DNVGL-RP-0232 Pipeline and cable laying equipment laying equipment. This recommened practice will...

The electronic pdf version of this document, available free of chargefrom http://www.dnvgl.com, is the officially binding version.

DNV GL AS

RECOMMENDED PRACTICE

DNVGL-RP-0232 Edition September 2018

Pipeline and cable laying equipment

FOREWORD

DNV GL recommended practices contain sound engineering practice and guidance.

© DNV GL AS September 2018

Any comments may be sent by e-mail to [email protected]

This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of thisdocument. The use of this document by others than DNV GL is at the user's sole risk. DNV GL does not accept any liability or responsibilityfor loss or damages resulting from any use of this document.

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Recommended practice — DNVGL-RP-0232. Edition September 2018 Pipeline and cable laying equipment

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CONTENTS

Changes – current.................................................................................................. 3

Section 1 General....................................................................................................61.1 Introduction......................................................................................61.2 Objectives......................................................................................... 61.3 Scope................................................................................................ 61.4 Application........................................................................................61.5 References........................................................................................ 71.6 Definitions and abbreviations........................................................... 81.7 Categorization.................................................................................141.8 Services.......................................................................................... 15

Section 2 Documentation and certification........................................................... 192.1 Documentation to be submitted......................................................192.2 Certification requirements.............................................................. 21

Section 3 Material and fabrication........................................................................ 243.1 General........................................................................................... 243.2 Rolled steel for welding..................................................................24

Section 4 Structural strength................................................................................254.1 General........................................................................................... 254.2 Design loads................................................................................... 254.3 Cases of loading............................................................................. 264.4 Strength calculations...................................................................... 27

Section 5 Machinery and equipments....................................................................285.1 General........................................................................................... 285.2 Special requirements for tensioners/drum machines/holdingassemblies/A&R winches/storage equipment...................................... 28

Section 6 Safety and safety equipment.................................................................316.1 General........................................................................................... 316.2 Safety philosophy........................................................................... 316.3 Methods.......................................................................................... 31

Section 7 Testing...................................................................................................337.1 General........................................................................................... 337.2 System testing................................................................................33

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7.3 Prime movers and fluid power systems.......................................... 367.4 Electrical installations.....................................................................367.5 Load test.........................................................................................367.6 Periodical surveys...........................................................................36

Changes – historic................................................................................................40


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SECTION 1 GENERAL

1.1 IntroductionThe standard for offshore and platform lifting appliance DNVGL-ST-0378 has been successfully usedfor pipeline and cable laying equipment. However there are some special considerations for this type ofequipment that are not covered in detail in DNVGL-ST-0378, particularly with respect to the definition ofsafe working load and of the relevant load cases, safety systems and testing for pipeline and cable layingequipment. This recommended practice addresses the specific needs for pipeline and cable laying equipmentand is based on the initial results from the joint industry project Development of codes for offshore cable andpipe laying equipment. This recommened practice will therefore be supplementary to the DNVGL-ST-0378.

1.2 ObjectivesThe objective of this recommended practice is to provide criteria and guidance for certification andverification of the design, materials, fabrication, safety, testing of the pipeline and cable laying equipmentand systems.These specifications have been developed with the view of promoting safety by providing industry unifiedcriteria for verification and certification of the pipeline and cable laying systems. It can therefore serve as atechnical guidance for manufacturers seeking verification or certification of equipment and systems used forpipeline and cable laying, retrieving, handling repair operations and handling maintenance operations.In summary, the objectives of this recommended practice are to:

— provide an internationally acceptable recommended practice of safety for pipeline and cable layingequipment and systems by defining minimum requirements for the design, materials, fabrication,installation and testing

— serve as a technical reference document in contractual matters between purchaser and contractor— serve as a technical reference document for classification, certification and verification services— serve as a guideline for designers, purchasers and contractors.

1.3 ScopeThese guidelines and specifications cover the equipment associated with pipeline and cable laying operations,regardless of the laying method (J lay, S lay, Flex lay, Reel Lay, etc. ). The laying operations cover thespectrum of operations from load-out, transportation and pipeline and cable handling to laying or retrieving,recovery and repair.

1.4 ApplicationThis document provides general requirements to reach the objectives as listed in [1.2].This recommended practice is applicable for certification of pipeline and cable laying equipment. For DNV GLclassification purposes, these vessels are identified by the class notation Pipe laying vessel or Cable layingvessel.This recommended practice may also be applied on a voluntary basis for verification or certification ofpipeline and cable laying equipment temporarily or permanently installed on any other supporting vessels.Figure 1-1 illustrates the workflow from project initiation to testing of equipment, with corresponding sectionsin this document.


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Figure 1-1 Use of this recommended practice

1.5 ReferencesOnly the latest revision of the following referenced standard at the time this document is applied shall beused.

Table 1-1 Rules and standards for certification

Document code Title

DNVGL-RU-SHIP DNV GL Rules for classification: Ships

DNVGL-ST-0378 Standard for offshore and platform lifting appliances

Table 1-2 Class programmes

Document code Title

DNVGL-CG-0156 Conversions of ships

DNVGL-CG-0197 Additive manufacturing - qualification and certificationprocess for materials and components

DNVGL-CP-0337 General description of services for certification of materialsand components


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Document code Title

DNVGL-CP-0338 Type approval scheme

Table 1-3 Other normative references

Document code Title

ISO 10474 Steel and steel products - Inspection documents

ISO 12482 Cranes - Monitoring for crane design working period

EN 10204 Metallic products - Types of inspection documents

1.6 Definitions and abbreviations

1.6.1 AbbreviationsTable 1-4 Abbreviations

Abbreviation Description

AP approved

A&R abandonment and recovery

FI for information

FMEA failure modes and effects analysis

HAZID hazard identification analysis

HAZOP hazard and operability study

ILO International Labour Organization

MBR minimum bending radius

MELL maximum exceptional line load (specific to active andpassive equipment, see [1.7])

MOLL maximum operational line load (specific to active andpassive equipment, see [1.7])

MSL maximum storage load (specific to storage equipment, see[1.7])

OLA test certificate for test and thorough examination of Liftingapliances (non-ILO)

PC product certificate

PLET pipeline end termination

QRA quantitative risk analysis

TA type approval

TD design temperature


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Abbreviation Description

TR test report

1.6.2 DefinitionsTable 1-5 Definitions

Term Definition

abandonment & recovery operation of abandoning and recovering the pipeline orcable to and from the seabed

abandonment & recovery system system whose primary function is to lower and retrieve theproduct to and from the seabed

aligner

radius controller typically located at the top of a layingtowerUsed to maintain a minimum radius and guide the productfrom inboard storage devices into the firing line bychanging its direction and accommodating differences inalignment. The Aligner is usually a larger diameter wheel,series of rollers in an arc, on a belt in an arc.

chute

equipment used for guiding the product during layingoperationsTypically used in horizontal lay systems to help overboardthe product and avoid bending less than the MBR in one ortwo planes. May be called an overboarding chute.

carousel/basket

equipment used for storage during transportation andinstallation of flexible pipelines, umbilicals, cables and otherproducts for offshore applicationsThe carousel's purpose is storing the product around acentral vertical core. The product is arranged in horizontalor vertical layers around the central core from the baseupwards.

clamp (friction)

equipment used to hold the product during layingoperationsThe friction clamp consists of a series of pads alignedaround the circumference of the product. The friction clampworking principle is based on generating grip between theclamp pads and the product, and thus holding the product(similar to the tensioner, however it has no paying out/incapabilities).

collar clamp (hang-off)

equipment used to hold the product during layingoperationsUnlike friction clamps, hang-off collar clamps workingprinciple is providing support to the product (product ishanging off from the clamp by means of a collar/flangewhich rests on the body of the hang-off clamp).


