ICS ship to ship transfer guide liquefied gases 1995

Table of ContentsFOREWORD III GLOSSARY VII CHAPTER 1 GENERAL PRINCIPLES .7 Manning for Salient Operations 3 CHAPTER 2 CONDITIONS AND REQUIREMENTS 2.5 Night Berthing and Unberthing Opera

Issued jointly by the International Chamber of Shipping Oil Companies International Marine Forum Society of International Gas Tanker and Terminal Operators Ltd

First Published 1980 Reprinted 1993 Second Edition 1995

© International Chamber of Shipping, London Oil Companies International Marine Forum, Bermuda

1980, 1995 ISBN 1 85609 082 5

British Library Cataloguing in Publication Data

International Chamber of Shipping

Oil Companies International Marine Forum

Society of International Gas Tanker and Terminal Operators Ltd

Ship to Ship Transfer Guide (Liquefied Gases)

I Title 2nd Ed

ISBN 1 85609 082 5

The International Chamber of Shipping (ICS) is a voluntary organisation of national shipowners'

associations Established in 1921, it represents more than half of world merchant tonnage The interests of ICS cover all aspects of maritime affairs, but it is particularly active in the field of marine safety, ship design and construction, pollution prevention and maritime law ICS has consultative status with several inter- governmental organisations, including the International Maritime Organization

The Oil Companies International Marine Forum (OCIMF) is a voluntary association of oil companies having

an interest in the shipment and terminalling of crude oil and oil products OCIMF is organised to represent its membership before, and consult with, the International Maritime Organization and other government bodies on matters relating to the shipment and terminalling of crude oil and oil products, including marine pollution and safety

The Society of International Gas Tanker and Terminal Operators (SIGTTO) is a non-profit-making

association dedicated to the protection and promotion of the interests of its members in the safe operation of liquefied gas tankers and liquefied gas loading and receiving terminals The Society was founded in 1979 and was granted consultative status at IMO in November 1983 The Society has over 90 companies in membership who own or operate over 80% of world LNG tankers and terminals and 50% of world LPG tankers and terminals

Notice of Terms of Use

While the advice given in this guide has been developed using the best information currently available, it is intended purely as guidance and to be used at the user's own risk No responsibility is accepted by the International Chamber of Shipping, the Oil Companies International Marine Forum, the Society of International Gas Tanker and Terminal Operators Ltd, or by any person, firm, corporation or organisation who or which has been in any way concerned with the furnishing of information or data, the compilation, publication, or authorised translation, supply or sale of this guide, for the accuracy of any information or data, for the accuracy of any advice given herein or for any omission herefrom or for any consequences whatsoever resulting directly or indirectly from compliance with or adoption of guidance contained herein even if caused

by a failure to exercise reasonable care

Published & Printed by WITHERBY&CO LTD 32/36 Aylesbury Street, London EC1R GET, England Tel No: 0171-251 5341 Fax No: 0171-2511296 International Tel No: +44171251 5341 International Fax No: +441712511296

This guide was first published in 1980 It was based on best industry advice and was well received Since then

it has been used by some governments as the basis for national regulations on Ship-to-Ship (STS) transfer operations covering liquefied gas STS transfer operations have now become routine in many parts of the world and further experience has been built up Accordingly, in this new edition the guide has been substantially updated to reflect current good operating practice The layout has also been improved and greater attention has been given to presenting the advice in a more logical manner

The guide is aimed at providing advice for masters, marine superintendents and others responsible for planning STS transfer operations It is primarily directed to the transfer of liquefied gas between ocean-going ships In general, it is aimed at operations taking place at sea (and therefore often beyond normal port services) However, it will also be of relevance in inshore waters or within harbour limits, although in such cases special regard will have to be taken of local regulations Similarly, the guide does not refer directly to ship movements where one ship may be brought alongside another that is already at a jetty Such operations, sometimes known as double-banking, should be subject to local regulation and will normally be conducted with the full benefit of all port services As before, the guide does not deal specifically with transfers between ships and barges or estuarial craft but can be used as guidance for such operations

The guide does not cover STS transfer operations at offshore production units Here it can be expected that local regulations will be enforced by terminal operators However, the guide may be of benefit to operators

of such facilities as they formulate their own regulations

By and large, the guide is limited in its scope to STS transfer operations involving Liquefied Petroleum Gas (LPG) and similar cargoes The transfer of Liquefied Natural Gas (LNG) cargoes has not yet become commonplace and, as there are some different procedures to be followed, the transfer of such cargoes should only be considered after the additional risks have been addressed

The guide is not a book of rules It contains recommendations on safety, minimum equipment levels and good operating practices, but it must always be remembered that more stringent international, national or local regulations must take precedence

ICS, OC1MF and SIGTTO always welcome suggestions for improvements which can be considered for

inclusion in future editions Comments may be addressed to these organisations at the following addresses:

