LNG bunkering ship - VeriSTAR

LNG bunkering ship

October 2015

Rule Note NR 620 DT R00 E

Marine & Offshore Division 92571 Neuilly sur Seine Cedex – France

Tel: + 33 (0)1 55 24 70 00 – Fax: + 33 (0)1 55 24 70 25 Website: http://www.veristar.com

Email: [email protected] 2015 Bureau Veritas - All rights reserved

ARTICLE 1

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

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

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

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

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

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

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

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

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

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

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

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

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

• "conducts surveys at the place of their construction;

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

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

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

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

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

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

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

ARTICLE 6

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

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

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

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

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

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

ARTICLE 8

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

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

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

ARTICLE 9

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

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

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

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

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

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

ARTICLE 10

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

ARTICLE 11

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

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

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

ARTICLE 13

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

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

MARINE & OFFSHORE DIVISIONGENERAL CONDITIONS

RULE NOTE NR 620

NR 620LNG bunkering ship

SECTION 1 GENERAL

SECTION 2 SHIP ARRANGEMENT

SECTION 3 HULL AND STABILITY

SECTION 4 TRANSFER SYSTEMS

SECTION 5 INERT GAS SYSTEMS

SECTION 6 ELECTRICAL INSTALLATIONS AND INSTRUMENTATION

SECTION 7 AUTOMATION SYSTEMS

SECTION 8 FIRE SAFETY

SECTION 9 ADDITIONAL SERVICE FEATURES

APPENDIX 1 RISK ANALYSIS

October 2015

Section 1 General

1 General 7

1.1 Application1.2 Scope1.3 Exclusion1.4 Classification notations

2 References 7

2.1 Acronyms2.2 Definitions2.3 Referenced documents

3 Document to be submitted 9

3.1 General

4 Tests and trials 9

4.1 LNG transfer system trials in working condition

Section 2 Ship Arrangement

1 General design requirements 10

1.1 Risk analysis1.2 Hazardous area

2 Material requirements 10

2.1 General

3 Arrangement of bunkering system 10

3.1 LNG bunkering station3.2 Bunkering control station

4 Ventilation in closed or semi- enclosed spaces 11

4.1 General

Section 3 Hull and Stability

1 Location of cargo tanks 12

1.1 General

Section 4 Transfer Systems

1 General 13

1.1 Application1.2 Requirements

2 Hoses 13

2.1 General2.2 Design requirements2.3 Type approval of bunkering hose

2 Bureau Veritas October 2015

2.4 Type approval testing2.5 Workshop Testing 2.6 Survey requirements2.7 Hoses onboard

3 Quick connect disconnect coupler (QCDC) 15

3.1 Type approval of QCDC3.2 Type testing3.3 Workshop testing

4 Break-away and emergency release coupling (ERC) 15

4.1 General4.2 Type approval of break-away and ERC4.3 Type testing4.4 Workshop testing

5 Electrical isolation flanges 15

5.1 General

6 Supports 16

6.1 General6.2 Transfer arm

7 Swivels 16

7.1 General

8 Auxiliary equipement 16

8.1 General

9 LNG transfer system 16

9.1 General9.2 Testing of the complete system

10 Bunkering transfer rate 16

10.1 General10.2 Sampling

11 Arrangement for draining the LNG transfer lines 17

11.1 General

12 Compatibility between receiving ship and bunkering ship 17

12.1 General

Section 5 Inert Gas Systems

1 General 18

1.1 Application1.2 Requirements

Section 6 Electrical Installations and Instrumentation

1 General 19

1.1 Application1.2 System of supply

October 2015 Bureau Veritas 3

2 Earth detection 19

2.1 Monitoring of circuits in hazardous areas

3 Gas detection 19

3.1 Gas detection in enclosed spaces3.2 Gas detection in open areas

4 Emergency shut-down systems (ESD) 20

4.1

Section 7 Automation Systems

1 General 21

1.1 Application1.2 Emergency shut-down systems (ESD)1.3 Alarms and safety actions1.4 Communication systems

Section 8 Fire Safety

1 General 22

1.1 Application1.2 Water Spray systems1.3 Dry chemical powder

2 Fire protection 22

2.1

3 Fire extinction 22

3.1 Water spray systems3.2 Dry chemical powder fire-extinguishing system

Section 9 Additional Service Features

1 Additional service feature RE 23

1.1 General

2 Additional service feature IG-Supply 23

2.1 General

3 Additional service feature Initial-CD 23

3.1 General

4 Additional service feature BOG 23

4.1 General4.2 Vapour return line


Appendix 1 Risk Analysis

1 General 24

1.1 Purpose of this appendix1.2 Form of the risk analysis1.3 Single failure concept1.4 Scope of the risk analysis

2 Systems to be analysed 24

2.1 General2.2 LNG tranfer system2.3 Gas detection system2.4 Control monitoring and safety systems

3 Unexpected events to be analysed 24

3.1 LNG leakage3.2 Risk related to the receiving ship3.3 Black-out



NR 620, Sec 1

SECTION 1 GENERAL

1 General

1.1 Application

1.1.1 The present Rule Note applies to ships carrying lique-fied natural gas (LNG) and intended to ensure the transfer ofLNG to ships using LNG as fuel.

Ships complying with this Rule Note may be assigned clas-sification notations defined in [1.4].

1.1.2 In general, this Rule Note applies to bunkering and gastransfer systems of the ship, which is additionally to complywith the applicable requirements indicated in Tab 1.

Table 1 : Additional applicable requirements

1.1.3 Ships complying with the requirements of this RuleNote are to comply with IGC Code except otherwise speci-fied.

This Rule Note provides additional requirements and inter-pretations of IGC Code, which are also mandatory classrequirements. The society may refer to IGC Code whendeemed necessary.

1.2 Scope

1.2.1 This Rule Note covers:

• the design and installation of the LNG transfer systemsfrom bunkering ship to the receiving ship and thevapour transfer system from the receiving ship to bun-kering ship, including LNG hoses, transfer arms andauxiliary equipment for handling the LNG system

• the design and installation of the equipment intendedfor the boil-off gas management of the bunkering ship

• the design and installation of the gas piping system ofthe bunkering ship

• the safety arrangements.