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Term Definition

dead loads

weights of all the fixed and mobile components ofequipment associated with laying operations and loose gearpermanently present during operationFor the purpose of marking, the dead loads of loose gearare designated as weight by the ILO. The unit is specified intons (t) or kilograms (kg).

deflector

equipment used for guiding the product during layingoperationsTypically used in flexible lay systems to help avoid bendingless than the MBR in one or two planes.

design temperature

reference temperature used as a criterion for the selectionof steel gradesThe design temperature TD for pipeline and cable layingequipment is defined as the lowest acceptable servicetemperature for the equipment.

drum machines (capstan)

machine consisting of a rotating drum used to hold andcontrol the product line loadThe capstan working principle is based on friction build-upbetween the drum and the product line.

emergency laying operationsoperation of assembling and laying the pipeline and cableon the seabed, from start-up point to lay-down point,during emergency conditions

gripping forceproduct holding force generated by the squeeze force anddependent on the friction between the product and thesqueezing assembly

holding assemblies friction clamps, hang-off clamps or Chinese fingers

inertia forces forces induced by change of linear or angular velocity

inspection certificate 3.1

document issued by the manufacturer which contains theresults of all the required testsIt shall certify that the tests have been carried out bythe manufacturer on samples taken from the deliveredproducts direct. See EN 10204 and ISO 10474.

loading arm

equipment consisting of a support structure/frame/tower, positioning mechanism, component for controllingand holding the product line and passive guides/radiuscontrollersUsed for loading or unloading flexible product to and from astorage device.

machinery componentsrotating components transferring torque for driving/brakingpurposeExamples ar gearboxes, wheels and shafts.

maximum dynamic braking load

maximum line load that it is developed during the stoppingin the minimum stopping time (emergency-stop time) theproduct line moving at maximum speed while loaded withMOLL or MELL as requestedIt is associated with structural strength SF= 1.0.


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Term Definition

maximum exceptional line load (MELL)

maximum emergency dynamic line load, which may bedetermined considering the selfweight of the product lineand the hydrodynamic effects acting on it (wave, current,drag, added mass, etc), inertia, product line stiffness,vessel movement and the catenary shape solutionIt is assumed that MELL is determined following aninstallation analysis and it shall be provided by thedesigner. MELL is defined as the equipment rating duringemergency conditions (eg. operation outside designweather window, emergency/accidental A&R operations).

maximum line speed maximum line speed at which the equipment can safelywork as per equipment design specification

maximum operational line load (MOLL)

maximum operational dynamic line load, which may bedetermined considering the selfweight of the product lineand the hydrodynamic effects acting on it (wave, current,drag, added mass, etc), inertia, product line stiffness,vessel movement and the catenary shape solutionIt is assumed that MOLL is determined following aninstallation analysis and it shall be provided by thedesigner. MOLL is defined as the equipment rating duringnormal operation.

minimum bending radius (MBR) minimum allowable bend radius as defined by the productmanufacturers

maximum storage load (MSL) maximum payload stored in the storage equipment, seeTable 1-7

minimum stopping time (quick stop time) minimum time required for the parking brake to stop theproduct line considering maximum laying speed

normal laying operationoperation of assembling and laying the pipeline and cableon the seabed, from start-up point to lay-down point,during normal operation conditions

offshore operation

variety of offshore operations covering a spectrum ofoperations from load-out, transportation and pipeline andcable handling to laying or retrieving, recovery, repair andmaintenance

pipeline and cable laying equipment

structural/mechanical assemblies (individual equipment)with functionality during pipeline and cable laying and/orretrieving and or handling maintenance and/or handlingrepair operations

pipeline and cable laying control systemsystem which controls and monitors the functionality of theinstallation spread or the individual equipment, may alsoinclude the safety system

pipeline and cable laying system (installation spread)equipment necessary to perform the pipeline and cablelaying and/or retrieving and/or handling maintenance and/or handling repair operations


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Term Definition

pipeline and cable laying safety system

essential system consisting of a series of sub-systems anperforming a series of essential functions (i.e. essentialsafety functions) preventing the use of the equipmentoutside its operational limitations (e.g. overload systems,etc.)

product certificate (general)

compliance document validated and signed by the issuingorganization:

— identifying the product that the certificate applies to— confirming compliance with referred requirements.

It is required that:

— the tests and inspections have been performed on thecertified product itself, or, on samples taken from thecertified product itself

— the tests were witnessed by a qualified representativeof the organization issuing the certificate, or, hisauthorized representative.

product certificate (DNV GL's)

a compliance document validated and signed by the issuingorganization and DNV GL's representative:

— identifying the product that the certificate applies to— confirming compliance with referred requirements.

It is required that:

— the tests and inspections have been performed on thecertified product itself, or on samples taken from thecertified product itself

— the tests were witnessed by a qualified representativeof the organization issuing the certificate and DNVGL's representative, or in accordance with specialagreements.

product the main object to be installed, i.e. rigid pipeline, flexiblepipe, umbilical or power cable

product linecontinuous string of product between storage device andseabed including intermediate and ancillary pieces e.g. endterminations, clamps, etc

quadrant

equipment used during handling of product line used toensure keeping the product within allowable strain limitsThe structure is normally loose and it's lifted by a craneduring handling operations.

pipeline end termination (PLET) handling equipment equipment used to handle the pipeline end termination

radius controller

equipment used to maintain a minimum bending radius(MBR) of the product, whilst changing its directionThe product is generally supported by a continuous surfaceor series of rollers.


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Term Definition

reel

equipment used for storage during transportation andinstallation of flexible pipe, umbilicals, risers and otherproducts for offshore applicationsThe reel principle is based on storing the product around acentral horizontal core.

reel drive systemsystem used for spooling and unspooling of rigid andflexible pipe, umbilicals, risers and other products foroffshore applications, stored on multiple reels

ship type notations

code used by the classification societies to define a type ofvessel related to its most typical service(Cable Laying vessel, pipe laying vessel, passenger shipand crane vessel are typical examples).

squeeze force force normal to product surface, applied to generate gripingforce

stinger

equipment used to support the product at the exit pointfrom the vessel, and ensures keeping the product withinallowable strain limitsThe structure is normally pinned/hinged to the hullstructure of the host vessel.

storage winch

part of the A&R system, it works in combination with thetraction winchIts purpose is storing the wire rope and maintaining aconstant hold-back force for the traction winch. It has lowload capabilities, relative to the traction winch.

straightener mechanism used to apply a reverse bending moment andrestore the straightness of rigid linel

tensioner

equipment used to grip, control the movement and/orhold the product line in its axial direction, by applying asqueezing force on the productTensioner normally consists of several caterpillar-type tracks mounted in a frame or multiple wheel pairdevice made up of vertically opposed rubber tires whichhydraulically close down on the product.

The tensioner working principle is based on generating gripdeveloped between the caterpillar-type tracks or the wheelpairs and the product, and thus controlling and holdingthe product. The grip force is independent of product linetension.

