deck. Where the ducts with a free cross-sectional areaexceeding 0,02 m2 pass through "A" Class bulkheads ordecks, automatic self-closing dampers should be fitted.

6.1.9 Where the ventilation ducts with a free cross-sec-tional area exceeding 0,02 m2 pass through "A" Class bulk-heads or decks, the opening should be lined with a steelsheet sleeve, unless the ducts passing through the bulk-heads or decks are of steel in the vicinity of passage throughthe deck or bulkhead and comply, in that portion of theduct, with the following:

a) For ducts with a free cross-sectional area exceeding0,02 m2, the sleeves should have a thickness of at least3 mm and a length of at least 900 mm. When passingthrough bulkheads, this length should preferably bedivided evenly on each side of the bulkhead. Ducts withfree cross-sectional area exceeding 0,02 m2 should beprovided with fire insulation. The insulation shouldhave at least the same fire integrity as the bulkhead ordeck through which the duct passes. Equivalent penetra-tion protection should be provided to the satisfaction ofthe Society; and

b) Ducts with a free cross-sectional area exceeding0,085 m2 should be fitted with fire dampers in additionto the recommendations of item a). The fire dampershould operate automatically but should also be capa-ble of being closed manually from both sides of thebulkhead or deck. The damper should be provided withan indicator which shows whether the damper is openor closed. Fire dampers are not required, however,where ducts pass through spaces surrounded by "A"Class divisions without serving those spaces, providedthose ducts have the same fire integrity as the bulkheadswhich they penetrate.


Pt D, Ch 20, Sec 6

6.1.10 Where they pass through accommodation spaces orspaces containing combustible materials, the exhaust ductsfrom galley ranges are to be constructed of "A" Class divi-sions. Each exhaust duct is to be fitted with:

• a grease trap readily removable for cleaning

• a fire damper located at the lower end of the duct

• arrangements, operable from within the galley, for shut-ting off the exhaust fans

• fixed means for extinguishing a fire within the duct.

The outlet ducts are to be easily accessible for cleaning.

7 Prevention of fire

7.1

7.1.1 The insulation of accommodation spaces, servicespaces, control stations and machinery spaces is to consistof non-combustible material.

The insulation of refrigerated spaces and fish holds mayconsist of self-extinguishing materials, at the satisfaction ofthe Society.

7.1.2 Impervious linings and adhesives used for the insula-tion of refrigeration plants, as well as for the insulation ofthe related piping, may be of combustible materials, buttheir quantity is to be as limited as possible and theirexposed surfaces are to have a resistance to the flamespread deemed satisfactory by the Society.

7.1.3 In spaces where penetration of oil products is possi-ble, the surface of insulation shall be impervious to oil or oilvapours.

7.1.4 All exposed surfaces in accommodation spaces, serv-ice spaces, control stations, corridors, stairways trunks andassociated hidden and inaccessible spaces behind bulk-heads, ceilings, panels and linings are to have low flamespread characteristics.

7.1.5 Paints, varnishes and other finishes used on exposedinterior surfaces should not be capable of producing exces-sive quantities of smoke or toxic gases or vapours. The Soci-ety should be satisfied that they are not of a nature to offerundue fire hazard.

7.1.6 Primary deck coverings within accommodation andservice spaces and control stations should be of approvedmaterial which will not readily ignite or give rise to toxic orexplosive hazards at elevated temperatures.

7.1.7

a) In accommodation and service spaces and control sta-tions, pipes penetrating "A" or "B" Class divisions shouldbe of approved materials having regard to the tempera-ture that such divisions are required to withstand.Where the Society permits the conveying of oil andcombustible liquids through accommodation and serv-ice spaces, the pipes conveying oil or combustible liq-uids should be of an approved material having regard tothe fire risk.

b) Materials readily rendered ineffective by heat should notbe used for overboard scuppers, sanitary discharges,and other outlets which are close to the waterline andwhere the failure of the material in the event of firewould give rise to danger of flooding.

7.1.8 All waste receptacles other than those used in fishprocessing should be constructed of non-combustible mate-rials with no openings in the sides and bottom.