1.3 Exclusion

1.3.1 This Rule Note does not cover the LNG storage tanks,associated piping and process systems which are to complywith the requirements of IGC Code and Ship Rules, Part D,Chapter 9.

1.4 Classification notations

1.4.1 Service notationShips complying with the requirements of this Rule Noteare to be granted the service notation LNG bunkering ship.

1.4.2 Additional service featuresThe service notation LNG bunkering ship may be com-pleted by the following additional service features, as appli-cable:• RE, where the ship is designed to receive LNG from a

gas fuelled ship for which the LNG fuel tanks have to beemptied.

• Initial-CD, where the ship is designed for initial coolingdown of the gas fuelled ship LNG fuel tank.

• IG-Supply, where the ship is designed to supply inert gasand dry air, to ensure gas freeing and aeration, to a gasfuelled ship complying with IGF Code, paragraph 6.10.4.

• BOG, where the ship is designed to recover and managethe boil-off gas generated during the bunkering operation.

2 References

2.1 Acronyms

2.1.1 The following acronyms are used:BOG : Boil-Off GasERC : Emergency Release CouplingESD : Emergency Shut-Down systemsLNG : Liquefied Natural GasMAAT : Maximum Allowable Applied TwistMBR : Minimum Bend RadiusQCDC : Quick Connect/Disconnect Couplers.

2.2 Definitions

2.2.1 Auxiliary equipmentAuxiliary equipement for handling the LNG transfer systemrefer to the following equipment:• Hydraulic systems• Power supply• Inert gas systems• Supporting equipment• Water curtains• etc ...

Item Reference

Ship arrangement NR467, Part B

Hull NR467, Part B

Stability NR467, Part B

Machinery and cargo system NR467, Part C

Electrical installations NR467, Part C

Automation NR467, Part C

Fire protection, detection and extinction

NR467, Part C

Carriage of liquefied gases NR467, Part D, Chapter 9

Note 1: NR467: Rules for the Classification of Steel Ships (hereafter referred as Ship Rules)


NR 620, Sec 1

2.2.2 LNG bunkering stationLNG bunkering station means the following equipment:• hoses and piping connections used for liquid and

vapour return lines, including the isolating valves andthe emergency shut-down valves

• Automation and alarms systems• the drip tray with its draining arrangement and other

arrangements intended for the ship structure protection• the gas and leak detection systems • the associated firefighting installations

• the monitoring systems (i.e. thermic camera).

2.2.3 Bunkering emergency shut-down system (ESD)

An ESD is a system that safely and effectively stops thetransfer of LNG (and vapour as applicable) between thereceiving ship and the bunkering ship in the event of anemergency during the bunkering operation, and puts thesystem in a safe condition.Note 1: In addition to the ESD required by IGC Code, if a separatetransfer system is provided.

2.2.4 Bunkering connectionsBunkering connections correspond to the end of the fixedpiping to the bunkering ship (i.e. manifold for a system withflexible hose and before the swivel for a system with transferarm).

2.2.5 Emergency release coupling (ERC)An ERC is a coupling located on the receiving ship bunker-ing manifold or on the LNG transfer system, which sepa-rates at a predetermined section, when required, eachseparated section containing a self-closing shut-off valve,which seals automatically.

An emergency release coupling can be activated:• by maximal allowable forces applied to the predeter-

mined section• by manual or automatic control, in case of emergency.

2.2.6 Enclosed spaceEnclosed space means any space within which, in theabsence of artificial ventilation, the ventilation will be lim-ited and any explosive atmosphere will not be dispersednaturally.

2.2.7 Hazardous areaAccording to IGC Code, hazardous area means an area inwhich an explosive gas atmosphere is or may be expectedto be present, in quantities such as to require special pre-cautions for the construction, installation and use of electri-cal apparatus.

Hazardous areas are divided into Zone 0, 1 and 2 asdefined below and according to the area classification spec-ified in Sec 2, [1.2]:• Zone 0:

Area in which an explosive gas atmosphere is presentcontinuously or is present for long periods

• Zone 1:Area in which an explosive gas atmosphere is likely tooccur in normal operation

• Zone 2:

Area in which an explosive gas atmosphere is not likelyto occur in normal operation and, if it does occur, islikely to do so only infrequently and will exist for a shortperiod only.

2.2.8 LNG transfer systemA LNG transfer system is a system used to connect the bun-kering ship and the receiving ship in order to transfer LNGonly or both LNG and LNG vapour.

The LNG transfer system includes:

• rigid pipes, hoses, swivels, valves, couplings

• supporting structure

• handling system and its control/monitoring system.

It also includes the compressors or blowers intended for theboil-off gas pressure management, when required.

2.2.9 LNG vapour return linesA LNG vapour return line is a connection between the bun-kering ship and the receiving ship to prevent pressureincrease in the receiving tank due to liquid transfer andassociated boil-off.

2.2.10 Non-hazardous areaNon-hazardous area means an area in which an explosivegas atmosphere is not expected to be present in quantitiessuch as to require special precautions for the constructions,installation and use of electrical apparatus.

2.2.11 Open deckOpen deck means a deck that is open on both ends, or isopen on one end equipped with adequate natural ventila-tion that is effective over the entire length of the deckthrough permanent openings distributed in the side panelsor in the deck above.

2.2.12 Quick connect disconnect coupler (QCDC)A QCDC is a manual or hydraulic mechanical device usedto connect the LNG transfer system to the receiving shipmanifold.

2.2.13 Receiving shipA receiving ship is a ship receiving LNG as fuel.

2.2.14 Safety zoneThe safety zone is a zone around the bunkering ship, thebunkering station of the receiving ship and the LNG transfersystem, where the only activities performed are the bunker-ing operations and related activities and where measuresare taken to prevent leakage of LNG or LNG vapour and tocontrol sources of ignition.

2.2.15 Semi-enclosed spaceSemi-enclosed space means a space limited by decks andor bulkheads in such manner that the natural conditions ofventilation are notably different from those obtained onopen deck.