International Chamber of Shipping Oil Companies International Marine Forum

12 Carthusian Street 15th Floor, 96 Victoria Street

Table of Contents

FOREWORD III GLOSSARY VII CHAPTER 1 GENERAL PRINCIPLES

.7 Manning for Salient Operations 3

CHAPTER 2 CONDITIONS AND REQUIREMENTS

2.5 Night Berthing and Unberthing Operations 6

CHAPTER 3 SAFETY - GENERAL

CHAPTER 5 OPERATIONAL PREPARATIONS BEFORE MANOEUVRING

5.1 Final Checks on Ship Compatibility 15

CHAPTER 6 MANOEUVRING AND MOORING

6.2 Positioning and Size of Fenders 17 6.3 Mooring Equipment and Preparations 18 6.4 Manoeuvring Alongside with Two Ships Under Power 19 6.5 Manoeuvring Alongside with One Ship Already at Anchor 20 6.6 Nautical Aspects Applicable to Cargo Transfer 20

CHAPTER 7 PROCEDURES ALONGSIDE

7.2 Tending of Fenders and Mooring Lines 23

7.4 Transfer of Personnel Between Ships 24

8.6 Cargo Transfer - General Requirements 26

8.8 Cargo Documentation and Customs Requirements 26 8.9 Operations After Completion of Cargo Transfer 26

11.7 Transfer Operations with a Ship Aground 40

Check List 1 Pre-Fixture Information 44

Check List 2 Before Operations Commence 45

Check List 3 Before Run-in and Mooring 46

APPENDIX 2 Part Reproduction of the International

NON-DEDICATED SHIP

A non-dedicated ship is a sea-going ship which is temporarily equipped to carry out STS transfer operations

on a short term (non-dedicated) basis

SHIP

Throughout this guide the word ship refers to a liquefied gas carrier

SHIP TO SHIP (STS) TRANSFER OPERATION

An STS transfer operation is an operation where liquefied gas is transferred between ocean-going ships moored alongside each other Such operations may take place when one ship is at anchor or when both are either drifting or under power In general, the expression includes the approach manoeuvre, berthing, mooring, unmooring, hose connecting, hose disconnecting and safe procedures for cargo transfer

STS AGENCY

An STS agency is an organisation which can provide services for the safe control of STS operations It can also provide the essential equipment needed such as hoses, fenders and support craft Generally, such agencies are most commonly used for operations involving non-dedicated ships

TRANSFER AT ANCHOR

The expression "transfer at anchor" describes a situation where a cargo transfer of liquefied gas is carried out between ships when they are moored alongside each other and one of the ships is at anchor It is used as an alternative to either under power or drifting transfer

UNDERWAY

By definition under the International Regulations for Preventing Collisions at Sea, a ship when underway is

not at anchor However, she may be either steaming or drifting freely with current and weather

This guide covers ship to ship (STS) transfer operations of liquefied petroleum gases (LPG) Primarily, it is intended to familiarise masters and ship operators with the general principles involved As found necessary, the advice contained in this publication may be supplemented by instructions from individual shipowners (or ship managers) in order that particular aspects of their own procedures can be covered Furthermore, in certain port areas it will be found that local regulations apply These regulations should be followed and where appropriate the recommendations made in these guidelines can be used as additional advice Other parties may also benefit from studying these guidelines Such parties can include ship charterers, gas traders and STS agencies, especially those responsible for organising an STS transfer

The STS transfer of LPG cargoes has become a common practice Experience gained from these regular operations has proved that STS transfer operations can be safe, given compliance with satisfactory procedures and suitable weather and sea conditions

This guide is directly concerned with STS transfer operations undertaken "at sea", and therefore in places which may be beyond the assistance of normal port services As will be seen, the recommendations apply to ocean-going ships when it is intended that they moor alongside each other However, the guide may also be useful as background when establishing rules for transfer operations between ocean-going ships and barges or estuarial craft in inshore waters A further use for the guide can be to provide background advice to companies operating offshore storage or production facilities where direct transfer to ocean-going ships takes place

In addition, the guide may also be of assistance to ships aground and requiring emergency lightening, but in such unique circumstances the procedures adopted may vary from this guidance on a case by case basis The guide is limited to the transfer of LPG (butane and propane), ammonia and propylcnc It excludes products such as ethylcnc and other chemical gases It also excludes STS transfer operations involving LNG (liquefied natural gas) because of their rarity and the specialised equipment required

STS transfer operations arc normally initiated by gas traders They may also be planned where national gas demand has outstripped shore-based storage and in such cases a dedicated ship or an established ship may be used on permanent station as a floating storage facility

When a gas trader has identified a need, he will normally approach the shipping community for assistance in setting up a safe operation

His choice will be limited to an operation involving a dedicated ship, an established ship or a non-dedicated ship In the case of the former he will probably approach a shipowner to set up either a dedicated ship or an established ship arrangement on a time chartered basis and the ship would be equipped accordingly Where the gas trader's need is only occasional, he will probably opt for an operation involving a non-dedicated ship Under these circumstances, he would approach the spot market and seek charterparty approval to carry out STS transfer operations However, to conduct a transfer successfully, the trader will require access to temporary equipment and the necessary expertise It is in this area that STS agencies come into play STS agencies usually have stockpiles of the necessary equipment, methods of moving it to the desired transfer area and STS superintendents available to advise locally on an operation with the aim of ensuring a successful outcome When it comes to the detail of an individual transfer, gas traders often delegate the issuance of voyage instructions concerning STS operations to the STS agency They may also wish the STS agency to complete pre-fixture information (see Check List 1) on their behalf Accordingly, in an operation involving a non-dedicated ship, it will be normal to find an STS agency acting as the shore-based organiser

1.5.1 General

The overall control of an STS transfer operation should be vested in the hands of one individual This is likely to be one of the masters concerned In some special circumstances it may be an STS superintendent

