NVIC 03-77: Code of safe practice for timber deck cargoes

DEPARTMENT OF TRANSPORTATION UNITED STATES COAST GUARD MAILING ADDRESS: U.S. COAST GUARD WASHINGTON, D.C. 20590 PHONE: 202-426-2188 (G-MMT-5/82) NVC 3-77 22 AUG 1977 NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 3-77 Subj: Code of Safe Practice for Ships Carrying Timber Deck Cargoes

Code of Safe Practice for Ships Carrying Timber Deck Cargoes — Purpose: Enclosure (1), "Code of Safe Practice for Ships Carrying Timber Deck Cargoes" was adopted by the Intergovernmental Maritime Consultative Organization on 20 November 1973 and is issued as information and guidance to naval architects, ship operators, marine surveyors, and others involved in the design or operation of vessels carrying timber deck cargoes.

Purpose: Enclosure (1), "Code of Safe Practice for Ships Carrying Timber Deck Cargoes" was adopted by the Intergovernmental Maritime Consultative Organization on 20 November 1973 and is issued as information and guidance to naval architects, ship operators, marine surveyors, and others involved in the design or operation of vessels carrying timber deck cargoes.

Code of Safe Practice for Ships Carrying Timber Deck Cargoes — Discussion. Enclosure (1) does not in any way supersede the requirements contained in 46 CFR 42.25, Special Requirements for Vessels Assigned Timber Freeboards or in 46 CFR 93, Stability for Cargo and Miscellaneous Vessels. Enclosure (1) primarily contains guidance material and the Coast Guard does not intend to implement this Code into regulations. It should be noted, that this Code may apply to U.S. vessels loading timber deck carg

2. Discussion. Enclosure (1) does not in any way supersede the requirements contained in 46 CFR 42.25, Special Requirements for Vessels Assigned Timber Freeboards or in 46 CFR 93, Stability for Cargo and Miscellaneous Vessels. Enclosure (1) primarily contains guidance material and the Coast Guard does not intend to implement this Code into regulations. It should be noted, that this Code may apply to U.S. vessels loading timber deck cargo in ports of countries which have adopted the Code into their national regulations. Encl:

(1) Code of Safe Practice for Ships Carrying Timber Deck Cargoes DIST: (SDL No. 105) A: None B: n(45); c(10); q(6); eg(3); bjp(1) C: em(4); o(2) D: ij(2); l(1) E: o(2); mm(1) F: None *List CG-12 Encl (1) NVC 3-77 22 AUG 1977 INTER-GOVERNMENTAL MARITIME CONSULTATIVE ORGANIZATION Dist: GENERAL A VIII/Res.287 21 December 1973 Original: ENGLISH IMCO RESOLUTION A.287(VIII) adopted on 20 November 1973 CODE OF SAFE PRACTICE FOR SHIPS CARRYING TIMBER DECK CARGOES THE ASSEMBLY, NOTING Article 16(j) of the Convention on the Inter-Governmental Maritime Consultative Organization concerning the functions of the Assembly, BEARING IN MIND Chapter IV of the International Convention on Load Lines, 1966 and Resolutions A.167(ES.IV) and A.206(VII) concerning intact stability for passenger and cargo ships under 100 metres in length, HAVING CONSIDERED the Code of Safe Practice for Ships Carrying Timber Deck Cargoes and the relevant Recommendation of the Maritime Safety Committee included in the Report on its twenty-fifth session, considered by Council at its twenty-eighth session and transmitted to the Assembly, RESOLVES:

(a) to adopt the Code of Safe Practice for Ships Carrying Timber Deck Cargoes, the text of which appears at Annex to this Resolution,

(b) to recommend that governments implement the Code,

(c) to authorize the Maritime Safety Committee to keep the Code up to date by considering and adopting such amendments as may be necessary, REQUESTS the Secretary-General to publish the Code of Safe Practice for Ships Carrying Timber Deck Cargoes together with its Annexes in the four official languages of the Organization for distribution (two copies each) to Member States and to States which participated in the International Conference on Safety of Life at Sea, 1960, and for general sale and to publish revised editions as necessary. ANNEX CODE OF SAFE PRACTICE FOR SHIPS CARRYING TIMBER DECK CARGOES TABLE OF CONTENTS Page SECTIONS 1. SCOPE 2 2. STOWAGE - GENERAL 2

Code of Safe Practice for Ships Carrying Timber Deck Cargoes — LASHINGS - GENERAL 3

LASHINGS - GENERAL 3

Code of Safe Practice for Ships Carrying Timber Deck Cargoes — LASHINGS, TESTING AND CERTIFICATION 3

LASHINGS, TESTING AND CERTIFICATION 3

Code of Safe Practice for Ships Carrying Timber Deck Cargoes — STOWAGE AND SECURING OF LOOSE OR PACKAGED SAWN TIMBER CARGOES 4