2.2.16 Transfer armTransfer arm refers to any system allowing supporting ahoses or rigid pipes during bunkering operations.


NR 620, Sec 1

2.3 Referenced documents

2.3.1 Ship Rules

Ship Rules means Rules for the Classification of Steel Ships(NR467).

2.3.2 NR320

NR320 means the latest version of NR320 CertificationScheme of Materials and Equipment for the Classification ofMarine Units.

2.3.3 NR216

NR216 means the latest version of NR216 Rules on Materi-als and Welding for the Classification of Marine Units.

2.3.4 IGC Code

IGC Code means the International Code for the Construc-tion and Equipment of Ships Carrying Liquefied Gases inBulk, published by the International Maritime Organization.

2.3.5 IGF Code

IGF Code means the International Code of Safety for Shipusing Gases or other Low-flashpoint Fuels, published by theInternational Maritime Organization.

The society may refer to IGF Code when deemed necessary.

2.3.6 SOLAS Convention

SOLAS Convention means the International Convention forthe Safety of Life at Sea, 1974, as subsequently amended.

2.3.7 IEC 60092-502IEC 60092-502 means the International ElectrotechnicalCommission standard: Electrical installations in ships (Part502: Tankers - Special features).

3 Document to be submitted

3.1 General

3.1.1 The drawing and related information to be submittedare listed in Tab 2, and, as relevant, in Sec 9.

3.1.2 The operating manuals and procedures to be submit-ted are listed in Tab 3.

4 Tests and trials

4.1 LNG transfer system trials in working condition

4.1.1 LNG transfer system, defined in [2.2.8], is to beexamined by Surveyor during the first LNG bunkering oper-ation. The following examinations are to be conducted during thefirst LNG transfer:

a) Examination of transfer piping systems including sup-porting arrangements.

b) Witness satisfactory operation of the following:• Control and monitoring systems• Connections systems (QCDC).

Table 2 : Documentation to be submitted

Table 3 : Operating manuals and procedures to be submitted

No A/I Documents

1 A General arrangement of the ship showing the location of the bunkering station and bunkering control station

2 I Risk analysis - LNG transfer system (see App 1) and the follow up report

3 A Details of maximum bunkering flow and maximum pressure (see Sec 4)

4 A Details of LNG transfer system (see Sec 4)

5 A Details of ESD Bunkering system (see Sec 4)

6 I Safety certificates for electrical equipment, concerning the bunkering, located in hazardous areas, where applicable

7 A Instrumentation list

8 A Drawing of transfer arm

Note 1:A : To be submitted for approval I : To be submitted for information

No A/I Documents

1 I Bunkering procedure, including inerting and gas freeing

2 I BOG management procedure

3 I Operating envelop of the bunkering ship

4 I Risk analysis of the bunkering operations

Note 1:A : To be submitted for approvalI : To be submitted for information


NR 620, Sec 2

SECTION 2 SHIP ARRANGEMENT

1 General design requirements

1.1 Risk analysis

1.1.1 LNG transfer systemThe design and the installation of the LNG transfer systemare to be substantiated by a risk analysis to be performed inaccordance with App 1.

1.2 Hazardous area

1.2.1 GeneralThe hazardous areas are to be in accordance with IGCCode, regulation 1.3.17.

1.2.2 Zone 1This zone includes in addition to IGC Code:

• LNG bunkering station

• areas on the open deck within spillage coamings sur-rounding gas bunkering manifold valves and 3 mbeyond these, up to a height of 2,4 m above the deck

• when applicable, transfer arm operating amplitude.

1.2.3 Classification of spaces adjacent to hazardous areas

A space separated by gastight boundaries (with or withoutopening) from an hazardous area may be classified as zone1, 2 or considered as hazardous, taking into account thesources of release inside that space, the type and arrange-ments of openings and the conditions of ventilation, as perIEC Publication 60092-502, paragraph 4.1.

A type approved gastight bulkhead penetration device is notconsidered as a source of release.

2 Material requirements

2.1 General

2.1.1 Materials used in LNG transfer systems, piping sys-tem for liquefied gas and other systems or components incontact with gas are to be in accordance with IGC Code,Chapter 6 and Ship Rules, Pt D, Chapter 9.

Materials are in general to be in accordance with NR216.

3 Arrangement of bunkering system

3.1 LNG bunkering station

3.1.1 GeneralThe LNG bunkering station is to be located in a area withsufficient natural ventilation. Closed or semi-enclosed bun-kering stations will be subject to special consideration.

The LNG bunkering station is to be physically separated orstructurally shielded from accommodation and control sta-tions.

Structural strength calculations and drawings manifolds areto be submitted to the Society and stated on the manifolds.

3.1.2 Hazardous area created during bunkering operations

A particular attention is to be paid to the hazardous areascreated during the bunkering operations and to restrict theaccess in order to avoid the presence of unauthorized per-sons in the vinicity of these hazardous areas and the possi-bility to create source of ignition.

3.1.3 Drip trays

Drip trays are to be fitted below the liquid bunkering con-nections and where leakage may occur which can causedamage to the ship structure.

Thermal sensors are to be positioned in way of bunkeringconnections in the drip tray.

The drip trays are to be made of stainless steel, and can tobe remotely drained over the ship’s side without risk ofdamage to the ship structure and to the receiving ship.

A water piping system is to be fitted in way of the hull underthe bunkering manifold to provide low-pressure water cur-tain for additional protection of the hull steel and the ship’sstructure. This system is to be in operation when transfersystem is in progress. Other solutions are acceptable withjustification.

3.1.4 Bow and stern arrangements

LNG bunkering station may be accepted at the ship bowand stern provided that the relevant requirements of IGCCode, paragraph 3.8, are satisfied.

3.2 Bunkering control station

3.2.1 The bunkering control station is to be considered as acontrol station with regard to requirements of Steel Ships,Part C and Part D and of the IGC Code.

3.2.2 Control of the bunkering operation should be possi-ble from a safe location with regards to bunkering opera-tions and may be from the cargo control room. At thislocation, overfilling alarm, automatic and manual shut-down are be indicated.


