SO-0939-C Neptune CHS LNG Carrier User Manual · IBC International Code for the Construction and...

Kongsberg Maritime Doc.no. SO-0939-B / 14-Apr-09

Neptune CHS LNG Carrier User manual

Neptune CHS

Cargo Handling Simulator LNG Carrier

User’s Manual


Neptune CHS LNG Carrier User manual

Neptune Cargo Handling Simulator

LNG Carrier

User’s Manual Steffen Hårstad Jensen (s) Terje Heierstad (s) Department/Author Approved

©2009 KONGSBERG MARITIME AS All rights reserved

No part of this work covered by the copyright may be reproduced or otherwise copied

without prior permission from KONGSBERG MARITIME AS


Neptune CHS LNG Carrier User manual i

DOCUMENT STATUS

Issue No. Date/Year Inc. by Issue No. Date/Year Inc. by A 28-Nov-2000 ABU/BEBA B 03-Feb-2004 ABU C 14-Apr-09 STHJ/beba

CHANGE IN DOCUMENT Issue No.

ECO No.

Paragraph No.

Paragraph Heading/ Description of Change

A First issue, replaces Doc.no. SO-0804. B MP-1496 Major upgrade. C MP-1696


ii Neptune CHS LNG Carrier User manual

Hazard Warnings And Cautions

Fire

If a fire condition arises, emission of toxic fumes can be anticipated from burning insulation, printed circuit boards, ETC.

Dangerous Voltages

This equipment is not fitted with safety interlocks and lethal voltages are exposed when the cabinets are open. Before removing any sub-units or component all supplies must be switched off. No user serviceable parts inside.

Electrostatic sensitive device

Certain semi conductive devices used in this equipment are liable to damage due to static voltage. Observe all precautions for handling of semi conductive sensitive devices.


Neptune CHS LNG Carrier User manual iii

ESD precautions

Refer service to qualified personnel. Turn power off prior to opening any of the consoles. Whenever doing work inside the consoles use an ESD protective wrist strap. Whenever a printed circuit board is put aside it must be put into an ESD protective bag or on a grounded ESD mat. Non-conductive items such as synthetic clothing, plastic materials, etc. must be kept clear of the working area, otherwise they may cause damage. Printed circuit boards must be kept in ESD protective bags at all times during storage and transport. The bags must only be opened by qualified personnel using ESD protective equipment as specified in this section.

Computer system

The simulator contains general purpose computers. Running non Kongsberg Maritime software in any of them will void the warranty. Connecting other keyboards, mice or monitors may also void the warranty.

Notice

The information contained in this document is subject to change without notice. Kongsberg Maritime shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this document


iv Neptune CHS LNG Carrier User manual

List of Abbreviations and Terms AP Aft Peak CBM Cubic Meter CC Chemical Carrier CCC Cargo Control Console CHS Cargo Handling Simulator COW Crude Oil Washing CT Center Tank DO Diesel Oil DS Dynamic Stability DW Dead Weight ECC Engine Control Console FP Fore Peak FS Free Surface FWD Forward Gb Giga byte GM Gravity to Metacenter OG Gas Oil GZ Righting moment HFO Heavy Fuel Oil HMI Human-Machine Interface Hz Hertz IFE Institutt For Energiteknikk IBC International Code for the Construction and the Equipment of

Ships Carrying Dangerous Chemicals in Bulk IG Inert Gas IMDGC International Maritime Dangerous Goods Code IMO International Maritime Organisation Kb Kilo byte LAN Local Area Net LCG Longitudinal Center of Gravity LEL Lower Explosion Limit LNG/C Liquefied Natural Gas Carrier LOA Length Over All LPG/C Liquefied Petroleum Gas Carrier LPP Length between the Perpendiculars MARPOL International Convention for the Prevention of Pollution from

Ships Mb Mega byte MEPC Marine Environment Protection Committee MFLOPS Million floating point operations pr.sec. MLC Meter Liquid Column MIPS Million Instructions pr.sec. MSC Marine Safety Committee ODM Oil Discharge Monitor (equipment) OTISS Operator Training Simulation System


Neptune CHS LNG Carrier User manual v

P Port PC Product Carrier PPM Parts Per Million P/V Pressure/Vacuum RAM Read Access Memory S Starboard SAST Special Analysis and Simulation Technology SL.TK SLOP Tank SOLAS International Convention for the Safety of Life at Sea SSC Single Strategy Controller (found on ECC) TC Tank Cleaning UEL Upper Explosion Limit UTC Universal Time Coordinated VCG Vertical Center of Gravity VLCC Very Large Crude oil Carrier WS Work Station WT Wing Tank


vi Neptune CHS LNG Carrier User manual

TABLE OF CONTENTS

Section Page

1 INTRODUCTION..................................................................1 1.1 Simulator Concept ........................................................... 2 1.2 Simulator Configuration.................................................... 4 1.3 Simulation Modes ............................................................ 5

2 TECHNICAL SPECIFICATION ..................................................7 2.1 Installation ..................................................................... 7 2.2 Environmental Requirements ............................................ 7

3 NEPTUNE INSTRUCTOR FUNCTIONALITY...................................9 3.1 Neptune Instructor Software Systems ................................ 9

4 FUNCTIONAL DESCRIPTION.................................................15 4.1 Graphic Workstation .......................................................15 4.2 Models ..........................................................................16 4.2.1 Pump Models .................................................................17 4.2.2 Pipe/Valve Models ..........................................................20 4.2.3 Tank Modells .................................................................21 4.2.4 Hull Models....................................................................22 4.3 Vessel Particulars ...........................................................29 4.4 Properties of LNG ...........................................................33 4.4.1 General.........................................................................33 4.4.2 Boiling point ..................................................................33 4.4.3 Composition of boil-off gas ..............................................33 4.4.4 Vapour pressure.............................................................33 4.4.5 Specific gravity of liquid ..................................................33 4.4.6 Specific gravity of gas .....................................................33 4.4.7 Volume ratio of vapour/liquid ...........................................33 4.5 Description of the Ship’s Equipment and Arrangements........34 4.5.1 Cargo Tanks and Cargo Tank Arrangement ........................34 4.5.2 Cargo tank insulation ......................................................35 4.5.3 Description of Cargo Pumps .............................................36 4.5.4 Spray Pump...................................................................40 4.5.5 H/D Compressor.............................................................44 4.5.6 L/D Compressor .............................................................46 4.5.7 Gas Heater ....................................................................47 4.5.8 Operation of H/D heater ..................................................49 4.5.9 Operation of L/D heater...................................................50 4.5.10 LNG Vaporizer................................................................50 4.5.11 Operation......................................................................52 4.5.12 Forcing Vaporizer ...........................................................53 4.5.13 Operation......................................................................54


Neptune CHS LNG Carrier User manual vii

4.5.14 Nitrogen Generating System............................................55 4.5.15 Inert Gas Generator Plant................................................57 4.5.16 Cargo Control Console (CCC) ...........................................59 4.5.17 IMS control function .......................................................60 4.5.18 BVG management system ...............................................60 4.5.19 Low duty compressor control ...........................................61 4.5.20 Control logic ..................................................................62 4.5.21 Forcing vaporizer control .................................................62 4.5.22 High duty compressor control ..........................................63 4.5.23 Spray pump start/stop....................................................64 4.5.24 Spray line cool down.......................................................66 4.5.25 Cargo pump start/stop....................................................67 4.5.26 Discharging ...................................................................70 4.5.27 Cargo tank temperature control .......................................72 4.5.28 Cargo tank pressure control.............................................73 4.5.29 Cargo tank protection system ..........................................74 4.5.30 Description of Ballast Tanks and Ballast Pumping................75 4.6 Mimic Diagrams .............................................................76 4.6.1 Cargo Tank Overview......................................................77 4.6.2 Ballast Tank Overview.....................................................78 4.6.3 Bunker/Consumables......................................................79 4.6.4 Shear Force...................................................................80 4.6.5 Bending Moment ............................................................81 4.6.6 Deflection .....................................................................82 4.6.7 Stability ........................................................................83 4.6.8 Shore Tanks ..................................................................84 4.6.9 Ship/Shore Connection ...................................................85 4.6.10 Cargo Tanks ..................................................................87 4.6.11 Hold Spaces ..................................................................88 4.6.12 Compressor Room..........................................................89 4.6.13 Low Duty System...........................................................90 4.6.14 High Duty System ..........................................................91 4.6.15 Vaporizers.....................................................................92 4.6.16 Boil-off and Vapour Gas Management................................93 4.6.17 NITROGEN PLANT ...............................................................96 4.6.18 Inert Generator..............................................................97 4.6.19 Ballast Tanks.................................................................98 4.6.20 Ballast Pump Room ........................................................99 4.6.21 H/D & Spray Control Panel ............................................ 100 4.6.22 Cargo Control Panel...................................................... 101 4.6.23 Picture Directory (Load Master) ...................................... 102 4.6.24 CCTV CAMERA ............................................................. 103 4.6.25 Load Master Ballast Tank Overview................................. 106 4.6.26 Load Master Bunker/Consumables .................................. 107 4.6.27 Load Master Shear Forces.............................................. 108


viii Neptune CHS LNG Carrier User manual

4.6.28 Load Master Bending Moment ........................................109 4.6.29 Load Master Deflection ..................................................110 4.6.30 Load Master Stability ....................................................111 4.6.31 Description of Legends ..................................................112

5 OPERATION OF THE CHS-LNG/C ......................................113 5.1 Introduction ................................................................113 5.2 Hold Drying .................................................................113 5.2.1 Introduction ................................................................113 5.2.2 Line up .......................................................................113 5.3 Inerting after Docking ...................................................115 5.3.1 Introduction ................................................................115 5.3.2 Cargo tank inerting.......................................................115 5.3.3 Liquid line inerting........................................................117 5.4 Nitrogen Gas Purge.......................................................125 5.4.1 Introduction ................................................................125 5.5 Gassing Up..................................................................126 5.5.1 Gassing Up (1), Venting from no. 1 vent mast ..................126 5.5.2 Gassing Up (2), Combustion in the boilers .......................130 5.5.3 Gassing Up (3), Compressor ..........................................134 5.5.4 Gassing up (4), vapour return line ..................................136 5.6 Initial Cool down ..........................................................138 5.6.1 Introduction ................................................................138 5.6.2 Line up .......................................................................138 5.6.3 Initial cool down...........................................................140 5.7 Loading.......................................................................142 5.7.1 Introduction ................................................................142 5.7.2 Loading.......................................................................142 5.8 Deballasting ................................................................146 5.9 Draining/Purging ..........................................................147 5.9.1 Introduction ................................................................147 5.10 Loaded Voyage (Forced Vaporization)..............................148 5.10.1 Introduction ................................................................148 5.10.2 Natural BOG supplying ..................................................151 5.10.3 Line up for forced vaporization .......................................152 5.11 Cool down by Liquid Line (By Ship) .................................155 5.11.1 Introduction ................................................................155 5.11.2 Line up .......................................................................155 5.11.3 Line cool down .............................................................158 5.12 Arm Cool down ............................................................159 5.12.1 Introduction ................................................................159 5.12.2 Preparation..................................................................159 5.13 Discharging .................................................................161 5.13.1 Cargo pump start .........................................................161 5.13.2 Discharging .................................................................162


Neptune CHS LNG Carrier User manual ix

5.14 Ballasting.................................................................... 163 5.14.1 Ballasting operation...................................................... 163 5.14.2 Ballasting by gravity ..................................................... 164 5.15 Ballast Voyage (Forced Vaporization) .............................. 164 5.15.1 Introduction ................................................................ 164 5.15.2 Line up for natural BOG supply....................................... 165 5.16 Warming Up ................................................................ 169 5.16.1 Introduction ................................................................ 169 5.16.2 Warming up the deck lines ............................................ 170 5.16.3 Warming up the tanks .................................................. 172 5.17 Inerting before Docking ................................................ 175 5.17.1 Introduction ................................................................ 175 5.17.2 Cargo tank inerting ...................................................... 175 5.17.3 Cargo tank inerting ...................................................... 176 5.17.4 LNG liquid line inerting.................................................. 178 5.17.5 Spray line inerting........................................................ 180 5.17.6 LNG vapour line inerting................................................ 183 5.18 Aeration...................................................................... 186 5.18.1 Introduction ................................................................ 186 5.18.2 Cargo Tank aeration ..................................................... 187 5.18.3 Liquid and spray line aeration ........................................ 188 5.18.4 Vapour line and machinery aeration................................ 190 5.18.5 Limiting Factors ........................................................... 191 5.18.6 Discharge Plans ........................................................... 192 5.18.7 Cargo Handling Training from the Graphic Workstation ...... 192 5.18.8 Picture Directory General .............................................. 193 5.18.9 Picture Directory LM ..................................................... 194 5.18.10 Pump Flow .................................................................. 197 5.18.11 Ballasting.................................................................... 199 5.18.12 Inert Gas System......................................................... 202 5.19 Stress and Stability Calculations..................................... 204 5.19.1 Online calculations ....................................................... 204 5.19.2 Offline calculations ....................................................... 208

6 UNIT CONVERSION ......................................................... 209

7 RULES, REGULATIONS AND PUBLICATIONS............................ 211 7.1 Tanker Safety Guide (Liquefied Gas) ............................... 211 7.2 International Maritime Dangerous Goods Code ................. 211 7.3 U.S. Coast Guard chemical data guide............................. 211 7.4 International Maritime Organisation ................................ 211 7.5 Int. Convention for the Safety of Lives at Sea 1974 .......... 212 7.6 Main Features of MARPOL 73/78, Annex II ....................... 212 7.7 Checklists ................................................................... 215 7.8 Cargo Record Book....................................................... 228 7.8.1 Inert Gas System manual.............................................. 228


Neptune CHS LNG Carrier User manual 1

1 INTRODUCTION Liquid chemical cargo handling is considered to be a highly demanding operation, as a great number of complex elements are involved. Technical requirements, commercial requirements, environmental requirements and safety requirements will always represent important, and often conflicting, factors that have to be dealt with during the cargo handling operations. This puts considerable pressure on the personnel involved and it raises an unquestionable demand for cognizance. The purpose of Kongsberg Maritime's Cargo Handling Simulator, CHS LNG/C, is to provide a training tool that gives a realistic replication of the dynamic behaviour of a typical LNG/C's cargo handling system and that reflects the interconnections between the subsystems related to loading and discharging. In this manner knowledge in liquid chemical cargo handling can be acquired without hazardous and catastrophic consequences.

TechnicalRequirements

CommercialRequirements

EnvironmentalRequirements

SafetyRequirements

Ships strength

Depth/trim

Operational skill

Cargo segregation

Time constraints

Minimizing of losses

Prevention Prevention

Internationalsafety regulations

CARGOHANDLING

Internationalenvironment

of oil spill

regulations

of explosions

constraints

constraints


2 Neptune CHS LNG Carrier User manual

In addition to giving the students operational training, the Cargo Handling Simulator is also a tool for more intimate theoretical studies for loading/discharging operations, such as: - Planning the cargo operations sequences using the loading computer - Running test conditions on the loading computer - Studying single components - Studying individual tank atmospheres - Monitoring the discharge time and subsequent costs - Providing training in non-routine operations - Shows you the results of incorrect operations without damaging the equipment - Presenting all relevant terminology in relation to associated hardware. 1.1 Simulator Concept The CHS Cargo Handling Simulator is designed to meet the demands for basic training of junior officers as well as advanced training for senior officers, ranging from fault effect studies to economical optimisation studies. The Cargo Handling Simulator enables both simulation of the total cargo handling operation and simulation of individual subsystems and independent components. The conceptual structure CHS Cargo Handling Simulator consists of two main parts: • The Operator Station(s) • The Instructor Station(s) The Operator Stations are manned by students acting as cargo handling operators (cargo officers). The Operator Stations may be furnished as Cargo Control Room Consoles for operational training or as workstations for theoretical studies or part task training or a combination of both. From the Operator Stations the students can open/close valves and start/stop pumps thereby generate flows to/from the tanks onboard and ashore.



The changed contents in the tanks, observed as changed tank levels, will influence the load distribution, the shear forces, the bending moment and the hull deflection. The changed contents in the tanks will also influence the ship's draught, trim and heel. The relationship between the various parameters is illustrated in the figure below:

The Instructor Station is manned by the instructor who acts both as a simulation conductor and as the 'world outside the Cargo Control Room', i.e. shore terminal personnel, deck personnel and engineer officer. The Instructor Station contains features and facilities needed for effective training, i.e.: simulation start/stop; freeze/run; snapshot/replay; fault setting; event logging etc. The Instructor Station also contains editing features for preparation of exercises. By the simulation of faults and deteriorations, the instructor can create a training situation that enables the trainee to meet and overcome these problems. This training environment will give the students experience in dealing with problems that would normally demand years of seagoing experience.



The instructor can acquire this by: - Changing operational and ambient conditions - Setting faults and deteriorations, single or in series - Simulate leaks in cargo lines and tank bulkheads 1.2 Simulator Configuration Hardware Configuration: The CHS Cargo Handling Simulator is implemented on a network of UNIX workstations with a common server. The network is an Ethernet (protocol UDP/IP) and the server is equipped with a hard disk. A Data Tape Station is provided for taking back-up of the System Software and loading new software versions. When fitted the Cargo Control Consoles and -Panels are connected to the same Ethernet via a serial link converter. In order to get an even more realistic impression of how a ship's cargo plant is run, the disturbing environment noises are essential. By means of a unique synthesised audio system, pump sounds are synchronised with the rpm of the cargo pumps and in addition the noises from diesel engines, generators, compressors, etc. are presented by separate sound amplifiers. Software Configuration: The simulator software is split into - the Man-Machine Interface Software - the Instructor Software - the Mathematical Models. The Man-Machine Interface Software provides the graphic displays on the workstations. The Instructor Software enables the setting of operational conditions and the control of the exercises. The Mathematical Models generate the dynamic behaviour of flows, levels, draughts etc. pursuant to the students' operations.



1.3 Simulation Modes Because of the flexible structure of the CHS various characteristic training modes can be followed: Integrated Training Mode: The Integrated Training mode is used in connection with operational training. - One common set of Mathematical Models is resident in the server. - Individual sets of Man-Machine Interface Software are running at the work stations. - The Instructor Software is available from the Instructor Station. The training team operates the Control Room Consoles, whilst the instructor operates one of the work stations, which together with the server forms the Instructor Station. From the Instructor Station work stations can be connected for observation of the exercise. As each workstation is equipped with separate sets of the Man-Machine Interface Software, each observer may individually choose graphic displays for the survey of the exercise. However, active operation on the Mathematical Model is not permitted from the work stations. Individual Training Mode: The Individual Training mode is used in connection with individual part task training, i.e., studies of subsystems or components, or in connection with individual total plant studies. The Individual Training mode implies the following software configuration: - Individual sets of Mathematical Models are running at the work stations. - Individual sets of Man-Machine Interface Software are running at the work stations. - The Instructor Software is available from the individual work stations.



2 TECHNICAL SPECIFICATION 2.1 Installation This chapter is to provide information guide-lines for installation of the simulator. Consistent and reliable performance of the system is dependent on its having an appropriate environment including power conditioning, air flow, cooling and humidity control as well as installation of the system in conformance to specified standards. Achievement of these standards is mandatory to ensure reliable operation and continued compliance with these standards is the basis for warranted performance. Specific requirements are provided for the computer and subsystems. These requirements are derived from several sources including manufacturer’s technical documentation, standard commercial practices, national and local building codes and regulation and, most importantly, our experience in designing, constructing and operating simulator facilities. Additional information is included below as recommended guide-lines for the system. This information is based on experience gained from Kongsberg Maritime’s many simulator installations. 2.2 Environmental Requirements Local climate conditions and the system configuration determine the requirements for heating, ventilation and air-conditioning. The heating ventilation and air-conditioning system must provide air flow to keep the ambient conditions within the specified temperature and humidity range. - Ideal temperature: 23°C± 3°C - Ideal relative humidity: 50% ± 10% - Dust: Air pressure in the simulator rooms should be higher than the pressure outside. Special demands are made on the air-conditioning unit’s filter if the air includes corrosive gases, salts, conductive particles or other unusual particles of dust. Minimum and maximum operational requirements: - Minimum temperature : 10°C - Maximum temperature : 30°C - Relative humidity : 15% to 80% If the humidity is lower than 40%, static electricity may become a problem. In order to ensure reliable operation of the air-conditioning unit, preventive maintenance should be carried out regularly. Thermostats must be installed in each room to permit temperatures to be controlled individually.



NOTE! The Air-conditioning equipment must include an automatic restart after a power failure.

It is necessary to maintain air-conditioning even when equipment is shut down, because parts of the system remain energised. If the humidity specifications are not maintained, condensation may accumulate which can cause damage to circuits when power is reapplied.



3 NEPTUNE INSTRUCTOR FUNCTIONALITY Kongsberg Maritime simulators have released for the Engine Room and Cargo Handling Simulators the “State of the Art” Instructor, Monitoring and Assessment system. Kongsberg in close cooperation with experienced world wide instructors, Norwegian Maritime Directorate and Dot Norske VERITAS (DEN), have designed and developed an Instructor, Monitoring and Assessment System that is excellent with regards to user-friendliness and efficiency. This chapter lists available features that can be delivered along with this simulator. 3.1 Neptune Instructor Software Systems The following will be provided: Item Content Neptune Instructorless

Neptune Instructorless gives instructor and students the option to run readymade exercises, where following features are included. Includes: All configurations includes well proven models Load simulation model on each station Run simulation Freeze simulation Stop simulation Load initial conditions Create new initial conditions Students can run the simulation independently Insertion of malfunctions Access to alarm list Access to variable list.

Neptune Basic Includes: Neptune Instructorless; as previously listed Power-up all student stations Recording of the complete exercise Replay the whole exercises Go back to any point in time for restart -Create exercises including Initial conditions Deploy exercises to student stations -Centralized Run/Freeze control of all student stations Connect student stations in clusters for team training Send Instant Messages to student(s) Send Instant Actions (Malfunctions or Events) Recording of the complete exercise Power shut-down of student stations

Neptune Professional

Includes: Neptune Basic; as previously listed



Item Content Student Station (Access) Configuration Exercise development, incl. triggers and actions E-Coach, Electronic guidance system to students Assessment

Item Description Instructor Station Classroom View

Monitor and control the students in the classroom (or full mission simulator). Instructor can tailor the view according to site layout

Instructor Station Classroom View

-Start exercises on Pac’s in the classroom -Run/pause exercises in the classroom -“Client Connect” to exercises in the classroom -Set up groups for team training



Item Description New Exercise Structure

Exercise Structure comprises: Initial Condition and Scenario Modules based on:

• Triggers • E-Coach Messages • Actions • Assessment

Instructor Controlled configuration for each of the Student Stations

Configuration of stations is part of the exercise. It is possible to add new stations to an ongoing exercise “on the fly”.

Trigger Overview

Displays the state (Active/Not Active) of all the triggers in the module. Displays users of the trigger (other triggers, actions, assessment and e-coach messages) Link to editors Instructor control of triggers (on the fly).



Item Description Logic Block Based Trigger Editor

Building block used in e-coach messages, actions and assessments Graphical editor Flexible and powerful Calculates output (true/false) based on input and logic blocks. Configurable input

E-Coach Overview

Displays the state (sent/ not sent) of all e-coach messages Link to trigger and message editor Possible for the instructor to disable messages (online).

E-Coach Editor

Initiated by trigger From “virtual instructor” or other “outside world” (e.g. Captain, VETS) To a selected screen or all screens.

Action and Malfunction Editor

Activated by trigger: Additional triggers to specify on/off conditions for the criterion Possible to select between different types of scoring (illustrated graphically) Possible to define “critical” criteria


Malfunction introduced as on/off. Instructor can freely decide when and for how long the malfunction shall be activated



Item Description Action and Malfunction Editor

Malfunction introduced as repeating on/ off.


Malfunction introduced as a repeating sine shape, where Amplitude and Time period is adjustable.


Malfunction introduced where intensity and duration is randomly selected.

Assessment Overview

Overview of all assessment criteria Calculates total score Instructor can define parameters for overall scoring Pass and Fail evaluation is completely based on objective criteria



4 FUNCTIONAL DESCRIPTION 4.1 Graphic Workstation Graphic Workstations are available at the instructor station, trainee’s workstation and in the operational consoles in cargo control room. In principle the stations are identical and the functions present on each similar. On the operator stations, the operator/student(s) can view mimic pages representing the various simulated systems. These graphic mimic process diagrams are interactive, i.e. the process can be both monitored and controlled. In principle, all the graphic workstations can be configured as instructor stations. Whenever a workstation is going to be used in part task mode, the student using it will act as his own instructor, meaning that he will have the instructor’s privilege to start/pause the simulation. Each individual can run the exercise at his own pace. The push-buttons on the operational keyboard are grouped together in logically arranged clusters. All the instructor functions are located on the left side of the keyboard. The keyboards have a physical key, with which the instructor can prohibit student(s) access to the instructor functions on the keyboard. The colours, symbols and abbreviations used in the mimic diagrams are common throughout all pictures and are described and explained in MD 150 Description of Legends.