If masters are unfamiliar with, or inexperienced in, STS transfer operations it is recommended that

an STS superintendent be employed to advise them There are specialised STS agencies providing such services on an international basis It should be noted that for cargo operations of a non- dedicated type it is recommended that an STS superintendent always be used

7.5.2 Procedures for Navigation

For ship manoeuvres involving a non-dedicated ship, the master taking overall advisory control must

be mutually agreed between the two ships and this should be clearly established by both masters prior to the start of operations

In an STS transfer operation involving an established ship or a dedicated ship, the master of that ship will normally be expected to have the overall advisory control

For some inshore areas the port authority may require a pilot to be taken In such circumstances the pilot will be in charge of the navigation and piloting but each master will remain in command of his own ship and should ensure that the check lists contained at the end of these guidelines are followed

1.5.3 Responsibility for Cargo Operations

Cargo transfer operations should be carried out in accordance with the requirements of the receiving ship

It is a general recommendation for all cargo transfer operations involving a non-dedicated ship, even those involving coastal ships, that an STS superintendent be employed to advise In such cases, the STS superintendent should be specially selected for his experience in cargo transfers involving liquefied gas

1.5.4 Responsibility for Safety

Throughout an STS transfer operation each master remains responsible for the safety of his own ship, its crew, cargo and equipment, and should not permit safety to be prejudiced by the actions of the other master, regulatory officials or others

STS transfer operations can put additional demands on ships' crews It has to be remembered that not only are personnel required for cargo transfer operations but also to keep a safe navigational or anchor watch Each master should take into consideration the estimated duration of operations to ensure that safe and fatigue-free watchkeeping can be maintained throughout

For the reasons described in this section, transfer operations taking place simultaneously from both sides of a ship are generally discouraged

Masters should ensure that sufficient crew members are available for the intended operations An adequate number of crew will be required from each ship for mooring operations, for hose handling and for derrick or crane control Due regard should also be taken of Section 8.6 where additional manning for the deck watch is recommended during cargo transfer operations

Where an STS transfer operation is to be arranged within national waters, it will be necessary for the organisers to check local regulations and to gain local approval This may require the organiser and shore authority to agree the transfer area to be used and to take into account other requirements Matters pertaining to contingency plans should also be addressed at this stage (see Section 11.3)

When an STS transfer operation is about to begin, the organiser should notify the local authorities and the government agencies concerned This may be done either directly by the organisers or, once local requirements are known, by formally delegating the task to the master of the ship in overall charge

When organisers are planning an STS transfer operation they should ensure that the ships to be used are compatible in design and equipment and that mooring operations, hose handling and communications can be conducted safely and efficiently The initial information to be agreed by the organiser, based on feedback from the two shipowners, and usually prior to charter, is given in Check List 1

Transfer areas may be relatively large or quite small: the space available will dictate the type of manoeuvre

In the case of manoeuvres at sea, where it is intended that both ships are underway, a large transfer area will

be needed to accommodate the necessary manoeuvres A ship approaching another ship at anchor will of course require a much smaller overall area Sometimes this can be within port limits

There should be prior agreement between the two masters about the location of the transfer area and the methods of mooring (and anchoring, if to be used)

Points to be considered by organisers when selecting the transfer area are:

(a) The destinations of the ships concerned to avoid unnecessary deviation

(b) The need to notify and obtain agreement of a coastal authority

(c) The shelter provided from the weather, particularly from sea and swell

(d) Present and forecast weather conditions

(e) Tidal current conditions

(f) Safe distances from off-shore installations

(g) The availability of a safe zone free from small craft

(h) The need for sea-room and water-depth to be sufficient for manoeuvring during berthing and unberthing

(i) Sufficient sea-room should be available to allow for normal drift or steaming distances when cargo transfer operations are to be conducted underway,

(j) Where cargo operations are to be undertaken at anchor, the transfer area should allow a safe anchorage, and the nature of the sea-bed should be taken into account,

(k) The traffic density

The preceding points should also be borne in mind by masters and STS superintendents if it becomes necessary to change the position of the transfer area due to bad weather

It is impracticable to lay down limiting weather conditions under which STS transfer operations can be carried out because much will depend on the effect of the sea and swell on the fenders and the relative rolling movement produced in the participating ships, taking into account their relative freeboards

If cargo transfer is to take place at anchor the combined effect of current and weather conditions on the yawing movements of the anchored ship and the ultimate strain on its anchor cable should be considered All available weather forecasts for the area should be obtained before and during operations

Throughout any berthing operation the visibility should be good enough for safe manoeuvring, taking into account safe navigation and collision avoidance requirements Manoeuvres should only start when both masters (and the STS superintendent) are satisfied that conditions are suitable for mooring and cargo transfer

Berthing and unberthing operations should be conducted during daylight unless the masters concerned are experienced in STS manoeuvring operations

For all STS transfer operations each master remains responsible for the safety of his own ship, its crew, cargo and equipment, and should not permit safety to be prejudiced by the actions of others Each master should ensure that the procedures recommended by this guide are followed and, in addition, that internationally accepted safety standards are maintained In this regard, the three most prominent international safety

manuals in use for cargo handling advice are (a) the International Safety Guide for Oil Tankers and Terminals, (b) the Tanker Safety Guide (Liquefied Gas) and (c) Liquefied Gas Handling Principles on Ships and in Terminals