NR 620, Sec 2

4 Ventilation in closed or semi- enclosed spaces

4.1 General

4.1.1 Ventilation of closed or semi-enclosed space is to beof mechanical type and take place in the lower part of thecompartment. Furthermore a gas detection system is to befitted.

4.1.2 Any ducts used for the ventilation of hazardous areasare to be separated from that used for the ventilation of non-

hazardous areas. The ventilation is to be capable of func-tioning at all temperature conditions the ship is designed tooperate in. Electric fan motors are not to be located in venti-lation ducts for hazardous areas unless the motor is certifiedfor the same area classification and operating conditions asthe space served.

4.1.3 Ventilation ducts shall have the same area classifica-tion as the ventilated space.

4.1.4 Ventilation capacity is to be in accordance with para-graph 12.1.2 of IGC Code.


NR 620, Sec 3


SECTION 3 HULL AND STABILITY

1 Location of cargo tanks

1.1 General

1.1.1 The location of cargo tanks are to be in accordancewith requirements of IMO resolution MSC.370(93),Chapter 2, paragraph 2.4.

NR 620, Sec 4

SECTION 4 TRANSFER SYSTEMS

1 General

1.1 Application

1.1.1 This Section covers the LNG tranfer systems, LNGvapour return transfer systems and their mandatory associ-ated systems including:

• Hoses

• QCDC

• Break-away

• Isolation flanges.

This Section also covers the following systems:

• ERC

• Support

• Swivels

• Auxiliary equipement.

1.2 Requirements

1.2.1 The LNG transfer system is to include a Quick Con-nect Disconnect Coupler (QCDC), a Break-away couplingor a ERC and insulation flanges.

1.2.2 Transfer systems and their associated systems are tobe considered as essential services as defined in Ship Rules,Part A, Ch 1, Sec 1, [1.2.1].

1.2.3 The transfer system is to be designed to avoid therelease of gas or liquid to the atmosphere during bunkeringoperations.

2 Hoses

2.1 General

2.1.1 The requirements of IGC Code, in particular para-graph 5.7, are to be fulfilled.

2.2 Design requirements

2.2.1 General

The following characteristics are to be defined by thedesigner and submitted to the Society:

• Extreme service temperature

• Maximum working load

• Maximum design pressure

• Minimum bend radius (MBR)

• Maximum allowable applied twist (MAAT).

2.2.2 Maximum design pressureThe maximum design pressure is not to be less than 10 barin accordance with paragraph 5.7.3 of IGC Code.

2.2.3 MaterialsAll materials are to be compatible with each other and withthe fluid conveyed (LNG and LNG vapours).

2.2.4 End connection and couplingThe end fittings are to be made of stainless steel and be inaccordance with IGC Code or NR216.

2.3 Type approval of bunkering hose

2.3.1 Bunkering hoses are to be type approved by the Soci-ety.

2.3.2 All hoses are to be tested at the plant of manufacturerin the presence of the Surveyor. An alternative surveyscheme, BV Mode I as per Rule Note NR320 as amended,may be agreed with the Society.

2.4 Type approval testing

2.4.1 Validation testAfter type approval testing, as defined in [2.4.2] to [2.4.9],the hose assembly is to be subjected to a hydraulic pressuretest to a pressure not less than 1,5 times the nominal pres-sure, to demonstrate that the hose assembly is capable ofwithstanding these tests without leaking.

2.4.2 Temperature and pressure cycle testThe hose assembly is to be subjected to a pressure cycle testat ambient temperature to demonstrate that the hose iscapable of withstanding 2 000 pressure cycle test from zeroto at least twice the specified maximum working pressure.

The hose assembly is also to be subjected to a cryogenictemperature and pressure cycle test with a minimum of 200combined test cycles.

2.4.3 Burst pressure testAfter the pressure cycle test, as defined in [2.4.2], has beencarried out, the prototype test is to demonstrate a burstingpressure of at least 5 times its specified maximum workingpressure at the upper and lower extreme service tempera-ture.

2.4.4 Bending cycle fatigue testThe hose assembly is to be subjected to a bending cyclefatigue test, at ambient and cryogenic temperature, with400 000 cycles without failure.

The fatigue bend radius is to be in accordance with designerrecommendation.


NR 620, Sec 4

2.4.5 Crushing test

The hose assembly is to be subjected to a crushing test atambient temperature and cryogenic temperature withoutdamage. The hose assembly is to be held between two rigidplates (an area equivalent to the diameter of the hose) and aforce of 1000N is to be applied ten times at the same loca-tion in the middle of each flexible hose.

2.4.6 Impact test

The hose assembly is to be subjected to an impact test toensure that the hose is capable of withstanding loads with-out damage at ambient and cryogenic temperature.

2.4.7 Tensile test

The hose assembly is to be subjected to a tensile test atambient and cryogenic temperature to ensure that the hoseis capable of withstanding the maximum working load.

2.4.8 Bending test to minimum bend radius (MBR)

The hose assembly is to be subjected to a bending test atambient and cryogenic temperature to ensure that the hoseis capable of withstanding the maximum working pressureat minimum working bend radius.

Hose should be gradually bent to the MBR and then pressu-rized to the maximum working pressure. Hose shall beexamined for leaks whilst being held for 15 min at MBR andno damage should be evident on return pre-test conditions.

2.4.9 Maximum allowable applied twist (MAAT) test

The hose assembly is to be subjected to a ambient and cryo-genic twist test to ensure that the hose is capable of with-standing its maximum working load whilst at MAAT.

The hose assembly is to be gradually twisted to the MAATand then pressurized to the maximum working pressure.The hose is to be examined for leaks whilst being held for15 min at MAAT and no damage should be evident onreturn pre-test conditions.

2.4.10 Electrical testing

The hose assembly is to be subjected to a electrical test.

The hose assembly is to be drained and supported aboveground by non-conductive means and the resistance meas-ured between the two end fittings (connection face). Electri-cally continuous hoses shall have a resistance of less than10 Ω. Electrically discontinuous hoses shall have a resist-ance of not less than 25 000 Ω.