Tensioners are normally required to operate over a range ofproduct types and diameters.

test report

document signed by the manufacturer stating:

— conformity with requirements given by a relevantstandard

— that tests are carried out on samples from the currentproduction


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Term Definition

traction winch

winch part of the A&R system, usually consisting of twodrumsThe traction winch working principle is based on frictionbuild-up between the drums and the wire rope.

travelling assemblystructural and mechanical component used to support theclamps which travel along a predefined guided path alongthe laying tower height

type approval

approval of conformity with specified requirements on thebasis of systematic examination of one or more specimensof a product representative of the production, see DNVGL-CP-0338

works product certificate

document signed by the manufacturer stating:

- conformity with rule requirements

- that tests are carried out on the certified product itself

- that tests are made on samples taken from the certifiedproduct itself

- that tests are witnessed and signed by a qualifieddepartment of the manufacturers,

see DNVGL-RU-SHIP Pt.1 Ch.3 Sec.5

1.6.3 Verbal formsTable 1-6 Definition of verbal forms

Term Definition

may verbal form used to indicate a course of action permissible within the limits of the document

shall verbal form used to indicate requirements strictly to be followed in order to conform to the document

shouldverbal form used to indicate that among several possibilities one is recommended as particularly suitable,without mentioning or excluding others, or that a certain course of action is preferred but not necessarilyrequired

1.7 CategorizationGenerally, the pipeline and cable laying systems components are categorized as follows.Depending on the system configuration, the below defined categories for various equipment shall be agreedwith DNV GL on a case-by-case consideration.


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Table 1-7 Categorization

Type Description

Active equipment - high risk

Equipment used to control and suspend the product line(e.g. tensioner, drum machines, friction and hang-offclamp, travelling assembly, A&R system, etc. and theirsupporting structure), whose failure to perform its functionis associated with significant risk to product line, propertyother than product (equipment and host asset), life orenvironment (i.e. failure in these equipment could lead toloss of load).

Active equipment - low risk

Equipment used to control and suspend the product linewhose failure to perform its function is associated withlow risks for product line, property other than product(equipment and host asset), life or environment (i.e.failure in these equipment will not lead to loss of load).Normally these are all the rest of the equipment other thanthe "active equipment - high risk" involved in the variousphases of the pipeline laying or retrieving operation (e.g.service crane, reeving assemblies inboard of tensioner/hang-off clamp, initiation winch and other winches,spooling equipment PLET handling equipment, etc.).

Passive equipmentEquipment used to alter the direction or guide the product(radius controller, centralizer, straightener, stinger, chute,deflector, quadrant, etc).

Storage equipment Equipment used to store the product (storage winch,carousels, reels, etc.).

1.8 Services

1.8.1 GeneralThe following activities are covered by this recommended practice:Basic certification:

— design review (approval), see [1.8.2]— survey during fabrication and installation, see [1.8.3]— witness testing and marking, see [1.8.6]. Verification

— design review (verification), see [1.8.4], [1.8.5] and [1.8.7.2].

Figure 1-2 describes the services offered and the associated documents issued by DNV GL to provecompliance.

Guidance note:Individual equipment, part of an installation spread, can be certified provided it is clearly defined whether it can function asstandalone or as integrated equipment. If the latter is applicable, then the integration with the rest of the installation spreadand control system should be considered by the responsible entity for the delivery of the pipeline and cable laying systems. Fordefinitions see Table 1-5.

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Figure 1-2 Alternatives for documentation that may be issued to customers depending on typeand combination of services requested.

1.8.2 Design review procedureLoad-carrying and other important components of a pipeline and cable laying system are subject to designreview with respect to strength and suitability for its purpose. A design approval is granted when the designreview has been concluded without any non-compliances.The design review may be substituted, partly or completely, by enhanced manufacturing survey and/ortesting. In cases where the substitutions are applied for by the customer, agreements shall be made betweenthe customer and DNV GL regarding possible reductions of documentation to be submitted for approval/information.Upon special agreement, the design review may be substituted by a strength evaluation based upon testinguntil failure.Structural strength review of the components related to power supply and safety equipment is normally notcarried out by DNV GL.


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1.8.3 Survey during manufacturing and installationNormally, a survey during manufacture of each separate pipeline and cable equipment shall be carried out byDNV GL's surveyor in order to ascertain compliance with the approved drawings, other requirements given inthis recommended practice as well as general good workmanship.As an alternative to survey during manufacture of each separate equipment, modified survey procedures andsurvey arrangements may be accepted, see DNVGL-CP-0337.After an equipment or installation spread has been installed on its permanent foundation in preparation forfunction testing, and before testing can take place, it shall be subjected to a survey by DNV GL.

1.8.4 Extension of scope of workUpon request from the customer, the scope of work may be extended beyond the subjects and aspectscovered in this certification standard. Extensions shall be agreed in writing. DNV GL may, if found necessary,require that the customer presents reference documents for the extended scope of work, such as authorityregulations, norms and standards.In case of disputes regarding interpretations of requirements on which extended work is based, thecustomer shall contact the publisher/owner of the requirements and obtain their written interpretation. If thepublisher/owner is not willing to interpret the disputed requirement, or an interpretation for other reasonscannot be acquired, DNV GL's interpretation will prevail.

1.8.5 Limitation of scope of workUpon request from and agreed with the customer, parts of the scope of work, components, systems orspecific aspects or requirements may be excluded from the scope of work specified in this certificationstandard. This will be annotated in the documentary evidence of the completed assignment.DNV GL will not agree to limit the scope of work or parts of the suggested services if they are of the opinionthat this may lead to hazards or unacceptable lowering of the safety standard.A limitation of scope of work is not applicable when a DNV GL product certificate is required.

1.8.6 TestingEquipment and installation spreads shall be subjected to functional testing and load testing as specified inSec.7.

1.8.7 Types of services1.8.7.1 Basic CertificationPipeline and cable laying equipment and systems found to comply with these basic requirements are qualifiedfor DNV GL's product certification, whereupon the product certificate Form 71.03a may be issued based onFAT (factory acceptance test) and survey. Following successful testing and survey after installation onboard, aDNV GL Product certificate will be issued for pipeline and cable laying system. This basic requirement coversboth individual pipeline and cable laying equipment and installation spread, see Table 1-5.For equipment not part of class, the certification may be concluded at the manufacturer, based on FAT andsurvey. On-board test procedures as well as witness/acceptance may be endorsed by a competent personaccepted by flag/state authorities.

1.8.7.2 VerificationDNV GL may upon request carry out specified examination or combination of separate services referring tothe requirements given in Sec.3 through Sec.7 or the related standards and services described in [1.8].


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The depth, thoroughness and completeness of the examinations shall be agreed upon for each specificverification assignment, and shall be unambiguously described in the contract and in the documentation ofthe verification service.

Guidance note:DNV GL is flexible in agreeing on type of documentation of verification services performed. Normally, DNV GL’s proposal will be toissue a verification report. For instance, for a completed design examination DNV GL will suggest issuance of a Design verificationreport.DNV GL endeavours to find the best solution for issuance of required verification documentation.


Whereas the scope, standards and acceptance criteria for a certification or classification assignment islaid down by DNV GL, the scope, standards and acceptance criteria forming the basis for a verificationassignment may, if requested, be adapted to the needs and desires of the customer. However, DNV GL willdecline to carry out a commission that may be used, intentionally or unintentionally, to mislead a third partywith regard to the safety of the object.A verification report may be edited in accordance with the customer’s needs and requests. DNV GL is,however, not prepared to omit non-conformities or other negative observations or results detected during theexaminations.

1.8.7.3 Pipeline and cable laying systems included in class scopeDNV GL certified pipeline and cable laying equipment and systems installed on board vessels and offshoreunits classed with DNV GL may be included in the scope of work covered by classification. In such casesthe vessel/offshore unit will be assigned the additional class notation Pipe laying vessel or Cable layingvessel.


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SECTION 2 DOCUMENTATION AND CERTIFICATION

2.1 Documentation to be submittedThe documentation requirements stated below in Table 2-1 are required for design approval and ensuingcertification.