4.2 Models The main element in the CHS Cargo Handling Simulator is a set of dynamic models. The models are based on physical laws and are updated at regular intervals thereby yielding a dynamic behaviour. The various models are linked together and replicate the mutual interactions and dependencies that can be experienced in real life. For overview, the models are grouped together into: - pump modells - pipe/valve modells - tank modells - hull modells

Open Valve/Start Pump

Flowto / fromtanks

Change in:-tank content-tank level

Change in: Change in:-draught-trim-heel

-load distr.-shear force-bend. moment-hull deflection

HULLMODELS

TANKMODELS

PIPE / VALVEMODELS

PUMPMODELS



4.2.1 Pump Models

4.2.1.1 The Centrifugal Pump The relationship between discharge head, flow and pump speed for centrifugal pumps can be expressed as follows: H = k0*n2 + k1*n*q + K2*q2

where H = discharge head (delivery pressure) n = relative pump speed q = relative volume flow k0, k1 and k2 are design related constants

H

q

n1n2

n3Flow resistance



Model variables & constants The model variables H, n and q are currently and

dynamically updated during the simulation, while the model constants k0, k1 and k2 are set initially, thereby 'designing' the capacity and the performance of the pump.

El. power The deep well pumps are hydraulically driven, which means that electric power has to be available. This is provided from the engine room (instructor).

Cavitation Even with deep well pumps cavitation may occur. This happens if the pump inlet pressure, pinlet , is getting lower than the vaporization pressure, pvap., for the actual fluid pumped. Then gas bubbles are generated in the fluid, resulting in fluctuating pump speed, unsteady flow and increasing bearing temperature. The dynamic inlet pressure, pinlet , is dependent on the static inlet pressure and the flow velocity (Net Positive Suction Head - NPSH).

Cavitation precautions The best way to avoid cavitating conditions when the static inlet pressure is reduced due to low liquid level, is to reduce the liquid flow rate, either by reducing the pump speed or by throttling the pump discharge valve.

Pvap The vapourisation pressure, Pvap., will vary from fluid to fluid. Thus the Pvap. for crude oil and refined products will be sufficiently high to cause cavitation problems, whilst the Pvap for ballast water will be below any critical limit.



4.2.1.2 The Stripping Eductor Stripping eductors are used complementary to conventional centrifugal pumps to remove the last parts of the liquid that remain in the tank (tank stripping).

B AC

D

Drivingflow

Suctionflow

The eductor works on the principle that the total sum of energy in a liquid flow is constant (Bernoulli's Law). When the liquid flows from A to B, and when it is constricted in C, a higher velocity is gained in this point. The kinetic energy will then increase in this point, too. Because of the fact that the total sum of energy is constant, the static energy is reduced accordingly, yielding a lower static pressure in C. This will create a suction flow through D. Thus an increased driving flow rate will result in a higher suction flow rate.



4.2.2 Pipe/Valve Models A flow through a pipeline is caused by different pressures in the two ends (nodes) of the pipeline. Flow is increased by increased pressure drop across the pipeline and reduced by increased resistance in the pipeline. The resistance may be caused by reduced pipe dimensions, bends, orifices or throttling valves. q = cv √Δp √ρ where q = flow 1/cv = flow resistance Δp = pressure drop ρ = specific density Often the various pipelines are connected in nodes. The flow is then distributed on various branches dependent on the actual difference in pressures and flow restrictions.

p0q0

cv1

cv2

cv3

p1q1

p2q2

p3q3

q1 = cv1 √Δp1 ; Δp1 = p0 - p1 √ρ q2 = cv2 √Δp2 ; Δp2 = p0 - p2 √ρ q3 = cv3 √Δp2 ; Δp3 = p0 - p3 √ρ q0 = q1 + q2 + q3



4.2.3 Tank Modells

4.2.3.1 Modelling Of Tank Levels Based on tables containing the tank geometry the actual tank levels are calculated currently from the actual contents of liquids in the tanks. The actual contents of liquids in the tanks are based on the current flows to or from the tanks as computed by the Pipe/Valve Models. Tank Level Gauging The tank levels are measured directly. I.e., Changing the

weight of the cargo/ballast without changing the volume(i.e. changing the specific density) will not change the actual level. Changing the volume without changing the total weight (e.g. due to variations in temperature) will result in changed levels.

Sensor Location The sensors are located aft and in the centrelines of the tanks. I.e.: The level measured are influenced by the ship's trim, but not by the heel.



4.2.4 Hull Models The content of liquids in the tanks will have an inevitable impact on the hull condition in terms of: - hydrostatic conditions: - draught - trim - heel - intact stability - meta centre height - hull stress - shear force - bending moment - hull deflection 4.2.4.1 Hydrostatic Conditions Draught The draught is adjusted until the weight of the displaced water, WD, equalizes the light ship weight, WLS, and the cargo weight, WC. WD = WLS + WC = γ * Δ where γ = specific gravity of water Δ = volume of displaced water

G

B dt

A W

T

When the weight of the cargo is changed the draught will be changed accordingly. The change in draught can be estimated from the formula for displacement (Tons) Per. Cm draught: dWD = rAW * 0.01(Tons/Cm)



This can be found in the tables and curve sheet for the hydrostatics.

t

W D

dWD

T Trim Trim is adjusted until the trimming moment from the gravity forces (light ship weight + cargo weight) equalizes the buoyancy moment from the displaced water. The trimming moment is calculated with the basis in the Longitudenal Centre Of Flotation (LCF) and the trimming takes place around this point. The location of the LCF is given by the shape and area of the hull's waterplane at the actual draught, as the total longitudenal moment of the waterplane-area is to be equal to zero at this point.

F

a

M 1 g

WL1 WL0

S

The amount of trimming can be estimated by means of the Moment To Trim 1 Cm. formula:

MT = δ ρ I L

L This can be found in the hydrostatics tables.



a

F t t A

M 1 g

t F

FPAP

WL2

Heel The heel is adjusted until the heeling moment is equalized by the buoyancy moment of the displaced water. The heel will always take place along the waterplane's longitudenal centre line.

B (x)

dx

x

LCF

L

Water - plane area L L AW = _ dAW = _ B(x) dx 0 0 Water - plane moment of area (longitudinal) L L FL = _ xdAW = _ B(x)x dx 0 0 Water moment of inertia (longitudinal) L L IL = _ x2dAW = _ B(x)x2 dx 0 0



4.2.4.2 Intact Stability As long as the vessel lies in upright position there will always be equilibrium between the weight forces (light ship + cargo) acting through the gravity centre, G, and the total buoyancy forces acting through the buoyancy centre, B. G and B will always be located on the same vertical line at a distance KG and KB from the keel respectively.

G

B

K

Ships heeling When the ship is inclined due to a heeling moment, the buoyancy centre will move to a new position due to the displacement's volume and shape.

Meta Centre The vertical line through B will cut the ship's centre line at an angle, φ, in the point M. At small angles of heeling the point M is denoted the Initial Meta Centre.

The horizontal distance between the centre of gravity, G, and the vertical line through the new centre of buoyancy, B', is denoted GZ and represents the arm of righting moment.

G

B

K

B'

M

ZØ



Meta Centre The distance between the Centre of Gravity, G, and the Meta Height, GM Centre, M, is denoted the Meta Centre Height, GM. Thus: When GM > 0: The heel will be counteracted by a righting moment. The ship is said to be stable. When GM = 0: The heel will remain. The ship is said to be indifferent. When GM < 0: The heel will increase. The ship is said to be unstable. Variable GM / variable GZ

Hydrostatic considerations will show that the meta centre height, GM, will decrease with increasing draught, T.

The GM will be further reduced if free surfaces occur in one or more tanks. The change in GM will inevitably have impact on the righting arm, GZ, which is the most relevant parameter for the intact stability.

15 degr.

30 degr.

45 degr.

60 degr.GZ

Displacement (draught)



4.2.4.3 Hull Stresses Load Distribution The forces acting on a ship's hull will be the distributed

weight forces (lightship + cargo) and the distributed buoyancy forces. As long as the ship lies still in water the sum of these forces balances each other. However, the resulting forces may be uneven distributed. This is particular the case during the loading and discharging operation.

Shear Forces As a result of the uneven distribution of load along the hull, shear forces will appear.

Mathematically, shear forces can be described as the integral of the distributed load.

L Q = ∫ q dL Q = shear force 0 q = distributed load L = ships (hulls) length

Shear forces will act as vertical cutting forces onto the hull structure and should be kept within the limits of the hull construction's tensile strength.

Bending Moment The distributed shear forces will result in a bending moment

for the hull. Mathematically, hull bending moment can be described as

the integral of the distributed shear forces. L M = ∫ Q dL M = longitudinal bending moment 0 Q = distributed shear force L = ships (hulls) length Longitudinal bending moment will cause strains in the hull construction and should be kept within pre-set limits.



The relationship between load distribution, shear forces and bending moment is schematically shown in the figure below.

q Q

-+ +

-

M

0

q: load distribution

Q: shear force

M: bending moment

Hull deflection As the steel in the hull is elastic the longitudinal bending moment will result in a certain deflection of the hull. The hull deflection curve will have the same shape as the bending moment curve.

Thermal deflection In addition to the deflection caused by the bending moment

the hull may be subjected to thermal deflection too. This is the case in tropical waters where the sun is heating the deck and the superstructure, while the submerged part of the hull is cooled by the water.

In these circumstances it should be noted that the deflection caused by the hogging moment in ballasted or unloaded condition will be superimposed on the thermal deflection.



4.3 Vessel Particulars The modelling of the Cargo Handling Simulator CHS - LNG/C is based on a vessel with double hull and double bottom.

Ships name LNG/C Polaris Signal letters LJLM3 IMO number 10034 Port of registry Horten Flag NIS Builder Ship No. 1395, Mitsui Engineering and

Shipbuilding Co Ltd., Chiba Works Length overall 293,00 m Length between perpendiculars 280,00 m Breadth moulded 45,75 m Depth moulded main deck 25,50 m Draught on summer freeboard 10,95 m Speed (designed full loaded cond.) 20,72 Knots Deadweight 71543 MT Gross tonnage (Int.) 110895 GT Net tonnage (Int.) 33269 NT Displacement 104999 MT Class Det Norske Veritas, 1A1, Tanker for

Liquefied Gas, E0, W1-0C, Ship Type 2G (-163°C, 500 kg/m³, 0.25 bar).

Cargo Tank capacities:

Compartment Capacity m3 98,5 % at –163°C Cargo Tank no 1 23148 m³ Cargo Tank no 2 27974 m³ Cargo Tank no 3 27974 m³ Cargo Tank no 4 27974 m³ Cargo Tank no 5 27974 m³ Total all tanks 135044 m³



Ballast Tank capacities: Capacity (m³) FWD.W.B. tank 2028,3 No 1 side W.B. tank (P&S) 2002,1 x2 No 2 side W.B. tank (P&S) 2941,7 x2 No 3 side W.B. tank (P&S) 2337,0 x2 No 4 side W.B. tank (P&S) 3586,2 x2 No 5 side W.B. tank (P&S) 2572,1 x2 No 6 side W.B. tank (P&S) 3612,9 x2 No 7 side W.B. tank (P&S) 2572,4 x2 No 8 side W.B. tank (P&S) 3571,5 x2 No 9 side W.B. tank (P&S) 1782,1 x2 No 10 side W.B. tank (P) 995,4 No 10 side W.B. tank (S) 910,2 No 1 CR W.B. tank 1740,1 No 2 CR W.B. tank 1777,9 No 3 CR W.B. tank 1777,9 No 4 CR W.B. tank 1777,9 AFT PEAK tank 1652,9 TOTAL 62616,6



Cargo pumps: 10 sets Type Centrifugal submerged Capacity 1100 m3/h x 135 mTH Drive Electric

Spray pumps:

5 sets Type Centrifugal submerged Capacity 50 m3/h x 135 mTH Drive Electric

High duty compressor

2 sets Type Centrifugal Suction capacity 24000 m3/h Suction condition -140ºC, 104 kPaA Delivery condition 200 kPaA Drive Electric

Low duty compressor

2 sets Type Centrifugal Suction capacity 8800 m3/h Suction condition -40ºC, 104 kPaA Delivery condition 200 kPaA Drive Electric

High duty heater

1 sets Type Hor. Shell and tube, direct steam heated. Heating capacity 12600 MJ/h Gas flow 43000 kg/h Inlet condition -55ºC, 200 kPaA Outlet condition +75ºC, 180 kPaA

Low duty heater

1 sets Type Hor. Shell and tube, direct steam heated. Heating capacity 1900 MJ/h Gas flow 8400 kg/h Inlet condition -70ºC, 200 kPaA Outlet condition +45ºC, 13 kPa



LNG Vaporizer 1 sets Type Hor. Shell and tube, direct steam heated. LNG Vaporization 18000 kg/h Inlet condition -163ºC, 290 kPa Outlet condition -60ºC, 29 kPa

Forcing Vaporizer

1 sets Type Hor. Shell and tube, direct steam heated. LNG Vaporization 6400 kg/h Inlet condition -163ºC, 290 kPa Outlet condition -40ºC, 25 kPa

Ballast pumps

3 Type Centrifugal Capacity 3000 m3/h – 35 mTH (SW) Drive Electric

Ballast stripping eductor

1 Type Ballast stripping eductor Capacity 300 m3/h – 20 mTH (SW) Drive Water spray pump



4.4 Properties of LNG 4.4.1 General LNG is liquefied gas. It is stored at cryogenic temperature and has a low specific gravity. It is non toxic and non corrosive. 4.4.2 Boiling point

The boiling point of methane, which is the main component of LNG, is -161.5°C Depending on other components, the boiling point of LNG is between -158°C and –164°C. The critical temperature of methane is –82°C. Above that temperature, it is impossible to liquefy natural gas by pressurisation. In other words, natural gas is always a gas at ambient temperatures. 4.4.3 Composition of boil-off gas The main component of the boil-off gas from Abu-Dhabi LNG is methane. During laden voyage, the percentage of methane in boil-gas will increase due to decrease of nitrogen in liquid. 4.4.4 Vapour pressure The relationship between the liquid temperature and vapour pressure is only realised on the top layer of the cargo liquid. CTS measures liquid temperature at pre-determined levels (0, 25, 50, 75, 100%) and can give “bulk” or “average” temperature only. 4.4.5 Specific gravity of liquid The Specific gravity of liquid methane is 0.425, this is less than a half that of water. 4.4.6 Specific gravity of gas Specific gravity of natural gas is about half (air=l.0 methane=0.555) that of air at the same temperature. Therefore, if gas leakage occurs the leaked gas will ascend to upper air without stagnating when its density is lighter than that of air. However, it is necessary for an operator to be aware of the phenomenon of "Vapour cloud". The specific gravity of a gas is related to the temperature. As the temperature decreases, the specific gravity increases. The specific gravity of methane is greater than that of air at about -112°C. Gas temperature immediately after evaporation is nearly equal to the liquid temperature. The evaporated gas stagnates in a low place because of its high specific gravity, and freezes the moisture in the surrounding air. This is known as a "Vapour cloud". A dangerous situation occurs when the cloud stagnates on the deck. However, as gas temperature increases, the cloud ascends and disperses. 4.4.7 Volume ratio of vapour/liquid Volume ratio of vapour to liquid is about 600 at ambient temperatures. When LNG evaporates at normal temperature, the volume will expand about 600 times.



4.5 Description of the Ship’s Equipment and Arrangements

This section contains all particulars of the ship’s equipment and arrangements necessary to enable the crew to follow the operational procedures set out in sections 3 and 4. 4.5.1 Cargo Tanks and Cargo Tank Arrangement There are a total of 5 main cargo tanks, where all are divided into two tanks with a common atmosphere. Moss type spherical tank design is adopted as the cargo containment system, and consists of an unstiffened spherical shell supported at the equator by a vertically stiffened skirt. Its fail-safe design concept based upon the principle of “leak before failure” has been widely acknowledged by the fact that no breakdown nor leakage has been reported in the operational history over 20 years. Cargo area is also separated from engine room /fuel tanks with cofferdams forward and aft of cargo area. 4.5.1.1 General Cargo tanks are designed and constructed according to the Moss-Rosenberg cargo containment concept that is a self-supporting spherical tank with a cylindrical skirt. The tanks are designed as "Independent tanks-type B" as defined in IGC Codes and the scantlings are decided by stress analysis, buckling analysis and fatigue analysis using a three dimensional finite element method considering combined loads due to ship motion, thermal effect and so on. The cargo tanks are able to be loaded to any level with cargo distributed evenly in each tank and are designed to allow one cargo tank to be empty with the remaining cargo tanks full in sea-going condition. 4.5.1.2 LNG tank structure The tanks are constructed of aluminium alloy (5083-0) and the internal diameter of the tanks at room temperature is 38.00m for the Nos.2-5 tanks and 35.65m for the NO.1 tank. Each tank is protected from weather by a hemispherical tank cover which is connected to the Upper Deck and permits control of the hold space atmosphere. One dome is provided at a top of each tank and they protrude from the tank covers. 4.5.1.3 Tank supporting structure The tank supporting structure is a cylindrical skirt connected to the spherical tank at the equator ring and welded to the Foundation Deck plate. The supporting skirt consists of three kinds of materials. The upper part is made of aluminium alloy (5083-H321), the middle part of stainless steel (SUS304 Mod) and the lower part of higher tensile steel.



The structural transition Joint (clad plate) is comprised of aluminium, titanium, nickel and stainless steel, and is inserted between aluminium alloy and stainless steel because welding at their connection is not possible. 4.5.1.4 Pipe tower structure One pipe tower made of aluminium alloy (5083-0) is provided in each tank. The pipe tower is strengthened against sloshing load due to partial filling of cargo. 4.5.2 Cargo tank insulation

4.5.2.1 General The cargo tank insulation system is designed for a max. cargo boil-off rate of 0.15% of 135000m3 per day, under the specified condition. The conditions specified for boil-off rate are; Air temperature 45°C Sea water temperature 32°C Temperature of cargo -161.5°C Properties of cargo Pure methane Cargo tank pressure 108 kPaA (1.1 kg/cm²A) (Vapour space) Sea condition Calm Cargo tank condition 100% wetted surface The properties of pure methane(at -161.5°C ) are; Specific Density 425 kg/m³ Latent heat 511 kj/kg (122 kcal/kg) The cargo tank and upper part of the skirt is thermally insulated to assure the boil-off rate does not exceed guaranteed value under the conditions described above. The type of insulation system applied to the used model is the spiral generation system. The insulation system is designed to meet the requirements of the small leak protection system. 4.5.2.2 Spiral generation system The spiral generation system utilises spiral generation logs and mould panels. The materials are as follows: Spiral generation log & U-shaped membrane : Extruded Polystyrene foam Mould panel : Expanded Polystyrene form Spiral generation logs are wound spirally around the spherical cargo tank surface by an automatic spinning machine.



Mould panels are applied to the rest of the spherical cargo tank surface i.e., north and south pole area and the inside and outside of the tank skirt. The transition area between the cargo tank and inside of the tank skirt utilises a U-shaped membrane made of elastic extruded polystyrene foam in order to absorb relative displacement between the tank skirt and the tank. The insulation is completely free from the cargo tank in order to enable leakage detection 4.5.2.3 Insulation disk The insulation disk is installed in the cargo tank dome in order to reduce heat entry into the cargo tank through the dome. The insulation disk is made of polyurethane foam covered with aluminium alloy plate. 4.5.2.4 Dome fire protection Each cargo tank dome is covered with stainless steel above the tank cover (Fire protection cover) to protect the tank dome in case of fire. The dome surface is coated with 2 layers of insulation material. The first layer is polyurethane foam as thermal insulation layer. The second layer is elastic rubber coating for fire and moisture protection. 4.5.2.5 Dome rubber The space between the cargo tank dome and the tank cover is sealed by a dome rubber made of synthetic rubber. The dome rubber is fixed to the dome top flange and the tank cover by a steel plate retainer with bolts and nuts. 4.5.3 Description of Cargo Pumps

4.5.3.1 General Two cargo pumps are installed in each cargo tank (total 10 cargo pumps), and one complete set is provided as spare. The cargo pumps are electric motor-driven, single stage, centrifugal types. The cargo pumps are submerged types and must be operated in LNG liquid. Do not operate when dry. Pump bearings are lubricated by LNG drawn in by the pump.



4.5.3.2 Description Particulars Liquid pumped LNG (S.G.=0.5) Capacity (rated flow) 1100 m³/h (design flow) 1250 m³/h (min flow) 250 m³/h (min cont. flow) 437.6 m³/h (max. flow) 1320 m³/h Discharge head (rated) 135.0 m (design) 127.5 m (shut off) 158.9 m NPSH at Rated Point 1.0 m (above inducer centre) Power required (rated) 265.8 kW (design) 278.1 kW (shutoff) 144.6 kW (max.) 285.9 kW Materials Pump casing Aluminium alloy (AA-A356-T6) Impeller Aluminium alloy (AA-A356-T6) Inducer Aluminium alloy (AA-A356-T6) Shaft Stainless steel (15-5PH) Suction screen Stainless steel (316) Weight 1746Kg (incl. Jun. box) Protection Over Current Relay 523 A (thermal type) Over Current Relay 519 A (instantaneous) Low Current Relay 226 A (5 sec) Low Discharge Press 250 kPa (5 sec) Cargo pumps are located at the bottom of the centre pipe tower. The pump suctions are located approximately 75mm from the tank bottom and are protected by suction screen of 4-mesh. LNG drawn through the suction screen is pressurised by the impeller and transferred between the motor housing and discharge spool, absorbing the motor heat and finally discharged to the end bell. A part of the discharged LNG is led through the conical filter screen and orifice into the

upper bearing assembly for cooling.

Thrust force generated by impeller rotation is balanced by a TEM (thrust equalising mechanism) which is provided at the backside of the impeller. An inducer is fitted to direct the flow of LNG and assist low suction head.



4.5.3.3 Remarks Cargo pumps should not be restarted if the tank level is below approximately 2.0m. For a second attempt at pump starting, wait a period in order to avoid overheating of motor winding as follows; (COLD RESTARTS) After pump has not been operated for at least one (1) hour. Consecutively start is within twice. In this case, to wait for at least ten (10). seconds until second restart. Further restarts, shall be limited to once within seventeen (17) minutes. (HOT RESTARTS) Except for the above condition and when tripped by U.C.R. and/or O.C.R., restarts shall be limited to once within seventeen (17) minutes. A winding heater control switch for the cargo pump motor is provided in each starter to prevent moisture during refit periods. Winding heating is achieved by supplying single phase AC 28V high current to the motor. As a safeguard a key switch is provided in each starter cubicle to control the heating circuit. Keep this key switch at off when the vessel is in service. Interlocking is provided to prevent the motor from being started with the heater in use, or vice versa. Ensure that the heating circuit is isolated before the refitted work of cargo pump will be started. All cargo pumps are fitted with an insulation monitoring device which will prevent the motor from starting when insulation resistance falls below 1 Ohm. The Insulation is measured during stop periods of a pump. Prior to the motors being merged, the monitor earth line switch must be "OFF". An MCB handle lock device (by padlock) is provided on each starter to prohibit the cargo pumps from starting at dry condition of cargo tank. Note On the following conditions, the cargo pump shall not be operated. (a) No load. (b) Discharge valve full close. (c) In cavitation zone. (d) Low insulation resistance. (e) Dry running.



4.5.4 Spray Pump

4.5.4.1 General One spray pump is installed in each cargo tank (total 5 spray pumps), and one complete set is provided as spare. The spray pump is of the electric motor-driven, two-stages, centrifugal type. The spray pump is a submerged type and must be operated in LNG liquid. Do not operate when dry. Pump bearings are lubricated by LNG drawn in by the LNG pump. 4.5.4.2 Description Particulars Liquid pumped LNG (S.G.=0.5) Capacity (rated flow) 50 m³/h (design flow) 50.5 m³/h (min. flow) 10.2 m³/h (min.cont.flow) 17.9 m³/h (max. flow) 60 m³/h Dis. head (rated) 135.0 m (design) 134.3 m (shut off) 168.5 m NPSH at Rated Point 0.6 m (above inducer centre) Power required (rated) 16.6 kW



(design) 16.6 kW (shut off) 8.4 kW (max.) 18.0 kW Materials Pump casing Aluminium alloy (AA-A356-T6) Impeller Aluminium alloy (AA-A356-T6) Inducer Aluminium alloy (AA-A356-T6) Shaft Stainless steel (15-5PH) Suction screen Stainless steel (316) Weight 177Kg (incl. jun. box) Protection Over Current Relay 40 A (thermal type) Over Current Relay 35 A (instantaneous) Low Current Relay 15 A ( 5 sec.) The spray pump is located at the bottom of the centre pipe tower. The pump suction is located approximately 25mm from the tank bottom and is protected by a suction screen of 4-mesh. LNG drawn through the suction screen is pressurised by the impeller and transferred between motor housing and discharge spool, absorbing the motor heat and finally discharged to the end bell. A part of the discharged LNG is led through the conical filter screen and orifice into the upper bearing assembly for cooling. Thrust force generated by impeller rotation is balanced by a TEM (thrust equalising mechanism) which is at the backside of the impeller. An inducer is fitted to direct the flow of LNG and assist low suction head. 4.5.4.3 Remarks Spray pumps should not be restarted when the tank level is below 2.0m. For a second attempt at pump starting, wait a period in order to avoid overheating of motor windings as follows; (COLD RESTARTS) After pump has not been operated for at least one (1) hour. Consecutively start is within twice. In this case, o wait for at least ten (10) seconds until second restart. Further restarts shall be limited to once within seventeen (17) minutes. (HOT RESTARTS) Except for the above condition and when tripped by U.C.R. and/or O.C.R., restarts shall be limited to once within seventeen (17) minutes.