2.5 Workshop Testing

2.5.1 Application

Each produced length of cargo hose completed with end-fit-tings is to be tested as defined in [2.5.2] to [2.5.4] (hosesused for prototype testing are not to be used onboard).

2.5.2 Pressure testThe hose assembly shall be subjected to a hydraulic pres-sure test at ambient temperature and a pressure test at cryo-genic temperature, to a pressure not less than 1,5 times thenominal pressure, but not more than two fifths of its burst-ing pressure, to demonstrate that the hose assembly is capa-ble of withstanding its pressure without leaking.

2.5.3 Leak testThe hose assembly shall be subjected to a pneumatic pres-sure test, at ambient temperature, to a pressure not less than1,1 times the design pressure, to demonstrate that the hoseassembly is capable of withstanding its pressure withoutleaking.

2.5.4 Inspection of welds Welds of the hose assembly are to be subjected to non d-descructive testing (NDT).

When applicable, all butt welds of the hose assembly withconnections systems are to be subjected to a 100% radiog-raphy examination.

2.6 Survey requirements

2.6.1 SurveyThe products are to be manufactured, examined and testedby the manufacturer. Arrangements shall be made for aSociety's Surveyor to attend the relevant tests and examina-tions at manufacturer's works or to perform the relevantaudits when an alternative survey scheme (BV Mode I) hasbeen agreed.

2.6.2 CertificationWhen the design assessment and testing are successfullycompleted and the documentation (study and test reports)are examined, a type approval certificate is issued andgiven a validity period of 5 years.

2.7 Hoses onboard

2.7.1 GeneralTransfer hose manufacturer’s instructions regarding testing,storage and number of temperature and pressure operatingcycles before removal from service are to be strictly fol-lowed.

The maximum service life of the hose assembly should notexceed 5 years and hoses are to be inspected periodicallyduring the annual survey of the LNG bunkering ship.

2.7.2 DocumentsA document containing the following information is to bekept on board:

• Hose identification number

• Type approval certificate

• Date of initial entry into service

• Initial test and certificates

• Records of all transfer operations.

This document is to be made available during any survey bythe Port Administration.


NR 620, Sec 4

2.7.3 Marking of products

Each hose is to be permanently marked with at least the fol-lowing information:

• Manufacturer's name or logo

• Hose designation and size

• Maximum working pressure

• Maximum and minimum working temperature

• Overall weight of the hose and end fittings assembly

• Date of manufacture

• Society's brand as relevant

• Date of last inspection and testing.

3 Quick connect disconnect coupler (QCDC)

3.1 Type approval of QCDC

3.1.1 QCDC are to be type approved by the Society.

3.1.2 All QCDC are to be tested at the plant of manufac-turer in the presence of the Surveyor. An alternative surveyscheme, BV Mode I as per Rule Note NR320, may beagreed with the Society.

Each produced QCDC is to be tested as defined in [3.3.1](QCDC used for prototype testing are not to be usedonboard).

3.2 Type testing

3.2.1 The QCDC is to be subjected to a type test to confirmthe release performance under ice built up condition.

3.3 Workshop testing

3.3.1 Pressure test

The QCDC is to be subjected to a hydraulic pressure test, atambient temperature, to a pressure not less than 1,5 timesthe design pressure, to demonstrate that the QCDC is capa-ble of withstanding its pressure without leaking.

4 Break-away and emergency release coupling (ERC)

4.1 General

4.1.1 The bunkering line is to be designed and arranged towithstand the surge pressure that may result from the activa-tion of the break-away or the ERC.

4.1.2 Justifications are to be submitted regarding the com-patibility with hoses and the maximum axial and shearforces likely to be exerted on the break-away or the ERCduring the bunkering operations.

Alternatively the manifold area may be suitably reinforced.Details of the manifold loads are to be submitted to thesociety for information.

4.1.3 ERC is to be designed for:

• Remote and local manual activation

• Automatic activation in case of excessive forces

• Automatic activation in case the safe working envelopeof the loading arm is exceeded.

4.1.4 In the event of activation of the break-away or theERC, the hoses are to be adequately supported and pro-tected to prevent potential damage, spark or rupture due tomechanical shocks.

4.1.5 All electrical components of the emergency releasecoupling actuator are to be of a suitable safe type.

When applicable, the availability of hydraulic power is tobe monitored. If the power supply of ERC by the hydraulicsource is no longer available, bunkering operation is to bestopped.

4.2 Type approval of break-away and ERC

4.2.1 Break-away and ERC are to be type approved by theSociety.

4.2.2 All break-away and ERC are to be tested at the plantof manufacturer in the presence of the Surveyor. An alterna-tive survey scheme, BV Mode I as per Rule Note NR320,may be agreed with the Society.

Each produced break-away and ERC are to be tested asdefined in [4.3.1] (break-away and ERC used for prototypetesting are not to be used onboard).

4.3 Type testing

4.3.1 The break-away or the ERC are to be subjected to atype test to confirm the values of axial and shear forces atwhich it automatically separates. The tightness of the self-closing shut-off valves after separation is to be checked.

4.3.2 The break-away or the ERC are to be subjected to atype test to confirm the release performance under ice builtup condition.

4.3.3 When applicable, the ERC is to be subjected to a typetest to confirm the automatic release in case of activation.

4.4 Workshop testing

4.4.1 Pressure testThe break-away or the ERC are to be subjected to a hydrau-lic pressure test, at ambient temperature, to a pressure notless than 1,5 times the design pressure, to demonstrate thatthe break-away or the ERC are capable of withstanding itspressure without leaking.

5 Electrical isolation flanges

5.1 General

5.1.1 Each insulation flange is to be subjected to a test ofelectrical resistance in air and the resistance is to be not lessthan 10 000Ω.


NR 620, Sec 4

5.1.2 The resistance of each insulation flange is to be meas-ured after installation in the complete LNG transfer systemand the resistance is to be not less than 1000Ω.

6 Supports

6.1 General

6.1.1 Hoses are to be suitably supported in such a way thatthe allowable bending radius is satisfied. They should nor-mally not lay directly on the ground. They are to bearranged with enough slack to allow for all possible move-ments between the receiving ship and the bunkering ship.