Table 2-1 Documentation requirements

Object Documenttype Installation spread

ActiveEquipment- high risk

ActiveEquipment- low risk

Passiveequipment

Storageequipment

C010 - DesignCriteria FI FI FI FI FI

C020 -Assembly orarrangementdrawings

FI FI FI FI FI

C030 -Detaileddrawing

AP AP AP AP AP

C040 - Designanalysis FI FI FI FI FI

C050 - Non-destructivetesting (NDT)plan

AP AP FI FI FI

Z060 -Functionaldescription

FI FI FI FI FI

Z252 - Testprocedure atmanufacturer

AP AP FI FI FI

Z253 - Testprocedure forquay and seatrial

AP AP FI FI FI

General

Z161 -Operationalmanual

FI FI FI FI FI

Power supplyA030 - Systemarrangementplan

FI FI FI FI FI

Electricalpower system

E170 -Electricalschematicdrawing

AP 1) AP FI FI FI


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Object Documenttype Installation spread

ActiveEquipment- high risk

ActiveEquipment- low risk

Passiveequipment

Storageequipment

Z090 -Equipment list FI FI FI FI FI

A011 - Systemdiagram(P&ID)

AP 1) AP FI FI FI

S042 -Hydrauliccontroldiagram

AP 1) AP FI FI FI

Z060 -Functionaldescription

FI FI FI FI FI

Hydraulicpower system

Z090 -Equipment list FI FI FI FI FI

Control andmonitoring

I200 -Control andmonitoringsystemdocumentation

AP 1) AP FI FI FI

Fire safety

G090 - Areasafety chart orfire protectiondata chart

AP 1) AP FI FI FI

Failure modeand effectanalysis

Z071 - Failuremode andeffect analysis(FMEA)

FI2) - - - -

Quantitativerisk analysis

Quantitativerisk analysis(QRA)

AP2)

AP = for approval, FI = for information1) If the installation spread is subject to certification, the general assembly drawings/documentation shall be submitted,and not detailed drawings/documentation for each equipment.

2) See also Sec.6.

Guidance note:Considering the type service requested (full scope certification see [1.8.7.1] or reduced scope see [1.8.7.2] the requirements fordocumentation will be accordingly adjusted. Examples below:

1) The documentation required for structural design verification in [1.8.5.3] may be limited to “General” object, see Table 2-1.

2) The documentation required for certification in [1.8.5.1] (complete review, including structural review and control systemreview) extends to the complete list provided in Table 2-1.



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2.2 Certification requirementsThe certification requirements stated in Table 2-2 below are required for ensuing certification of installationspreads. The certification requirements stated in Table 2-3 to Table 2-6 below are required for ensuingcertification of pipeline and cable laying equipment.

Table 2-2 Certification requirements - installation spread

Object Certificate type

Active equipment - high risk PC

Active equipment - low risk PC

Passive equipment PC

Storage PC

Table 2-3 Certification requirements - active equipment - high risk

Object Certificate type Issued by Additional description

Slewing rings PC DNV GL

Hydraulic cylinders PC DNV GL applicable also foraccumulators

Winches PC DNV GL

Sheaves PC DNV GLworks product certificate willbe satisfactory for unweldedmetallic sheaves

Tensioner track PC Manufacturer design approval and worksproduct certificate

Track chain PC Manufacturer

Track pads - -

designer and client/owner/operator shall agree theperformance requirementsfor the track pads

Wire rope PC DNV GL

certificate of test andthorough examinationof loose gear (CG4)Alternatively ILO form No.4.

Transmission gears, screwjacks and brakes PC Manufacturer design approval and works

product certificate

Slewing gear PC Manufacturer works product certificate

Hydraulic components TR Manufacturer

Electrical motors with rating100kW and above PC or TA DNV GL applicable for class notation

only


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Motor starters and frequencyconverters with rating100kW and above

PC or TA DNV GL applicable for class notationonly

Control&monitoring system PC DNV GL applicable for class notationonly

Slip rings, with rating 100kW and above PC DNV GL applicable for class notation

only

PC = product certificate, TA = type approval, TR = test report

Table 2-4 Certification requirements - active equipment - low risk


Service crane PC DNV GL category - platform crane

Slewing rings PC Manufacturer when not installed on theservice crane

Hydraulic cylinders PC DNV GL Applicable also foraccumulators

Winches PC DNV GL

Sheaves PC DNV GLworks product certificate willbe satisfactory for unweldedmetallic sheaves

Tensioner track PC Manufacturer design approval and worksproduct certificate

Track chain PC Manufacturer

Wire rope PC DNV GL

certificate of test andthorough examinationof loose gear (CG4).Alternatively ILO form No.4

Transmission gears, screwjacks and brakes PC Manufacturer design approval and works

product certificate


Hydraulic components TR Manufacturer except mountings

PC = product certificate, TA =type approval, TR = test report

Table 2-5 Certification requirements - passive equipment


Hydraulic cylinders PC Manufacturer

Transmission gears, screwjacks and brakes PC Manufacturer

Hydraulic components TR Manufacturer


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Table 2-6 Certification requirements - storage equipment


Slewing rings and bearings PC Manufacturer

Transmission gears, screwjacks and brakes PC Manufacturer works product certificate


Hydraulic components TR Manufacturer except mountings



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SECTION 3 MATERIAL AND FABRICATION

3.1 GeneralGenerally, the material and fabrication requirements listed in DNVGL-ST-0378 are valid for pipeline and cablelaying systems. This section specifies requirements specific to pipe and cable laying systems which replacethose listed in the aforementioned sections.The use of materials, products and components made by additive manufacturing technologies (defined asmanufacturing processes involving sequential layer material addition throughout a 3D work envelope underautomated control) shall be subject to approval and qualification according DNVGL-CG-0197 on a case bycase basis. The designer shall preventively inform DNV GL about the intended use of additive manufacturingcomponents during the production/assembly process.

3.2 Rolled steel for weldingRequired impact test temperatures are dependent on design temperature (see Table 1-5) and the materialthickness. Impact test temperatures for structural steel for special, primary and secondary applications aregiven in Table 3-1 which replace the requirements listed in DNVGL-ST-0378 Table 3-1.

Table 3-1 Impact properties for welded structural steel

Impact test temperatures in °C1)

Material thickness t in mm Structural steel for specialand primary members 2)

Structural steel forsecondary members2)

6 ≤ t ≤ 12 3) T D + 20 Test not required

12 ≤ t ≤ 25 T D + 10 Test not required

25 ≤ t ≤ 50 T D - 10 T D + 10

t > 50 T D - 30 T D

1) For steel with yield stress below 500 MPa, the test temperature need not be taken lower than -40°C. For steel withyield stress above 500 MPa, the test temperature shall not be taken higher than 0°C and not lower than -60°C.

2) See Table 1-5 for definitions.

3) For plate less than 6 mm, Charpy V testing will not be required.


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SECTION 4 STRUCTURAL STRENGTH

4.1 GeneralGenerally the load definitions listed in DNVGL-ST-0378 Sec.4 are valid for pipeline and cable layingequipment. This section provides requirements specific to pipeline and cable equipment which replace thoselisted in the aforementioned standard.

4.2 Design loads

4.2.1 Principal loadsThe principal loads are:

— The loads due to dead weight of the components (SG).— The loads due to maximum operational line load (MOLL). The maximum operational line load is considered

to be of continuous dynamic nature; to be defined by the designe.— The loads due to maximum storage load (MSL). For storage equipment the maximum operational load is

considered the maximum selfweight of the product, in addition to any relevant line tension.

The horizontal components due the heel and trim of the vessel, shall be taken into account. The values to beconsidered are the maximum angles expected during laying or retrieving operation with no wind and wavesacting. If not otherwise specified by the designer, minimum values to be used, are given in Table 4-1.