Note : On the following conditions, the spray pump shall not be operated; (a) No load. (b) Discharge valve full close. (c) In cavitation zone. (d) Low insulation resistance value. Dry running.



4.5.5 H/D Compressor

4.5.5.1 General Two sets of High Duty (H/D) compressors are provided in the cargo machinery room for the following purposes: During loading to return LNG vapour to shore b) During initial coo1 down to return gas/vapour to shore c) During warm-up to circulate heated cargo vapour through cargo tanks 4.5.5.2 Particulars Main particulars are as follows: Type : Horizontal, Turbo-compressor, Electric motor driven Manufacturer : Atlas Copco Energas GmbH (GTO63 Tl Kl) Capacity : 24000 m³/h Suction press. : 104 kPaA Suction temp : -140°C Discharge press. : 200 kPa Electric motor : 760 kW



4.5.5.3 Construction The H/D compressors are single-stage radial types equipped with a spur gear. The impeller is arranged in an overhung position on the pinion shaft. The spiral is screwed to the gear by means of a cast flange. The suction nozzle is arranged axially, and the discharge nozzle tangentially. A shaft seal, fitted where the rotor passes through the casing, consists of 5 floating carbon ring seals and prevents gas leakage. The installed shaft seal has two chambers. Leakage gas is drawn from. the impeller-side chamber and returned to the suction side. The second chamber is fed with dry nitrogen, which seals against the leakage gas from the impeller side. Seal gas pressure is set manually at the reducing valve. Pressure can be set from 20 to 60 kPa. The recommended setting is 30 kPa. Seal gas consumption is approximately 2.5m³/h at 20°C and 0.11 Mpa. The compressor gearbox is a 2-shaft involute helical spur with thrust collars. The shafts are borne in sleeve bearings. The thrust collars transfer the axial thrust of the pinion shaft to the axial bearing of the low-speed driving shaft. The running speed of the input shaft is 3570 rpm (elec. Motor revolutions) and speed of the output shaft is 9552 rpm constant. A bulkhead seal assures gas tightness between the cargo machinery room and motor room. The seal, located in the motor room side of the bulkhead, consists of a system of chambers with multiple carbon seal rings (consisting of three pieces) held by hose springs. The chambers are pressurised with dry air normally (10kPa) and with nitrogen as back up (5kPa). Consumption is 0.5 m³/h (dry air) and 0.3 m³/h (nitrogen). The seal housing is on an independent support which allows easy adjustment and attached to the bulkhead with stainless steel bellows. Lubricating oil is supplied to the compressor prior to starting by an electric motor driven auxiliary L.O. pump. After the compressor has started, the auxiliary L.O. pump continues to run for about 45 seconds and stops automatically. At shutdown, the auxiliary L.O. pump starts automatically and continues to run for about 55 minutes. If oil pressure falls below 120 kPa, the auxiliary L.O. pump switches on automatically. The pump and motor units are located in the motor room and serve as a stand-by unit when the main, shaft driven L.O. pump fails. A L.O. cooler is provided to keep the L.O. temperature at 48oC. Cooling water for the L.O. cooler is supplied from the Auxiliary Control Cooling Fresh Water System (60oC). If the L.O. temperature is low, L.O. in the sump tank can be heated by a steam heater which is controlled by a temperature control valve (set value 50oC).



4.5.6 L/D Compressor

4.5.6.1 General Two Low Duty (L/D) compressors are provided in the cargo machinery room for maintaining constant cargo tank pressure and for delivering boil-off gas according to the boiler demand. Main particulars are as follows: Type : Horizontal, Turbo-compressor, Electric motor driven Manufacturer : Atlas Copco Energas GmbH (GTO32 Tl Kl) Capacity : 8800 m³/h Suction press. : 104 kPaA Suction temp : -40°C Discharge press. : 200 kPaA Electric motor : 330 kw 4.5.6.2 Construction The construction and materials are the same as for the high duty (H/D) compressors except for the compressor capacity control. The compressor capacity control is as follows: The capacity of the L/D compressor is controlled by adjusting the inlet guide vane and motor speed. The inlet guide vane and motor speed are controlled according to main boiler demand within the respective split ranges that follow: • When the capacity is below 50%, the motor speed is kept at 1775 rpm and the Inlet

Guide Vane (IGV) is adjusted by a pneumatic actuator between –80o and +20o according to the main boilers demand signal from SSC on the Engine Control Console (ECC).

• When the capacity is above 50%, IGV is full open, the motor speed is adjusted by a

step less and variable speed static inverter between 1775 rpm and 3550 rpm according to demand signal from the SSC on the ECC.

• The stable operating range of the compressor is restricted by the surge limit. Surges

which may cause damage to a compressor are prevented automatically by increasing the flow through the compressor by means of a surge control valve on the compressor discharge. Surge control is achieved by comparing the difference in pressure between compressor suction and discharge with actual flow measured by venture in the suction line. If the ratio of the above two signals falls below the set value, the anti-surge controller will open the surge control valve and allow gas to be recirculated to the compressor suction. The surge control is independent of the main control system.



4.5.6.3 Operation Compressor starting can be carried out from the Engine Control Console (ECC) using the start push button. The operational condition can be read on custom group display 2. After pressing the “RUN” button, the compressor will be controlled by the Single Strategy Controller (SSC) on the ECC to meet with the boiler demand according to the set value of SSC. The compressor can also be started from either a local control panel, a starter in the cargo switch board room and push button next to motor side. Remote start (from ECC, local panel and motor side) is possible when the local/remote change-over switch on the starter is set on “REMOTE”. Setting the switch on “LOCAL” permits the start from the starter. This change-over switch is normally set on “REMOTE”. However, the compressor can be stopped from any control position. A normal/lock switch is also provided next to motor side. This will inhibit motor start from any control position when “LOCK” is selected. Note: At free flow operation (motor stops), the aux. lubricating oil pump should be running. 4.5.6.4 Start-up 1. Confirm that the gland sealing nitrogen gas pressure is at the present value (30 kPa)

and bulkhead sealing air at correct pressure (10 kPa). 2. Confirm that the inlet guide vanes are at the minimum position (-80°) 3. Confirm that the surge control valves are open. 4. Confirm that the compressor L.O. sump tank level is acceptable and L.O.

temperature is above 25oC, start the auxiliary L.O. pump to circulate oil and heat the oil.

5. Confirm that the L.O. cooler coolant water valves are open. 6. Open the compressor suction valves from the Engine Control Console (ECC). 7. Open the compressor discharge valves manually. 8. When the start-up procedures are completed, the "READY' lamp for the L/D

compressor will light up on the ECC and local control panel. 9. Confirm that the "READY" lamp is lit. 4.5.7 Gas Heater

4.5.7.1 General A High Duty (H/D) gas heater and a Low Duty (L/D) gas heater are located in the cargo

machinery room. They are horizontal shell and U-tube, direct steam heating types.

The heaters are used for the following purposes; a) H/D heater Heating LNG vapour to warm-up the cargo tank for tank inverting, gas freeing and aeration. Back-up of the L/D heater. b) L/D heater Heating boil-off gas from cargo tanks to use as gas fuel in the boiler.



4.5.7.2 Particulars The design capacity of the H/D and L/D heaters is as follows; H/D Heater L/D Heater Gas inlet pressure 200 kPaA 200 kPaA Gas inlet temperature -55oC -70oC Gas outlet pressure 180kpaA ΔP=13kPa Gas outlet temperature +75oC +45oC Maximum gas flow 43000Kg/h 8400Kg/h Heating capacity 12600MJ/h 1900mJ/h Heating steam pressure 834kPa 834kPa Heating steam temperature 177oC 177oC

Supply steam for each heater is fed from the low pressure steam generator (LPSG) in the engine room. Each heater is provided with a steam condense drain pot and a steam trap. Condense from each heater is returned to the drain inspection tank in the engine room through the gas heater drain cooler and the gas heater drain tank. 4.5.7.3 Control System Each heater has a local control board located near each heater. All control systems and the local control board are pneumatic operated. The gas outlet temperature can be set by the temperature controller fitted on the local control board. Control valves for flow to the heater inlet and by-pass flow to the heater outlet are adjusted according to the set temperature. The L/D heater has two control valves (VG-941 & 943), VG-941 controls the flow to the heater inlet and VG-943 controls the by-pass flow to the heater outlet. The H/D heater has four control valves (2 pairs of valves). The large valve pair (VG-945 & 947) is used by the H/D heater (warm-up mode) and the small valve pair (VG-946 & 948) is used for L/D heater back-up (gas burning mode). The warm-up mode and the gas burning mode can be selected using the selector switch on the local control board. When heating steam condense level is detected in the drain pot, all control valves are closed to prevent icing in the heater shell. Under normal conditions, the condition indicator on the local control board shows green. At trip condition, drain pot level is shown by red/white strips. And the trip condition in also monitored by the Integrated Monitoring System(IMS). When tripped, all control valves are closed. They can be reset manually using the reset switch fitted on the local control board. The gas heater alarm set points are as follows; Gas outset temperature high : 90oC Gas outlet temperature low : 10oC Drain pot level high : 195mm (Temp. control valves close)



4.5.8 Operation of H/D heater

4.5.8.1 Start up Select the operation mode, either WARM-UP or GAS BURN. Set the Auto / Manual selector switch on the temp. controller to "M". This is done at the local control board. Ensure that the gas detection system on the gas vent drain tank in operating. Ensure that the auxiliary central cooling system Is operating and cooling water is being supplied to the gas heater drain cooler. Ensure that instrument air is being supplied to the local control board and the system works well. Manually open the vent valve on the heater shell. Open the drain pot steam trap isolating valve. Open the steam inlet valve and pass heating steam into the heater slowly and gradually. Close the vent valve when steam begins to spurt out. Check that the H/D heater outlet valve (VG-916) is open. Check the H/D heater inlet valve (VG-915) is open. At local control board, open the temperature control valve (VG-945 & 947 for warm-up, VG-946 & 948 for L/D heater back up) and adjust the gas outlet temperature. When the gas outlet temperature is steady, change the operation mode Auto/Manual switch

to “A”.

4.5.8.2 Stop Change the operation mode Auto Manual switch to 'M' on the local control board. Close the gas inlet control valve and stop the gas slowly and gradually. Close the steam inlet valve slowly so as to prevent icing after the temp. control valves are closed. Slowly open the vent valve an the heater shell. Close the vent valve after the inside temperature of the shell and gas inlet and outlet piping reach ambient temperature. Notes: Heating steam is supplied before gas flow into the heater to prevent icing. When stopping, the gas flow is stopped before shutting off steam. Drain in the heater shall be discharged enough after using the heater to avoid drain attack in the drain pipe.



4.5.9 Operation of L/D heater The operation of the L/D heater, start up and stop is the same as the H/D heater except the selection of operation mode. The L/D heater has no operation mode selection switch, the L/D heater is only used for GAS BURNING. Notes for H/D heater also apply. Valve No. corresponding to the L/D beater as follows. • Steam inlet valve : 3SV~704 • Drain pot steam trap isolating valve : 3DV-702 • L/D heater gas inlet control valve : VG-913 • L/D heater outlet valve : VG-914 4.5.10 LNG Vaporizer

4.5.10.1 General The LNG Vaporizer is of horizontal shell and U tube, direct steam heating type. It is located in the cargo machinery room. The LNG Vaporizer is used for the following; Purging inert gas from the cargo tanks prior to cool down. LNG is supplied from the shore to the vaporizer and the vaporized gas is led to the cargo tanks. During cargo unloading, if the shore dose not supply return-vapour to the cargo tanks, the LNG vaporizer produces vapour by bleeding LNG from the main line and supplies it to the cargo tanks. In the event that both cargo pumps fail in a cargo tank, emergency discharge by pressurising the cargo tank is done using the LNG vaporizer. Liquid LNG is supplied to the vaporizer by a spray pump and the vapour is led to the cargo tank for pressurising. In the event that the inert gas generator is unable to produce inert gas, the LNG vaporizer can produce nitrogen gas using liquid nitrogen from the shore.



4.5.10.2 Particulars The design capacity is as follows; Inert gas purging Unloading without return gas Gas evaporation 8500 kg/h 18000 kg/h LNG inlet temperature -163oC -163oC LNG inlet pressure 290 kPa 200 kPa Gas outlet temperature +20oC -60oC Gas outlet pressure 29 kPa 29 kPa

Steam for the LNG vaporizer is supplied from the low pressure steam generator (LPSG) in the engine room. The vaporizer is provided with a steam condense drain pot and a steam trap. Condense drain from the vaporizer is returned to the drain inspection tank in the engine room through the gas heater drain cooler and the gas heater drain tank. 4.5.10.3 Control system The LNG vaporizer has a local control board located near the vaporizer. Outlet gas temperature is controlled by the temperature controller fitted on the local control board. The outlet gas temperature can be set by the temperature controller. A pneumatic operated control valve (VS-902), is adjusted according to the set temperature. Outlet gas temperature is monitored by IMS. The flow rate can be controlled using the remotely operated valve (VS-901). It is adjusted from the Cargo Control Console (CCC). When heating steam condense level is detected in the drain pot, the temperature control valve and the flow rate control valve are closed to prevent icing in the vaporizer shell. Under normal conditions, the condition indicator on the local control board shows green. At trip condition, the drain pot level is shown by red / white strips. The trip condition is also monitored by the IMS. If the flow rate control valve is fully closed due to accidental operation at the CCC, then the temperature control valve is forced closed. This condition is interpreted by the Integrated Monitoring System (IMS) as a trip condition. The condition indicator on the local control board also shows red / white strips instead of green. When tripped, both temperature and flow rate control valves are closed. They must be reset manually using the reset switch on the local control board. LNG vaporizer alarm set points are as follows; • Gas outlet temperature high : 80oC • Gas outlet temperature low : -70oC • Drain pot level high : 195mm



4.5.11 Operation

4.5.11.1 Start up Select the spray nozzle according to the operation mode. These modes are inert gas purging, unloading without return gas or emergency discharge. In unloading without return gas mode, use a 1-1/2 inch spray nozzle. Use a 1 inch spray nozzle for the other modes. (a 1 inch spray nozzle is set in the vaporizer at delivery.) At the local control board, set the Auto / Manual selector switch on the temp controller to "M. Ensure that the gas detection system on the gas vent drain tank is operating. Ensure that the auxiliary central cooling system is operating and cooling water is being supplied to the gas heater drain cooler. Ensure that instrument air is being supplied to the local control board and the system works well. Manually open the vent valve on the vaporizer shell. Open the drain pot steam trap Isolating valve (3DV-704) Open the steam inlet valve (3SV-706) and pass heating steam into the vaporizer slowly and gradually. Close the vent valve when steam begins to spout out. Open the flow control valve (VS-901) using the local valve handle and then open the temperature control valve (VS-902) using the local temp. controller. Do this slowly and gradually. Adjust both flow and temperature control valves locally until gas outlet temperature is steady. When the gas outlet temperature is steady, then change the operation mode Auto / Manual switch on the temperature controller to "A". Under normal operating conditions, the flow rate is adjusted by the flow control valve (VS-501). This is done manually from the CCC in accordance with the cargo tank pressure. 4.5.11.2 Stop Change the operation mode Auto / Manual switch on the local. temperature controller to “M”. Close the flow control valve using the local valve handling and the temperature control valve using the local temperature controller. Stop the LNG slowly and gradually. Close the steam inlet valve slowly so as to prevent icing after the flow and temp. control valves are closed. Slowly open the vent valve for the vaporizer shell. Close the vent valve completely after the inside temperature of shell and LNG inlet and outlet piping reach the ambient temperature.



Notes: Heating steam is supplied first to prevent icing.

When stopping, the LNG liquid supply is stopped before shutting off steam. The flow control valve is not closed fully during normal operation. When exchanging the spray nozzle, the vaporizer is purged with nitrogen gas. Drain in the heater shall be discharged enough after using the heater to avoid drain attack in the drain pipe. Do not start the vaporizer to vaporize LNG unless the drain pot is at operational temperature. 4.5.12 Forcing Vaporizer

4.5.12.1 General The forcing vaporizer is a horizontal shel1 and U tube, direct steam heating type. It is located in the cargo machinery room. The forcing vaporizer is used for producing LNG vapour to be sent to the main boiler as fuel gas. The produced LNG vapour is added to natural boil-off gas from cargo tanks. 4.5.12.2 Particulars The design capacity of the forcing vaporizer is as follows; • Gas evaporation : 6400 Kg/h (min. 1000Kg/h) • LNG inlet temperature : -163oC • LNG inlet pressure : 290 kPa • Gas outlet temperature : -40oC • Gas outlet pressure : 25 kPa Supply steam for the forcing vaporizer is fed from the engine room. 4.5.12.3 Control system The forcing vaporizer is provided with a local control board located near the vaporizer. Outlet gas temperature is controlled by the temperature controller fitted on the local control board. Outlet gas temperature can be set by the temperature controller and a pneumatic control valve (V32904)-MD 329, is adjusted according to the set temperature. Temperature of the outlet gas is monitored by the Integrated Monitoring System (IMS). The outlet gas flow rate is controlled by a PID controller. The control signal of the flow rate is determined as the additional flow to the natural boil-off gas flow. The control signal is calculated using the following formula by the SSC: Main boiler gas consumption minus available gas flow from cargo tanks. The gas flow rate is adjusted by the pneumatic type flow control valve (V32903)-MD 329, according to the signal from the PID.



When the gas temperature in the mist separator becomes too low because of mixing with the natural boil-off gas, a low temperature signal is sent to the IMS and both temperature control valve and flow rate control valve are closed as trip condition so as not to send cold gas, which might include LNG mist, to the gas compressor. The trip condition must be reset by the reset switch fitted on the local control board after recovery of trip cause. Forcing vaporizer alarm/trip set points are as follows; Gas outlet temperature high : 80oC Gas outlet temperature low : -70oC Mist separator temperature low : -145oC 4.5.13 Operation

4.5.13.1 Start up Change the operation mode of the flow and temp. control valves from "A" to "M". This is done at the manual loader and temp. controller on the local control board. Ensure that the heating steam. supply pressure is at 0.3 MPa. Open the steam inlet valve (V32980)-MD 329 and pass heating steam into the vaporizer slowly and gradually. Open the flow control valve (V32903) and the temp. control valve (V32904)- MD 329 using the manual loader and temp. controller. Do this slowly and gradually. Adjust both flow and temp. control valves locally until the gas outlet temperature is steady. When the vaporizer gas outlet temperature is steady, then change the operation mode of the flow and temp. control valves to "A" on the local control board. Under normal operating conditions, the flow rate is controlled automatically according to a control signal from the SSC. 4.5.13.2 Stop Change the operating mode of the flow and temp. control valves from “A” to “M”. This is done at the manual loader and temp. controller on the local control board. Close the flow and temp. control valves (V32903 & V32904) manually from the manual loader and temp. controller. Stop the LNG flow slowly and gradually. Close the steam inlet valve slowly so as to prevent icing after the flow and temp. control valves are closed. Open the vent valve for the vaporizer shell slowly.



Close the vent valve completely after the Inside temperatures of the shell, LNG inlet and outlet piping reach ambient temperature. Note: Heating steam is supplied first to prevent icing. When stopping, LNG liquid supply is stopped before shutting off steam. Drain in the heater shall be discharged enough after using the heater to avoid drain attack in the drain pipe. Do not start vaporizer to vaporize LNG unless the drain pot is at operational temperature. 4.5.14 Nitrogen Generating System

4.5.14.1 General The nitrogen generating system is installed on the 2nd deck in the engine room. It is used for the following purposes: • Cargo line purging. • Cargo compressors (H/D,L/D) gland sealing & bulkhead sealing. • Cargo tank insulation space inerting. • Vent riser fire extingnishing. • Engine room gas line purging. 4.5.14.2 Particulars Nitrogen generator; 2 sets Type : Membrane permeation Capacity : 90 Nm3/h Outlet press. : 490 kPa Nitrogen purity : 97% (by vol.N₂+Ar) Max. outlet temp. : 50oC Dew point at atm. press. : -65oC Feed air compressor ; 2 sets Type : Screw compressor electric motor driven Capacity : 280 Nm3 /h Discharge press. : 1450 kPa N2 buffer tank ; 1 set Capacity : 10 m3 Working press. : 300 ∼ 500 kPa 4.5.14.3 Construction Ambient air is compressed by the water cooled screw compressor. Some condense water will be. separated in the cyclone separator (F-4A/B) and automatically drained out. Then the saturated air passes through three filters (F-1A/B,2A/B,3A/B).



The treated compressed air is heated by the electric heater before entering the membranes. The heated air then passes the membranes and is separated into two streams. One stream is nitrogen, the other is the remaining gases. In downstream of the membranes, the nitrogen passes through the flow indicator (F1-1A/B), the purity control valve (HCV-1A/B) and the back pressure regulator (PCV-1A/B), and is led to the nitrogen buffer tank. The other gases are discharged to the atmosphere. 4.5.14.4 Operation The nitrogen generator is started / stopped locally. Once the system has been started from the local control panel, the feed air compressor is started and stopped automatically in response to the pressure in the nitrogen buffer tank (start : 300 kPa, stop : 500 kPa). When plant is stopped which means that the generator inlet and outlet valves are closed and vent valves are open, the compressor will continue idling for a few more minutes and stop. If the plant has been stopped for several hours, the membranes are cold and will therefore not separate properly for about 15 minutes after start-up. The nitrogen gas can be sent after about 15 minutes. Confirm that the oxygen content is below 3.5% before supply on custom group display 13 on the VDU. 4.5.14.5 Initial Start-up Before start-up, check all drain valves on the filters for the presence of water. Switch ON the isolating switch on the El. Heater control panel. Switch ON the main isolating switch on the Nitrogen system control panel. Switch ON the oxygen analysers and calibrate in accordance with manufacturer's manual. Select the process trains and put the selector switch in the position corresponding to the following operational scenarios. 4.5.14.6 Single train operation Position 1.: (Crossover valve XV-4 is CLOSED) Compressor A operates with side A of the nitrogen generator or compressor B operates with side B of the nitrogen generator. Position 2.: (Crossover valve XV-4 is OPENED) Compressor A operates with side B or compressor B with side A.



Note: SELECTORS SWITCH Position 1 COMPR A→ N2 GEN. A COMPR B→ N2 GEN. B Position 2 COMPR A→ N2 GEN. B COMPR B→ N2 GEN. A 4.5.14.7 Double train operation Position 1 should always be selected. Confirm that the manual isolation valves are OPEN. Confirm that all valves upstream of the nitrogen buffer tank are OPEN. Put the local panel compressor selector on REMOTE. Shut-off valve will remain in the "SHUT" position and vent valve in the "OPEN" position until oxygen content is less than the set point of alarm OAHH-1A (Ref to alarm list). Once the oxygen content is less than the set point of the alarm, the shut-off valve will OPEN and start to deliver nitrogen gas to the buffer tank. 4.5.14.8 Stop Press the STOP button on the compressor control panel. Open all filter drain valves. If the system is to be out of service for a long time, switch off the isolating switches (Nitrogen system control panel, electric heater panel, oxygen analyser). 4.5.14.9 Safety Nitrogen is a non-toxic but asphyxiating gas. Its density is slightly lower than air. 4.5.15 Inert Gas Generator Plant

4.5.15.1 General The inert gas generator plant sends inert gas or dry air to cargo tanks and cargo holds. The plant consists of two air blowers, an inert gas generator, an Inert gas refrigerating unit and an inert gas dryer unit (the two latter shown as only one unit). The inert gas generator plant is in the IGG Room on the 3rd deck of the engine room. 4.5.15.2 Particulars The design capacity of the IGG is as follows;



Inert gas capacity : 11000 Nm3/h Discharge pressure : 0.025 MPa Temperature : Average 30oC (Max 65oC) Dew point after expansion : Maximum –45oC to atmospheric pressure Dry inert gas composition is as follows; Oxygen O2 : Maximum 1.0 % Carbon-dioxide CO2 : Maximum 14.0 vol % Carbon-monoxide CO : Maximum 100 ppm Sulphur-oxides SOx : Maximum 10 ppm Nitrogen N2 : balance 4.5.15.3 Construction of the Inert gas generator (IGG) The inert gas generator consists of a combustion chamber and a cooling/washing tower. In the combustion chamber, fuel oil and air are burnt and inert gas is generated. Then the inert gas is sent to the cooling/washing tower. At the cooling/washing tower, a sea water shower cools the inert gas and washes out sulphur oxides which are contained in the gas. The NO.3 ballast pump supplies sea water to the cooling/washing tower and the cooling jacket of the combustion chamber. The IGG fuel Oil Pump supplies fuel oil from IGG gas oil tanks. The combustion air is supplied by roots type air blowers. The final discharge pressure of the dryer unit is maintained by the air blowers, and the pressure is controlled by a pressure control valve. 4.5.15.4 Inert gas refrigerating unit (Freon R-22) The inert gas refrigerating unit cools the inert gas as the first step of drying. The inert gas refrigerating unit consists of a Freon compressor with capacity control, a Freon condenser, a Freon evaporator and a demister. The Freon evaporator is a shell and tube type cooler. Direct expanded Freon 'R-22' cools inert gas and condenses excess water in the inert gas. 4.5.15.5 Inert gas dryer unit The dryer unit absorbs water in the inert gas with activated alumina. The inert gas dryer unit has two dryer vessels. When one vessel is working, the other vessel is regenerating. The change-over between working/regenerating is carried out automatically every 8 hours. In the regenerating phase, the vessel is heated by hot air for at least 4 hours, and then cooled. The hot air is generated by both electric and steam heaters. The temperature of hot air is controlled about 220oC by electric heater. 4.5.15.6 Control and monitor The final discharge pressure (0.25MPa) of the inert gas plant is controlled by the pressure control valve.