6.2 Transfer arm

6.2.1 When applicable, the maximum allowable operatingamplitude for the system is to be defined and hose handlingarm shall be approved by the Society.

7 Swivels

7.1 General

7.1.1 Pressure swivels

The pressure parts of a pressure swivel are to be designedand manufactured according to the requirements of Pt C,Ch 1, Sec 3 of the Ship Rules or other recognised pressurevessel code.

A pressure swivel is to be isolated from the structural loadsdue to the connection with the receiving ship.

Means are to be provided to collect and safely dispose ofliquid leaks.

7.1.2 Static resistance test

Pressure swivels are to be subjected to a pressure resistancestatic test, according to its design code.

7.1.3 Dynamic test

Rotation and oscillation test including rest periods are to beperformed at design pressure with measurement of startingand running moments.

At least two complete rotations, or equivalent, in eachdirection are to be performed.

8 Auxiliary equipement

8.1 General

8.1.1 The auxiliary equipement, as defined in Sec 1, [2.2.1]are to be in accordance with Ship Rules.

9 LNG transfer system

9.1 General

9.1.1 The requirements [9.2.1] and [9.2.2] apply to com-plete LNG transfer systems including additional safetydevices such as dry break-away coupling/self-sealing quickrelease, ERC, swivels, etc. (i.e: all parts which are after thebunkering manifold).

9.2 Testing of the complete system

9.2.1 Pressure test

The LNG transfer system is to be subjected to a hydraulicpressure test, at ambient temperature, to a pressure not lessthan 1,5 times the nominal pressure, to demonstrate that thehose assembly is capable of withstanding its pressure with-out leaking.

9.2.2 Inspection of welds

When applicable, the welds of the LNG transfer systemwith connections systems are to be subjected to a non-destructive examination (NDE) test and all butt welds of theLNG transfer system with connections systems are to besubjected to a 100% radiography examination.

10 Bunkering transfer rate

10.1 General

10.1.1 The bunkering transfer rate is to be kept within thecapabilities of the receiving ship.

10.1.2 The maximum LNG transfer rate is to be justified,taking into consideration:

• The management of the BOG generated during bunker-ing operation

• The temperature of the LNG supplied to the ship

• Characteristics of the receiving tank

• The maximum flow permitted by the ERC

• The maximum flow permitted by the hose

• The maximum flow permitted by the QCDC.

10.1.3 The LNG velocity in the piping system is not toexceed 10m/s in order to avoid the generation of static elec-tricity and to limit the heat transfer due to friction inside thepipes.

10.2 Sampling

10.2.1 Connections for taking LNG samples are to be inaccordance with IGC Code and Ship Rules.


NR 620, Sec 4

11 Arrangement for draining the LNG transfer lines

11.1 General

11.1.1 In order to prevent cryogenic liquid spills, thedesign of the transfer system is to be such that the lines canbe drained before disconnection and purged after an emer-gency disconnection.

12 Compatibility between receiving ship and bunkering ship

12.1 General

12.1.1 The ship working limits of bunkering are to bechecked with regards to at least the following aspects:

• Draught and freeboard difference between the receivingship and the LNG bunkering ship

• Compatibility of the bunkering arm or hose operatingamplitude with the bunkering station location

• Pressure and temperature difference between the LNGtanks of receiving ship and bunkering ship

• Vapour management

• Vapour return line (pressure and temperature)

• Delivery flow rate (maximum and minimum)

• Type and size of hose connections systems.

• Compatibility of the ESD link

• Mooring arrangement.


NR 620, Sec 5


SECTION 5 INERT GAS SYSTEMS

1 General

1.1 Application

1.1.1 This Section covers the inert gas systems for purgingthe bunkering lines.

1.2 Requirements

1.2.1 The inert gas systems are to be in accordance withthe requirements 9.5 of the IGC Code.

1.2.2 The inerting capacity is to be designed according thebunkering operations and it is not to be less than 5 times thevolume of the hose and pipes to be purged.

NR 620, Sec 6

SECTION 6 ELECTRICAL INSTALLATIONS AND INSTRUMENTATION

1 General

1.1 Application

1.1.1 The requirements of IGC Code, as amended, relatingto electrical installations are to be complied with.

The present Section includes additional requirements andinterpretations of IGC Code, which are to be consideredmandatory for class.

1.1.2 In case of conflict between this Section and IGCCode, the Society is to be consulted for clarification.

1.2 System of supply

1.2.1 Acceptable systems of supply

The following systems of generation and distribution of

electrical energy are acceptable:

a) direct current:

• two-wire insulated

b) alternating current:

• single-phase, two-wire insulated

• three-phase, three-wire insulated.

In insulated distribution systems, no current carrying part isto be earthed, other than:

a) through an insulation level monitoring device

b) through components used for the suppression of inter-ference in radio circuits.

1.2.2 Earthed system with hull return

Earthed systems with hull return are not permitted, with thefollowing exceptions to the satisfaction of the Society:

a) impressed current cathodic protective systems

b) limited and locally earthed systems, such as starting andignition systems of internal combustion engines, pro-vided that any possible resulting current does not flowdirectly through any hazardous area

c) insulation level monitoring devices, provided that thecirculation current of the device does not exceed 30 mAunder the most unfavourable conditions.

1.2.3 Earthed system without hull return

Earthed systems without hull return are not permitted, withthe following exceptions:

a) earthed intrinsically safe circuits and the following othersystems to the satisfaction of the Society

b) power supplies, control circuits and instrumentation cir-cuits in non-hazardous areas where technical or safetyreasons preclude the use of a system with no connec-tion to earth, provided the current in the hull is limitedto not more than 5 A in both normal and fault condi-tions, or

c) limited and locally earthed systems, such as power dis-tribution systems in galleys and laundries to be fedthrough isolating transformers with the secondary wind-ings earthed, provided that any possible resulting hullcurrent does not flow directly through any hazardousarea, or

d) alternating current power networks of 1,000 V rootmean square (line to line) and over, provided that anypossible resulting current does not flow directly throughany hazardous area; to this end, if the distribution sys-tem is extended to areas remote from the machineryspace, isolating transformers or other adequate meansare to be provided.