The overall safety of any STS transfer operation depends on the type and condition of the equipment in use and strict adherence to well documented safety procedures

Check lists (presented in chronological order) for STS transfer operations will be found in the appendices to this guide These should assist organisers and masters to adhere to relevant safety procedures The check lists should be used not only at the time of transfer, but also when organisers are planning an operation (refer

to Check List 1) Adherence to check list procedures will ensure that the most essential aspects of an operation are covered

The basic industry related safety requirements for a transfer operation are similar to those for a normal port

cargo operation as contained in the International Safety Guide for Oil Tankers and Terminals (ISGOTT),

particularly Appendix A (Parts A and C) For convenience, the relevant check list from that guide will be found in Appendix 2 However the following points are emphasised for an STS transfer operation:

3.3.1 Smoking and Naked Lights

Regulations regarding smoking and the use of naked lights should be strictly enforced Warning notices should be displayed and smoking rooms should be designated and clearly marked

3.3.2 Earths on Electrical Switchboards

Earth indicator lights showing on the main switchboard indicate a faulty circuit; such faults should be immediately traced and isolated This is to avoid the risk of arcing - especially in deck areas where hazardous accumulations of gas may be present

3.3.3 Boilers and Diesel Engines

On steamships, in order to avoid hot ash falling onto a ship's decks during cargo transfer, soot- blowing of boilers should be carried out before commencing the approach manoeuvre

The combustion characteristics of diesel engines should be closely monitored

In case of sparking from the funnel, transfer operations must be stopped immediately

3.3.4 Ship to Ship Electrical Currents

3.3.4.1 The Elimination of Electrical Current and Electrostatic Charge in Cargo Hoses

In order to eliminate the potential for incendive arcing between the two ships when presenting the hose string for connection, either:

(a) A single insulating flange should be fitted within each hose string (or at one ship's manifold), or (b) One length of electrically discontinuous hose should be fitted in each hose string

The reasons for this precaution are as follows A ship's hull may obtain a significantly different electrical potential relative to the surrounding sea This usually depends on the amount of cathodic protection being applied to the external hull, and on ships such cathodic protection can be provided

by an impressed current system These systems are automatically controlled and when functioning correctly, will maintain a hull at an electrical potential of between 0.15 and 0.2 volts relative to built-

in reference cells If both ships' systems are working correctly, within the above range, potential differences between the ships will be insignificant If, however, there is an imbalance between the two ships' systems, or if one system is inoperative or the other overworking, then the ship to ship potential difference could be as much as 0.4 volts Such a difference could give rise to incendive arcing if an intermittent low resistance path is made Electrically continuous cargo hose provides such a path Therefore, on cargo hose connection or disconnection, unless precautions are taken, arcing could take place between the hose and manifold flanges This risk is addressed by fitting a single insulating flange, or one length of electrically discontinuous hose, as mentioned above

To prevent localised accumulation of electrostatic charge in a hose, the hose string should be electrically continuous to both ships on either side of the point of insulation This means that when

an insulating flange is used at a ship's manifold, it is essential that it only be used on one ship To do otherwise would leave an insulated hose length between the two ships upon which an electrostatic charge could accumulate (It is also important that, apart from the advice above regarding the need for one length of electrically discontinuous hose, only electrically continuous hose be used throughout each hose string.)

3.3.4.2Other Places where Electrical Arcing may Occur

The probability of each ship having a different electrical potential gives rise to the possibility of electrical currents (and arcing) not only at the cargo manifold but also at other points This section indicates the other areas at risk

All ship to ship mooring lines should be insulated either by using the natural properties of soft mooring lines such as nylon, or by attaching a soft rope tail of nylon (or similar material) to the eye

of each steel wire mooring line Soft rope tails should have a similar safe working load (SWL) to the wires on which they are fitted They should also be of suitable length so that they extend to the outboard side of the ship receiving the mooring

Care should also be taken to avoid low resistance ship to ship electrical contact in the following areas: (a) Non-insulated metallic ladders or gangways between the ships - by the fitting of rubber ends (b) Derrick or crane wire runners and hooks - by careful operation

(c) Unprotected bare wires and chains within fender support nets or cages - by good quality

maintenance

3.3.5 The use of Radio and Satellite Communication Equipment

Transmissions from a ship's main radio station can cause electrical resonance in insulated parts of some ship fittings such as mast-stays and this can cause arcing across deck fittings Similar arcing can occur on ship's radio aerials, especially over the surface of insulators when they have a coating of salt, dirt or water

Therefore, the use of a ship's main radio equipment during cargo operations can be dangerous and transmission should not be permitted during periods when there is the possibility of flammable gas in the region of the aerials or where there is doubt about the effective earthing of stays, derrick equipment and other such fittings

Accordingly, the main radio transmitting aerials on both ships should be earthed (grounded) and neither ship should use this equipment whilst alongside one another When available, satellite communications equipment can be used for communications; however, the risks described below should be taken into account

Satellite communications equipment normally operates at 1.6 GHz and the power levels generated are considered to present few ignition hazards However, this equipment should not be used when flammable gas is in the vicinity of antennae

VHP and UHF communications are of low energy and therefore do not produce the same potential dangers as might be expected from a ship's main radio station Accordingly, such equipment can be used for communication even while ships are together and may also be an alternative to the main radio when within range of a suitable coast station