7.1.9 Machinery driving fuel oil transfer pumps, fuel oilunit pumps and other similar fuel pumps should be fittedwith remote controls situated outside the space concernedso that they can be stopped in the event of a fire arising inthe space in which they are located.

7.1.10 Drip trays should be fitted where necessary to pre-vent oil leaking into bilges.

7.1.11 Electric heating appliances are to be so designedand installed as to reduce fire risks to a minimum. Thedecks and bulkheads on which they are installed are to beadequately protected with non-combustible material.Heating appliances having exposed electrical parts ornaked flame and stoves burning solid fuels are not permit-ted.

8 Means of escape

8.1

8.1.1 Stairways and ladders leading to and from all accom-modation spaces and in spaces, in which the crew is nor-mally employed, other than machinery spaces, should be soarranged as to provide ready means of escape to the opendeck and thence to the survival craft. In particular in rela-tion to these spaces:

a) at all levels of accommodation at least two widely sepa-rated means of escape should be provided which caninclude the normal means of access from each restrictedspace or group of spaces

b)• below the weather deck the means of escape should

be a stairway and the second escape can be a trunkor a stairway; and

• above the weather deck the means of escape shouldbe stairways or doors to an open deck or a combina-tion thereof. Where it is not practicable to fit stair-ways or doors, one of these means of escape can beby means of adequately sized portholes or hatchesprotected where necessary against ice accretion

c) exceptionally the Society can permit only one means ofescape, due regard being paid to the nature and loca-tion of spaces and to the number of persons who nor-mally might be accommodated or employed there

d) a corridor or part of a corridor from which there is onlyone route of escape should preferably not exceed 2,5 min length and in no case be greater than 5,0 m in length,and

e) the width and continuity of the means of escape shouldbe to the satisfaction of the Society.


Pt D, Ch 20, Sec 6

8.1.2 Two means of escape should be provided from everymachinery space of category A, which should be as widelyseparated as possible. Vertical escapes should be by meansof steel ladders. Where the size of the machinery spacesmakes it impracticable, one of these means of escape canbe omitted. In such cases special consideration should begiven to the remaining exit.

8.1.3 Lifts should not be considered as forming one of therequired means of escape.

9 Fire detection

9.1

9.1.1 Where appreciable amounts of combustible materialsare used on the construction of accommodation spaces,service spaces and control stations, special considerationshould be given to the installation of an automatic firealarm and fire detection system in those spaces, having dueregard to the size of those spaces, their arrangement andlocation relative to control stations as well as, where appli-cable, the flame-spread characteristics of the installed furni-ture.

10 Storage of gas cylinders and dangerous materials

10.1

10.1.1 Cylinders for compressed, liquefied or dissolvedgases should be clearly marked by means of prescribedidentifying colours, have a clearly legible identification ofthe name and chemical formula of their contents andshould be properly secured.

10.1.2 Cylinders containing flammable or other dangerousgases and expended cylinders should be stored, properlysecured, on open decks and all valves, pressure regulatorsand pipes leading from such cylinders should be protectedagainst damage. Cylinders should be protected againstexcessive variations in temperature, direct rays of the sun,and accumulation of snow. However, the Society can per-mit such cylinders to be stored in compartments complyingwith the requirements of [10.1.3] to [10.1.5].

10.1.3 Spaces containing highly flammable liquids, such asvolatile paints, paraffin, benzole, etc., and, where permit-ted, liquefied gas should have direct access from opendecks only. Pressure-adjusting devices and relief valvesshould exhaust within the compartment. Where boundarybulkheads of such compartments adjoin other enclosedspaces they should be gastight.

10.1.4 Except as necessary for service within the space,electrical wiring and fittings should not be permitted withincompartments used for the storage of highly flammable liq-uids or liquefied gases. Where such electrical fittings areinstalled, they should be to the satisfaction of the Society foruse in a flammable atmosphere. Sources of heat should bekept clear of such spaces and "No Smoking" and "No NakedLight" notices should be displayed in a prominent position.