2 Earth detection

2.1 Monitoring of circuits in hazardous areas

2.1.1 The devices intended to continuously monitor theinsulation level of all distribution systems are also to moni-tor all circuits, other than intrinsically safe circuits, con-nected to apparatus in hazardous areas or passing throughsuch areas.

An audible and visual alarm is to be given, at a mannedposition, in the event of an abnormally low level of insula-tion.

3 Gas detection

3.1 Gas detection in enclosed spaces

3.1.1 Permanently installed gas detectors are to be fitted inall hazardous areas including bunkering station, bunkeringprocess room and other enclosed spaces containing gaspiping or other equipment without ducting.


NR 620, Sec 6

3.1.2 The number of detectors in each space is to be con-sidered taking into account the size, layout and ventilationof the space. At least two independent gas detectors arerequired in each hazardous area.

3.1.3 The detection equipment is to be located where gasmay accumulate and in the ventilation outlets. Gas disper-sion analysis or a physical smoke test is to be used to findthe best arrangement.

3.1.4 An audible and visual alarm is to be activated beforethe vapour concentration reaches 30% of the lower explo-sive limit (LEL).

3.1.5 Audible and visual alarms from the gas detectionequipment are to be located on the bridge and in the bun-kering control room.

3.2 Gas detection in open areas

3.2.1 Permanently installed thermal imaging camera are tobe fitted for the following hazardous areas when located onopen areas:• Bunkering station• Bunkering process systems.

Monitoring of thermal imaging camera is to be possiblefrom a safe location with regards to bunkering operationsand with a permanent observation during transfer opera-tions.

4 Emergency shut-down systems (ESD)

4.1

4.1.1 All electrical components of the ESD systems are tobe of suitable safe type.


NR 620, Sec 7


SECTION 7 AUTOMATION SYSTEMS

1 General

1.1 Application

1.1.1 This section provides requirements for the automa-tion systems of the LNG transfer system.

1.2 Emergency shut-down systems (ESD)

1.2.1 The design of the ESD systems is to take into accountthe possible excessive bunkering ship (or receiving ship)motions.

1.2.2 Any activation of the ESD systems is to be imple-mented simultaneously on both bunkering facility andreceiving ship. The timing sequence is to ensure that theinvolved pumps and vapour return compressors (if any) stopbefore the closure of any manifold valves.

1.2.3 The bunkering line is to be designed and arranged towithstand the surge pressure that may result from the activa-tion of the emergency release coupling and quick closing ofESD valves. If not demonstrated to be required at a highervalue due to pressure surge considerations, a default time of5 seconds from the trigger of the alarm to full closure of theESD valves is to be adjusted, in accordance with IGF Code.

1.2.4 At least one local manual activation position for theESD system is to be at a safe distance from the manifold andis to have a clear view of the manifold area.

1.2.5 Any pipeline or component containing liquid, whichmay be isolated due to the ESD activation, shall be providedwith pressure relief valve.

1.3 Alarms and safety actions

1.3.1 If the ventilation in closed or semi-enclosed bunker-ing station stops during bunkering operations, a visual andaudible alarm is to be provided at bunkering control loca-tion and the ESD shall be activated.

1.3.2 The alarms and safety function actions required forthe transfer system are given in Tab 1.

1.4 Communication systems

1.4.1 A communication system with back-up is to be pro-vided between the bunkering ship and the receiving ship.This may be achieved by electric, fibre-optic or pneumaticlinks, or a combination of these systems.

1.4.2 Communications are to be maintained between thebunkering ship and the receiving ship at all times during thebunkering operation. In the event that communications can-not be maintained, bunkering is to be stopped and notresumed until communications are restored.

1.4.3 The components of the communication systemlocated in hazardous and safety zones are to be of a suita-ble safe type.

Table 1 : Alarms and safety actions required for the transfer system

Parameters AlarmActivation of the

ESD systemsAutomatic activation of the emergency release coupling

Low pressure in the supply tank X X

Sudden pressure drop at the transfer pump discharge X X

High level in the receiving tank X X

High pressure in the receiving tank X X

LNG leak detection or vapour detection (anywhere) X X

Gas detection around the bunkering lines X X

Manual activation of the emergency release coupling X X

Safe working envelope of the loading arm exceeded X X X

Disconnection of the ERC X X

NR 620, Sec 8


SECTION 8 FIRE SAFETY

1 General

1.1 Application

1.1.1 This section provides requirements for the fire safetysystem in the safety zone.

1.2 Water Spray systems

1.2.1 Water spray systems are to comply with the require-ments of Ship Rules, Pt D, Chapter 9.

1.3 Dry chemical powder

1.3.1 Dry chemical powder fire-extinguishing systems areto comply with the requirements of Ship Rules, Pt D, Chap-ter 9.

2 Fire protection

2.1

2.1.1 When applicable, the bunkering station is to be sepa-rated by class A-60 insulation towards other spaces, exceptfor spaces such as tanks, voids, auxiliary machinery spacesof no fire risk, sanitary and similar spaces where insulationstandard may be reduced to class A-0.

3 Fire extinction

3.1 Water spray systems

3.1.1 The water spray system is to be fitted to protect thebunkering manifold, associated piping installations and thetransfer area.

3.1.2 The system is to be designed to cover all areas asspecified in [3.1.1] with an application rate of 10 l/min/m²for horizontal projected surfaces and 4 l/min/m² for verticalsurfaces.

3.1.3 For the purpose of isolating damage sections, stopvalves are to be fitted at least every 40 m or the system maybe divided into two or more sections with control valveslocated in a safe and readily accessible position not likely tobe cut-off in case of fire.

3.1.4 The capacity of the water spray pump is to be suffi-cient to deliver the required amount of water to the hydrau-lically most demanding area as specified in [3.1.3] in theareas protected.

3.1.5 Remote start of pumps supplying the water spray sys-tem and remote operation of any normally closed valves tothe system is to be located in a readily accessible positionwhich is not likely to be cut off in case of fire in the areasprotected.