Table 4-1 Minimum heel and trim angles, still water

Type of vessel Heel Trim

Ships and vessels having ship-shapehull properties Min. 5° Min 2°

Barges of length less than 4 timesbreadth, and catamarans Min. 3° Min 2°

Semi-submersibles Min. 3° Min. 3°

Significant inertia forces induced due to the change of velocity in the product line shall be considered.The inertia due to angular acceleration/deceleration of rotating machinery components shall be taken intoaccount when this effect is significant.

4.2.2 Loads due to motion of the vessel1) For normal laying, retrieving and maintenance operations, the inertia forces due to ship motion shall be

calculated. The vessel accelerations for the operational cases shall be stated by the designer (SMop).2) For emergency laying, abandonment and retrieving operations, the inertia forces due to ship motion shall

be calculated. The vessel accelerations for the emergency cases shall be stated by the designer (SMEm).3) For transit conditions the inertia forces due to ship motion shall be calculated. The vessel accelerations

for the transit/survival case shall be based on the extreme values given in the governing code for thesupporting vessel (SM).

The inertia forces caused by the vessel motions shall be combined according to relevant rules/calculations forthe vessel considered.


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4.2.3 Loads due to climatic effects4.2.3.1 Loads due to windLoads due to wind shall be calculated in accordance with DNVGL-ST-0378 App.A or a recognized code orstandard:

1) Loading due to working wind (SW).2) Loading due to emergency wind (SEm). For emergency laying, abandonment and retrieving operations,

the wind forces shall be stated by the designer.3) Loading due to out of service wind (SWmax).

4.2.3.2 Loads due to ice and snowSnow and ice loads may be neglected in the design calculations except for equipment working underexceptional conditions, or for equipment of special design being particularly sensitive to such effects.

4.2.3.3 Loads due to sea pressureThese loads will vary according to vessel type and the actual location of the equipment on vessel.Sea pressure loads shall be calculated according to DNVGL-RU-SHIP Pt.3 Ch.4 Sec.5 and DNVGL-CG-0156.

4.2.3.4 Air temperatureUnles otherwise specified in this recommended practice, systems and equipment shall be designed foroperation under ambient air temperature:— between the minimum design temperature and 45°C— inside machinery housing or other compartments containing equipment between 5°C and 55°C .

4.3 Cases of loading

4.3.1 IntroductionFor the purpose of making the nominal safety dependent upon the probability of occurrence of the loading,three general cases of loading are defined, for which the required safety margins are different:

Case I = pipeline and cable laying equipment subject to normal working conditionsCase II = pipeline and cable laying equipment subject to emergency operational loading

conditionsCase IIIa and IIIb = pipeline and cable laying equipment subject to transit/survival and accidental loading

conditions.

4.3.2 Case I: Pipeline and cable laying systems subject to operationalloadingThis load case includes the loads that will occur under normal laying operations.

Guidance note:Due to the complex nature of the operations, during the different phases of laying (initiation, laying/retrieving, abandonment,etc.), the loading scenario/main load path is subject to change. This implies that the various components of the system (individualequipment) will become active or on standby, depending on the phases of operation. Therefore, each component, as well as thepipeline or cable laying system assembly should be designed considering the most onerous relevant load combinations.



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Defined by symbols listed above and in [4.2.1], the following load combinations shall be considered in loadcase I:

SG + MOLL + MSL (as applicable)+ SMop + SW

Guidance note:For the equipment to which MOL or MSL is not the direct load, then the loading associated with normal operational loading shouldbe applied in the above formula.


4.3.3 Case II: Pipeline and cable laying systems subject to emergencyoperational loadingThis load case includes the loads that will occur during laying operations, generally associated with moderate(low to medium) probability level of occurrence. This is to be acknowledged as an intermediate load case,between normal operation and accidental conditions. Applicability of this case shall be agreed on a case bycase basis.

SG + MELL + MSL (as applicable) + SMEm + SWEm

Guidance note:Generally, this load case includes loads that will occur during weather escalation or increased line load as a result of an accident(i.e. pipe flooding). The equipment could be designed to maintain its functionality, possibly with reduced parameters, when layingin higher seastates than normal operation weather window or with higher line load. These conditions would generally be consideredundesirable and, therefore, having much lower probability of occurrence than normal operation.The loads should be agreed between the designer and client/owner/operator.


4.3.4 Case IIIa: Pipeline and cable laying systems subject to transitThis case is defined as:

SG + MSL (or relevant load during transit) + SM + SWmax

Guidance note:The active or passive equipment will normally not be in operation during transit conditions. Therefore the formula above should beapplied without MSL (since this is not applicable for active or passive equipment).


4.3.5 Case IIIb: Pipeline and cable laying systems subject to accidentalloadsAccidental loads, which are defined as load with low probability of occurrence in accordance with relevantproduct installation code, are generally associated with accidental loads in the product line and degradedmode of equipment. These shall be identified by the designer and evaluated on a case-by-case basis.The loads shall be agreed between the designer and client/owner/operator.

4.4 Strength calculationsThe strength calculations shall follow the requirements listed in DNVGL-ST-0378 [4.3] with respect toexcessive yielding, buckling and fatigue fracture.


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SECTION 5 MACHINERY AND EQUIPMENTS

5.1 GeneralGenerally the requirements listed in DNVGL-ST-0378 Sec.5 are valid for pipeline and cable laying systemswith the following additions.

5.2 Special requirements for tensioners/drum machines/holdingassemblies/A&R winches/storage equipment

5.2.1 Tensioners

5.2.1.1 Brake redundancy philosophy and capacityThe tensioner brakes shall be dimensioned considering:

— The holding capacity for tensioners shall be dimensioned based on the greater between the maximumoperational line load (MOLL) and maximum exceptional line load (MELL), see Table 1-5, as applicable.

— The equipment shall be designed to be fail safe with respect to braking and holding capacity (i.e. suchthat any single failure shall not lead to loss of holding and braking capacity (eg. failure of a squeezingcomponent, failure in a braking component, etc.). The equipment shall be capable of holding and brakingthe operational load while in a degraded mode (while one of the components of the holding or brakingassembly has lost its functionality and capacity). Component reliability study shall be performed tosupport the system design solution with respect to redundancy and to confirm that the above criteria ismet. This paragraph replaces the requirement for brakes redundancy listed in DNVGL-ST-0378 [8.4.2.13].Guidance note:When a discreet equipment, part of an installation spread, is subject to approval and/or certification by DNV GL, the equipment'sredundancy philosophy shshould be subject to review. The redundancy will be clearly listed in the design approval letter and/orproduct certificate as equipment operational limitation.


— For the equipment relying on squeezing force for the generation of gripping force, see Table 1-5, thesqueezing arrangements shall be designed for the maximum squeezing force, corresponding to Case Iloading, see [4.3].


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Guidance note:The structural strength of the tensioners, holding assemblies and the brake foundation is understood different to the brakescapacity. Capacity rating corresponds to the brake ultimate frictional capacity. The structural strength assessment should be basedon the corresponding case of loading. E.g.:

— If the MOLL is the dimensioning load, then the structural strength of the assembly should be based on MOLL and acceptancecriteria for case I.

— If the MELL is the dimensioning load, then the structural strength of the assembly should be based on MELL and acceptancecriteria for case II or III, as applicable, see [4.3].

— If the maximum dynamic braking load is the dimensioning load, and this is considered as exceptional load and acceptance criteriafor case III .

Unless otherwise specified by the manufacture considering the safety operation philosophy, minimum values listed in Table 5-1apply.