The hand-held VHP and UHF radios, as used for mooring and cargo operations, should be of intrinsically safe manufacture

3.3.6 The Use of Radar

3.3.6.1 General

The use of radar involves the operation of electrical equipment which is not intrinsically safe Furthermore, and depending on the relative size of the two ships, the radar beam of one ship may at times sweep the cargo deck of the other during cargo transfer operations, and be close enough to create potentially hazardous power densities in areas where flammable gas mixtures could be present Therefore, consultation between masters is advisable before a radar is used during cargo transfer operations

3.3.6.2The Use of 3 cm and 10 cm Radars

Radiation from radars operating at frequencies above 9000 MHz (3 cm) may be considered safe at distances of over 10 metres Accordingly, the radiated power from such radars should not present an ignition hazard provided scanners are correctly sited above the superstructure Thus, radars operating in the 3 cm waveband will normally be safe but should only be used with discretion

At the lower frequencies, as used by 10 cm radars, the possibility of induced arcing in parts of a ship's structure is present at ranges up to 50 metres As a consequence, 10 cm radars should not be used when there is a possibility that a scanner may point directly at or near the cargo deck of the other ship

3.3.7 Gas Accumulation

An STS transfer operation should be suspended if there is risk from cargo vapours around the decks, manifold or vents of either ship It should not be resumed until the cargo leak has been identified and stopped, and all gas has dispersed

The operation of slip-tube apparatus for measuring tank levels on pressurised ships can produce gas evolution on deck but, if operated safely, this practice is normally acceptable

3.3.8 Electrical Storms

When an electrical storm is present or expected in the transfer area, a cargo transfer operation should be suspended

3.3.9 Galley Stoves

Oil or gas fired galley stoves must be extinguished during cargo transfer operations

3.3.10 Readiness of Fire Fighting Equipment

Fire fighting equipment should be ready for immediate use on both ships Dry powder monitors on each ship should be pointed towards the cargo manifold in use and left in a suitable condition for hands-off operation

3.3.11 Accommodation Openings

All access doors to the accommodation should remain closed during cargo transfer operations The master of each ship should designate those access doors that will be used for personnel transit All doors opened for personnel transit should be closed immediately after use

The air conditioning system for the accommodation should be switched to the recirculation mode

3.3.12 Safety Zone Round the Ships

During cargo transfer operations no craft should be allowed alongside either ship or within a pre- agreed exclusion zone set at a safe distance It would be normal to exclude such craft from within a

500 metre range In national waters such restrictions should be possible under port authority approval For operations further off-shore, where jurisdiction is less clear, the subject should be addressed in Navigational Warnings (see Section 4.5) and by proper selection of the transfer area (see Section 2.3)

Good communications between the ships is an essential requirement for successful STS transfer operations The principal recommendations on this subject are addressed below

To avoid any misunderstanding, a common language for communication should be agreed before operations

commence In this connection, attention is drawn to the Standard Marine Communication Phrase, using the

English language, published by the International Maritime Organization (IMO)

•i^Hi^B^M^H^H^^MHI

4.3.1 Non-Dedicated Ships

For operations involving a non-dedicated ship, it is usual for an STS agency to be contracted by gas traders to supply the necessary additional equipment and expertise Normally such agencies send advance voyage instructions to the ships concerned A typical message is appended to this chapter (see Annex 4.1)

4.3.2 Established Ships and Dedicated Ships

For those operations where either an established ship or a dedicated ship is involved it would be normal for the other ship to expect advance advice on the operation, as if arriving at a normal port

The ships should establish initial contact by satellite communications or radio as early as practicable to plan operations and to agree to the transfer area

If the transfer area is outside the jurisdiction of a coastal authority, the master having overall advisory control (see Section 1.5.2) should broadcast a navigational warning to all ships advising:

Name and nationality of the ships involved

Geographical position of operations

Time of starting operations

Nature of operations

Expected duration

Request for wide berth

On completion of the transfer, the master having overall advisory control should cancel the navigational warning

As the ships come into the transfer area, contact should be established on VHP Channel 16 or 72 at the earliest opportunity, thereafter switching to a mutually agreed working channel Approach and mooring should not be attempted until good VHP communication has been confirmed between the two ships At this time, in accordance with the information exchanged, Check Lists 2 and 3 should be satisfactorily completed The same VHP communication must be confirmed before unmooring, at which time Check List 5 should be satisfactorily completed

Ships' officers responsible for mooring stations should be provided with hand-held radios

the International Regulations for Preventing Collisions at Sea

During cargo operations, in the event of a breakdown of communications on either ship, the emergency signal (see Section 11.1) should be sounded and all operations in progress should be suspended immediately

In general, operations should not be resumed until satisfactory communications have been re-established

5.1.1 Communications

Satisfactory communications between the ships should be confirmed by checking:

(a) That both ships are fitted with operational VHP

(b) The VHP frequencies (channels) to be used

(c) Whether it is possible to communicate readily in English; if not, the alternative common

language that is to be used (see also Section 4.2)

If the above checks find a serious communication problem or lack of understanding of the operation among either of the crews, then action should be taken to solve this issue by, for example, transferring an experienced person from one ship to the other, before operations begin

5.1.2 Mooring Checks

The ships should exchange the following information:

(a) The length overall and parallel body length of the ship

(b) The distance from the cargo manifold centre to the stern

(c) Whether the ship's side to be used for mooring the other ship is free of obstructions

(d) The number of enclosed fairleads and mooring bitts and their distance from the bow and the stern on the side of the ship used for berthing In this respect the master having overall advisory control should prepare a sketch of the proposed mooring layout with distances marked thereon

(e) The maximum expected freeboard differential between the two ships

The information requested in (e) above is important for determining the efficiency of mooring lines Pxperience suggests that a problem is likely if the freeboard difference exceeds 10 metres Beyond this distance the vertical orientation of mooring lines is increased such that their efficiency is seriously affected

5.7.3 Cargo Hose Checks

The ship supplying the cargo hose should determine from the other ship:

(a) The diameter and class (ANSI (ASA), DIN etc.) of cargo manifold flange to be used

(b) The anticipated minimum and maximum height of the cargo manifold from the waterline during the transfer operation (This is so that the correct hose length can be determined.) (c) The suitability of the hose for the properties of the cargo, including temperature and pressure (d) Whether the cargo cranes or derricks are in a satisfactory condition and of suitable safe working load (SWL) to handle cargo hose

(e) The adequacy of hose supports, at the ship's side, to ensure that hoses do not chafe and that they are not bent beyond their minimum allowable bending radius

The following preparations should be made by the masters of both ships before manoeuvres begin:

(a) A study of the procedures given in this guide, supplemented by any instructions issued by shipowners

(b) Appropriate checks, such as the testing of essential cargo equipment Procedures of this type

are described in the Tanker Safety Guide (Liquefied Gas) - see Reference 2

(c) Crews fully briefed in procedures and hazards, with particular reference to mooring and

(f) Ship upright (having no list) and at a suitable trim

(g) Cargo manifolds and hose handling gear prepared

(h) Area weather forecasts for the transfer period obtained,

(i) Fenders and mooring equipment checked

5.3./ Check Lists

Check lists are essential reminders of the principal safety factors to be considered They should be supplemented by continuous vigilance throughout the whole operation Operational Safety Check Lists to be used during the various stages of the operation are given in the Appendices

Before mooring operations commence, each ship should confirm with the other that all items on Check Lists 2 and 3 have been checked and found correct

5.3.2 Action in Case of Infringement of Safety

If either ship fails to observe any of the safety requirements at any time during the STS transfer operation, this should be brought to the attention of the master of the ship concerned and operations suspended until the situation is rectified

Mooring during the hours of darkness should only be undertaken by experienced masters or with the assistance of an STS superintendent

It is necessary that adequate lighting is available in the area of the fenders and around the ships' sides (see also Section 6.4.1)

The navigation lights and shapes to be shown, and the sound signals made, during STS transfer operations are

those required by the International Regulations for Preventing Collisions at Sea, and local port regulations

From the start of the approach manoeuvre, each ship should display the appropriate visual signals and should keep them displayed until the operation is completed and the ships have separated

6.1.1 Manoeuvres with Two Ships Under Power

Experience has shown that a successful manoeuvre to achieve a satisfactory berthing operation can

be carried out with both ships making way and, in general, this is the preferred manoeuvre for open waters One ship (the constant-heading ship), normally the larger, maintains steerage way at slow speed on a constant heading, usually with wind and sea from right ahead (as requested by the manoeuvring ship) The smaller ship (the manoeuvring ship) then manoeuvres alongside

It is recommended that the manoeuvring ship approaches and berths with her port side to the starboard side of the constant-heading ship

It is customary to use mooring lines from the manoeuvring ship but it may be necessary to supplement these with lines from the constant-heading ship

6.1.2 Manoeuvres with One Ship at Anchor

In fine weather conditions, equally successful berthing operations can be undertaken while one ship

is already at anchor This manoeuvre can be preferred for more constrained transfer areas, especially when tug assistance is available It is not a difficult operation given a positive current and a steady wind from the same direction Where current and wind are not from the same direction or the wind varies in speed or direction the anchored ship can yaw (or lie cross-current), making it difficult for the manoeuvring ship to berth alongside In these circumstances tug assistance may be advisable to hold the anchored ship on a steady heading during berthing (Tug assistance for the manoeuvring ship is also used at some in-port transfer areas.) Berthing should not be attempted when the tidal stream is due to change

When approaching a ship at anchor some masters recommend a wider angle of approach than that adopted for manoeuvres underway A wider angle of approach, especially when tugs are not available, helps to avoid early ship to ship contact in cases where the anchored ship might yaw unexpectedly It is usually recommended that the manoeuvring ship approaches and berths with her port side to the starboard side of the other ship However, mooring alongside a ship at anchor may

be performed on either side with the aid of tugs and a pilot

It is customary to use mooring lines from the manoeuvring ship but it may be necessary to supplement these with lines from the ship at anchor

6.2.7 Fender Positioning

For dedicated ships, it is probable that they will be fitted with permanent fenders operated by winches and davits These fenders will be positioned at pre-assigned locations along the hull

For established ships, fendering operations will be carried out in accordance with local practice

For non-dedicated ships, it is probable that fendering operations will be carried out with the assistance of an STS agency Such companies usually have service craft available and these tugs will normally tow the fenders into position The fender string may be made up to a pre-arranged length

to suit each ship's parallel body Alternatively, individual fenders will need to be positioned alongside with their towing pennants (see Section 10.1.4)