10.1.5 Separate storage should be provided for each type ofcompressed gas. Compartments used for the storage of suchgases should not be used for storage of other combustibleproducts nor for tools or objects not part of the gas distribu-tion system. However, the Society may relax these require-ments considering the characteristics, volume and intendeduse of such compressed gases.


Pt D, Ch 20, Sec 6



Chapter 21

OFFSHORE PATROL VESSELS

SECTION 1 GENERAL

SECTION 2 STABILITY

SECTION 3 MACHINERY

SECTION 4 ELECTRICITY AND AUTOMATION

SECTION 5 FIRE SAFETY


Pt D, Ch 21, Sec 1

SECTION 1 GENERAL

1 General

1.1 Application

1.1.1 Ships complying with the requirements of this Chap-ter are eligible for the assignment of the service notationOPV, as defined in Pt A, Ch 1, Sec 2, [4.15.8].

1.1.2 Requirements apply as a function of number of per-sons on board as defined in [1.2] and in any case thenumber of passengers as defined in [1.2.3] is limited to 12.

1.1.3 Ships dealt with in this Chapter are to comply with:• Part A of the Rules• NR216 Materials and Welding• applicable requirements according to Tab 1.

1.1.4 References given in Tab 1 are specified for the use oftechnical criteria and do not mean the full adoption of refer-enced documents.

1.1.5 Attention is to be drawn on the possible additionalrequirements of the flag administration, if any.

1.2 Number of persons on board

1.2.1 The number of persons on board, N, is defined as thesum of:

• number of members of the crew

• number of special personnel, as defined in [1.2.2]

• number of passengers, as defined in [1.2.3], limited to12.

1.2.2 Special personnel means all persons who are not pas-sengers or members of the crew or children of under oneyear of age and who are carried on board in connectionwith the special purpose of that ship because of specialwork being carried out aboard that ship.

1.2.3 Passengers means every persons other than:

• The captain and the members of the crew or other per-sons employed or engaged in any capacity on board aship on business of that ship and

• A child under one year of age.



Ship arrangement and hull integrity

L ≥ 65 or 90 m (1)• Part B• Part C, Chapter 1 (2)

• NR566 (3)

L < 65 or 90 m (1)• NR600• Part C, Chapter 1 (2)

• NR566 (3)

HullL ≥ 65 or 90 m (1)

• Part B• NR396 (4)

• Part B• NR396 (4)

L < 65 or 90 m (1) • NR600 (3) • NR600 (3)

Stability• NR566• Ch 21, Sec 2

• NR566• Ch 21, Sec 2

Machinery• Part C• Ch 21, Sec 3

• NR566 (3)• Ch 21, Sec 3

Electrical installations and automation

N ≤ 60 (5) • Part C • NR566 (3)

N > 60 (5)• Part C• Ch 21, Sec 4

• NR566 (3)• Ch 21, Sec 4

Fire protection, detection and extinction • See Tab 2 • See Tab 2

(1) Refer to the scope of application of NR600.(2) Applicable requirements with respect to discharges and scuppers. see Pt C, Ch 1, Sec 10, [8].(3) Application of these requirements are to be applied except that specific rules for passenger ships are not to be taken into

account.(4) In addition, requirements of NR396, Ch3 apply if V ≥ 7,16Δ1/6 where V is the ship speed, in knots, and Δ is the displacement of

the ship, in tons.(5) The number of persons N is defined in [1.2].Note 1:NR396: Rules for the Classification of High Speed CraftNR566: Hull Arrangement, Stability and Systems for Ships less than 500 GTNR600: Hull Structure and Arrangement for the Classification of Cargo Ships less than 65 m and Non Cargo Ships less than 90 m.


Pt D, Ch 21, Sec 1

Table 2 : Applicable requirements for fire safety

Greater than 1000 GT

Between 500 and 1000 GT

Less than 500 GT

Unrestricted navigation Restricted navigation

Steel or aluminium material N ≤ 60

• Part C, Chapter 4• Ch 21, Sec 5

• NR566 • NR566 • NR566

N >60 (1)• Part C, Chapter 4• Ch 21, Sec 5



• NR566• Ch 21, Sec 5

Composite material N ≤ 60 NA (2) • NR566 • NR566 • NR566

N >60 (1) NA (2) NA (2) NA (2)• NR566• Ch 21, Sec 5

(1) Offshore patrol vessels with more than 200 persons will be subject to special consideration by the Society.(2) The present Chapter does not include this case (NA = not applicable).