Table 5-1 Tensioner brake capacity requirement

Load due toCase of loading -

structural strengthBrake capacity

Hydraulic restrictioncapacity (if used as a brake)

MOLL I 1.5 × MOLL 1.5 × MOLL

MELLII/III

as applicable, see [4.3]1.33/1.1 × MELL 1.33/1.1 × MELL

Dynamic braking due to MOLL2) III1.0 × maximum dynamicbraking load1)

1.0 × maximum dynamicbraking load1)

Dynamic braking due to MELL2) III1.0 × maximum dynamicbraking load1)

1.0 × maximum dynamicbraking load1)

1) The dynamic braking capacity should be based on corresponding dynamic friction coefficient.

2) If considered applicable.


5.2.1.2 Hydraulic restriction as brakeHydraulic restriction may be acceptable as brake, considering the following conditions are proven:

— brake engagement/disengagement time shall be adequate to the intended application, with dueconsideration for mitigating the risks associated with lack of braking capacity or overload of the system,see DNVGL-ST-0378 [8.4.2.13] and DNVGL-ST-0378 [8.4.2.4], respectively.

— the hydraulic motor shall have a closing valve directly at the high-pressure (load) connection (no pipe orhose connection in between).

— the closing valve shall close as a result of pressure loss at the low-pressure connection (inlet connectionduring lowering). This function shall be accomplished by direct bore or piping between the closing valveand the low-pressure connection.

— the hydraulic motor shall always be ensured sufficient working fluid, also in the event of power failure, i.e.gravity feeding.


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5.2.2 Drum machinesThe drum machines brakes shall be dimensioned considering:

— The holding capacity for drum machines shall be dimensioned based on the greater between themaximum operational line load and maximum exceptional line load, see Table 1-5, as applicable.

— The equipment shall be designed to be fail safe with respect to braking and holding capacity (i.e. suchthat any single failure shall not lead to loss of holding and braking capacity (eg. failure in a transmissionor a braking component, etc.). The equipment shall be capable of holding and braking the operational loadwhile in a degraded mode (while one of the components of the holding or braking assembly has lost itsfunctionality and capacity). Component reliability study shall be performed to support the system designsolution with respect to redundancy and to confirm that the above criteria is met. This paragraph replacesthe requirement for breaks redundancy listed in DNVGL-ST-0378 [8.4.2.13].

5.2.3 Holding assembliesThe holding capacity for holding assemblies shall be dimensioned based on the greater between themaximum operational line load (MOLL) and maximum exceptional line load (MELL), see Table 1-5, asapplicable.For the equipment relying on squeezing force for the generation of gripping force, see Table 1-5, thesqueezing arrangements shall be designed for the maximum squeezing force, corresponding to Case Iloading, see [4.3].

5.2.4 A&R winchesGuidance note:The A&R winches may have different maximum line pull than the MOLL of the active risk equipment, due to the addition of thePLET. This should be considered during design.


5.2.4.1 Brake capacityUnless otherwise specified by the manufacture, considering the safety operation philosophy, the minimumvalues listed in Table 5-1 apply.

5.2.4.2 Wire rope safety factorGenerally the requirements listed in DNVGL-ST-0378 [5.2.5] apply.Deviation from the safety factor for the wire could be granted on case by case assessment. A non-comprehensive list of conditions to be considered are:

— used infrequently— surveyed and maintained closely— replaced more frequently than those used in normal lifting appliances— integrity or inspection programme.


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SECTION 6 SAFETY AND SAFETY EQUIPMENT

6.1 GeneralAll pipeline and cable laying equipment shall be provided with safety functions, reducing the risk connectedto their operation. The safety function requirements are to be founded on a risk based approach, carried outby the manufacturer and reviewed by DNV GL. This section scope is to introduce the philosophy and indicatepossible methods for defining the requirements.It is up to the customer to select the technological platform for the safety functions. In principle, allalternatives documenting an equivalent level of safety will be accepted.

6.2 Safety philosophyThe safety philosophy report shall identify, define and describe the following:— overall principles and functionality for the safety systems handling accidental events— description of the functions that shall be implemented as automatic actions, manual action, remotecontrol, local control, emergency control, back-up control/operation— specification of failure handling and safe state(s)/condition(s) for the equipment.The above shall be proposed by the designer. A systematic review or analysis shall be carried out at allphases in order to identify and evaluate the consequences of single failures in the pipeline and cable layingsystems, such that necessary remedial measures can be taken. The extent of the review or analysis shallreflect the criticality of the pipeline and cable laying operations, and previous experience with similar systemsor operations.

6.3 MethodsA methodology for such a systematic review is quantitative risk analysis (QRA). This may provide anestimation of the overall risk to human health and safety, environment and assets and comprises:

— hazard identification— assessment of probabilities of failure events— accident developments— consequence and risk assessment.

Other methodologies for identification of potential hazards are failure modes and effects analysis (FMEA) andhazard and operability studies (HAZOP).As a minimum the following hazards are identified as generic risk contributors for pipeline and cableLay systems and shall be addressed in the risk assessment. The following are identified as generic riskcontributors for pipeline and cable laying equipment:

— over-loading may lead falling product and/or to structural collapse— emergency stop may lead to over-loading the product or equipment due to activation of the emergency

stop— inadequate product back tension may lead to stress beyond the system's structural strength and to

operational hazards— lack of visibility due to poor sight or due to laying operations in the driver's blind zone may lead to

operational hazards— lack of communication between the operators of various equipment part of the laying operation may lead

to operational hazards— failure in control systems may result in unintentional system response and movements— failure in safety components/systems may result in hazardous situations due to override of safety limits— lack of braking capacity may lead to falling product and uncontrolled system movements— lack of load holding capacity may lead to falling product and uncontrolled system movements


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— blackout/shutdown of power may lead to laying normal operation stop with the system and the load inunfavourable and unsafe position

— unintended activation of safety functions may lead to system response giving unintentional hazards/risks— spurious trip of safety functions. Initiation of a safety functions in no-hazardous situations and where

there is no true demand for safety activation due to safety- or control system failure, may cause othertypes of hazards/risks

— hazards due to activation of safety functions which may lead to secondary effects that may be harmful tothe system and/or the product

— fire/fire ignition may arise from the system itself or from the ship/installation, and thereby lead todisaster.


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SECTION 7 TESTING

7.1 GeneralThe testing requirements listed in DNVGL-ST-0378 Sec.14 are considered valid for the pipeline and cable laysystems with the following consideration.Safety and functional tests shall be performed as applicable, based on the functionality and operation of thespecific equipment. The testing procedure shall be harmonized with the conclusions from the risk analysis,see [6].The design of equipment shall incorporate suitable arrangements to facilitate initial load testing and anyperiodic testing.The test setup shall be suitable in making the system properties described in the test objective observable tothe surveyor.Test setup documentation shall describe properties of the test setup needed to execute the test cases asintended. It shall consist of description and argumentation showing that the test setup is adequate in makingsystem properties observable to the surveyor.

Guidance note:The description should include what parts of the equipment or installation spread are included or excluded from the test setup,together with the rationale for doing so.All inputs and outputs to/from the target system, and why they are included or excluded from the test setup, should also bedescribed.


The functional and failure testing shall be carried out in accordance with the approved testing procedure.The order and objective of the individual test cases to be part of the test scope shall be included in the testprocedure. For each test case the following shall be provided:

— unique identifier— objective— initial condition— how to perform the test case, including the inputs (signals, button-push, etc.)— what to observe during the test— acceptance criteria for each test (expected result)— actual test result.