Fenders can be secured in place on either ship However, it is normally preferable that fenders be secured to the manoeuvring ship (as it is usually the smaller ship) By this means, the number of fenders can be minimised by positioning them to cover the actual areas of ship to ship impact irrespective of where it may occur For some operations involving established ships, fendering of the established ship is commonly practised as an alternative This requires care in design and greater care during manoeuvring

When fenders are fitted to the manoeuvring ship, primary fenders should be positioned one at each end of her parallel body, with similar additional units fitted in between (see Section 10.1) In some operations, where four fenders are used it has been found beneficial to position them in two groups

of two In this way, and with each group positioned well forward or well aft on the parallel body, better protection can be provided in case one fender bursts on impact If necessary, secondary fenders may be positioned fore and aft of the parallel body where ship to ship contact may occur particularly during mooring or unmooring when ships may not be lying parallel to each other

To minimise the possibility of fenders riding onto the deck of either ship, primary fenders should be floating throughout the operation (see Section 10.1) On the other hand, due to the shape of a ship's hull at the ends of the ship, secondary fenders are often hauled up into position close to main-deck level

6.2.2 Size of Fenders

Apart from other considerations, fender size will also be dictated by the freeboard of the ships Fenders that are too big may ride up and roll onto the deck due to ship motion The diameter of each floating fender should be no more than half the minimum freeboard of the smaller ship

The importance of good quality mooring lines, efficient winches and deck machinery should be recognised This is especially true on board the manoeuvring ship whose mooring lines will be used most commonly However, it should also be addressed on the constant-heading ship where rope-messengers have to be made ready between fairleads and deck winches Mooring operations should be managed to ensure expeditious mooring line handling Moorings should be arranged and rigged to allow safe and effective line tending when the ships are secured together

The mooring plan adopted will depend upon the size of each ship and the difference between their sizes As

a general guide the diagram below illustrates a recommended and proven mooring-plan for an STS transfer operation in off shore waters (see also Section 10.3)

It is important when agreeing a mooring plan to ensure the following:

(a) Mooring lines are of sufficient length to avoid overstressing during freeboard changes

(b) Mooring lines are not too long so allowing unacceptable movement between ships

(c) Mooring lines leading in the same direction are of similar material

(d) Mooring lines are not likely to escape from open fairleads

6.4.1 General Advice for Controlling the Two Ships

Each ship should take the following into account:

(a) Engine controls, steering gear and all navigation and communications equipment should be in working order

(b) A proficient helmsman should be assigned to steer each ship

(c) Small changes of course, as requested by the manoeuvring ship, should be followed by the constant-heading ship

(d) Ship's speed should be controlled by adjusting engine revolutions (or propeller pitch) rather than using the relatively coarse engine room telegraph system Engine speed adjustments on the constant-heading ship should only be made at the request of the manoeuvring ship Any adjustment should be limited: for example, to plus or minus 5 rpm

(e) At night the deck should be adequately lit and, if possible, the ship's side and fenders should be spot lighted

(f) The side for mooring should be clear of all over-side obstructions, permanent or otherwise (g) The navigation lights and shapes referred to in Section 5.5 should be displayed

(h) There should be radio (or telephone) contact between the bridge and mooring gangs,

(i) There should be effective VHP communications between the masters of each ship

6.4.2 Detailed Advice for Manoeuvring Alongside

Although individual masters will have their own preference for the method of manoeuvring their ship, the following points are emphasised for STS transfer operations:

(a) The masters of both ships should always be prepared to abort a berthing operation if necessary The decision should be taken in ample time while the situation is still under control The masters of both ships should be immediately informed of each other's actions The sound

signals specified in the International Regulations for Preventing Collisions at Sea must be

complied with

(b) At all times each ship is responsible for keeping its own lookout

(c) Throughout manoeuvring the wind and sea should be ahead or nearly ahead

(d) The angle of approach adopted by the manoeuvring ship should not be excessive

(e) Experience has shown that the best method of berthing is for the manoeuvring ship to approach the constant-heading ship from broad on the quarter on the side of berthing On closer

approach she should parallel the course of the constant-heading ship, about 50 to 100 metres off The manoeuvring ship should then position her cargo manifold in line with that of the constant-heading ship Contact is then made by the manoeuvring ship reducing the distance by appropriate rudder movements until fenders touch

(f) The two ships should make parallel contact at the same speed with no astern engine movements being necessary

(g) The effects of ship interaction should be anticipated when manoeuvring at close quarters Hydrodynamic interaction between ships varies, and knowledge of pressure fields around two ships moving through the water is important For example, the forward motion of the two ships driving the sea between them can push the bows of the ships apart and it is therefore important

to secure the forward breastlines and headlines as soon as possible

(h) It is normal for all mooring lines to be deployed from the manoeuvring ship and for the eyes of these lines to be put on the mooring bitts on the constant-heading ship - but see (i) below (i) Consideration should be given to unmooring procedures when the mooring plan is agreed It is usually recommended that the final mooring lines to be let go (when unmooring) be turned-up

in a figure-of-eight on mooring bitts on the constant-heading ship

(j) If it is intended to use a line throwing gun, the foredeck of the other ship should be cleared of any aerials or similar overhead obstructions A warning should be given by loud hailer before firing, at which time all personnel on the other ship should be abaft the cargo manifold

(k) Strong rope messengers should be readied on the constant-heading ship and, in addition, rope stoppers should be shackled in way of each mooring bitt Weighted heaving lines should be ready for immediate use and, as appropriate, they should be pre-connected to mooring lines (1) When mooring at night, all unnecessary lights should be switched off and visual lookouts

supplemented by a continuous radar watch on one ship (Caution: see Section 3.3.6.)