Pt D, Ch 21, Sec 2


SECTION 2 STABILITY

1 General

1.1 Application

1.1.1 Offshore patrol vessels may be assigned the servicenotation OPV only after it has been demonstrated that theirstability is adequate.

Adequate stability means compliance with standards laiddown by the relevant Administration or with the require-ments specified in this Section.

In any case, the level of stability is not to be less than thatprovided by the Rules.


Ships granted with service notation OPV are to complywith:

• the provision of NR566, Ch 1, Sec 3, [2] regardingintact stability

• additional requirements of this Section, as applicable.

1.1.3 Damage stability

Damage stability should comply with provisions of NR566,Ch 1, Sec 3, [3] and additional requirements of this Section,as applicable, when at least one of the following conditionsis met:

• the additional class notation SDS is granted

• the offshore patrol vessel is carrying more than 60 per-sons on board.

When damage stability is required the additional class nota-tion SDS is to be granted to the offshore patrol vessel.

In case a double bottom is not fitted or is not in accordancewith the applicable rules then it is to be demonstrated thatthe ship is capable of withstanding bottom damages as per[3.2].

2 Intact Stability

2.1 Maximum turning angle

2.1.1 The angle of heel on account of turning may notexceed 10° when calculated using the following formula:

where:MR : heeling moment, in t.mV0 : Maximum service speed, in m/sT1 : Mean draught above the keel, in mKG : Height of centre of gravity above keel, in mLWL : Length measured at waterline corresponding to

mean draught T1.

2.2 Crowding angle for offshore patrol vessels carrying more than 60 persons

2.2.1 The angle of heel on account of crowding of personsto one side as defined below may not exceed 10°:• A minimum weight of 75 kg is to be assumed for each

person except that this value may be increased subjectto the approval of the Society

• The height of the centre of gravity for person is to beassumed equal to 1m above deck level for person stand-ing upright

• Persons are to be considered as distributed to producethe most unfavourable combination of person heelingmoment and/or initial metacentric height, which may beobtained in practice. In this connection, a value higherthan four persons per square meter is not necessary.

3 Damage stability


3.1.1 Application of requirements in NR566, Ch1, Sec3,[3] where the ship is considered as a passenger ship. How-ever the requirement regarding the margin line is not to beconsidered.

3.2 Bottom damages

3.2.1 Bottom damage stability should comply with provi-sion of NR566, Ch 1, Sec 3, [3] assuming bottom damagesat any position along the ship’s bottom and with an extentspecified in Tab 1.

Table 1 : Assumed extent of damage

MR 0 02 V02Δ KG T1 2⁄–( )

LWL

--------------------------------,=

For 0,3 L from the forward perpendicular of the ship

Any other part of the ship

Longitudinal extent 1/3 L2/3 or 14,5 m, whichever is less 1/3 L2/3 or 14,5 m, whichever is less

Transverse extent B/6 or 10 m, whichever is less B/6 or 5 m, whichever is less

Vertical extent, measured from the keel line B/20 or 2 m, whichever is less B/20 or 2 m, whichever is less

Pt D, Ch 21, Sec 3


SECTION 3 MACHINERY

1 General

1.1 Application

1.1.1 This Section concerns specific requirements regard-ing:• Capacity of service tanks for offshore patrol vessels with

GT ≥ 500• Bilge pumping arrangement and prevention for progres-

sive flooding for ship where damage stability is requiredin accordance with Ch 21, Sec 2, [1.1.3].

1.2 Capacity of service tanks for offshore patrol vessels with GT ≥ 500

1.2.1 Notwithstanding Pt C, Ch 1, Sec 10, [11.9.2], itemsb), c) and d), the capacity of service tanks should complywith NR566, Ch 2, Sec 6, [4.2.2], Note 2 excluded.