All test activities shall be documented into a document providing a description of:

— what has been tested— where and when the testing has been performed— who has attended the testing— all results from the testing, together with any limitation to the testing— list of non-conformities, tagged with a responsible party for follow up within a set due date.

The findings shall, as a minimum, be categorised into safety critical and non-safety critical. Thiscategorization shall be agreed with the DNV GL.

7.2 System testing

7.2.1 General7.2.1.1 Equipment in class scopeThe equipment or installation spread shall be subject to on-board tests prior to be taken into use.


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If the equipment shall be installed on vessel assigned DNV GL class notation Pipe Layer Vessel or CableLayer Vessel, DNV GL shall approve on-board test procedures, conduct on-board installation survey as wellas witness final on-board testing of the equipment or installation spread.If complete functional and failure testing are documented to have been carried out at manufacturers'location, limited functional and failure testing may be carried out after final installation. In such case, theproposed test plan shall specify the extent of the limited test scope to be done after final installation.Systems/equipment shall be tested under working conditions (or equivalent), according to a written testprogram.

7.2.1.2 Equipment not in class scopeIf the certification of the equipment has been concluded at the manufacturer, on-board test procedures aswell as witness/acceptance may be endorsed by a competent person accepted by flag/state authorities.

7.2.2 Functional and failure testingSystem testing is function and failure testing which shall be performed to demonstrate that systems andequipment fulfil the requirements of this recommended practice.Failure testing shall be performed to demonstrate that the systems and equipment reacts to failures asdescribed by manufacturer, and in accordance with applicable requirements concluded from QRA, see Sec.6.Scope shall as a minimum include the following:

— Function testing according to requirements defined from Sec.6 (based on FMEA).

— Failure testing according to requirements defined from Sec.6 (based on FMEA).

— Verification of system settings, such as adjustment of controllers and system calibration of sensors andalarms.

It shall be verified that control systems function satisfactorily during normal, abnormal and degradedoperational procedures. The failure modes associated with the above functions identified and addressed inthe failure mode description document and/or FMEA shall also be included in the testing program. Normally,the test scope shall be focusing on single and common failure modes and common components.

7.2.3 Simulator-based testingFor software dependent systems/equipment, providing safety functions or essential functions, the systemtesting shall be performed as simulator-based testing in accordance with [7.2.3.1] to [7.2.3.4], unless therequired system acceptance testing can be performed on the complete system, as built.Simulator-based testing shall, when applied, provide objective evidence of required functionality (duringnormal, abnormal and degraded condition) of the specified target control system (operative essential /safety).

7.2.3.1 Test set-up requirementsSimulator based testing shall be executed on the actual control system hardware to be installed on the vesselor on a replica control system, subject to DNV GL approval.

Guidance note:Replica setup may be used subject to approval. Cloud-based testing by use of soft-PLC may also be accepted.


The simulator shall run on a unit separate from the control system.Testing shall be performed on released software revisions for both simulator and control system(s) such thatthe software is uniquely identified.Testing shall be executed on the same test setup and software as validated through the test setup validationactivity, see [7.2.3.3], and according to DNV GL approved test scope/program.Testing shall be performed and test results shall be documented in the presence of the DNV GL surveyor.


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7.2.3.2 Simulator frameworkAll (relevant) I/O shall be interfaced between control system and simulator. If any signals are ignored/notinterfaced, this shall be documented and agreed upon in writing before test is executed.It shall be possible to monitor and/or trend all I/O-signals between simulator and control system.It shall be possible to introduce/simulate typical control system failures to the system, such as broken wire,value out of range, noise on signals, command errors (functions being executed without being commanded),execution errors (functions not being executed when commanded etc.The simulator shall be adequate for the type of failures intended to be tested.

Guidance note:Failures may either be introduced by manipulating the command or sensor signal, while others may have dynamic and/or spreadeffects, requiring to be generated from the simulator to propagate correctly to all affected signals.


7.2.3.3 Simulator accuracy and test setup validationThe simulator and control system shall run in closed-loop and the simulator outputs shall render a real-lifebehavior of the system.It shall be possible to run all the functions in the control system (target system) without the need of manualmanipulation of simulator signals.A simulator based test setup shall be validated with validation tests demonstrating adequacy/suitability forthe purpose (test objective) and that it does not mask errors in the target system.Before the validation testing is performed, it shall be verified that there are no active nor ignored/suppressedalarms in the system that may have impact on the testing.Test setup validation shall be performed and validation test results shall be documented in the presence ofthe DNV GL surveyor.

Guidance note:

1) The key element for planning the validation activities is to analyse the test objective, and identify possible critical factors/elements in the test setup which may invalidate the test results. A set of relevant validation activities for the test setup shouldbe identified, and measures for limiting possible inaccuracies and uncertainties should be described.

2) One possible cause of masking errors in the target system, is that a parameter in the target system is just copied into thesimulator configuration. If this parameter is wrong, it will be wrong in the simulator as well, making it difficult to identify theerror when both the target system, and the simulator is using the same (wrong) parameter value.

3) The validation tests may be performed before the surveyor arrive at test site. Results from the validation tests should be madeavailable for the surveyor for review, and the surveyor may request some of the validation tests to be repeated before testingstarts.


7.2.3.4 Redundancy and failure response testsFor redundant systems, a selection of tests within each system analysed in the FMEA shall be carried out.Specific conclusions of the FMEA for the different systems shall be verified by tests when redundancy, failsafe response, or independency is required. The test selection shall cover all specified technical systemconfigurations.The test procedure for redundancy shall be based on the simulation of failures and shall be performed underas realistic conditions as practicable, e.g. by use of simulators.

Guidance note:It is understood that not all failure modes in all systems are possible to simulate. For such failure modes the acceptance of thesystem will be based on the theoretical FMEA, and hence the documentation analysis of these failure modes should be emphasizedin the FMEA.



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7.3 Prime movers and fluid power systemsRelevant parameters such as power, ambient temperature and pressure, exhaust gas temperature etc. shallbe measured and recorded.Pressure testing of hydraulic components may be witnessed by the surveyor. The tightness of the systemsshall be checked after the installation of the components and during functional testing.Automatic control, remote control and alarm systems connected with power systems shall be tested.After the test, the lubricating and/or hydraulic oil filters shall be checked for solid particles. Othercomponents of machinery may be required opened up by the surveyor.

7.4 Electrical installationsInsulation-resistance test shall be carried out for all outgoing circuits between all insulated poles and earthand, where practicable, between poles. Under normal conditions a minimum value of 1 mega ohm shall beobtained. This also applies to instrumentation and communication circuits with voltages above 30V A.C. orD.C.The insulation resistance of a motor shall not be less than:

tested on a clean and dry motor when hot.When found necessary by the surveyor, switchgear shall be tested on load to verify its suitability and thatoperating of over-current release and other protective measures are satisfactory. Short circuit tests in orderto verify the selectivity may also be required.

7.5 Load test

7.5.1 Pipeline and cable laying equipment (active and passive)The test load applied to a pipe and cable laying equipment shall be agreed with DNV GL, keeping compliancewith ILO 152 requirements. It is recommended that testing is carried out with corresponding MOLL orequivalent maximum operating load.In addition the testing of equipment will consider also the harmonization of equipment with the producthandled and the calibration of load cells.

7.5.2 Pipeline and cable laying equipment (storage)With respect to the heavy storage equipment, functional testing at lower load than maximum storage load(MSL), see Table 1-5, may be permitted and shall be confirmed with DNV GL on a case by case.

7.6 Periodical surveys

7.6.1 GeneralFor vessels with class notation Pipe laying vessel or Cable laying vessel, it is the owners responsibilityto arrange for periodical surveys, to record substantial repairs, modifications, etc., and to maintain adequaterecords to ensure traceability in accordance with class/statutory/flag requirements.In the remaining of this subsection recommendation for surveys, tests and follow up are described ensuringthis traceability.