3.1.6 The nozzles are to be of an approved full bore typeand they are to be arranged to ensure an effective distribu-tion of water throughout the space being protected.

3.1.7 An equivalent system to the water spray system maybe fitted provided it has been tested.

3.2 Dry chemical powder fire-extinguishing system

3.2.1 In the bunkering station area a permanently installeddry chemical powder extinguishing system is to cover allpossible leak points. The capacity is to be at least 3,5 kg/sfor a maximum of 45 s discharges. The system is to bearranged for easy manual release from a safe location out-side of the protected area.

3.2.2 One portable dry powder extinguisher of at least 5 kgcapacity is to be located near the bunkering station.

NR 620, Sec 9


SECTION 9 ADDITIONAL SERVICE FEATURES

1 Additional service feature RE

1.1 General

1.1.1 Handling systemThe BOG handling system of the LNG bunkering ship is tobe sized to handle the extra vapours generated during thisoperation taking into account the fact that the level in thereceiving cargo tanks is increasing.

1.1.2 Document to be submittedThe following documents are to be submitted to the Societyfor information in addition to the information required inSec 1, [3.1]:• Bunkering procedure for LNG receiving from a gas

fuelled ship.

2 Additional service feature IG-Supply

2.1 General

2.1.1 Piping systemThe lines used for the inert gas are to be independent fromthe liquid and vapour lines used for normal operation.

2.1.2 Document to be submittedThe following documents are to be submitted to the Societyfor review in addition to the information required in Sec 1,[3.1]:• Diagram of the gas freeing system• Procedure for gas freeing.

3 Additional service feature Initial-CD

3.1 General

3.1.1 The bunkering ship is to be capable of handling all orpart of the boil-off gas from receiving ship, in addition to itsown boil-off, generated during the initial cooling downwithout release to the atmosphere. The boil-off gas handlingcapacity of the bunkering ship is to be indicated and justi-fied.

3.1.2 Document to be submittedThe following documents are to be submitted to the Societyfor information in addition to the information required inSec 1, [3.1]:

• Procedure for initial cooling down.

4 Additional service feature BOG

4.1 General

4.1.1 The bunkering ship is to be capable of handling all orpart of the boil-off gas from receiving ship, in addition to itsown boil-off, generated during the LNG bunkering opera-tion without release to the atmosphere. The boil-off gashandling capacity of the bunkering ship is to be indicatedand justified.

4.1.2 Different ways to dispose of the BOG may to be con-sidered:

• liquefaction

• cooling

• utilization by the gas consuming equipment of the ship(e.g. gas or dual-fuel engines or boilers)

• gas combustion unit.

A combination of these means is possible for the BOG andother solutions may be accepted if they are duly justified tothe Society.

4.1.3 Document to be submittedThe following documents are to be submitted to the Societyfor information in addition to the information required inSec 1, [3.1]:

• Bunkering procedure for boil-off gas management.

4.2 Vapour return line

4.2.1 The system is to be operational and capable ofaccepting the maximum vapour flow rate generated at load-ing rate defined by the designer. The maximum vapour flowrate is to be indicated and justified to the Society.

NR 620, App 1

APPENDIX 1 RISK ANALYSIS

1 General

1.1 Purpose of this appendix

1.1.1 The purpose of this Appendix is to define the scope ofthe risk analysis which is required for the LNG transfer sys-tem and the bunkering operation to assess the conse-quences of:

• A failure affecting the concerned systems

• A LNG leakage

• A tank over-pressurization

• ...

1.1.2 Detailed follow-up report of actions and mitigationmeasures taken in response to risk analysis findings is to besubmitted to the society for information.

1.2 Form of the risk analysis

1.2.1 The required analysis can be a HAZOP analysis oranother type of analysis providing equivalent informationfor the LNG transfer system.

1.3 Single failure concept

1.3.1 The required analysis is to be based on the single fail-ure concept, which means that only one failure needs to beconsidered at the same time. Both detectable and non-detectable failures are to be considered. Consequences fail-ures, i.e failures of any component directly caused by a sin-gle failure of another component, are also to be considered.

1.4 Scope of the risk analysis

1.4.1 The scope of the risk analysis is to:

• Identify all the possible failures in the concerned sys-tems which could lead to a loss of assigned function

• Evaluate the consequences

• Identify the failure detection method

• Identify the corrective measures.

The results of the risk analysis are to be documented.

1.4.2 The means of protection to prevent failures are to bedefined.

a) In the system design, such as:

• redundancies

• safety devices, monitoring or alarm provisionswhich permit restricted operation of the system

b) in the system operation, such as:

• initiation of redundancy

• activation of an alternative mode operation.

2 Systems to be analysed

2.1 General

2.1.1 The risk analysis is to be performed at least for thesystems and functions defined in [2.2] to [3.3].

2.2 LNG tranfer system

2.2.1 FunctionThe function of the LNG transfer system is to connect thebunkering ship to the receiving ship and transfer the LNG.

2.3 Gas detection system

2.3.1 DefinitionGas detection systems includes:• The gas detection sensors• The centralized monitoring unit and its power supply• The wiring between the sensors and the centralized

monitoring unit.

2.3.2 FunctionThe function of gas detections systems is to detect any gasleakage by measuring gas concentration in air taking intoaccount the actual air parameters at the measuring point (inparticular air velocity).

2.4 Control monitoring and safety systems

2.4.1 DefinitionControl, monitoring and safety systems include the relevantequipment serving:• LNG transfer systems• Gas detection systems.

3 Unexpected events to be analysed

3.1 LNG leakage

3.1.1 The consequences of a LNG leakage are to be ana-lysed. The following sources of leakage are to be consid-ered:• Leakage of hoses• Leakage within the piping enclosure.

3.2 Risk related to the receiving ship

3.2.1 The risk related to the receiving ship should include,but is not limited to:• Unexpected overpressure on the receiving ship• Unexpected venting on the receiving ship• Unexpected movement of the receiving ship.


NR 620, App 1

3.3 Black-out

3.3.1 The risk analysis referred to in [1.1.1] is also to coverthe consequences of a black-out during the bunkering oper-ation.