STOWAGE AND SECURING OF LOOSE OR PACKAGED SAWN TIMBER CARGOES 4

Code of Safe Practice for Ships Carrying Timber Deck Cargoes — STOWAGE AND SECURING OF LOG CARGOES, PULP WOOD AND PITPROP CARGOES 4

STOWAGE AND SECURING OF LOG CARGOES, PULP WOOD AND PITPROP CARGOES 4

Code of Safe Practice for Ships Carrying Timber Deck Cargoes — STABILITY 4

STABILITY 4

Code of Safe Practice for Ships Carrying Timber Deck Cargoes — COMPACTING OF DECK STOW IN SHELTERED WATERS 4

COMPACTING OF DECK STOW IN SHELTERED WATERS 4

Code of Safe Practice for Ships Carrying Timber Deck Cargoes — HEIGHT OF CARGO 4

HEIGHT OF CARGO 4

Code of Safe Practice for Ships Carrying Timber Deck Cargoes — PROTECTION OF CREW 5

ANNEXES A.

TEXT OF REGULATION 44 OF THE INTERNATIONAL CONVENTION ON LOAD LINES, 1966 5 B.

RECOMMENDATION ON INTACT STABILITY FOR PASSENGER AND CARGO SHIPS UNDER 100 METRES IN LENGTH AS AMENDED WITH RESPECT TO SHIPS CARRYING DECK CARGOES 6 C.

SUGGESTED PRACTICES TO MEET THE PROVISIONS OF THE CODE OF SAFE PRACTICE FOR SHIPS CARRYING TIMBER DECK CARGOES 18 CODE OF SAFE PRACTICE FOR SHIPS CARRYING TIMBER DECK CARGOES Section 1 - SCOPE 1.1 The provisions given hereunder are recommended for all ships of 24 metres (79 feet) or more in length engaged in the carriage of timber deck cargoes. 1.2 Administrations are invited to adopt these recommendations unless they are satisfied that operating experience justifies departure therefrom. 1.3 Nothing in these recommendations shall preclude the application of Regulation 44 of the 1966 Load Line Convention as far as slips with timber loadlines are concerned or any national requirements. 1.4 For the purpose of these recommendations "Timber Deck Cargo" or "Cargo" means a cargo of timber carried on an uncovered part of a freeboard or superstructure deck, which should include logs, sawn timber whether loose or packaged.

Section 2 - STOWAGE - GENERAL 2.1 Openings in the weather deck on which cargo is stowed should be securely closed and battened down.

Ventilators and air pipes should be effectively protected from damage by cargo and the check valves in air pipes should be examined to ascertain that they or similar devices are effective against the entry of sea water. 2.2 The cargo should be compactly stowed and should be chocked, as necessary, for this purpose; it should not interfere in any way with the navigation and necessary work of the ship and should be stowed as level as practicable.

Equipment, devices for remote operation of valves and sounding pipes should be clearly marked and left accessible. 2.3 Steering gear components should be efficiently protected from damage and the arrangements made for steering in the event of a breakdown in the main steering gear should not be obstructed by deck cargo. 2.4 Safe and satisfactory access to the crew's quarters, machinery spaces and all other forward and after parts of the ship used in the necessary working of the ship should be provided at all times.

Cargo in the vicinity of the openings which give access to such parts should be so stowed that the openings can be properly closed and secured against the entry of water. 2.5 Uprights, when required by the nature or height of the timber, should be of adequate strength which should not exceed the strength of the bulwark and the spacing should be suitable for the length and character of timber carried, but should not exceed 3 metres (9.8 feet).

Strong angles or metal sockets or equally efficient means should be used as means should be provided for securing the uprights.

Where suitable, permanent ship's structure may be used as uprights. 2.5.1 The uprights should be of such height as to extend above the outboard top edge of the cargo. 2.5.2 They should preferably be fitted with a locking pin or other arrangement to retain the upright in its housing. 2.5.3 They may be secured by a metal bracket attaching the upright to the top of the ship's bulwark, or a similar arrangement. 2.5.4 As far as is practicable, the stowage should be such that the cargo throughout its full height is in solid contact with each upright. 2.5.5 Each port and starboard pair of uprights should be linked by athwartship lashings, set up taut at the top level of the cargo as possible to give additional strength to these uprights.

The lashings should be in accordance with the recommendations of Section 4.

Section 3 - LASHINGS - GENERAL 3.1 At the completion of loading, a system of overall independent athwartship lashings to the specification given in Section 4 should be set up throughout the entire length of a deck stow.

The spacing between adjacent lashings is given in Section 4 should be set up taut.