The oxygen content can be adjusted manually by changing the fuel oil/air ratio. (This is done automatically in the simulator). When oxygen content rises above the high level (2 %), the discharge valve will close and the purge valve will open. The inert gas is blown-off to the atmosphere. Dew point is measured continuously by the dew point analyser. If a high high condition (-40oC) continues for 15 minutes, the inert gas is blown-off too. 4.5.15.7 Preparation of Starting-up Before starting the system: Open IGG cool SW overboard valve and SW valve (2WV-41). Start the No.3 ballast pump after lining up for cooling of IG system scrubber. Line up from the IG system to the tanks or holds in question. Dryer unit and inert gas refrigerating unit which is shown as one unit will work automatically, and need no attention here. Set the O2 analyser to OFF. Open the valve to above funnel. 4.5.15.8 Inert gas production Open the fuel supply valve to the burner. Line up and start one or two fans. Switch on the burner. After the O2 has stabilised at a low level switch ON the O2 analyser and change over from above funnel to delivery line. Adjust pressure level at the PID control. 4.5.15.9 Dry air production (on cargo tank aeration) Use the same procedure as for inert gas production, but leave the burner and the O2 analyser OFF. 4.5.15.10 Stop There is a certain way to shut down the IG plant in real life. On the simulator you may shut of the different valves for supply, and then shut down the complete plant step by step without any great concern. Remember to shut down the ballast pump no 3 and its valves as well. 4.5.16 Cargo Control Console (CCC) The CCC is in the Cargo Control Room. 4.5.16.1 Composition

• The simulator works in a semi mode where all mimic panels are presented on the screen. Therefore it may act as “real equipment” where the operator are walking on deck and adjusting the different valves directly. Or it may act as a mimic panel in the CC room where the operation of the equipment will be remotely controlled.



• Most mimic pictures are of this semi type. However the Cargo Control Panels (1-5), and H/D & Spray Control Panels are looked upon as if they where positioned in the CC room.

• These panels are composed of the following equipment for remote operation; • Port and Starboard cargo pumps with discharge control and tank temperature setter

control for each tank. • Cargo tank spray pump and spray header control for each tank. • Control for high duty compressor no 1 & 2. • See also the IMS control. 4.5.17 IMS control function

4.5.17.1 General The IMS provides the following control functions. For machinery: - Low duty compressor control - Forcing vaporizer control For cargo: - High duty compressor control - Tank pressure control - Spray pump start/stop, (Spray pump load control), (spray header press control). - Spray line cool down - Equator temperature control - Cargo pumps start/stop, (Cargo pump load control). - Discharging The main components of the control functions are the Signal Strategy Controller (SSC) for continuous PID control of sequence and logic control. The Single Strategy Controller (SSC) is a stand alone programmable controller and is located on the CCC. The data setter allows setting of variable data for cargo pump stop/striping level. 4.5.18 BVG management system

4.5.18.1 General The BVG (Boil-off and Vapour Gas) management system is a total gas flow control from cargo tanks to main boilers. The total gas flow consists of the following two kind of gas; • Natural boil-off gas (Natural BOG) from cargo tanks. • Forcing boil-off gas (Forcing BOG) generated by forcing vaporizer. The natural BOG is sent to the main boilers by the L/D compressor through the low duty heater and the flow rate is controlled by an L/D compressor speed & inlet guide vane



(IGV). If natural BOG does not meet boiler demand, the forcing vaporizer will generate forcing BOG and add it to the natural BOG for full speed range of ship. 4.5.18.2 System configuration BVG management system consists of the following control system: Vent control • The vent valve is operated by the signal from the cargo pressure controller for tank

protection. • The vent valve is opened at 23Kpa in vapour header and closed at 21Kpa. Tank pressure control • The control system maintains the pressure in cargo tanks at a present value. • The control system calculates the available gas flow and excess gas flow. Forcing vaporizer control • The control system controls the flow rate of forcing vaporizer. Gas heater control • The control system controls the outlet temperature of low duty heater at a present

value. Low Duty (L/D) compressor control The control system controls the inlet vane opening and revolutions of. The low duty compressor according to boiler fuel gas demand. 4.5.19 Low duty compressor control

4.5.19.1 General This control system controls the inlet vane opening and the revolutions of the low duty compressor according to boiler fuel gas demand. 4.5.19.2 Operation Line up for use of the L/D compressor. Start the aux. L.O. pump of the selected low duty compressor. Confirm that L.O. temperature and pressure are OK, and that the READY lamp is lit. Start the low duty compressor on the compressor control panel by pushing START. After confirming steady running of the low duty compressor, change the control mode of

the PID controller to AUTO mode.

The low duty compressor can be controlled according to the boiler fuel gas demand. Stop operation Push the STOP button for the low duty compressor on the control panel.



The Aux. L.O. pump starts automatically and continues running 55min after the stop signal. The PID control mode will change to MANUAL automatically when both low duty compressors are stopped. 4.5.20 Control logic Boiler fuel gas demand is detected by the boiler gas flow control valve position. The valve position signal which is selected from NO.1 and NO.2 boilers by high selector is sent to the PID controller as the process value (PV). The difference between the process value and the pre-set value (SP) in the PID controller becomes the output signal. The out-put signal is divided into two signals; the inlet vane control signal and the revolution control signal for the low duty compressor. Inlet vane control 0 ∼ 35% Revolution control 35 ∼ 100% When the vapour header pressure decreases to the pre-set value (3kpa), the SSC outputs a F.O. back-up order signal to the boiler automatic combustion control system(ACC). After confirmation of F.O. burning signal from the ACC, the output signal from the PID controller is set to minimum, the inlet vane fully closed and revolutions set to minimum. When both low duty compressors are stopped, the SSC control mode is set to MANUAL automatically. 4.5.21 Forcing vaporizer control

4.5.21.1 General This control system controls the flow rate of the forcing vaporizer based on the difference between actual boiler gas flow (fuel gas consumption) and available natural Boil Off Gas (BOG) from cargo tanks. 4.5.21.2 Start operation Change the operation mode of the flow and temp. control valves from "A" to "M". This is done at the manual loader and temp. controller on the local control board. Ensure that the heating steam. supply pressure is at 0.3 MPa. Do this by adjusting the press. reducing valve (3SV-718). Open the steam inlet valve (3SV-801) and pass heating steam into the vaporizer slowly and gradually. Open the flow control valve (VS-905) and the temp. control valve (VS-904) using the manual loader and temp. controller. Do this slowly and gradually. Adjust both flow and temp. control valves locally until the gas outlet temperature is steady. When the vaporizer gas outlet temperature is steady, then change the operation mode of the flow and temp. control valves to "A" on the local control board.



Ensure that the PID controller operate in order to help the set value to approach the process value. Confirm the forcing vaporizer outlet temperature controller is operating. Change the control mode to “C”. 4.5.21.3 Stop operation Change the control mode to “A”. Change the flow control valve manual loader on the local control board to “M”. Local operation at the local control board is carried out. 4.5.21.4 Control logic The total fuel gas consumption of both boilers is measured by the boiler automatic combustion control (ACC) and is compared with the available BOG flow from cargo tanks. The difference between those values is sent to the PID controller as set point. The measured flow signal from the forcing vaporizer is also sent to the PID controller and the output signal from the PID controller is sent to the forcing vaporizer gas flow control valve. 4.5.22 High duty compressor control

4.5.22.1 General Two high duty compressor controllers (SSC) are on the Cargo Control Console (MD500). The control system controls the inlet vane in the high duty compressor so as to keep the vapour header pressure constant. 4.5.22.2 Start operation Switch to mimic MD 319 and start the aux. L.O. pump for the high duty compressor in question by clicking with the left mouse button on the LO icon. Open N2 Supply. Open suction inlet valve and discharge valve. Check that the vane is set to -80º L.O. temperature, pressure and the related valves are confirmed ready. Ensure that the READY lamp is lit. Ensure that the START AVAIL lamp on is lit. Ensure that the SSC is in MAN mode. Start the high duty compressor by pushing the START button. Set the vapour header pressure (which is the pressure in the Vapour. line which the compressors are sucking from). Typical setting is 5-10 kPa. After confirming that the high duty compressor is running steady, change the control mode of the SSC to AUTO. Adjust the set point of vapour header pressure according to the actual vapour header pressure. The second high duty compressor is started if necessary.



4.5.22.3 Stop operation Change the control mode on the SSC to MAN. Decrease the PID output signal to 0 gradually. Push the STOP button. The aux. L.O. pump will start automatically and continue running for 55 min after the stop order. 4.5.22.4 Control logic The measured vapour header pressure signal is sent to the PID controller as a process value. The difference between the set point and the process value in the PID controller becomes the output signal and is sent to the inlet vane actuator. 4.5.23 Spray pump start/stop

4.5.23.1 General The spray pump is started and stopped sequentially by controlling a discharge valve and a return valve. The spray pumps and the relevant valves are controlled by the spray pump load controller (SSC) and the spray header pressure controller (SSC). The flow chart of the control function is shown below. 4.5.23.2 Sequence control The sequence control will carry out the following operation by choosing AUTO mode. The spray pump discharge valve opens to the present position (7%) The tank spray return valve opens to 100% Spray pump starts Timer counting (10 sec) Initial control set point (35% motor load) of the SSC is set. Initial control set point (Spray header press: 350 kPa) of the SSC is set, Motor load is controlled by the adjustment of the spray pump discharge valve. Spray header pressure is controlled by the adjustment of the tank spray return valve. The control set point of SSC returns to the initial set point just before the finish of PLC. The sequence control will carry out the following operation by choosing MAN mode. The tank spray return valve opens to 100% The spray pump discharge valve closes to 0% The spray pump will have to be stopped manually by clicking the right mouse button on the icon. 4.5.23.3 Caution Spray pump cannot be started at the tank level less than 2.0 m normally. It is necessary to block the low level alarm (CTS) when the pump is started at the tank level less then 2.0 m.



4.5.24 Spray line cool down

4.5.24.1 General Spray line cool down is controlled from the Cargo Control Console (CCC). Spray line cool down is carried out before spraying, if necessary. 4.5.24.2 Sequence control The sequence control will carry out the following operation: All spray valves open. Time counting (60 sec). All spray valves close. Activate chime ring for ten seconds (works only if acoustic alarm is enabled).



4.5.25 Cargo pump start/stop

4.5.25.1 General The cargo pump is started and stopped sequentially by controlling a discharge valve and a filling valve. The flow chart of the control function is shown below. The cargo pumps and the relevant valves are controlled by the Programmable Logic

Controller (PLC) in combination with the cargo pump load controller (SSC).



4.5.25.2 Pump stop level There are two modes for the stop sequence: “STOP MODE” and “STRIPPING MODE”. In both modes stop level should be input manually. Each pump will be in the following mode automatically by the stop level input. Where L01 = stop level for No.1 pump L02 = stop level for No.2 pump Mode of pump No.1 pump No.2 pump L01 < L02 Stripping Stop L02 < L01 Stop Stripping L01 = L02 Stop Stop

Note: Allowable input level range as follows: 0 ≤ L01 ≤15m 0 ≤ L02 ≤ 15m The cargo pump is protected against low current which will be caused by running at low tank level.



4.5.25.3 Sequence control The sequence controller will carry out the following after pushing the START button on the Automatic Sequence panel. This manual shows the normal start of cargo pumps in No.1 cargo tank. 4.5.25.4 Pump start Confirmation of cargo pump start available The Cargo Pump Discharge valve opens to the preset position (12%). The Filling valve opens to 100%. The Liquid Branch valve (out of the tank) closes to 0%. Pump starts (No.1 or No.2) Timer counting Initial control set point (42.3% motor load) of the SSC is set In compliance with the set point, the pump discharge valve opens or closes to maintain the motor current constantly. (Starting Discharge operation see next page) 4.5.25.5 Pump stop “STOP MODE” When the tank level reaches the stop level (L1 or L2), the pump discharge valve closes to the preset position. Timer counting Pump stops The pump discharge valve closes to 0%. (Required time about 20 ∼ 30 sec.)

4.5.25.6 Pump stop “STRIPPING MODE” When the tank level reaches the stop level, chime activates. Note: In this case the operator must stop cargo pump manually. 4.5.25.7 Caution The Cargo pumps cannot be started at a tank level less than 2.0m normally. It is necessary to block the low level alarm (CTS) when the pump is started at a tank level less then 2.0m. This figure is adjustable by keyboard operation on CTS. When this sequence control is started when the cargo pump is running, the discharge valve is returned to the preset position (initial load). Cargo pump stop sequence control utilises the level signal (0-15 meters) from CTS main level segment. 4.5.26 Discharging

4.5.26.1 General The liquid branch valve and filling valve automatically open and close by the Programmable Logic Controller (PLC).



4.5.26.2 Sequence control The sequence controller will carry out the following operation by pushing the START button on the Automatic Sequence panel. This manual shows the discharging of No.1 tank. Confirmation of the setting of the Filling valve (≥95 %) and the Liquid branch valve (≤ 3%). Liquid branch valve opens to 100% • Timer counting (20 seconds from the open signal of this valve) • The Filling valve closes to 0%. • • Note: The CTS measuring system must be on during cargo operations.



4.5.27 Cargo tank temperature control

4.5.27.1 General During ballast voyage, the equator temperature of the cargo tank can be maintained at a present value by automatic control of spraying. Temperature control is done through the NO.3 spray nozzle valve (nominal capacity 2,35 t/h /tank ) of each tank. The control temperature is measured by four thermo resistance bulbs (three wire type pt 100 Ω at 0oC) which are provided forward, aft, port and starboard at equator level of each tank. “Cargo tank pressure control” stops spraying when the tank pressure reaches the preset value. 4.5.27.2 Operation Preparation: • Start spray pump (refer to “Spray pump”) • Cool down spray line • Set the variable value for spray header pressure controller. • Push the “START” button at the Auto Sequence panel on the Tank Temp Setter. Set the equator temperature. Caution: Equator temperature should reach below –124oC before starting of normal loading. To stop push the “STOP” switch at the Auto Sequence panel on the Tank Temp Setter.



4.5.28 Cargo tank pressure control

4.5.28.1 General During ballast or laden voyage, pressure of the cargo tank can be maintained at a present value by controlling amount of vapour generated by forcing vaporizer. 4.5.28.2 Description Two sets of controllers are provided for this function. One controls tank pressure by measuring gauge pressure at the vapour header, and the other controls by measuring absolute pressure.



Selection one of the two tank pressure controllers is done using the changeovers switch on the CCC. The way to control tank pressure in relation with the gas supply and demand condition is as follows;

• Natural BOG > boiler demand → Dump, Vent or Pressurising • Natural BOG + spraying > boiler demand → Dump, Vent or Pressurising • Natural BOG + forcing + spraying > boiler demand → Decrease the flow from

vaporizer • Natural BOG + forcing + spraying < boiler demand → Increase the flow from

vaporizer • Natural BOG + spraying < boiler demand → Forcing • Natural BOG < boiler demand → Forcing and/or Spraying Regarding the acceptable pressure range of the cargo tank, refer to "Cargo tank protection system”. 4.5.29 Cargo tank protection system

4.5.29.1 General An instrumented tank protection system designed for Moss spherical cargo tanks is provided. In addition to the level measurement, three adjustable level alarms for each tank (in the custody transfer system) are provided. Thermo-resistance bulbs are provided to monitor the temperature of the cargo tank and hold. 4.5.29.2 Level alarm and safety A High level alarm is provided in each cargo tank. It is initiated by a capacitance level sensor and is set at 97.0% volume. A High-High level alarm is provided in each cargo tank. It is initiated by a capacitance level sensor and is set at 99.0 % volume level. The tank filling valve for each cargo tank is closed automatically by the High-High level signal mentioned above. Moreover, an Emergency Shut Down system (ESD) is activated by the signal from a capacitance spot sensor at 99.5 % volume level. 4.5.29.3 Pressure alarm and safety A High pressure alarm for each cargo tank is provided, and is set at 22 kPa. The vapour header pressure control valve is opened at 23 kPa. The pilot operated relief valve of each cargo tank releases excess vapour in the cargo tank to the atmosphere at 25 kPa.



A Low pressure alarm is provided for each cargo tank and is set at 1 kpa. An automatic trip system for the gas compressors, cargo pumps, spray pumps, IGG, ESD valves, spray inlet valves and fuel gas master valve is activated when the pressure of any one of the cargo tanks is equal to the atmosphere. A High pressure alarm for each hold is provided, and is set at 12kPa. The pilot operated relief valves of each hold space release excess air in the atmosphere at 15kPa. A Low pressure alarm for each hold is provided, and is set at -2kPa. A Dry air supply request alarm for each hold is provided and set at -2kPa. The pilot operated relief valves of each hold introduce atmospheric air to the hold space when the pressure drops to -5kPa. A high differential pressure alarm for each tank and hold is provided, and is set at 3kPa of excess pressure in hold. An automatic trip system for gas compressors, cargo pumps, spray pumps, IGG, spray inlet valves, fuel gas master valve and emergency shut down valves is activated at 4kPa of excess pressure in the hold. Moreover differential pressure relief valves (for each hold) release air in the hold to the atmosphere at 5kPa of excess pressure in the hold. 4.5.29.4 Temperature alarm and safety Ten temperature sensors in each tank are provided. Five are for service and five are for spare. They are located at bottom, 25% level, 50% level, 75% level and 100% level in each tank. Four temperature sensors are provided at the equator level for each tank. There are four temperature sensors for each hold space (side bulkhead, foundation deck, double bottom and drip-pan), and three temperature sensors for the forward bulkheads. A low temperature alarm indicates a cargo leakage or tank insulation failure. 4.5.30 Description of Ballast Tanks and Ballast Pumping

4.5.30.1 Segregated Ballast System The ship is equipped with a segregated ballast system comprising a total of 25 water ballast tanks. All valves in the ballast system are single actuated butterfly valves. All the valves are hydraulically remote controlled from the cargo control room. Three electrically driven self priming ballast pumps, with a capacity of 3000 m3/h at 35 mTH (SW) each, are provided. One ballast ejector with a capacity of 300 m3/h at 20 mTH (SW) is also provided. The above pumps and ejector cannot be used in the cargo system and consequently they do not require consideration with Annex II in MARPOL 73/78.



4.6 Mimic Diagrams The Picture Directory will give the operator an overview of all process pictures. From this directory any picture can be selected by clicking on the name field of the picture.



4.6.1 Cargo Tank Overview The Cargo Tank Overview will give the operator a total view of the cargo tanks with information about the cargo and tank level, shown as a bar graph, as well as vital data of the ship’s condition like trim, list, deadweight, stability and draught. The small picture of the ship at the bottom of the page makes it possible to quickly change the picture to either one of the cargo tanks, or holds by just clicking at the corresponding area of the small ship.



4.6.2 Ballast Tank Overview The Ballast Tank Overview picture will give an overview of all the ballast tanks with information about the filling level of the tanks shown as a bar graph. Ship conditions will be dynamically updated based on tank ullage.



4.6.3 Bunker/Consumables The Bunker/Consumables Picture gives an overview of all tanks not related to cargo operations like HFO, DO, FW and forepeak/aft peak tanks. The picture displays both a layout of the tanks as well as an ullage bar graph shown in %. These tanks can be manually filled or emptied in this picture. A summary of the tanks will also be shown.



4.6.4 Shear Force The Shear Forces are calculated from the load distribution of the ship including the steel weights of the different hull sections, and the corresponding buoyancy forms. The graphic picture will display three different curves: yellow shows maximum permitted shear forces in harbour condition; red curve the maximum permitted shear forces in seagoing condition and the blue curve is the actual shear forces.



4.6.5 Bending Moment The Bending Moments are calculated from the Shear Forces. The actual bending moment curve is drawn in blue; the yellow and red curves give maximum limits for respectively harbour and seagoing condition.



4.6.6 Deflection The hull’s deflection (from the straight line) is calculated from the bending moments and from the elasticity of each hull section. Positive deflection represents a hogging hull condition; negative deflection represents a sagging hull condition.



4.6.7 Stability The stability curve in the form of righting arm values is calculated for heel angles ranging from 0 to 60 degrees. All righting arm values are corrected (reduced) for possible "free surface" effects. The reduction in meta centric height is specifically given. The area under the stability curve represents the heel resistance or dynamic stability.



4.6.8 Shore Tanks The Shore Tanks picture gives an overview of the shore tank which we can load from or discharge to. There is only one shore tank. Note also the Emergency Shutdown Button in the lower right corner.



4.6.9 Ship/Shore Connection Ship/Shore connection shows the shore and the vessel manifold. Shore has two liquid manifolds and two vapour manifolds. It also indicates a lightering barge/vessel which can be used. The manifold all the way to the left in the picture is the ballast discharge manifold on the vessel and the ballast receiving manifold on the shore side



Manifolds and lines There are four liquid manifold connections, and one vapour line connection. All tanks are connected to the same mainlines onboard, but divide into five tanks in one end and four manifolds in the other end.



4.6.10 Cargo Tanks There are five tanks. We use tank no 1 as an example here, and you will only be able to see the top of the tank. We have a view of the two cargo pumps and one spray pump. From the two cargo pumps there is a discharge line connected, each with their own discharge valves. These lines are then merged into one common line. A filling line is also shown between the two discharge lines. A vapour line is connected as well. From the spray pump there is a line going onto the main deck as well as a pipe going back to the tank and dividing into the three spray line nozzle systems. Control of the cargo pumps and spray system can be found to the right, where there are four PID controllers. Vital info on the ship and the tank/cargo is shown to the left. An Emergency Shutdown button is shown in the lower right corner. A picture of the ship at the top makes it possible to quickly change the picture to either one of the cargo tanks or holds by just clicking at the corresponding area of the small ship. Buttons with picture numbers make it possible to quickly change to other pictures in the simulator.



4.6.11 Hold Spaces There are five hold spaces. Hold space no 1 is used as an example here. It shows how the tank is constructed, and the hold space surrounding the tank. There are various lines and valves connected to the hold space making it possible to inert, aerate, take of the pressure or build up the pressure. Vital info on the ship and the tank/cargo is shown at the top. An Emergency Shutdown button is shown in the lower right corner. A picture of the ship at the top makes it possible to quickly change the picture to either one of the cargo tanks, or holds by just clicking at the corresponding area of the small ship. Buttons with picture numbers make it possible to quickly change to other pictures in the simulator.



4.6.12 Compressor Room This picture gives us an overview of the compressor room, consisting of the H/D and L/D compressors as well as the heaters (L/D and H/D heaters) and vaporizers (LNG and forcing vaporizer). Connections are made to the deck lines as well as to the engine room (boiler supply).



4.6.13 Low Duty System The Low Duty System consists of the Low Duty compressors and the Low Duty heater. The controllers for the L/D compressors are also in this picture. It will not be possible to start the compressors unless the correct preparation is done. Only after getting the READY signal will it be possible to start the system.

These compressors will require that you open up the supply and delivery valves, lube oil pressure will have to be sufficient, nitrogen supply for the sealing will have to be in place, and the start position of the vane will have to be set to -80. Then the Ready light will appear. The L/D controller controls both compressors. The AUTO button will have to be chosen for the controller to get access to the control of the compressors. (This means that you may run one in manual and one in automatic mode). The L/D vaporizer has a working temp of around +45 degrees C.



4.6.14 High Duty System The High Duty system consists of the H/D compressors and the H/D heater. The controllers for the H/D compressors are also in this picture It will not be possible to start the compressors unless the correct preparation is done. Only after getting the READY signal will it be possible to start the system. Same rules apply to these compressors as for the L/D compressors. The H/D vaporizer has a working temp of around +75 degrees C.



4.6.15 Vaporizers Under the page of “Vaporizers” we will find the Forcing vaporizer and the LNG vaporizer as well as a schematic picture of the L/D and the H/D compressors. This is only to be able to look more into detail on the vaporizers which are positioned in the Compressor room. The Forcing vaporizer has a working temp of around -40 degrees C, and the LNG vaporizer has a working temp of around -60 degrees C.