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For pipeline and cable laying equipment included in the class scope, the surveys and approvals are carriedout as part of classification's periodical survey scheme (see DNVGL-RU-SHIP Pt.7 Ch.1) including:

— annual survey— a survey every five years (renewal survey).

Before carrying out a periodic examination or test, the surveyor shall refer to the initial certificate and to theperiodical inspection report.

7.6.2 Survey, tests, repairs7.6.2.1 GeneralThe surveyor may require other or additional tests and examinations, and dismantling if considerednecessary.

7.6.2.2 ProcedureIt shall be verified that initial certification, or thorough examination every five years for installations olderthan five years, has been carried out and is valid up-to-date.Parts which are found to be worn or corroded to a significant degree shall be required to be replaced orrepaired as found appropriate. For alterations typically involving structural modifications and/or modificationsto systems and safety functions/ equipment see [7.6.5].

7.6.3 Annual surveyTo be conducted at least once every 12 months (surveys accepted to take place within a time-period ±3months from the anniversary date of the initial certification/re-certification of the pipeline and cable layingequipment.

Items to be considered for annual survey:

— Structural condition (damage (cracks, deformations), wear-and-tear, corrosion). NDT shall be appliedwhen deemed necessary. Damages affecting the primary structure shall be reported. For repairs see[7.6.5].

— It is expected that a list of consumables is included in the operational/maintenance manual of the pipelineand cable laying equipment. Consequently, it shall be checked that regular maintenance has beenperformed as per manufacturer’s specification and that worn-out components have been/shall be replacedwith equivalent parts.

— Thorough visual inspection of bolted connections (no dismantling is required, unless deemed necessary bythe surveyor).

— Support structure (foundation and connections to the deck).— Excessive clearance and proper lubrication in hinged connections.— Wire-rope, including end attachments, with respect to wear, broken wires and corrosion.— Visual inspection of the pipeline and cable laying equipment’s general operational condition, with particular

focus on:

— the slewing system (slewing bearing condition, proper lubrication, bolt condition and pretension, etc.)— the telescoping system (including sliding surfaces)— the luffing system.

— Functional test, including assessment of the control, safety and emergency systems (including powersupply) and alarms.

— Visual inspection of the hydraulic system (e.g. leakages, corrosion, etc.) and correct safety valveadjustments.

— Examination of electrical installation with respect to general condition, support, physical protection, firehazard and personal safety.


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— It is expected that software and hardware change/update procedures are included in the operational/maintenance manual of the pipeline and cable laying equipment. Consequently, it shall be checkedthat the changes/updates have been handled according to the pipeline and cable laying equipmentmanufacturer’s specifications by the manufacturer’s appointed representative. It shall be documentedthat these changes do not affect the safety of the pipeline and cable laying equipment. In case majoralterations are identified, the follow up shall be as per [7.6.5].

— Marking (as per test certificates).

— Provisions for securing of the pipeline and cable laying equipment during open sea conditions.

— Fire extinguishing system (sprinkler), if relevant.

7.6.4 Renewal (5-yearly) surveyTo be conducted at least once every five years (surveys accepted to take place within a time-period of ±threemonths from the anniversary date of the initial certification/re-certification of the pipeline and cable layingequipment and systems).In addition to the examinations listed in [7.6.3], the following additional inspections and load test shall becarried out:

— Load testing and examination after testing as required for initial certification.— Hinge pins for the luffing and telescoping systems (i.e. connecting pins for the hydraulic cylinders,

sheaves, equipment hinges, etc.) to be confirmed documented as dismantled (opened-up), examined andfound in order once during the last five years, or to be opened now.

— Visual examination of all bolted connections, including checking of correct torque setting for 20% of thebolts in each connection. If any significant torque variation is found during this examination another 20%of the bolts shall be checked. If any significant torque variation is found during the second examination,then all bolts in the connection shall be re-tightened as per manufacturer’s specification.

— Slewing bearings to be opened up and internal fillets, raceway and bolts to be subjected to MPI.Exemption to opening-up of a bearing will be granted provided:

i) The equipment has an approved securing device (retainer) fitted.ii) The slewing bearing has been specially adapted and approved by DNV GL for non-destructive crack

detection.iii) A company is available, possessing method, skill and specially trained operators within non-

destructive crack detection of bearings in question. The company, operators and qualification tests tobe approved by DNV GL in each case.

iv) A procedure including regular clearance measurements established when the equipment was new,grease sampling and fatigue evaluations are adopted in agreement with the equipment and slewingbearing manufacturer.

For single ball slewing bearings, opening up may be waived unless required upon detection ofunacceptable clearances, excessive noise, etc. holding-down bolts:

— 20% of bolts shall be removed and examined. The initial 20% shall be taken in the most loaded sectorof the equipment. If any significant defects are found during this examination another 20% are drawn.If any of this second set is found to be defective then all bolts shall be drawn.

— If the first 20% are found to be acceptable and the examination is stopped, a maintenance scheduleshall be established for examining the remaining 80% during the 5 years period.

— When refitting, all bolts shall be pre-stressed as stated in the equipment manual or as found onapproved drawings.

— Functional testing of manual protection system and automatic protection system.

— In case the equipment control system has been tested by means of simulator based testing, the follow-upshall include retesting of the control system as per previously approved test procedure updated to reflect:

— changes in the target system


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— changes in the simulator test tool— to vary and increase the total test scope during the system lifetime.

7.6.5 Alternative SurveyThe traditional time based survey may be replaced by a lifetime assessment program and correspondingoverhaul plan based on continuous monitoring of design work periods for all main pipe or cable layingsystem's components. A data recorder system accepted (approval may be required) by DNV GL and coveringall movements of main components shall be used. The lifetime assessment program and correspondingoverhaul plan shall be approved by during the design phase of the pipe or cable laying system, and beaccording to ISO 12482.

7.6.6 Repairs and modificationsAfter renewal or substantial repair of damaged parts of the primary structure of a pipeline and cable layingequipment, it shall be surveyed. This may include strength testing. Renewal or repair of damaged parts shallbe carried out using DNV GL approved manufacturing procedures and materials which are at least equivalentto the original.Modifications affecting the primary load bearing structure shall be submitted for approval.The repair shall be noted on the certificate and the repair report shall be attached to the certificate as anappendix.If a pipeline and cable laying equipment is rebuilt, repaired with different materials or profiles with differentcross-sections or otherwise significantly modified (e.g. increased length, etc.), it shall be re-approved. Theold certificate shall be marked deleted and attached to the new certificate.For software modifications, it will be required to assess the impact that the changes might have on theoriginally approved system and advise regarding any testing to be performed in order to maintain the validityof the DNV GL product certificate.

Cha

nges

– h

isto

ric


DNV GL AS

CHANGES – HISTORICThere are currently no historical changes for this document.

About DNV GLDNV GL is a global quality assurance and risk management company. Driven by our purpose ofsafeguarding life, property and the environment, we enable our customers to advance the safetyand sustainability of their business. We provide classification, technical assurance, software andindependent expert advisory services to the maritime, oil & gas, power and renewables industries.We also provide certification, supply chain and data management services to customers across awide range of industries. Operating in more than 100 countries, our experts are dedicated to helpingcustomers make the world safer, smarter and greener.

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DNVGL-RP-0232 Pipeline and cable laying equipment laying equipment. This recommened practice will...

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Transcript of DNVGL-RP-0232 Pipeline and cable laying equipment laying equipment. This recommened practice will...