6.4.3 Manoeuvring a Combined Two-Ship System to Anchor

On completion of mooring, the constant-heading ship will power all future manoeuvres and, if a transfer at anchor is planned, proceed to the agreed anchoring position which should be right ahead and at close distance During this time, the manoeuvring ship will have its engines stopped and rudder amidships or angled towards the constant-heading ship It should be emphasised that, in order to avoid severe problems for the manoeuvring ship, which can be created by stern wash from the propeller, the constant-heading ship should not use strong astern engine movements In fact, at the slow speed under which the berthing manoeuvre is carried out, the ships will tend to lose speed rapidly without the need for strong astern movements

The constant-heading ship should use the anchor on the side opposite that on which the other ship is moored

A summary of anchoring procedures may therefore be given as follows:

(a) From the time the manoeuvring ship is secured alongside to the time the constant-heading ship

is anchored, the latter assumes responsibility for the navigation of the combined "two-ship" system

(b) The manoeuvring ship should be informed of any engine and rudder movements made by the constant-heading ship as she manoeuvres to anchor

(c) Once at anchor, each ship is responsible for keeping its own anchor watch

STS transfer operations involving one ship already positioned at anchor are encountered quite frequently For such operations, one ship anchors in a predetermined position using the anchor on the side opposite that

on which the other ship will moor A berthing operation should only be carried out after the anchoring ship

is brought up to her anchor and is lying on a steady heading with reference to prevailing current and wind conditions When this is achieved, the master of the anchored ship should advise the other master

The type of berthing operation then undertaken by the manoeuvring ship is similar to a normal approach to a jetty However, a careful watch should be kept on the heading of the anchored ship and the manoeuvring ship should be advised immediately by the anchored ship if she has any tendency to yaw Where there is a tendency to yaw excessively, a tug should be employed to hold the anchored ship on a steady heading or the operation postponed (see also Section 6.1.2)

The two principal methods of berthing and mooring have been described above in Sections 6.4 and 6.5 Each method suggests that, for cargo transfer, a transfer at anchor is the preferred solution However, when ships are manoeuvred together under power (Section 6.4), suitable alternatives to anchoring are (a) transfer while making way and (b) drifting transfer, described in Sections 6.6.2 and 6.6.3 respectively For these operations reference should also be made to Section 5.5 regarding navigation lights and shapes

6.6.1 Transfer at Anchor

The nautical aspects of bringing a combined two-ship system to anchor have been covered in Sections 2.3, 3.3.6, 3.3.12 and 6.4.3 These procedures attend to the principal nautical aspects needing to be covered for transfers at anchor

However, attention is again drawn to earlier comments on the need for safe watchkeeping, including anchor and deck watches on both ships

6.6.2 Transfer While Making Way

Local conditions, such as those where water depths are too great for anchoring, sometimes demand that cargo transfer be carried out with the two-ship system under power and making way through the water As long as adequate sea room is available, traffic conditions are suitable, weather and sea conditions and forecasts are satisfactory, then transfers while making way can be carried out, but suitable large diameter fenders should be used

Under such circumstances, while the ships are moored together as a unit, safe navigation and collision avoidance is usually the responsibility of the constant-heading ship (see Section 6.4.3) Transfer while making way requires a full navigational watch to be maintained on the bridge of each ship

When mooring has been completed and the heaving movements of the fenders are acceptable to both masters, hose connecting and cargo operations may commence in the manner indicated in Chapters 7 and 8

For transfers while making way, after completion of mooring (as described in Sections 6.4.1 and 6.4.2) the constant-heading ship, rather than anchoring, maintains steerage way at slow speed on a steady course and the manoeuvring ship keeps its rudder amidships and remains (with engines stopped) as a towed ship If it is necessary to minimize towing loads on the moorings, the constant- heading ship should alter her engine revolutions sparingly, adjusting speed very gradually The chosen course and speed should be agreed by the two masters and should result in minimum relative movement between the two ships and minimum turbulence in the gap between the hulls

Throughout the cargo transfer, close attention should be paid to mooring lines and fenders to avoid chafing and undue stress, particularly that caused by towing loads If at any time mooring lines need

to be re-positioned or adjusted, bearing in mind that the ships are under power, this should only be done under very strictly controlled conditions

6.6.3 Drifting Transfer

As an alternative to transfer at anchor and provided conditions are satisfactory and a transfer area of suitable size is available, it can be advantageous to carry out cargo transfer while the two ships are allowed to drift freely under the effects of the weather

If deteriorating weather conditions are likely to cause the ships to roll unacceptably, by careful use of engine movements, the ships should be brought to a heading which results in minimum movement Constant attention should be paid to mooring lines and fenders to avoid chafing and undue stress, particularly that caused by changes in relative freeboard If at any time mooring lines need to be re- positioned or adjusted, this should only be done under strictly controlled conditions