4.6.16 Boil-off and Vapour Gas Management This page represents an overall view of the boil-off and vapour gas management system from the tank through the L/D compressors to the boiler. It utilizes the natural boil-off from the various tanks, monitoring the tank pressure all the time. In case off low pressure the forced vaporizer kicks in and makes sure the boiler gets the amount of gas needed.



The L/D Compressor controller is the same one you will find in MD309. When set to M you control the compressors manually. By choosing A, they are set to automatic control (set point is chosen by opening up the control window by clicking on the “C” to the left and setting the value). The C mode stands for CASCADE, and means that the compressors are controlled by something outside of the compressor sphere. In this case it will be in accordance with the boiler demand. The Tank Pressure controller shall take care of the pressure in the tank in relation to the demands of the boiler. On top there is a lamp for Excess gas indication. This will light up when the tank pressure is too high. There are two choices either DUMP or NON. If DUMP is chosen, then the boiler will start to dump steam, which will require more gas to be burned for running of the ship. If NON is chosen the boiler will continue as before, but we will have to either dump through the mast riser on deck, or continue burning gas in the boiler, but prevent the Forced Vaporization system from delivering any supply, and hence make the tank pressure gradually to fall. The next buttons on the Tank Pressure controller is the LADEN and BALLASTED buttons. These speaks for them self. The difference is the amount of gas available at the moment depending on tank pressure (different tables to be used). If ABSOLUTE is chosen, then we will use reading of absolute pressure which is tank pressure plus atmospheric pressure. GAUGE is only the tank pressure. The two controllers underneath belongs to the ABS/GAUGE buttons. If ABSOLUTE is chosen, then the left hand controller shall be used. If GAUGE is chosen then the right hand controller shall be used. Set point for GAUGE (normally used will be 6-8 kPa). These two controllers check the tank pressure and condition, and figures out how much gas is available in the cargo tanks and compares it with the boiler demand. If satisfied then



there are no more actions, but if not satisfied then the Forcing Vaporizer is given a signal to start delivery of gas (FV must also be set to CASCADE mode).

The vent control makes sit possible to control the venting to the mast raiser on deck. AUTO is default mode. Then the controller will open up whenever the pressure is too high. By choosing INHIBIT the gas will NOT be vented to the mast raiser. By choosing MANUAL the valve will be forced open and venting will start. A value for the percentage of open valve may be set.



4.6.17 NITROGEN PLANT The Nitrogen plant consists of two Nitrogen compressor systems delivering Nitrogen supply to the ship wherever needed.



4.6.18 Inert Generator The cargo handling simulator is modelled with an inert gas plant where HFO is burned effectively and directed through the scrubber to the main inert gas deck line. The capacity of the inert gas plant is approximately 5000 m3/h. The scrubber washes and cools the flue gas in order to reduce soot and SO2 content. The inert gas plant is fitted with two air inlets, one for each fan, allowing the plant to take air instead of inert gas for ventilating and gas-freeing cargo tanks. The drier unit consists of two units: the refrigerating/cooling unit and a drier unit containing activated alumina. They are in this model fully automated.



4.6.19 Ballast Tanks All ballast tanks are situated in the double bottom. They give a graphic view of the content of the different tanks as well as the sounding. All connections between the tanks with lines and valves are shown. In addition we are also given the trim, list and draft measurements.



4.6.20 Ballast Pump Room The ballast pump room picture shows a schematic view of the actual ballast pump room. In this room there are three ballast pumps and an ejector. There is a connection to the deck ballast manifold, which van be used if ballast is to be discharge ashore. These ballast pumps have a capacity of 3000 m3/h – 35 mTH (SW). The ejector has a capacity of 300 m3/h – 20 mTH (SW).



4.6.21 H/D & Spray Control Panel In this panel we are positioned in the cargo control room. We have the control panel for the Cargo Tank Spray pumps and Spray Header (which are connected and work together) as well as the control panel for the two H/D compressors positioned in the Compressor Room. The Spray Sequences are started from these panels.



4.6.22 Cargo Control Panel This is another part of the panels in the Cargo Control Room. From these panels we control the cargo pumps start up, their changeover to discharge and the temperature setter of the tank which is only used under a voyage. The Automated Tank measurement system is also started from these panels (CTS).



4.6.23 Picture Directory (Load Master)

The purpose of the Load Master Computer is to avoid excessive bending stresses in the hull structure by offering the stress calculations off-line in advance. These stresses vary with the cargo distribution throughout the length of the ship. Incorrect loading can damage the ship and hence the cargo/ballast must be placed according to a carefully calculated plan. Standard plans are often prepared by the shipyard. However, it is impossible to foresee all cargo distributions, it is therefore necessary to have a sophisticated calculator on board which can provide all the appropriate stresses for every load distribution case which is manually input.



4.6.24 CCTV CAMERA If CCTV functionality is installed: At MD page nr 140 can the CCTV Camera picture be seen. It is three different views, vessels manifolds Port or Starboard and from the dock. This can be chosen from buttons in the picture.

This is visualizing the connection/disconnection of loading arm or cargo hoses. If there is a leakage in the manifold connection or blind flange this will also be visible. Leakages can be triggered either from wrong procedure during disconnection or from a malfunction set by the instructor.



From the operation page which is accessed via the “F5” button it is possible to change the operating scenario. “Weather scenario” and “Ship state” can be changed



Load Master Cargo Tank Overview From this picture it is possible to try out various tank settings, and it does not matter whether you put in the sounding, the volume (in %) or the mass of the cargo. The load master will do the right calculation anyway. The corresponding trim and list will change accordingly.



4.6.25 Load Master Ballast Tank Overview Here you may have a look at the different values of the ballast tanks shown as bar graphs.



4.6.26 Load Master Bunker/Consumables All consumables may be entered here in a simple way, and the trim and list will change accordingly. This makes it easy to try out and plan a stowage for a trip.



4.6.27 Load Master Shear Forces This picture shows the actual shear forces which will affect the ship in this situation. This makes it possible to check if the wanted condition is suitable for the ship or not.



4.6.28 Load Master Bending Moment This picture shows the actual bending moments which will affect the ship in this situation. This makes it possible to check if the wanted condition is suitable for the ship or not.



4.6.29 Load Master Deflection This picture shows the actual deflection which will affect the ship in this situation. This makes it possible to check if the wanted condition is suitable for the ship or not.



4.6.30 Load Master Stability This picture shows the actual stability of the ship in this situation. This makes it possible to check if the wanted condition is suitable for the ship or not. Damage Stability To check the vessels damage stability it is possible to simulate how the stability will become if you get water ingress into the engine room or into hold spaces. This can be seen at the off line load calculator. In the Variable page Directory you can find a line called “Damage Stability”. From here you can choose which compartment there is damage to. If the damage is in the engine room, you can set the amount of water inside. If the damage is in the ballast tanks the water level in the damaged tank will be decided by the actual loading condition you have in the Load Calculator



4.6.31 Description of Legends In this diagram an explanation is given of all colours, symbols and abbreviations used in the various mimic diagrams throughout the system.



5 OPERATION OF THE CHS-LNG/C 5.1 Introduction This Chapter describes the cargo handling principles and operations relevant to the simulator. The first section documents standard procedures for loading, discharging and inerting of the CHS-LNG/C. The second section describes the cargo handling operations by means of the Graphic Workstation (from 5.5-5.6). The third part contains these operations by means of the cargo consoles. This section is only relevant if the consoles have been installed (from 5.7). The normal cycle of tanker operations comprises loading/deballasting, laden voyage, discharging/ballasting, ballast voyage and reloading. Loading is accomplished by following directions given in the ship's loading orders. Discharging is accomplished by discharging the cargo directly into a terminal tank storage area. Ballasting is a process whereby sea water is taken aboard into the segregated ballast tanks to ensure proper stability, propeller immersion and to provide good manoeuvring and sea-keeping characteristics. 5.2 Hold Drying 5.2.1 Introduction This operation is carried out after dry docking, to prevent tank insulation damage due to condensation on tank insulation during initial cool down. 5.2.2 Line up Line up valves and lines from the inert gas generator to the hold and open up the exhaust valves in accordance with the drawings below. Open the following valves Hold Gas free isolation Vlv (V12002) - MD 120 CT 1 Hold Sp Esc Vlv (V21190) and CT 1 Hold Space Gas Free Vlv (V21195)-MD211 CT 2 Hold Sp Esc Vlv (V21290) and CT 2 Hold Space Gas Free Vlv (V21295)-MD212 CT 3 Hold Sp Esc Vlv (V21390) and CT 3 Hold Space Gas Free Vlv (V21395)-MD213 CT 4 Hold Sp Esc Vlv (V21490) and CT 4 Hold Space Gas Free Vlv (V21495)-MD214 CT 5 Hold Sp Esc Vlv (V21590) and CT 5 Hold Space Gas Free Vlv (V21595)-MD215



Connection to the other three tanks holds

Picture taken from MD211



Make the IGG system MD350 ready for start, and confirm supply of cooling water. See Chapter: Use ballast pump no 3. Leave the drain valve closed until the low alarm returns to normal (around 0.4 m). Start one or more fans. The O2 analyser is set to OFF until the IGG runs smoothly. Set the burner to ON. The “air” will be purged to the funnel. The drier/refrigerating unit will work on automatic supplying dry inert to the holds. Regulate the differential pressure between the cargo tank and hold to be as follows, P (Hold) - P (Tank) ≤ 1.5 kPa Adjust the PID control (CTR 35050) on the IGG mimic in order to enable the above condition. The differential pressure is indicated at the various hold mimic display MD211-MD215 This operation is finished when the dew point in each hold is less than -20°C. The dew point is measured with a portable dew point meter at sampling points for the hold's top and bottom. Then pressurise to about 1 kPa in the hold. Stop the IGG system locally and then No.3 ballast pump. Open or close the relevant valves to the normal position Close: Hold Gas free isolation Valve (V12002) - MD 120 Close: Hold Sp Esc Valves (V21190, V21290, V21390, V21490 & V21590) Open: Hold Space Gas Free Valves (V21195, V21295, V21395, V21495 & V21595) 5.3 Inerting after Docking 5.3.1 Introduction Before initial cool down, moisture content and oxygen content in cargo tanks are reduced in order to avoid formation of ice, and an explosive atmosphere. Inert gas is supplied to the cargo tanks through the liquid filling line and displaced air is vented to the atmosphere through the vapour line, the vent mast (and the manifolds). Inerting is finished when the dew point in the cargo tank is below -20°C and the oxygen content in the cargo tank is below 2% by volume. All lines and equipment are inerted during inerting of cargo tanks. The dew point and the oxygen content are periodically measured with a portable instrument at the sampling lines. Inerting can be done with nitrogen gas as well. In this case, liquid nitrogen is supplied from a shore terminal. It is vaporized and heated by the LNG vaporizer. Be aware of the wind direction during this operation. Caution: All pump discharge valves must be closed, in order to protect the high speed revolution of the pump without lubricant (pump is normally cooled and lubricated by the cargo). 5.3.2 Cargo tank inerting “Connect” the flange between the inert gas line and LNG liquid line (F12001-MD120)



Open the valves from the IGG to the different tanks via the liquid line and with exhaust through the vapour line to the forward vapour mast as shown on the drawings below. Vapour/ Inert Gas to Liquid Header Valve (V12702) - MD120 Vapour Header Vent Control Valve (V12771)- MD330 CT 1 Vapour Valve (V20170) and CT 1 Liquid Isolation Valve (V20110)- MD211 CT 2 Vapour Valve (V20270) and CT 2 Liquid Isolation Valve (V20210)- MD212 CT 3 Vapour Valve (V20370) and CT 3 Liquid Isolation Valve (V20310)- MD213 CT 4 Vapour Valve (V20470) and CT 4 Liquid Isolation Valve (V20410)- MD214 CT 5 Vapour Valve (V20570) and CT 5 Liquid Isolation Valve (V20510)- MD215 CT 1 Liquid Filling Valve (V20100) - MD211 CT 2 Liquid Filling Valve (V20200) - MD212 CT 3 Liquid Filling Valve (V20300) - MD213 CT 4 Liquid Filling Valve (V20400) - MD214 CT 5 Liquid Filling Valve (V20500) - MD215

Tank No 2 and 3 are lined up in the same way as tank No 4 and 5.

This is the line to the forward vent mast.



IGG Start Make the IGG system ready for start, and confirm that the seal water is supplied. Start the IGG as described under 5.3. After the above operation, inert gas is supplied to the cargo tanks. This operation is finished when the oxygen content is below 2% by volume, and the dew point is below -20°C in each tank. Caution: Inert gas flow to each cargo tank should be adjusted at adequate intervals in order to minimise required time. 5.3.3 Liquid line inerting This operation is carried out during inerting.

Vent mast

This picture shows the No 1 tank top. The only difference from the other tanks is the vent mast.



5.3.3.1 LNG liquid manifold line inerting See drawing below:

Manually open the manifold double shut off valves (inner) and the ESD valves plus the liquid manifold purge valves at both sides. For Port Side it is these valves: 1P Double Shut Valve (V12013) and 1P ESD Valve (V12011)- MD120 2P Double Shut Valve (V12023))and 1P ESD Valve (V12021)- MD120 3P Double Shut Valve (V12033) and 1P ESD Valve (V12031)- MD120 4P Double Shut Valve (V12043) and 1P ESD Valve (V12041)- MD120

Inert gas to the three forward tanks

Vapour gas from tank no 4 and 5 to the vapour mast at tank no 1.



During this operation, inert gas is vented to the atmosphere. When the oxygen content is below 2% by volume and the dew point is below -20°C the operation is finished, and all the valves may be closed. 5.3.3.2 LNG liquid line fore end inerting Manually open the most forward valve on the liquid line. Confirm that the oxygen content in the sampling valve is below 2%. Manually close the valve when condition is satisfied. 5.3.3.3 Spray line inerting This operation is carried out after cargo tank inerting. Line up the lines and valve systems as shown in the following drawings:



After the above operation, inert gas is discharged to the cargo tanks through the liquid crossover cool down and the spray header line.

The LNG eductor drive valve and flange.



Take off the blank flanges of the LNG eductor drive connection (in this situation it means that the valve to the eductor drive is opened and that the flange is left unconnected - read open). Confirm that the oxygen content and the dew point are below 2% by volume and below -20°C respectively. Manually close the eductor drive valves when the above mentioned values are met. Monitor as well the oxygen content and the dew point until readings are satisfying after the forcing vaporizer and the LNG vaporizer. After five minutes of inerting the spray line system, shut the relevant valves and continue to the next item.



5.3.3.4 LNG vapour line inerting Start LNG vapours line inerting after cargo tank inerting is finished. Line up in accordance with the following drawings:



Note: The valve between the vapour line and the ventilation mast as well as the valve between the Pressure build up line and the ventilation mast should be closed until later.



Vapour manifold inerting The shut off valve between the vapour line and the vapour manifolds is to be kept open for five minutes, and then closed to force the inert through the compressor room. Compressor and heater line inerting Start L.O. Pumps for H/D & L/D compressor sealing. Do not start the compressors. The valve between the vapour line and the ventilation mast as well as the valve between the Pressures build up line and the ventilation mast should now be opened. After the above operation, the inert gas is vented to the atmosphere from No.l vent mast. Keep this situation for five minutes. Confirm that the oxygen content and the dew point are below 2% by volume and below -20°C respectively. The line system should by now be inerted, and all valves should be closed as well as the IGG shut down and the ballast pump no 3 stopped.



5.4 Nitrogen Gas Purge 5.4.1 Introduction Before initial cool down the moisture and carbon dioxide (CO2) content in the cargo tanks is reduced to avoid freezing during cool down. First, the cargo manifold, liquid header line, spray line and LNG vaporizer supply line are purged with nitrogen (N2) gas which is generated by the N2 generator. Next LNG is supplied to the ship from the loading terminal, vaporized and heated by LNG vaporizer. Then hot LNG vapour (about 20°C) is supplied to the cargo tanks through the vapour line. The liquid and other lines are purged simultaneously. Displaced inert gas is discharged to the loading terminal or vented to the atmosphere, if permitted, through the filling line. Purging is finished when the dew point and the CO2 content in the cargo tanks are below -40°C and 1% by volume respectively. The dew point and the CO2 content are periodically measured using the portable dew point meter and the portable gas detector (CO2) at the sampling valves. Prior to the commencement of the operation, water curtain for the side shell on the side of the loading station should be started. 5.4.1.1 Nitrogen gas purge The cargo tanks and the line system on deck can be purges with Nitrogen either from the vessels own N2 Generators or from the shore side Nitrogen supply.



5.5 Gassing Up 5.5.1 Gassing Up (1), Venting from no. 1 vent mast Line up in accordance with the drawings supplied: Connect the Vapour Line-Liquid Line Flange (F12000)-MD 120 Open the Valve Vapour/Inert Gas to Liq. Header (V12072)-MD 120 Open the Liquid Line/Vapour Line Flange (F12002)-MD 120



Open valves: CT 1 Vapour Valve (V20170) and CT 1 Liquid Isolation Valve (V20110)- MD211 CT 2 Vapour Valve (V20270) and CT 2 Liquid Isolation Valve (V20210)- MD212 CT 3 Vapour Valve (V20370) and CT 3 Liquid Isolation Valve (V20310)- MD213 CT 4 Vapour Valve (V20470) and CT 4 Liquid Isolation Valve (V20410)- MD214 CT 5 Vapour Valve (V20570) and CT 5 Liquid Isolation Valve (V20510)- MD215 CT 1 Liquid Filling Valve (V20100) - MD211 CT 2 Liquid Filling Valve (V20200) - MD212 CT 3 Liquid Filling Valve (V20300) - MD213 CT 4 Liquid Filling Valve (V20400) - MD214 CT 5 Liquid Filling Valve (V20500) - MD215 LNG Vaporiser/Vapour Header Connection Valve (V30605)- MD 300 LNG Vaporiser Outlet Valve (V32918)-MD 300

This spool piece is used to get the gas vapour from the liquid line and out through the vent mast



Liquid Manifold Cool Down Valve 3P(V12065)-MD 120 LNG Vaporiser Supply Valve(V12056)-MD 120 Close the Compressor Suction Valve(V30601)-MD 300

Confirm that the LNG vaporizer is ready to start. (refer to chapter 4 LNG vaporizer). Open Liq.Head to No1 Vent Mast Valve(V12000)- MD 120 Open Liq Manif 3P ESD Valve(V12031)- MD 120 Request loading terminal to start LNG supply. Open LNG Vapour Quick Gas purge Valve(V32990)-MD 329 Caution: Until the loading arm is fully cooled down, vapour, then vapour/ liquid mixture is supplied to the LNG vaporizer. Therefore adjust the flow with LNG Vaporiser Temp Ctrl Valve(V32902)- MD 329 so that the outlet temp. of hot vapour does not exceed +80°C. Measure the hydrocarbon content at the gas sampling valves for the cargo tanks. Finish gassing up venting from No. 1 vent mast when the desired hydrocarbon level (abt. 0.1% by vol.) is reached in the vent mast, and in each tank. Close the valve from the liquid line to the vent mast.



Caution: Adjust opening degree of each tanks filling valve so that inert gas purging will finish at the same time. The recommended opening degrees are: Tank 1: 30% Tank 2: 100% Tank 3: 100% Tank 4: 50% Tank 5: 40% Adjust LNG supply to the LNG vaporizer so that the cargo tank pressure is kept within the normal zone.



5.5.2 Gassing Up (2), Combustion in the boilers The following descriptions show the case in which inert/hydrocarbon mixture is passed through the L/D compressors and supplied to the boilers. The maximum combustion capacity of the boilers (dumping mode) is about 5,000 kg/h (pure methane base). Therefore adjust LNG supply to the LNG vaporizer so that the tank pressure is kept within the normal zone. Caution: “DUAL” fuel mode for the boilers should be selected during this operation. The fuel oil flow should be increased manually while observing the burner flame. Line up in accordance with the drawings supplied: Open Valves: Vapour/Inert Gas to Liquid Header Valve(V12702)-MD 120 Hot Vapour/Compr.Suct Valve(V30603)- MD 300 L/D Compr Discharge Valve(V30903 & 30906)- MD 309 or MD 300 L/D Compr Surge Valve(V30931 & V30932) – MD 309 L/D Compr Suction Inlet Valves(V30901 & V30904)-MD 309 L/D Heater Outlet Valve(V30914)- MD 309 L/D Heater Inlet Bypass Valve(V30943)- MD 309 L/D Heater Inlet Valve(V30913)-MD 309 Fuel Gas Master Valve(V30610)-MD 309 Confirm That Compressor Suction Valve(V30601)-MD 300 is closed:



Set up: Inform engine room that the purge gas is being supplied to the boilers. In the Engine Room, thr Boiler Iso Valve(V33001) need to be open & Boiler Flow Ctrl Valve (V33000) Needs to be adjusted. Both on MD 330. Continue purging until all sampling points show the following conditions: The dew point ≤ -40°C CO2 content ≤ 1% 5.5.2.1 Spray line and forcing vaporizer line purging When the inert gas purge of the cargo tanks have reached halfway start line purging. Confirm that the dew point and the CO2 content are below -40°C and 1.0% by volume respectively. Proceed to the next operation when the above conditions are satisfied. 5.5.2.2 Cargo pump and spray pump discharge line purging When cargo tank purging operation reaches the final value up to the bottom sampling point of each of the cargo tank, start each cargo pump and spray pump discharge line purging by opening the sampling valves on each line (not possible on the simulator since there is very few sampling points). Manually close the above valves when the dew point and CO2 content are below -40°C and 1.0% by volume respectively. 5.5.2.3 LNG eductor discharge line purging Take off the blank flanges fitted at the LNG Discharge Eductor Connection. Open the valve to the LNG Discharge Eductor. Manually close the above valves when the dew point and are CO2 content below -40°C and below 1% by volume respectively. Fit blank flanges when finished.



5.5.2.4 Spray line and forcing vapour line purge completion When completed with Spray line and Forcing Vapour line purge, close the relevant valves and proceed to the next operation. 5.5.3 Gassing Up (3), Compressor

5.5.3.1 L/D and H/D compressor purging The line up on deck will be in the same way as for the previous operation. But the Compressor room it will look slightly different:



This situation is only a line up, the compressors are not started. We only want the inert gas to be purged through the system. Confirm that the dew point and the CO2 content at Gas Sampling points are below -40°C and 1.0% by volume respectively. Manually close the valves to and from the H/D compressor and H/D heater when the above condition is satisfied. Stop the supply of purge gas to the boilers when the following conditions are satisfied at all sampling points. CO2 content ≤ 1% The dew point ≤ -40°C Inform engine room that the supply of purge gas to the boilers is finished.

Close the valves to and from the L/D compressors and the L/D heater.



5.5.4 Gassing up (4), vapour return line Line up in accordance with the drawings below:



Confirm that the dew point and the CO2 content are below -40°C and 1.0% by volume respectively. Open or close the relevant valves for the cool down operation.



5.6 Initial Cool down 5.6.1 Introduction This operation is carried out after dry docking, to cool down the cargo tank to the prescribed temperature (-110°C) in preparation for LNG loading. It is carried out at the loading terminal. All loading arms are connected before start of initial cool down. LNG liquid for the spraying of cargo tanks is supplied from the loading terminal. Boil-off gas from the cargo tanks is returned to the terminal by the H/D compressor. 5.6.2 Line up After connecting manifolds, line up from shore to the tanks to be cooled down through the liquid line and the spray system. The spray pump will not be used in this phase. Vapour return will be lined up through the HD compressor and back to the shore. See drawings below: Open Valves: Liquid Manifold Cool Down Valve 3P (V12065)-MD 120 Spray Cross Over Isolation Valve (V12050)-MD 120 CT 1 Spray Isolation Valve (V20155) - Vapour Valve (V20170)-MD 201 CT 2 Spray Isolation Valve (V20255) - Vapour Valve (V20270)-MD 202 CT 3 Spray Isolation Valve (V20355) - Vapour Valve (V20370)-MD 203 CT 4 Spray Isolation Valve (V20455) - Vapour Valve (V20470)-MD 204 CT 5 Spray Isolation Valve (V20555) - Vapour Valve (V20570)-MD 205 Spray Header Iso Valves (V12055, V12751, V12752 & V12753)-MD120 Compressor Suction Valve (V30601)-MD 300 H/D Comr Suction Valves(V31907 & V31910)-MD 319 H/D Comr Discharge Valves(V31909 & V31912)-MD 319 Control Cooldown Rate with the FLW Valves Liq Manif 3P ESD Valve (V12031)-MD 120 Spray nozzle Valves: CT 1 Spray Lower Valve (V20151) - Mid Val (V20152)- Up Val (V20153)-MD 201 CT 2 Spray Lower Valve (V20251) - Mid Val (V20252)- Up Val (V20253)-MD 202 CT 3 Spray Lower Valve (V20351) - Mid Val (V20352)- Up Val (V20353)-MD 203 CT 4 Spray Lower Valve (V20451) - Mid Val (V20452)- Up Val (V20453)-MD 204 CT 5 Spray Lower Valve (V20551) - Mid Val (V20552)- Up Val (V20553)-MD 205 Vapour Return Throttling Valve (V31900)-MD 319 Vapour Manifold ESD Valve (V12071)-MD 120



5.6.3 Initial cool down

• Make the H/D compressors ready for start. • Set the No 1 and 2 H/D Compressor Capacity Control MAN mode. • Request LNG liquid supply of small quantity for spray line cooling from the loading

terminal. • After start of delivery, spray line cooling is started. • Spray line cooling is finished when the amount of liquid LNG passing the spray

nozzles are raising from almost zero up to almost 10 m³/h. • Close the upper and middle spray line valves. • • The recommended LNG flow rate from the terminal and the valves to be opened or

closed are in the following table. TIME (Hr) 0 ~ 3 3 ~ 8 8 ~

Total 53.5 73.0 104.0

No.1 TK 9.5 13.0 18.0 SPRAY RATE (T/Hr)

No.2 ~ 5 TK 11.0 15.0 21.5

No.1 TK (L) (L) (M) + (L) Spray nozzle no. No.2 ~ 5 TK (L) (U) + (L) (U) + (M) + (L) SPRAY NOZZLE PRESS. (KPa)

abt. 150 abt. 210 abt. 120



When the cargo tank pressure is raised, push the “START” button of the no. 1 & 2 H/D compressors on the CCC, and after confirm that the “READY” and “START AVAIL” indicator lamps are lit. Caution: Before the H/D compressors are started, the notification should be sent to the shore side. Change the No 1 and 2 H/D Compressor Capacity Control mode to AUTO from MAN on the CCC, after the steady running of H/D compressors is confirmed. Monitor the following items and record them at every one (1) hour: Cargo tank temperature Cargo tank pressure Vapour return flow Spray nozzle pressure Cargo tank liquid/ vapour temperature Cargo hold pressure Cargo hold temperature Close the spray nozzle valves in order when the temperature in all cargo tanks is -110°C. Push the STOP button of the No.1 & No. 2 H/D compressors on the CCC and notify to the shore side. Open or close the relevant valves to the normal position, and proceed to loading operation.