1.3 Offshore patrol vessels for which damage stability is required

1.3.1 Offshore patrol vessels with GT ≥ 500• Reference to Pt B, Ch 3, Sec 3 as stated in Pt C, Ch 1,

Sec 10, [5.5] is to be replaced by NR566, Ch 1, Sec 3,[3].

• In addition to the requirements as stated in Pt C, Ch 1,Sec 10, [6], provision of NR566, Ch 2, Sec 5, [1.6]should apply.

1.3.2 Offshore patrol vessels with GT < 500Requirements as stated in NR566, Ch 2, Sec 4, [5.9] andNR566, Ch 2, Sec 5, [1.6] should apply.

Pt D, Ch 21, Sec 4


SECTION 4 ELECTRICITY AND AUTOMATION

1 General

1.1 Application

1.1.1 The requirements in this Section apply to offshorepatrol vessels carrying more than 60 persons.

1.2 General alarm for ships with GT < 500

1.2.1 In addition to the requirements required in NR566,Ch 3, Sec 2, [3.11.1], the following requirements in NR566,Ch 3, Sec 2, [3.11.2], item b), should apply.

1.3 Emergency source of electrical power for ships with GT ≥ 500

1.3.1 Notwithstanding Pt C, Ch 2, Sec 3, [2.3.13], items b)and c), where the emergency source of electrical power is agenerator, it shall be started automatically upon failure ofthe electrical power supply to the emergency switchboard

and shall be automatically connected to the servicesreferred in Pt C, Ch 2, Sec 3, [3.6.7]. The automatic startingsystem and the characteristics of the prime mover shall besuch as to permit the emergency generator to carry its fullrated load as quickly as is safe and practicable, subject to amaximum of 45 s.In addition, a transitional source of emergency electricalpower as specified in Pt C, Ch 2, Sec 3, [2.3.16] is to beprovided in all cases when the emergency source of poweris a generator.

1.4 Public address system for ships with GT ≥ 500

1.4.1 Where the public address system is used to supple-ment the general emergency alarm system as per Pt C, Ch 2,Sec 3, [3.14.2], it is to be arranged to operate on the mainsource of electrical power, the emergency source of electri-cal power and the transitional source of electrical power asrequired in [1.3] and Pt C, Ch 2, Sec 3, [3.6].

Pt D, Ch 21, Sec 5


SECTION 5 FIRE SAFETY

1 General

1.1 Application

1.1.1 The applicable requirements are defined in Ch 21,Sec 1, Tab 2. Part C, Chapter 4 and Rule Note NR566 are to be appliedexcept that specific rules for passenger ships are not to betaken into account.

1.1.2 Fire safety of offshore patrol vessels carrying morethan 200 persons will be subject to special consideration bythe Society.

2 Materials

2.1 Steel or equivalent

2.1.1 In case the application of Part C, Chapter 4 isrequired, all indications “steel” (without the extension “orequivalent”) in these rules, can be replaced by “steel orequivalent”.

2.1.2 In case the application of Part C, Chapter 4 isrequired, aluminium bulkheads are generally to be insu-lated on both sides. However, if one of the two spaces havelittle or no fire risk such as voids, sanitary spaces, carbon

dioxide rooms and similar spaces, insulation need only tobe applied on the side that is exposed to the greatest firerisk.

3 Specific requirements


3.1.1 For offshore patrol vessels carrying more than 60 per-sons and when the application of NR566 is authorised, thefollowing additional rules apply:

• exposed surfaces of bulkheads, walls, linings and ceil-ings in accommodation and service spaces and controlstations are to be low flame spread

• remote starting of one fire pump is to be provided fromwheel house.

3.2 Ammunition storage compartments

3.2.1 The protection of ammunition storage compartmentswill be subject to special consideration by the Society.Applicable rules will be based on a common agreementwith the shipowner and the shipyard, including aspects offire detection, structural fire integrity, ventilation, fire fight-ing and electrical equipment protection.

RSS

Documents

Transcript of RSS