5.7 Loading 5.7.1 Introduction Loading a full cargo of LNG through three or two liquid arms with a loading rate of 10,000m3/h (max. design rate 11,000m3/h) needs 100 mLC (three arms) or 152 mLC (two arms) at the manifold presentation flange. After the liquid areas and liquid line are cooled down and ESDS trip test at cold condition is carried out, liquid cargo is introduced in the cargo tank through the filling line while vapour is returned to the loading terminal by the H/D compressors. If the equator temperature is -124°C or colder, normal loading without spraying can commence. If the equator temperature is between -110°C and –124°C loading with spraying can commence. In this case continuous liquid surface passes the equator level. During the loading operation, deballasting is carried out.. Usually, deballasting is carried out using two ballast pumps in parallel. 5.7.2 Loading Line up from the manifold connection through the liquid line system all the way to the different tanks to be loaded as shown in the drawings below.



Based on two liquid arms and one H/D Compressor Open Valves : CT 1 Liq Filling Valve (V20100) - Liq Iso Val (V20110)-MD 201 CT 2 Liq Filling Valve (V20200) - Liq Iso Val (V20210)-MD 202 CT 3 Liq Filling Valve (V20300) - Liq Iso Val (V20310)-MD 203 CT 4 Liq Filling Valve (V20400) - Liq Iso Val (V20410)-MD 204 CT 5 Liq Filling Valve (V20500) - Liq Iso Val (V20510)-MD 205 Vapour Return Throttling Valve (V31900)-MD 300 H/D Compr Suction Vlv (V31907 or V31910)-MD 300 or MD 319 H/D Compr Discharge Vlv (V31909 or V31912)-MD300 or MD 319 Liq Manif Double Shut Valves(V12013, V12023 & V12033)-MD 120 CT 1 Vapour Valve (V20170)-MD 201 CT 2 Vapour Valve (V20270)-MD 202 CT 3 Vapour Valve (V20370)-MD 203 CT 4 Vapour Valve (V20470)-MD 204 CT 5 Vapour Valve (V20570)-MD 205 When the ESD Test is completed, Open. Liq Manif ESD Valves(V12011, V12021 & V12031)-MD 120 Vapour Manif P.ESD Valve (V12071)-MD120



Make sure all valves are open. Vapour returns from the tank tops to shore via the HD compressor system. One or two HD compressors may be used as appropriate. Check that equator temperature is below -124°C at all tanks. If the equator temperature is between -110°C and –124°C loading with spraying can commence. In this case continuous liquid surface passes the equator level. Request the loading terminal to start loading LNG with agreed flow. Check the flange connection tightness. Check that the “No 1 H/D Compressor” and “No 2 H/D Compressor” are in mode MAN on MD500. Push the start button of the No. 1 H/D compressor after “READY” and “START AVAIL” indicator lamp are lit after notification to the shore side. (Picture from MD319). Request the loading terminal to increase loading rate. Monitor: Cargo Tank Pressure Cargo Tank Level Should the vapour header pressure reach 15 kpaG or more, push the “START” button of No.2 H/D Compressor after “READY” and “START AVAIL” indicator lamps are lit. After loading rate is set at full, the following items are measured and informed to the shore side hourly: cargo tank level for each tank remaining quantity for each tank loading rate accumulative loading quantity total remaining quantity cargo tank pressure First alarm sounds when liquid level is 97%. Request the loading terminal to decrease loading rate during topping-off. Close the filling valves one by one, when each tank level reaches full. Request the loading terminal to stop the shore loading pump. Push “STOP” button of H/D compressor(s) after notification to the shore side. Open or close the relevant valves to the normal position. Caution: At least one valve on liquid line and spray line should remain open to avoid liquid blockage.



5.8 Deballasting Deballasting operation is performed in parallel with loading operation. The No. 1 and No. 3 ballast pumps are usually used for deballasting (No. 2 ballast pump is on stand-by). Line up the valves and tanks in question to be able to deballast from the wanted tanks through the ballast pumps 1 and 3, through the low discharge. Deballasting is started after commencement of loading. Start the different ballast pumps by the use of the left button. Remember to keep discharge valve closed until pump has started. Monitor items: Trim and list Ballast tank level Mooring tension Ship condition Ballast pump condition Adjust ballast tank valves to keep adequate draft and upright condition. Deballasting should be finished before reducing of cargo loading rate. Open or close the relevant valves to the normal position. Remaining ballast water should be deballasted by ballast stripping eductor. Deballasting by gravity Deballasting may be carried out by gravity when the levels in the Side W.B. tanks are above the waterline. This will not work for the Centre B.W. tanks since they are positioned below the waterline. Open the valves to the tanks which are chosen for deballasting by gravity. When tank levels decrease to nearly waterline, change over to deballasting by ballast pumps. Do not wait too long. The capacity by using the gravity method will decrease rapidly as the height difference between the tank level and the waterline decreases.



5.9 Draining/Purging 5.9.1 Introduction After completion of loading/discharging, this operation is carried out prior to disconnecting the liquid arms and vapour arm. LNG liquid and vapour in the liquid arm is fed to the cargo tanks through the spray line by nitrogen (N2) gas supplied from the shore terminal. Vapour in the gas arm is fed to the cargo tanks through the vapour header by N2 gas supplied by the shore terminal. This is not implemented in full manner in the simulator. It is possible however to line up and try it out somewhat, but you will have to supply your own N2 by use of the N2 plant onboard. This is not described here.



5.10 Loaded Voyage (Forced Vaporization) 5.10.1 Introduction During a loaded voyage, the boiler uses natural boil-off gas (natural BOG) generated in the cargo tanks and forced boil-off gas (forced BOG) supplied by the forcing vaporizer. Both forced BOG and natural BOG are supplied to the boiler through an L/D compressor and an L/D heater. This manual explains the following case. Spray pump : No.4 spray pump L/D compressor: No.1 L/D compressor

In CASCADE mode on the controller for the Forced Vaporizer, the flow rate of forced BOG is automatically controlled by the boiler demand and natural BOG flow (available gas flow). (A controller has either two or three modes to choose from. These are MANUAL, AUTO or CASCADE).

During a loaded voyage, the cargo tank pressure is kept between 6 and 8 kPa (recommended zone). The pressure in a cargo tank can be controlled at an absolute pressure base. Monitor ambient pressure in order to protect the cargo tank. Line up from the tanks by opening the vapour line valves to the compressor room. Open the suction and discharge valves of the L/D compressor (start with only one compressor), and through the L/D heater. Open Valves: CT 1 Vapour Valve (V20170)-MD 201 CT 2 Vapour Valve (V20270)-MD 202 CT 3 Vapour Valve (V20370)-MD 203 CT 4 Vapour Valve (V20470)-MD 204 CT 5 Vapour Valve (V20570)-MD 205 Compressor Suction Valve (V30601)-MD300 L/D Compressor Disch Valve (V30903)-MD 309 or MD 300 L/D Suction Valve (V30901)-MD 309 or MD 300 L/D Heater Inlet Valve (V30913)- MD 309 L/D Heater Outlet Valve (V30914)- MD 309 Open the Fuel Gas Master Valve (V30610)-MD 300 or MD 309



After lining up we need to start the L/D compressor. 5.10.2 Natural BOG supplying Make the L/D compressor ready for start, and start an L/D heater. (Refer to the chapter on the Gas compressor and the Heater under chapter 4). A quick reference is found here:



• Check inlet and discharge valves open • Check nitrogen supply for sealing • Check lube oil is running • Check vane position (-80 degrees) • Confirm that the PID controller for the L/D compressors is set to MAN. • Confirm that the “READY” indicator lamp is lit for the L/D compressor in question. • Start the boiler gas burning. (set the controller to AUTO and set the required supply

of gas). • Push the “START” button of the L/D compressor. • Change the PID control mode from MAN to AUTO after steady running of the L/D

compressor is confirmed. If you push the “STOP” button of the L/D compressor, then the PID control mode is changed from AUTO to MAN. 5.10.3 Line up for forced vaporization Open Valves: Spray Master Isolation Valve CT4 (V20455)-MD 204 Spray Header Isolation Valve (V12752)-MD 120 Close Valves: Spray Header Isolation Valves (V12751 & V 12053)-MD 120 Select the following switches position on the Cargo Control Console (CCC): Vapour header pressure control to GAUGE (instead of ABSOLUTE). Tank pressure control to LADEN (instead of BALLAST). Confirm that the Controller for “GAUGE” is on mode AUTO (button recessed and text is yellow). Set point should be from 6-8 kPa. Make the forcing vaporizer (F/V) ready for start (refer to Chapter 4 Forcing Vaporizer) On the ECC switch the “DUMP CONTROL” to “DUMP” or “NON”. Confirm that the Controller for “FV CONT” is on mode MANUAL (button not recessed).



Push “START” button for no.4 spray pump on the Automatic Sequence panel. By the above operation, the spray pump is started and the set position of spray pump discharge valve and spray return valves controlled. Gradually raise the set point of the PID controller for the planned flow. (refer to ESTIMATED CAPACITY VS CURRENT CURVE in chapter 4: spray pump, but 20-25 A will normally do). Change the forcing vaporizer control mode from MAN to AUTO. On the PID control, adjust the set value in order that the set value is approached to the process value. Normal working temperature for the forcing vaporizer is -45 degrees C. On the local control board, change the control mode of the flow control valve to AUTO. Change the forcing vaporizer control mode from AUTO to CASCADE. It will then be controlled according to the demand of the boiler and the pressure in the cargo tanks.



Monitor items: Cargo tank pressure Cargo tank level Vapour header pressure F/V outlet temperature Spray pump current Note: Monitoring during night time should be done at suitable intervals. Push “STOP” button of “SPRAY PUMP SEQ.” when the operation is finished. Change the forcing vaporizer control mode from CASCADE to MAN. Stop forcing vaporizer (refer to chapter 4: Forcing Vaporizer) Open or close the relevant valves to the normal position.



5.11 Cool down by Liquid Line (By Ship) 5.11.1 Introduction Liquid lines are cooled down prior to berthing at the unloading terminal. This manual explains the following case: Using unit: No.4 spray pump. Vapour generated/displaced from the crossover piping passes through the liquid header, the spray bypass and return valves of No. 1, 2, 3 and 5 cargo tanks. Vapour from the tanks are burned in the boilers using the L/D compressor and L/D heater. Caution: It is recommended that the tank pressure is kept at the lower side of the normal operation range prior to the start of cool down, in order to cope with a certain increase in tank pressure during cool down and subsequent “shut-in” conditions during Custody Transfer Measurement (CTM). Caution: During line cool down, the ship should be kept “up-right” (no trim, no heel) as far as possible, to enable uniform cool down of the piping. 5.11.2 Line up Open valves: CT 1 Vapour Valve (V20170)-Spray By Pass Vlv(V20156)-MD 201 CT 2 Vapour Valve (V20270)- Spray By Pass Vlv(V20256)-MD 202 CT 3 Vapour Valve (V20370)- Spray By Pass Vlv(V20356)-MD 203 CT 4 Vapour Valve (V20470)-MD 204 CT 5 Vapour Valve (V20570)- Spray By Pass Vlv(V20556)-MD 205 Spray Master Isolation Valve CT4 (V20455)-MD 204 Liq Cross Over Cool Down Vlvs(V12051 & V12052)-MD 120 Spray Cross Over Isolation Vlv(V12050)-MD 120 Spray Header Isolation Valves(V12055, V12751, V12752 & V12053)-MD 120 CT 1 Liq Iso Vlv (V20110)-Spray Return Vlv(V20154)-MD 201 CT 2 Liq Iso Vlv (V20210)- Spray Return Vlv(V20254)-MD 202 CT 3 Liq Iso Vlv (V20310)- Spray Return Vlv(V20354)-MD 203 CT 4 Liq Iso Vlv (V20410)- Spray Return Vlv(V20454)-MD 204 CT 5 Liq Iso Vlv (V20510)- Spray Return Vlv(V20554)-MD 205 Slightly Open (5-10%) CT 4 Filling Vlv(V20400)-MD 204 Then Close Valves: CT 1 Filling Vlv (V20100)- Spray Master Isolation Vlv(V20155)-MD 201 CT 2 Filling Vlv (V20200)- Spray Master Isolation Vlv(V20255)-MD 202 CT 3 Filling Vlv (V20300)- Spray Master Isolation Vlv(V20355)-MD 203 CT 5 Filling Vlv (V20500)- Spray Master Isolation Vlv(V20555)-MD 205



As described in the following drawings:

On tank No 1, 2, 3 and 5 this valve is opened to bleed to the spray system and into the tanks.



5.11.3 Line cool down On completion of line-up. Proceed with line cooling as follows: Push “START“ button on “SPRAY PUMP SEQ.“ for tank no 4. By the above operation the spray pump is started and the set position of spray pump discharge valve and spray return valve are controlled. Gradually raise the set point of the PID “SPRAY PUMP CONTROL” for the planned flow. The spray pump is started after spray pump discharge valve is set at about preset position and spray return valve is set at full open, and the position of both are controlled by monitoring the motor current and the discharge pressure condition. Commence liquid cool down. During line cool down, monitor the following: Cargo tank pressure Liquid X-Over press. fore and aft, Liquid X-Over temp., fore and aft, Liquid Header temp., fore and aft, Vapour Header press. Caution : Check the flanges for liquid leaks. Line cool down is completed when the liquid header temperature falls below -100°C. When cool down is completed, push stop button on spray pump sequence. If the liquid header temp. raises above -100°C before the unloading is commenced, then the cool down operation should be redone.



5.12 Arm Cool down 5.12.1 Introduction Arm cool down, discharging and other necessary operations for discharging should be conducted in compliance with “LNG STANDARD GUIDELINES FOR CARGO HANDLING”. Before and after arm cool down operation, ESD trip tests are carried out to confirm that ESD is in good condition. Arm cool down is carried out prior to discharging using the spray pump. During arm cool down a minimum flow should be maintained through the ship’s pipelines to maintain them in a cold condition if the liquid header temperature rises over –100°C. During discharging, vapour is supplied from the discharging terminal in order to keep a positive tank pressure. If vapour cannot be supplied from the discharging terminal, vapour is generated by the LNG vaporizer of the ship. 5.12.2 Preparation Before berthing : The “Safety Check List” should be checked beforehand. In addition, check the following items; a) CTS correctly working? b) Manifold connections (strainer, flange) OK? c) ESD test (pre-arrival) OK? d) Fire line pressurised and fire pump on stand-by? e) Water curtain on stand-by? f) Fire-fighting gear prepared? g) Fire detector system OK? h) Gas detector system OK? i) Cargo pump insulation OK? After berthing : The following items are checked. a) Mooring tension OK? b) Ballast pumps on stand-by? c) Valve hydraulic pumps (main) running/on stand-by? d) Liquid header temp. (F&A) < -100°C? e) Sufficient electric power available? Liquid/ vapour arm connection: Connect arms. Purge manifold connections so that O2 < 1%. Check for leaks in the manifold connection using N2 gas from shore at regulation pressure. Start water curtain. Stop gas burning before CTM. After completion of CTM :



Open manifold ESD valves. Push the ESD button to test the valves. Re-open manifold ESD valves. Line up : This manual explains the following case Using unit: No.4 spray pump. Line up in accordance with the following drawings:

Arm cool down: After ESD test (hot) and completion of line up, Start No.4 Spray Pump. Slowly open Liquid Manifold Cool down Valves Following valves should be adjusted to provide sufficient flow to the arms. Tank Spray Return and Tank Filling valves. If required, increase flow from spray pump by increasing motor load, or by increasing spray line pressure. During this operation monitor liquid header temperature to ensure it remains sufficiently cold. Shore will advise when arm cool down is completed. Stop spray pump. RUN Post-cool down ESD test (cold). Re-open manifold ESD valves.



5.13 Discharging 5.13.1 Cargo pump start “CARGO PUMP START/ STOP” sequence control is used for this operation. Check that liquid manifold ESD valves are open. MD 120 Open Liquid Manifold Double shut valves. Close liquid manifold cool down valves. Prior to cargo pump start, confirm that all Tank Liquid Branch valves are closed and all Filling valves are opened. Confirm the following set point: Cargo pump stop level…… Refer to Chapter 4 “AUTO SEQUENCE CONTROL”. Push start button on Port (or Stbd) Cargo Pump Automatic Sequence Control for tank No.1. (Note: any tank can be selected). Push start button on Stbd (or Port) Cargo Pump Automatic Sequence Control for tank No.1. Note: The cargo pump can be started manually as well as by sequence control. During cargo pump start operation, attention should be paid to the following: MOTOR CURRENT MIN. CONT. FLOW ABT. 320 (A) RATED ABT. 440 (A) DISCH. PRESSURE RATED ABT. 662 (kPa) Motor current will drop and stabilise within a few seconds after pump start. After achieving stabilisation, proceed to the discharging operation.



5.13.2 Discharging Discharge Sequence control is used for this operation. Prior to discharging confirm that all Tank Liquid Branch valves are closed and all Filling valves are opened. Push START button of Discharge Sequence control on no.1 tank (Same tank must be selected as in “CARGO PUMP START/ STOP” sequence control). During starting operation, attention should be paid to the following items. Motor current Discharge pressure Valve position Liquid branch valves : close – open Filling valves: close – open When the valve operation for discharging is completed, the start lamp of Discharge Sequence goes out.

Note : The valve operations for discharging can also be carried out in manual mode.

Start of cargo pumps and cargo discharging for other cargo tanks is carried out in the same manner. 5.13.2.1 Operation during discharging Adjust discharging rate by setting the control set point for cargo pump load controller (SCC) to keep about 11,000 m3/h. As the tank pressure falls, request discharging terminal to start the return gas blower (R.G.B.) and fully open Vapour Supply Throttling Valve to maintain tank pressure. Note: If a return vapour supply is not available, cargo liquid is used by the LNG vaporizer

to generate vapour to maintain tank pressure. Monitor the following items during discharging. Cargo tank levels Cargo tank pressure Cargo pump motor load and discharge pressure Draft, trim and heel Ship condition (Loading calculator) Mooring tension If stripping is planned for several tanks, it is recommended to keep a certain difference in the tank levels to avoid congestion. Adjust the R.G.B. (request shore to start/stop as required) to maintain the adequate tank pressure. Close or open Vapour Supply Throttling Valve as well as appropriate.



5.13.2.2 Cargo pump stop The cargo pump can be stopped automatically by using the Cargo Pump START/STOP sequence. If the pump is in Stripping MODE, the pump must be stopped by an operator manually. (Refer to Chapter 4: AUTO SEQUENCE CONTROL). Cargo pump can be stopped manually at any time. When the cargo tank level reaches to 2.0m, a low level alarm are sounded. When cargo tank level reaches less than 2.0m, closely monitor the pump condition to avoid dry running. After discharging, at least one filling valve is kept open to avoid pressurisation of the liquid line (cargo boiling). Liquid draining and vapour purging: Liquid draining and vapour purging in the arm is performed after completion of cargo discharging. The detailed procedure is shown in “Draining And Purging”. After completion of draining and purging the following operations are carried out: Custody transfer measurement after discharging is performed (Cargo calculation). Arm disconnection and de-icing (if necessary). Water curtain is stopped. Operation mode of valve hydraulic system is changed from main pump to small pump. 5.14 Ballasting The ballasting operation is performed in parallel with cargo discharging operation. No.1 and 3 ballast pumps are usually used for ballasting. (No.2 pump is on stand-by.) Line up for from the High Suction Sea Chest through the two ballast pumps to be used to the wanted tanks. Remember to leave the discharge valves to the pumps closed until the pump is started. 5.14.1 Ballasting operation Ballasting is started after commencement of discharging. Open ballast tank valves. Start the ballast pump No 1 by the use of the left mouse button. Open the discharge valve. After setting up No.1 ballast pump, start No.3 ballast in the same way. Confirm that ballast pumps are running normally. Monitor items. Trim and list Ballast tank level mooring tension ship condition (Loading calculator) Ballast pump condition Adjust ballast tank valves to keep adequate draft and upright condition.



Ballasting should be finished before reducing cargo discharge rate. Stop the ballast pumps by the use of the right mouse button. Close all relevant valves. 5.14.2 Ballasting by gravity Partial ballasting may be carried out by gravity by by-passing the ballast pumps until the levels in the ballast tanks approach the water line. When tank levels increase to nearly water line, change the valves so ballasting will be done through the ballast pumps. Proceed as described above. 5.15 Ballast Voyage (Forced Vaporization) 5.15.1 Introduction During a ballast voyage, the boiler uses forced boil-off gas (forced BOG) in addition to natural boiled-off gas (natural BOG). Both forced BOG and natural BOG are supplied to the boiler through an L/D compressor and an L/D heater. This manual explains the following case: Spray pump : No.4 spray pump L/D compressor : No.1 L/D compressor In Cascade mode on the PID Controller for Forcing Vaporizer control, the flow rate of the forced BOG is automatically controlled based on boiler demand and natural BOG flow (available gas flow). During a ballast voyage, the pressure in the cargo tank is kept between 4 and 20 kPa. Prior to arrival loading port, spraying is carried out to have tanks ready for loading. This means that the equator temperature is -124°C or below. Spray pump capacity is sufficient to supply LNG liquid for both the forcing vaporizer and the spraying simultaneously. If the spray pump is started at a tank level of 2.0m or below, cancel the low level signal from the custody transfer system (CTS) at the CTS control panel.



5.15.2 Line up for natural BOG supply Line up for natural BOG supply as shown on the drawing below. This is done after completion of final CT measurement. Following Valves to be open: CT 1 Vapour Valve (V20170)-MD 201 CT 2 Vapour Valve (V20270)-MD 202 CT 3 Vapour Valve (V20370)-MD 203 CT 4 Vapour Valve (V20470)-MD 204 CT 5 Vapour Valve (V20570)-MD 205 Compressor Suction Valve (V30601)-MD 300 L/D Compressor 1 Discharge Valve (V30903)-MD 300 or MD309 L/D Heater Outlet Valve (V30914)-MD 300 L/D Compressor 1 Suction Valve (V30901)-MD 300 L/D Heater Inlet Valve(V30913)-MD 300



5.15.2.1 Natural BOG Supplying Make the L/D compressor ready for start, and start the L/D heater. (Refer to Chapter 4 Gas Compressor and Heater) Confirm that the Single Strategy Controller (PID controller) for the L/D Compressor Control is in mode MAN, and confirm that the “READY” indicator lamp is lit (will only be lit after the lube oil pump is started, and the N2 supply is on). Start the boiler gas burning. Push the START button for the L/D compressor. Change the L/D Compressor Control from mode MAN to AUTO, after steady running of the L/D compressor is confirmed. Push the “STOP” button of the L/D compressor. Then the SSC “L/D COMP CONT.” mode is changed from “A” to “M” automatically. 5.15.2.2 Line up for spraying Open the Spray Master and the Spray Header Isolation valves: CT 1 Spray Iso Valve (V20155)-MD 201 CT 2 Spray Iso Valve (V20255)-MD 202 CT 3 Spray Iso Valve (V20355)-MD 203 CT 4 Spray Iso Valve (V20455)-MD 204 CT 5 Spray Iso Valve (V20555)-MD 205 Spray Header Iso Valves(V12055, V12751, V12752 & V12053) Confirm that the L/D compressor and L/D heater are running.



5.15.2.3 Spraying Start the spray pump. Push the START button on the Automatic Spray Line Cool Down Seq. on the Control panel. Spray line cool down is finished automatically after 60 seconds, and the START indication lamp will go out. Push the START button of the Automatic Sequence for the Tank Temperature Setter on the CCC. By the above operation, the Upper Spray Nozzle valves are operated automatically and spraying is started. CAUTION: Be aware that the pressure in the cargo tank at spraying start will drop about 2 kPa, due to sudden cooling of LNG gas in the cargo tank. Monitor these items: Cargo tank pressure Cargo tank temperature Vapour header pressure Cargo tank level Cargo hold pressure Equator temperature Once all equator temperatures are at -124°C or below push the STOP button of SPRAY PUMP SEQ” on CCC for spray pump stop. Push the STOP button of the Automatic Sequence for the spray pump. CAUTION: Be aware that the pressure in the cargo tank at spraying stop will increase

about 3 kPa. Open or close the relevant valves to the normal position. 5.15.2.4 Line up for forced vaporization Open the No.4 TANK SPRAY MASTER (V20455)and SPRAY HEADER ISOLATION valves(V12055, V12751, V12752 & V12053)-MD 120 Confirm that the L/D compressor and L/D heater are running. 5.15.2.5 Forcing vaporization Make the Forcing Vaporizer (F/V) ready for start (refer to Chapter 4: Forcing Vaporizer) Confirm that the Forcing Vaporizer Flow controller (PID) is on mode MAN. Push “4” button of Spray Control on the CCC. Push the START button on the Spray Pump Sequence. By the above operation, the spray pump is started and the set position of spray pump discharge valve and spray return valves are controlled. Gradually raise the set point of the Spray Pump Control for the planned flow. Open the Forcing Vaporizer Supply valve of spray liquid to the Forcing Vaporizer after completion of forcing vaporizer stand-by. Change the Forcing Vaporizer control mode from MAN to AUTO after the local operation is completed.



On the Forcing Vaporizer controller, adjust the set value in order that the set value is approached to the process value. On the local control board, change the control mode of the flow control valve to AUTO. Change the Forcing Vaporizer control mode from AUTO to CASCADE. Monitor items. Cargo tank pressure Cargo tank level Vapour header pressure F/V outlet temperature Spray pump current Note: Monitoring during night time should be done at suitable intervals. Push STOP button of Spray Pump Sequence when the operation is finished. Note: The No 4 Tank Spray Return valve is opened in order to prevent excessive pressure

in spray line. Change the Forcing Vaporizer controller mode from CASCADE to MAN. Stop Forcing Vaporizer (refer to Chapter 4: Forcing Vaporizer) Open or close the relevant valves to the normal position.



5.16 Warming Up 5.16.1 Introduction Prior to docking, the cargo tanks are warmed up in order to avoid icing in the cargo tanks. Prior to warm up, it is essential to ensure that all lines are liquid free. Vapour is taken from the cargo tank by the H/D compressors, heated by the H/D heater and returned to the cargo tank. Hot vapour is led into the cargo tank through the LNG liquid filling line and the displaced gas is taken through the LNG vapour line. Vapour generated during warm-up is used at the boilers. If permitted by the Authority, vapour can be vented to the atmosphere. But if the vapour temperature is below -80°C, then the vapour must be heated by the H/D heater, after which the vapour is vented via the No.1 vent mast through the Pressure Build Up line. Warming-up is continued until the temperature across the cargo tanks rises to about 5°C.



5.16.2 Warming up the deck lines Line up in accordance with the drawings below:

Supply N2 through this connection if the pressure (natural boil-off) builds up too slow.



Liquid lines pressurise themselves up to 200-300 kPa. If line pressure does not build up, supply N2 gas by the connection indicated. Open the Spray Return valves after the pressure has build up. Start spray using self-pressure. Continue operating the spray return valves open and closed, until liquid free is confirmed. This means that the line pressure does not rise when the valves are closed and the temperature in the lines start rising. Open or close the relevant valves to the normal position.



5.16.3 Warming up the tanks Line up as shown in the drawings below: Partly open valves: CT 1 Tk Filling Valve (V20100)- Liq Iso Valve(V20110)-MD 201 CT 2 Tk Filling Valve (V20200)- Liq Iso Valve(V20210)-MD 202 CT 3 Tk Filling Valve (V20300)- Liq Iso Valve(V20310)-MD 203 CT 4 Tk Filling Valve (V20400)- Liq Iso Valve(V20410)-MD 204 CT 5 Tk Filling Valve (V20500)- Liq Iso Valve (V20510)-MD 205 Open Valves: Compressor Suction Valve (V30601)-MD 300 L/D Compressor 1 Suction Valve (V30901)-MD 300 H/D Compressor 1 Suction Valves(V31907 & V31910)-MD 319 H/D Heater Inlet Valve(V31915)-MD 319 Fuel Gas Master Valve(V30610)-MD 309 L/D Heater Inlet Valve(V30913)-MD 300 CT 1 Vapour Valve (V20170)-MD 201 CT 2 Vapour Valve (V20270)-MD 202 CT 3 Vapour Valve (V20370)-MD 203 CT 4 Vapour Valve (V20470)-MD 204 CT 5 Vapour Valve (V20570)-MD 205 L/D Compressor 1 Discharge Valve (V30903)-MD 300 or MD309 H/D Compressor Discharge Valves (V31909 & V31912)-MD 319 L/D Heater Outlet Valve (V30914)-MD 300 Vapour/Inert connection to Liq Header Valve(V12702)-MD120



Make the H/D heater ready for start. (Refer to Chapter 4: Gas Heater) Make the H/D compressor ready for start. (Refer to Chapter 4: Gas Compressor) Confirm that the No 1 and 2 H/D Compressor Capacity Control are on mode MAN. Push the “START” button of the No.1 H/D Compressor on the CCC after “READY” and “START AVAIL.” indicator lamps are lit. Change the No 1 H/D Compressor Capacity mode to “AUTO from MAN on the CCC after the steady running of H/D compressors is confirmed. The No.2 H/D compressor is started in the same manner. Hot LNG vapour is supplied to each cargo tank by the H/D compressors. The outlet temperature of the H/D Heater must be kept below 75°C. Monitor following items: Cargo tank pressure Cargo tank temperature Note : This data should be measured and recorded at every hour. Warming-up is completed when the vapour throughout all tanks is above 5°C. Push the “STOP” button of the H/D compressors on the CCC. Stop H/D heaters. Open or close the relevant valves to normal position.



5.17 Inerting before Docking 5.17.1 Introduction This operation is carried out after warming up. Before aeration, the hydrocarbon content in cargo tanks and piping is reduced in order to avoid the formation of explosive atmosphere. Inert gas is supplied to the cargo tank through the filling line. The displaced cargo vapour/inert gas mixture is burnt in boilers and/or vented to the atmosphere through the vapour line and the vent mast. Inerting is finished when hydrocarbon content in cargo tank is below 2% by volume. All lines and equipment are inerted during inerting of cargo tanks. The gas content is periodically measured and recorded at every 1 hour with a portable gas detector at sampling lines. Inerting can be done with nitrogen gas as well. In this case, liquid nitrogen is supplied from a shore terminal. Be aware of the wind direction during this operation. Caution: Pump discharge valves must not be opened, in order to protect the high speed revolution without the lubricating function of the cargo. 5.17.2 Cargo tank inerting Open As follows: Inert Gas/Liq Line Spool piece( F12001)-MD120 CT 1 Vapour Valve (V20170)-MD 201 CT 2 Vapour Valve (V20270)-MD 202 CT 3 Vapour Valve (V20370)-MD 203 CT 4 Vapour Valve (V20470)-MD 204 CT 5 Vapour Valve (V20570)-MD 205 Vapour/Inert to Liq Header(V12702)-MD 120 Compressor Suction Valve (V30601)-MD 300 L/D Compressor 1 Discharge Valve (V30903)-MD 300 or MD309 L/D Heater Outlet Valve (V30914)-MD 300 CT 1 Tk Filling Valve (V20100)- Liq Iso Valve(V20110)-MD 201 CT 2 Tk Filling Valve (V20200)- Liq Iso Valve(V20210)-MD 202 CT 3 Tk Filling Valve (V20300)- Liq Iso Valve(V20310)-MD 203 CT 4 Tk Filling Valve (V20400)- Liq Iso Valve(V20410)-MD 204 CT 5 Tk Filling Valve (V20500)- Liq Iso Valve (V20510)-MD 205 Fuel Gas Master Valve(V30610)-MD 309 L/D Heater Inlet Valve(V30913)-MD 300 L/D Compressor 1 Suction Valve (V30901)-MD 300



5.17.3 Cargo tank inerting Line up in accordance with drawings below:



Connect the spool piece between the Inert gas line and LNG liquid line (F12001) and the Vapour Inert to Liq Header (V12702)-MD 120 IGG start: Make the IGG system ready for start, No.3 ballast pump is started and confirm that seal water is supplied. Start the ballast pump. Start the IGG system. After the above operation, cargo vapour/ inert gas mixture is burnt in the boilers. Confirm that the dew point and the oxygen content at the dryer unit outlet are below -45°C and 1.0 % respectively. This operation is finished when the hydrocarbon content in each tank is below 25 by volume. The hydrocarbon content is measured and recorded every 1 hour with a portable gas detector at the sampling points for the cargo tank’s top, middle bottom and dome. When the hydrocarbon content falls to a low level, stop the gas burning in the boilers and redirect the tank atmosphere to the vent mast on tank no 1.



5.17.4 LNG liquid line inerting This operation is carried out during cargo tank inerting. LNG liquid manifold line inerting Line up in accordance with the drawings below:



Open all relief valves. 1P Liq Manif Double Shut Vlv (V12011)- Liq Manif ESD Vlv(V20154)-MD 201 2P Liq Manif Double Shut Vlv (V12021)- Liq Manif ESD Vlv(V20254)-MD 202 3P Liq Manif Double Shut Vlv (V12031)- Liq Manif ESD Vlv(V20354)-MD 203 4P Liq Manif Double Shut Vlv (V12041)- Liq Manif ESD Vlv(V20454)-MD 204 And belonging Manifold flanges On a real vessel it will be drain cocks or purge valves, but as they are not implemented in the SIM we need to open the blind flanges to let the pressure out of the pipelines Repeat the procedure on STBD side Liq Line fore end, Open the Liq Head to Vent Mast Conn Vlv (V12000)-MD 120 And the belonging flange. Manually close all relief valves five (5) minutes after opening. Confirm that the hydrocarbon content is below 2% by volume.



5.17.5 Spray line inerting This operation is carried out after cargo tank inerting. Line up in accordance with drawings below:



After the above operation, inert gas is discharged to the cargo tanks through the liquid crossover cool down and the spray header line. Take off the blank flanges of the LNG Eductor Drive Connection on each tank. Confirm that the hydrocarbon content is below 2% by volume. Manually close the following valves when the above condition is satisfied. Fit the blank flanges.



5.17.6 LNG vapour line inerting Start LNG vapour line inerting after cargo tank inerting is finished. Line up in accordance with the drawings below:



Manually open the spectacle flange located between the pressure build up line and No.1 vent mast.



Leave the inerting for at least 5 minutes and open the various sampling points (not supplied on the simulator) one by one, and measure the O2 content and dew point. Confirm that the oxygen content and the dew point are below 2% by volume and below -20°C respectively. Inerting finish Stop the IGG system locally and the No.3 ballast pump. Open or close the relevant valves to the normal position. Take off spool piece between the inert gas line and the LNG liquid line. Manually close the spectacle flange which is between the pressure build up line and No.l vent mast.



5.18 Aeration 5.18.1 Introduction Aeration of the cargo system is carried out after inerting. IGG is used for aeration. There are two operational patterns, “TOP FILLING” and “BOTTOM FILLING”. Operation Flow Top filling Supply : IGG → Vapour line (dry air) → Cargo tank Exhaust (I.G.) : cargo tank → liquid line → No.1 vent mast. The top filling method is described in this manual. Bottom filling Supply : IGG → Filling line (dry air) → Cargo tank Exhaust (I.G.): cargo tank → vapour line → No.1 vent mast. Aeration is continued until the following conditions in all tanks are reached. O2 content ≥ 20% by volume CO content ≤ 50 ppm CO2 content ≤ 0.5% CH4 content : Should be checked prior to aeration. (Should be at least less than 2 %). All relief valves aeration should be done.



Line up in accordance with the drawings below:

Connect from the inert gas line to the vapour/liquid connection line by a spool piece. Liquid line is connected with vapour line and the vent mast by a spool piece (elbow type). 5.18.2 Cargo Tank aeration

IGG Start Make the IGG system ready for start, and confirm that the seal water is supplied. Caution: When supplying seal water the no.3 ballast pump is started after the seal

water overboard valve (2WV-501) is completely open. The burner is not to be used in this operation. Start the IGG system locally. The air is purged to the atmosphere. Confirm that the dew point at the dryer unit outlet has dropped to -45°C or below. Change the operation over to the tank system. After the above operation, dry air is supplied to the cargo tank (cargo tank aeration start). Check the oxygen content regularly at the sampling valves (DOME U, M & L) Adjust the following Filling valves to minimise the required time and carry out effective operation.



Aeration is continued until the content at all sampling points in the tank reach the target value. 5.18.3 Liquid and spray line aeration

Aeration of piping is performed during tank aeration after sufficient oxygen content (≥ 20%) is confirmed at the sampling point of the tank bottom. Line up as described in the drawing below:

5.18.3.1 Liquid line manifold aeration Open the various valves in the manifold area, and leave them open for at least five minutes. Check oxygen content at the LIQ. MANIFOLD PURGE valves on every manifold liquid line and confirm the following: O2 content ≥ 20%



5.18.3.2 Cargo and spray pump discharge line aeration Manually open the Gas Sampling valves on the tanks. Check oxygen content at the GAS SAMPLING valves on every cargo pump discharge line and confirm the following. O2 content ≥ 20% After confirming O2 content, close GAS SAMPLING valves. 5.18.3.3 Spray line aeration Open the Spray Master and the Lower, Medium and Upper Spray valves. After confirming O2 content, close SPRAY NOZZLE (L, M, U) valves, SPRAY RETURN valves and SPRAY MASTER valves. Manually open the LNG EDUCTOR DISCH. CONN. valves for a few minutes to purge inert gas. 5.18.3.4 Spray line (from the manifold to the tank) Open the valves from the manifolds all the way to the tank, and let off at the sampling point just before the tank (not supplied in the simulator). Check the O2 content ≥ 20%. 5.18.3.5 Forcing vaporizer supply line aeration Line up all the way through the FV and then open the sampling point after the FV to let of the IG. Check the O2 content ≥ 20%.



5.18.4 Vapour line and machinery aeration Line up in accordance with the drawings below:



5.18.4.1 Forcing vaporizer aeration The various sampling valves and breather valves are opened and the O2 content is checked by the portable measurement equipment. When the values are satisfying (>20 %) Close the different valves and revert to normal situation. • Aeration completion • On completion of aeration, adjust the vapour header pressure so as to avoid negative

tank pressure due to change of air temperature. • Stop the IGG blowers and dryer units locally and the No.3 ballast pump. • Open or close the relevant valves for dry-docking. • Take off two sets of spool pieces. 5.18.5 Limiting Factors Temperature It is vital that the tank temperatures are kept as close as possible to the temperature of the cargo since this will hamper the loading and/or discharging time. Berth Time Some terminals limit berth time. In order to fully outturn cargo it may be necessary to reduce ballasting time by taking on reduced ballast alongside and ballasting in river passage, or ballasting during discharge. Stress



The vessel must not exceed maximum stress limits (harbour condition) at any time during cargo operations. The vessel may also have operating constraints such as: leaking pipelines, failing valves, inoperative pumps. These difficulties may be overcome during the discharging by a carefully planned operation which compensates for them. 5.18.6 Discharge Plans These plans are to be prepared prior to the vessel's arrival and should include instructions on: - Cargo stowage and quantity. - Discharge rate. - Permissible pump pressure. - Approximate discharge time. - Ventilation method. - Emptying of loading arms and lines. - Ballasting. - Method of how to stop cargo pumps and to raise alarm in case of fire or pollution. Copy of the discharge plan should be given to Terminal representative. 5.18.7 Cargo Handling Training from the Graphic Workstation Cargo handling training with the CHS LNG/C can be performed from the graphic workstation by means of mimic pictures or from the cargo consoles by means of the cargo operation panels. All operations are similar in both versions; the only difference is the presentation method to the trainee. In the case of the graphic workstation presentation it is essential to have the correct mimic diagram available. The directory pages have to be used for such.



5.18.8 Picture Directory General



5.18.9 Picture Directory LM



Layout

As the LNG/C is equipped with two pumps in each tank, there is no central cargo pump room. From the manifold all cargo and vapour is distributed to/from the tanks via the network of cargo/vapour deck lines and cargo/vapour crossover lines. Commands controlled by the use of the mouse buttons: - Start/Stop Pumps - Open/Close Valves. Trim The trim is changed by changing the load moments of the fore and aft halves of the ship. NOTE: This change may cause another load distribution which results in different distribution of shear forces, bending moments and hull deflection.



Heel (list) The heel (list) is changed by changing the load moments to/from the side ballast tanks. Manifold Only the pressure at the manifold connections can be monitored just as you would onboard a real ship. These figures will give information about the functioning of the pumps, leaking connections etc. The flow will be possible to monitor at the different tank pictures. 5.18.10 Pump Flow The pump flow is generated by starting the pump and opening the discharge valve(s). This ship requires that the cargo pump system is started and controlled by a sequence controller. The flow rate will depend on: - The pump speed - The flow resistance caused by pipe characteristics - Valve characteristics and valve settings - The suction head (cavitation)



The liquid density Tank pressure Open/Close The discharge valve setting is controlled by means of clicking on the screen at the individual tank picture. The pump flow and the pump pressure are controlled by the PID controller. Cavitation If the suction head is too low, the pump will start cavitation. The critical suction head for cavitation will depend on the vaporizing pressure of the liquid to be pumped and the current NPSH (Net Positive Suction Head) of the pump. Cavitation will occur on the cargo pumps, but not on the ballast pump. Stopping The pump is stopped by Automatic Sequence controller. Depending on stop mode, the pump will be stopped by the controller, or will have to be stopped manually. After the electric supply is stopped, the pump is brought to a complete stop after a while.



5.18.11 Ballasting The LNG/C is fitted with a double bottom in which ballast tanks are located. These tanks are interconnected by means of a separate set of ballast water lines. The ballast water pumps (3) are located in the ballast pump room (picture MD 401). Ballasting is a process where sea water is loaded into segregated ballast tanks to ensure proper immersion and to provide good manoeuvring and stability characteristics. In order to lessen hull immersion and thus reduce fuel consumption, minimum quantities of ballast should be taken. However, the quantity must be sufficient to submerge the propeller, maintain vessel manoeuvrability, to avoid excessive vibration, to operate within approved stress limits and to retain sufficient bow immersion. Ballast should be evenly distributed to minimize stress. Tanks should be either empty or full. Partially full or slack tanks should be avoided. Start-up The appropriate ballast tanks are chosen and the ballast tank valves are opened by clicking on the symbols.



Sounding During the ballast operation the tank soundings can be monitored on the level indicator. The total content can be viewed on the Bunker/consumables picture (MD 103). Heel/Trim Furthermore the changes in heel and trim of the vessel will be shown on the indicators on the same mimic picture.

Pumps The pump room can be viewed by clicking on the symbol for the ballast pump room (MD 401). Starting Procedure The pumps can be started/stopped by use of the left/right mouse buttons. The following is normal start procedure for centrifugal type pumps: - Close the discharging valve. - Open the suction valve. - Fill the pump with liquid. - Start the pump. - Open the discharging valve.



Segregated Ballast The Segregated Ballast Tanks (SBT) is completely separate from the cargo and fuel system and are permanently allocated to the carriage of ballast water only. SBT require separate pumps and pipes dedicated to handling ballast water only. Segregated ballast may be retained on board in order to restrict the air draught if it is necessary because of weather conditions or restrictions of loading arms or shore gangway. However, care must be taken not to exceed the maximum draught for the Terminal or for hull stress.



5.18.12 Inert Gas System From the Inert Generator and distribution pictures the operator can carry out and control the following operations: - Operation of inert gas generator. - Inerting of cargo tanks. - Ventilation (gas freeing) of cargo tanks Start-up Procedures The Inert generator is ready for operation as long as the burner is on. 1. Ensure that the oxygen analyzer and Inert Gas pressure indicator are working. 2. Open valves and start scrubber pump. 3. Start the blowers and open inlet valves. 4. Start burner by pushing "on" after opening fuel supply. 5. Open Inert Gas main valve on deck. 6. The Inert Gas-plant is now ready to deliver gas to the cargo tanks or the cargo

holds.



Shutdown Procedures 1. Close the Inert Gas main valve on deck. 2. Shut down the burner. 3. Close the blower discharge valves and stop blowers. 4. Keep full water supply on the scrubber for a minimum of 1 hour. Inerting/Venting The operator can choose inerting or air venting by either starting the burner or leaving the burner off. NOTE: Before commencing ventilation by fresh air, the tanks must be measured for hydro carbon gas concentration. If the readings indicate gas concentration above 2 % by volume, the tanks are to be purged with Inert Gas until the hydrocarbon gas concentration has decreased to less than 2 % by volume. This will ensure that the atmosphere is kept below the lower explosion limit throughout the ventilation process. Inert Press/Flow The current Main Line Inert Gas Pressure and Flow can be read from separate indicators on the Inert Gas plant picture. Distribution From the Inert Gas plant there is a network of deck lines to all tanks and holds for the distribution of Inert Gas. Tank Pressure The tank pressure is indicated at each tank and should be closely watched in order to avoid over-pressure or under-pressure when discharging or loading cargo. It can also happen that due to temperature change of the cargo a pressure difference is created which will have to be compensated by either the spray system or the H/D compressor(s). Pressure During cargo operations the tank pressures are shown in order to monitor the variations. Vapour return lines are connected to shore at the manifold so as to take away excess vapour.



5.19 Stress and Stability Calculations For the purpose of calculating permissible stresses and stability the Cargo Handling Simulator both in operational as well as workstation version is equipped with both an "online" and an "offline" DataLoad load computer. 5.19.1 Online calculations During simulation the online DataLoad load computer will constantly calculate and show in the respective mimic pictures the results that occur from loading, discharging, ballasting or any other changes in the vessels weight distribution. The relevant mimic diagrams are given in the picture directory nos.: 104 Shear Force 105 Bending Moment 106 Deflection 107 Stability Curve These can be called up in the normal way, but not be influenced during the running of the simulation. Actual weights, volumes and levels can be read in the mimic diagrams: 101 Cargo Tank Overview 102 Ballast Overview 103 Bunker/Consumables Care should be taken when running simulation in fast speed. As the amount of calculations for the stress and stability are numerous there can be a backlog in the updating of the pictures in the mimic diagrams. This holds the danger of temporary inaccurate values being represented in the various graphs thus resulting in wrong conclusions being drawn. After resuming normal speed simulation again the correct graphical representations will appear again on the mimic diagram displays.



5.19.2 Offline calculations In order to perform preloading/discharging calculations as is common practice to ensure no critical limit values are exceeded during the loading or discharging operations the system is equipped with an offline DataLoad load computer. This feature is represented by the mimic diagrams nos. 601 Cargo Tank Overview (LM) 602 Ballast Tank Overview (LM)

603 Bunker/Consumables (LM). 604 Shear Force (LM) 605 Bending Moment (LM) 606 Deflection (LM) 607 Stability Curve (LM) Once the cargo loading or discharging plan has been drawn up and the tank sequence chosen, the values can be entered in the cargo bar graph and tank diagrams. As this can be done step by step and tank by tank it is possible to monitor and check the values of shear force and bending moment against the allowable limits indicated in the respective screens. The input of the values for cargo should be done on the mimic diagram of the cargo bargraph. Underneath each tank a changeable value for "% full" is given. A value entered here will result in an indicative bar in the tank. Switching then to the shear force and bending moment graphs will show the actual status blue curve. This status curve can then be compared with the yellow harbour condition and the red open sea condition curves. If at any stage the yellow curve should be exceeded and the simulator is in harbour condition an alarm will sound and a flashing indicator will appear at the bulkhead concerned. The same will happen if the simulator is in sea condition for exceeding of the red curve.



6 UNIT CONVERSION The "Unit Conversion" field is on the lower part of the VDU and by pressing this soft button a menu of different conversions "pops up" (Length, Volume, Area, etc.). Press one of the soft keys in the menu. Press the middle button on the tracker-ball and type the value of the specific unit you want to be converted. And read the converted values in the other fields.



7 RULES, REGULATIONS AND PUBLICATIONS The set of rules and regulations we have in the maritime business today are determining the way gas ships are run today. They are a result of the seamen’s, the shipbuilder’s and the authorities’ experiences through the last 30 years. Transport of liquid gas is subject to very strict rules, and hardly any other trade is so critically assessed as the trade of liquid gas transport. Quite a few rules and regulations have been published by international and national authorities. This section will briefly mention some of the most important rules, regulations and publications which influence on the safe transport of liquid gas. 7.1 Tanker Safety Guide (Liquefied Gas) This guide is developed by ICS (International Chamber of Shipping), an international organisation of ship owners. This guide is the most up to date source of information concerning transport of liquefied gas in bulk. 7.2 International Maritime Dangerous Goods Code Binder 2 contains information’s which apply to liquid gasses. All information of current value for the safe transport of liquefied gasses are displayed here. 7.3 U.S. Coast Guard chemical data guide The U.S. Coast Guard has done a lot to safeguard the transport of condensed gasses in bulk. They have a large database of all products and which precautions to follow when handling this cargo concerning compatibility and so on. 7.4 International Maritime Organisation To reduce the risk the various products may induce on the ship and its crew, and to take care of the safety IMO has established a set of rules. These regulations are called the “Gas Code”. Primarily it takes into consideration the design of the ship and its equipment, and subsequently gives a model on how to design , equip and operate a gas ship with focus on security. IMO’s regulations are divided into three, depending on the age of the build: “Code for existing ships carrying liquefied gases in bulk” (pub.no.76.11.E) which deals with ships contracted after 31st of December 1976. “Code for construction and equipment of ships carrying liquefied gases in bulk” (pub.no. 782.83.16.E) which deals with ships contracted after 31st of December 1976 and before 1st of July 1986.



“Volume III International code for the construction and equipment of ships carrying liquefied gases in bulk” (pub.no. 104.83.12.E) which deals with ships laid down after 1st of July 1986. 7.5 Int. Convention for the Safety of Lives at Sea

1974 The SOLAS convention of 1974 with amendments of 1983 contains IMO’s regulations with focus on the rescue and distress equipment needed onboard the ship to take care of the seamen’s safety. The “Gas code” is a mandatory part of the SOLAS regulations. 7.6 Main Features of MARPOL 73/78, Annex II The requirements of Annex II apply to all ships carrying noxious liquid substances in bulk. Substances posing a threat of harm to the marine environment are divided into four categories X, Y, Z and OS, and listed as such in Appendix II to Annex II. Category X substances are those posing the greatest threat to the marine environment, whilst Category OS (Other Substances) are those posing the smallest threat. Annex II prohibits the discharge into the sea of any effluent containing substances falling under these categories, except when the discharge is made under conditions which are specified in detail for each category. These conditions include, where applicable, such parameters as: - the maximum quantity of substances per tank which may be discharged into the sea - the speed of the ship during the discharge - the minimum distance from the nearest land during discharge - the minimum depth of water at sea during discharge - the maximum concentration of substances in the ship’s wake of the dilution of substances prior to discharge - the need to effect the discharge below the waterline For certain sea areas identified as “Special Areas” more stringent discharge criteria are given. Under Annex II the special areas are the Baltic Sea Area*, the Black Sea Area**, and the Antarctic Area***. Annex II requires that every ship is provided with pumping and piping arrangements to ensure that each tank designated for the carriage of Category Y and Z substances does not retain after unloading of residue in excess of the quantity given in the Annex. For each tank intended for the carriage of such substances an assessment of the residue quantity has to be made. Only when the residue quantity as assessed is less than the quantity prescribed by the Annex, may a tank be approved for the carriage of a Category Y or Category Z substance. In addition to the conditions referred to above, an important requirement contained in Annex II is that the discharge operations of certain cargo residues and certain tank cleaning



and ventilation operations may only be carried out in accordance with approved procedures and arrangements based upon standards developed by the International Maritime Organisation (IMO). To enable this requirement to be complied with, this Manual contains in Section 2 all particulars of the ship’s equipment and arrangements, in Section 3 operational procedures for cargo unloading and tank stripping and in Section 4 procedures for discharge of cargo residues, tank washing, slops collections, ballasting and deballasting as may be applicable to the substance the ship is certified fit to carry. By following the procedures as set out in this Manual, it will be ensured that the ship complies with all relevant requirements of Annex II to MARPOL 73/78. NOTE! MARPOL 73/78, Annex II defines these areas as follows: * The Baltic Sea Area means the Baltic Sea proper with the Gulf of Bothnia, the Gulf of Finland and the entrance to the Baltic Sea bounded by the parallel of the Skaw in the Skagerrak at 57 degr. 44.8 min North. ** The Black Sea Area means the Black sea proper with the boundary between the Mediterranean and the black Sea constituted by the parallel 41 degr. North. *** The Antarctic Area means the area south of latitude 60 degr. South. Special areas in connection with Annex II.



7.7 Checklists A typical SHIP/SHORE Safety Check List used before loading or discharging at a terminal is supplied below: SHIP/SHORE SAFETY CHECK LIST Ship’s Name Berth Port Date of Arrival Time of

Arrival

INSTRUCTIONS FOR COMPLETION The safety of operations requires that all questions should be answered affirmatively . If an affirmative answer is not possible, the reason should be given and agreement reached upon appropriate precautions to be taken between the ship and the terminal. Where any question is not considered to be applicable a note to that effect should be inserted in the remarks column.

— the presence of this symbol in the columns ‘ship’ and ‘terminal’ indicates that checks shall be carried out by the party concerned. The presence of the letters A and P in the column ‘Code’ indicates the following: A — the mentioned procedures and agreements shall be in writing and signed by both parties. P — in the case of a negative answer the operation shall not be carried out without the permission of the Port Authority. PART A Bulk Liquids - General

Remarks

A1 Is the ship securely moored? A2 Are emergency towing wires correctly positioned?

A3 Is there a safe access between ship and shore?

A4 Is the ship ready to move under its own power?

P

A5 Is there an effective deck watch in attendance on board and adequate supervision on the terminal and the ship?

A6 Is the agreed ship/shore communication system operative?

A

A7 Have the procedures for cargo,



bunker and ballast handling been agreed? A A8 Has the emergency shut down procedure been agreed?

A

A9 Are fire hoses and fire fighting equipment on board and ashore positioned and ready for immediate use?

A10 Are cargo and bunker hoses/arms in good condition and properly rigged and, where appropriate, certificates checked?

A11 Are scuppers effectively plugged and drip trays in position, both on board and ashore?

A12 Are unused cargo and bunker connections including the stern discharge line, if fitted, blanked?

A13 Are sea and overboard discharge valves when not in use, closed or lashed?

A14 Are all cargo and bunker tank lids closed?

A15 Is the agreed tank venting system being used?

A

A16 Are hand torches of an approved type?

A17 Are portable VHF/UHF transceivers of an approved type?

A18 Are the ship’s main radio transmitter aerials earthed and radars switched off

A19 Are electrical cables to portable electrical equipment disconnected from power?

A20 Are all external doors and ports in the amidships accommodation closed?

A21 Are all external ports and doors in the after accommodation leading onto or overlooking the tank deck closed?

A22 Are air conditioning intakes which may permit the entry of cargo vapours closed?

A23 Are window-type air conditioning units disconnected?

A24 Are smoking requirements being observed?

A25 Are the requirements for use of the galley and other cooking appliances being observed?

A26 Are naked light requirements being observed?



A27 Is there provision for an emergency escape possibility?

A28 Are sufficient personnel on board and ashore to deal with an emergency?

A29 Are adequate insulating means in place in the ship/shore connection?

A30 Have measures been taken to ensure sufficient pump room ventilation?

A31 Is IG system, if fitted, fully operational and tested?

P

A32 Have hull stresses been considered with regard to the operations to take place while alongside?

SHIP SHORE Are tank cleaning operations planned during the ship’s stay alongside the shore installation?

Yes/No*

If so, have the port authority and terminal been informed? Yes/No* Yes/No* Declaration We have checked, where appropriate jointly, the items on the check list, and have satisfied ourselves that the entries we have made are correct to the best of our knowledge, and arrangements have been made to carry out repetitive checks as necessary. For Ship For Terminal Name Name Rank Position Signature Signature

Time: Date:



PART C Additional Checks - Bulk Liquefied Gases

Remarks

C1 Is information available giving necessary data for the safe handling of the cargo including, where applicable, a manufacturer’s inhibition certificate?

C2 Is the water spray system ready for use?

C3 Is sufficient and suitable protective equipment (including self-contained breathing apparatus) and protective clothing ready for immediate use?

C4 Are void spaces properly inerted where required?

C5 Are all remote control valves in working order?

C6 Are cargo tank safety relief valves lined up to the ship’s venting system and are by-passes closed?

C7 Are the required cargo pumps and compressors in good order, and have the maximum working pressures been agreed between ship and shore?

A

C8 Is reliquefication or boil off control equipment in good order?

C9 Is gas detection equipment set for the cargo, calibrated and in good order?

C10 Are cargo system gauges and alarm correctly set and in good order?

C11 Are emergency shut down systems working properly?

C12 Does shore know the closing rate of ship’s automatic valves; does ship have similar details of shore system?

A

C13 Has information been exchanged between ship and shore on minimum working temperature of the cargo system?

A



Declaration We have checked, where appropriate jointly, the items on the check list, and have satisfied ourselves that the entries we have made are correct to the best of our knowledge, and arrangements have been made to carry out repetitive checks as necessary. For Ship For Terminal Name Name Rank Position Signature Signature

Time: Date:



GUIDELINES FOR COMPLETING THE SHIP/SHORE SAFETY CHECK LIST, PART 'A' A1 Is the ship securely moored? In answering this question, due regard should be given to the need for adequate rendering arrangements. Ships should remain adequately secured in their moorings. Alongside piers or quays ranging of the ship should be prevented by keeping all mooring lines taut; attention should be given to the movement of the ship caused by currents or tides and the operation in progress. Wire ropes and fibre ropes should not be used together in the same direction (i.e. breasts, springs, head or stern) because of the difference in their elastic properties. Once moored, ships fitted with automatic tension winches should not use such winches in the automatic mode. Means should be provided to enable quick and safe release of the ship in case of an emergency. The method used for the emergency release operation should be agreed, taking into account the possible risks involved. Anchors not in use should be properly secured. A2 Are emergency towing wires correctly positioned? Emergency to Wing wires should be positioned both on the off-shore bow and quarter of the ship. At a buoy mooring, towing wires should be positioned on the side opposite to the hose string. The eyes of these wires should be maintained about the waterline and regularly checked and adjusted if necessary during the operations. They should be properly made fast on the ship's bollards, while having sufficient slack on deck. Means should be provided to prevent the slack from accidentally running into the water. These means should be so arranged that they can easily be broken by a tug boat's crew.



A3 Is there safe access between ship and shore? The access should be positioned as far away from the manifolds as practicable. The means of access to the ship should be safe and may consist of an appropriate gangway or accommodation ladder. It is advisable to fit and properly secure a safety net under the means of access. Particular attention to safe access should be given where the difference in level between the point of access on the vessel and the jetty or quay is large or likely to become large. When terminal access facilities are not available and a ship's gangway is used, there should be an adequate landing area on the berth so as to provide the gangway with a sufficient clear run of space and so maintain safe and convenient access to the ship at all states of tide and changes in the ship's freeboard. Near the access ashore suitable life-saving equipment should be available. A lifebuoy should be available on board the ship near the gangway or accommodation ladder. The access should be safely and properly illuminated during darkness. Persons who have no legitimate business on board, or who do not have the master's permission, should be refused access to the ship. The terminal should control access to the jetty or berth in agreement with the ship. A4 Is the ship ready to move under its own power? The ship should be able to move under its own power at short notice, unless permission to immobilize the ship has been granted by the harbourmaster and the terminal manager. Certain conditions may have to be met for permission to be granted. A5 Is there an effective deck watch in, attendance on board and adequate supervision on the terminal and on the ship? The operation should be under constant control both on ship and shore. Supervision should be aimed at preventing the development of hazardous situations; if, however, such a situation arises, the controlling personnel should have adequate means available to take corrective action. The controlling personnel on ship and shore should maintain an effective communication with their respective supervisors. All personnel connected with the operations should be familiar with the dangers of the substances handled. A6 Is the agreed ship/shore communication system operative?



Communication should be maintained in the most efficient way between the responsible officer on duty on the ship and the responsible person ashore. When telephones are used, the telephone both on board and ashore should be continuously manned by a person who can immediately contact his respective supervisor. Additionally, the supervisor should have the possibility to override all calls. When RT/VHF systems are used, the units should preferably be portable and carried by the supervisor or a person who can get in touch with his respective supervisor immediately. Where fixed systems are used the guidelines for telephones should apply. The selected system of communication together with the necessary information on telephone numbers and/or channels to be used should be recorded on the appropriate form. This form should be signed by both ship and shore representatives. The telephone and portable RT/VHF systems should comply with the appropriate safety requirements. A7 Have the procedures for cargo, bunker and ballast handling been agreed? The procedures for the intended operation should be pre-planned. They should be discussed and agreed upon by the ship and shore representatives prior to the start of the operations. The agreed arrangements should be recorded on a form and contain at least the information shown in the annex to these guidelines. The form should be signed by both representatives. Any change in the agreed procedure that could affect the operation should be discussed by both parties and agreed upon. After agreement has been reached by both parties substantial changes should be laid down in writing as soon as possible and in sufficient time before the change in procedure takes place. In any case the change should be laid down in writing within the working period of those supervisors on board and ashore in whose working period agreement on the change was reached. The operations should be suspended and all deck and vent openings closed on the approach of an electrical storm. The properties of the substances handled, the equipment of ship and shore installation, the ability of the ship's crew and the shore personnel to execute the necessary operations and to sufficiently control the operations are factors which should be taken into account when ascertaining the possibility of handling a number of substances concurrently. The manifold area both on board and ashore should be safely and properly illuminated during darkness. The initial and maximum loading rates, topping off rates and normal stopping times should be agreed, having regard to: -the nature of the cargo to be handled; -the arrangement and capacity of the ship's cargo lines and gas venting systems; -the maximum allowable pressure and flow rate in the ship/shore hoses and loading arms; -precautions to avoid accumulation of static electricity; -any other flow control limitations.



A note to this effect should be entered on the form referred to above. If the static electricity properties of the substance handled and the situation in the tank so requires, no conducting object should be inserted into that tank during loading and during a period of at least 30 minutes after the cessation of loading. A8 Has the emergency shut down procedure been agreed? An emergency shut down procedure should be agreed between ship and shore and recorded on an appropriate form. The agreement should designate in which cases the operations have to be stopped immediately. Due regard should be given to the possible introduction of dangers associated with the emergency shut down procedure. A9 Are fire hoses and fire fighting equipment on board and ashore positioned and ready for immediate use? Fire fighting equipment both on board and ashore should be correctly positioned and ready for immediate use. Adequate units of fixed or portable equipment should be stationed to cover the ship's cargo deck and on the jetty. The ship and shore fire main systems should be pressurized, or be capable of being pressurized at short notice. Both ship and shore should ensure that their fire main systems can be connected in a quick and easy way utilising if necessary the international ship/shore connection. A10 Are cargo and bunker hoses/arms in good condition and properly rigged and, where appropriate, certificates checked? Cargo hoses and metal arms should be in a good condition and should be properly fitted and rigged so as to prevent strain and stress beyond design limitations. All flange connections should be fully bolted. Other types of connections should be properly secured. It should be ensured that the hoses or metal arms are constructed of a material suitable for the substance to be handled taking into account its temperature and the maximum operating pressure. Cargo hoses should be identifiable with regard to their suitability for the intended operation. A11 Are scuppers effectively plugged and ddp trays in position, both on board and ashore? Where applicable all scuppers on board and drain holes ashore should be properly plugged during the operations. Accumulation of water should be drained off periodically.



Both ship and jetty should ideally be provided with fixed drip trays; in their absence portable drip trays may be used. All drip trays should be emptied in an appropriate manner whenever necessary but always after completion of the specific operation. Where corrosive liquids or refrigerated gases are being handled, the scuppers may be kept open, provided that an ample supply of water is available at all times in the vicinity of the manifolds. A12 Are unused cargo and bunker connections including the stern discharge line, if fitted, blanked? Unused cargo and bunker fine connections should be closed and blanked. Blank flanges should be fully bolted and other types of fittings, if used, properly secured. A13 Are sea and overboard discharge valves, when not in use, dosed and lashed? Experience shows the importance of this item in pollution avoidance on ships where cargo lines and ballast systems are interconnected. The security of the valves in question should be checked visually. A14 Are all cargo and bunker tinIi lids closed? Apart from the openings in use for tank venting (see A15) all openings to cargo tanks should be closed gastight. Ullaging and sampling points may be opened for the short periods necessary for ullaging and sampling. Closed ullaging and sampling systems should be used where required by international, national and local regulations and agreements. A15 Is the agreed tank venting system being used? Agreement should be reached by both parties, as to the venting system for the operation, taking into account the nature of the cargo and international, national and local regulations and agreements. There are three basic systems for venting tanks: 1. Open to atmosphere via open ullage ports, protected by suitable flame screens. 2. Fixed venting systems which includes inert gas systems. 3. To shore through other vapour handling systems. A16 Are hand torches of an approved type? A17 Are portable VHF/UHF transceivers of an approved type? Battery operated hand torches and VHF radio-telephone sets should be of a safe type which is approved by a competent authority. Ship/shore telephones should comply with the



requirements for explosion-proof construction except when placed in a safe space in the accommodation. VHF radio-telephone sets may operate in the internationally agreed wave bands only. The above-mentioned equipment should be well maintained and damaged units, though capable of operation, should not be used. A18 Are the ship's main radio transmitter aerials earthed and radars switched off? The ship's main radio transmitter should not be used during the ship's stay in port, except for receiving purposes. The main transmitting aerials must be disconnected and earthed. The ship's radar installation should not be used unless the master, in consultation with the terminal manager, has established the conditions under which the installation may be used safely. A19 Are electric cables to portable electrical equipment disconnected from power? The use of portable electrical equipment on wandering leads is prohibited in hazardous zones. The supply cables should be disconnected and preferably removed from the hazardous zone. Telephone cables in use in the ship/shore communication system should preferably be routed outside the hazardous zone. Wherever this is not feasible, the cable should be so positioned and protected that no danger arises from its use. A20 Are all external doors and ports in the amidships accommodation closed? A21 Are all external doors and ports in the after accommodation leading onto or overlooking the tank deck closed? External doors, windows and portholes in the amidship's accommodation should be closed during the operations. In the after accommodation external doors, windows and portholes facing or near the cargo zone should be closed during operations. These doors should be clearly marked, but at no time should they be locked. A22 Are air conditioning intakes which may permit the entry of cargo vapours closed? A23 Are window-type air conditioning units disconnected? Air conditioning and ventilator intakes which are likely to draw in air from the cargo area should be closed. Air conditioning units which are located wholly within the accommodation and which do not draw in air from the outside may remain in operation.



Window-type air conditioners should be disconnected from their power supply. A24 Are smoking requirements being observed? Smoking on board the ship may only take place in places specified by the master in consultation with the terminal manager or his representative. No smoking is allowed on the jetty and the adjacent area except in buildings and places specified by the terminal manager in consultation with the master. Places which are directly accessible from the outside should not be designated as places where smoking is permitted. Buildings, places and rooms designated as places where smoking is permitted should be clearly marked as such. A25 Are the requirements for the use of galley and other cooking appliances being observed? Open fire may be used in galleys whose construction, location and ventilation system provides protection against entry of flammable gases. In cases where the galley does not comply with the above, open fire may be used provided the master, in consultation with the terminal manager, has ensured that precautions have been taken against the entry or build up of flammable gases. On ships fitted with stern discharge lines no open fire in galley-furnaces and cooking appliances is allowed when these lines are used, unless the construction of the ship's accommodation allows for the safe use of open fire. A26 Are naked light requirements being observed? Naked light or open fire comprises the following: fire, spark formation, naked light and any surface with a temperature that is equal to or higher than the minimum ignition temperature of the products handled in the operations. The use of open fire on board the ship -- other than covered in questions A24 and A25 -- and within a distance of 25 m of the ship is prohibited, unless all applicable regulations have been met and subject to agreement by the port authority, terminal manager and the master. A27 Is there provision for an emergency escape possibility? In addition to the means of access referred to in question A3, a safe and quick emergency escape should be available both on board and ashore. On board the ship it may consist of a lifeboat ready for immediate use, preferably at the after end of the ship. A28 Are sufficient personnel on board and ashore to deal with an emergency? At all times during the ship's stay at the terminal, a sufficient number of personnel should be present on board the ship and in the shore installation to deal with an emergency. A29 Are adequate insulating means in place in the ship/shore connection?



Unless measures are taken to break the continuous electrical path between ship and shore pipe work provided by the ship/shore hoses or metallic arms, stray electric currents, mainly from corrosion protection systems, can cause electric sparks at the flange faces when hoses are being connected and disconnected. The passage of these currents is prevented by an insulating flange inserted at each jetty manifold outlet or incorporated in the construction of metallic arms. Alternatively, the electrical discontinuity may be provided by the inclusion of one length of electrically discontinuous hose in each hose string. It should be ascertained that the means of electrical discontinuity is in place and in good condition and that it is not being by-passed by contact with external metal. A30 Have measures been taken to ensure sufficient pump room ventilation? Ship's pump rooms should be mechanically ventilated and the ventilation should be kept running throughout the operation. Ventilation should be aimed at maintaining a safe atmosphere throughout the pump room.



7.8 Cargo Record Book The cargo record book shall be completed in the appropriate places on completion of cargo loading or unloading. (All handling of the cargo). 7.8.1 Inert Gas System manual IMO Inert Gas Systems 1990 Edition Part 1 Guidelines for Inert Gas Systems (MSC/Circ.282 as amended by MSC/Circ.353 and MSC/Circ.387) 7.8.1.1 Introduction The International Conference on Tanker Safety and Pollution Prevention held in February 1978 passed resolution 5 recommending that the International Maritime Organisation develops Guidelines to supplement the requirements of amended regulation 62 of chapter II-2 of the 1974 SOLAS Convention by taking into account the arduous operating conditions of inert gas systems and the need to maintain them to a satisfactory standard. In addition regulation 62.1 requires that an inert gas system shall be designed, constructed and tested to the satisfaction of the Administration. These Guidelines have accordingly been developed to supplement and complement the Convention requirements for inert gas systems. They are offered to Administrations to assist them in determining appropriate design and constructional parameters and in formulating suitable operational procedures when inert gas systems are installed in ships flying the flag of their state. 7.8.1.2 Definitions Inert Gas: means a gas or a mixture of gases, such as flue gas, containing insufficient oxygen to support the combustion of hydrocarbons. Inerting: means the introduction of inert gas into a tank with the object of attaining the inert condition in which the oxygen content throughout the atmosphere of a tank has been reduced to 8% or less by volume by addition of inert gas. Gas-freeing: means the introduction of fresh air into a tank with the object of removing toxic, flammable and inert gases and increasing the oxygen content to 21% by volume. Purging: means the introduction of inert gas into a tank already in the inert condition with the object of: further reducing the existing oxygen content and/or reducing the existing hydro carbon content to a level below which combustion cannot be supported if air is subsequently introduced into the tank Topping up: means the introduction of inert gas into a tank which is already in the inert condition, with the object of raising the tank pressure to prevent ingress of air.



7.8.1.3 Instruction Manuals Instruction manuals required to be provided on board by regulations 62(21) should contain the following information and operational instructions. 1. A line drawing of the inert gas system showing the positions of the inert gas pipe work from the boiler or gas generator uptakes to each cargo tank and slop tank; gas scrubber; scrubber cooling water pump and pipe work up to the effluent discharge overboard; blowers including the suction and discharge valves; recirculation or other arrangements to stabilise the inert gas plant operation; fresh air inlets; automatic gas pressure regulating stop valve; deck water seal and water supply; heating and overflow arrangements; deck nonreturn stop valve; water traps in any supply, vent, drain and sensing pipe work; cargo tank isolation arrangement; purge pipes/vents; pressure vacuum valves on tanks; pressure/vacuum breakers on the inert gas main; permanent recorders and instruments and the take-off points for their use, arrangements for using portable instruments, complete and partial wash bulkheads, mast risers, mast riser isolating valves; high velocity vents; manual and remote controls. 2. A description of the system and a listing of procedures for checking that each item of the equipment is working properly during the full cycle of the tanker operation. This includes a listing of the parameters to be monitored such as inert gas main pressure, oxygen concentration in the delivery main, oxygen concentration in the cargo tanks, temperature at the scrubber outlet and blower outlet, blower running current or power, scrubber pump running current or power, deck seal level during inert gas discharge to cargo tanks at maximum rate, deck seal level at nil discharge etc. Established levels for these parameters during acceptance trials should be included, where relevant. 3. Detailed requirements for conducting the operations described in the sections on Operation of the Inert Gas Plant and Application to Cargo Tank Operation, particular to the installation of the ship such as times to inert, purge and gas-free each tank, sequence and number of tanks to be inerted, purged and gas-freed, sequence and number of purge pipes/vents to be opened or closed during such operations, etc. 4. Dangers of leakage of inert gas and hydrocarbon vapours and precautions to be taken to prevent such leakages should be described relating to the particular construction and equipment on board. 5. Dangers of cargo tank over pressure and under pressure during the various stages in the cycle of tanker operation and the precautions to be taken to prevent such conditions from arising should also be described in detail relating to the particular construction or the equipment on board.

SO-0939-C Neptune CHS LNG Carrier User Manual · IBC International Code for the Construction and...

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