The lashings should be in accordance with Sub-Sections 3.2 and 3.3 such that each lashing should pass over cargo lashings should be in the sheer strake, deck stringer plate or other strengthened point, and be shackled to eye plates positioned in the sheer strake, deck stringer plate or other strengthened point, and shackles and brackets or other such points of insufficient strength should not be used for the securing of Stanchions and brackets or other such points of insufficient strength should not be used for the securing of lashings. 3.2 Stretching devices or similar devices for lashing shall be either a turnbuckle or of a type that produces upright by a lever action having a proven mechanical arrangement whereby tightening to the required tension uplifting by a lever action having a proven mechanical arrangement whereby tightening to the required tension uplifting by a lever action and subsequent adjustments can be rapidly effected, each specified device should be so placed in a lashing that it can be safely and efficiently operated when required. 3.3 When such devices are of a portable type, a sufficient number should be carried on board. 3.4 A device capable of quick cargo release, if fitted, should be so designed that it cannot be accidentally released or activated. 3.5 When other devices are substituted for splicing to form an eye in wire rope, they should be sufficient to equal the strength of the splice. 3.6 Lashings should be inspected as required.

Section 4 - LASHINGS, TESTING AND CERTIFICATION 4.1 All testing, marking, and certification of the chains should conform with national regulations. 4.2 In addition to the requirements stated, a visual examination at intervals not exceeding 12 months is recommended. 4.3 Any lashing used in compliance with these Recommendations should withstand an ultimate load of not less than 13600 kg (30,000 lb). 4.4 After testing there should be no treatment applied to chain which would invalidate its test certificate, e.g. galvanizing heat treatment. 4.5 Shackles, stretching devices and all other ancillary components incorporated into a chain or wire rope lashing and its securings should have a minimum ultimate load of 14100 kg (31,000 lb).

Each component lashing and its securings should have a minimum ultimate load of 14100 kg (31,000 lb).

Each component lashing and its securings should have a minimum ultimate load of 14100 kg (31,000 lb).

Each component should be proof loaded to 5600 kg (12,300 lb).

No part should be damaged or permanently deformed after proof loading.

Section 5 - STOWAGE AND SECURING OF LOOSE OR PACKAGED SAWN TIMBER CARGOES 5.1 The timber should be loaded to produce a compact stow with a level surface as far as practicable. 5.2 The spacing of the lashings should be determined by the maximum height of the cargo above the weather deck in the vicinity of the lashing:

(a) for the height of 4 metres (12 feet) and below the spacing should be 3 metres (9.8 feet);

(b) for the height of 6 metres (19.6 feet) and above the spacing should be 1.5 metres (4.9 feet).

(c) at intermediate heights the average spacing should be obtained by linear interpolation. 5.3 When timber is in lengths less than 3.6 metres (11.8 feet) the spacing of the lashings shall be reduced or other suitable provisions made to suit the length of timber. 5.4 The spacing should also be such that the first and the final athwartship lashing of each section of continuous deck stow should be positioned as close as is practicable to the extreme end of the stow.

Section 6 - STOWAGE AND SECURING OF LOG CARGOES, PULP WOOD AND PITPROP CARGOES 6.1 Whenever possible logs should be compactly stowed in a fore and aft direction to give a level or crowned top surface such that each log is adequately restrained from movement when the system of crown top surface such that each log is adequately restrained from movement when the system of securings is in place and set up taut. 6.2 Where uprights are required by the height of the stow they should be fitted to conform with the recommendations of Sub-Section 2.5. 6.3 The stowage of pulp wood and pitprop cargoes on deck should comply with any locally accepted practice which has been shown to be safe so that, at the completion of stowage, the cargo shall be compact, having a level or crowned surface and be secured at least to meet the provisions of this Code. 6.4 When only a part of a total timber deck cargo consists of pulp wood or untow or untow logs, the logs should be stowed and secured separately when practicable, but if the nature and quantity of the remainder of the timber deck cargo is such that the pulp wood or pitprop portion can be compactly stowed and contained within the main stowage, and the lashings required by the main stowage will efficiently restrain the pulp wood or pitprops, then such stowage method should be adopted.

Section 7 - STABILITY 7.1 All ships should be supplied with suitable information on stability which takes into account deck cargo to enable the master of the ship to meet national requirements. 7.2 Where no national requirements exist, information on stability should be supplied in accordance with the Annex to IMCO Assembly Resolution A.167(ES.IV) as amended by Resolution A.206(VII) (see Annex B). 7.3 The master should establish or verify the stability of his vessel for the worst service condition having regard to the increased weight of deck cargo due to water absorption and/or ice accretion and to variations in consumables.

It should be kept in mind that excessive stability might cause more severe force on the lashings in heavy seas.

Section 8 - COMPACTING OF DECK STOW IN SHELTERED WATERS 8.1 At the completion of loading and securing, all tightening devices fitted into the lashings should, after the initial tightening, be left with not less than half the threaded length of screw, or of tightening capacity, to be available for future tightening. 8.2 All vessels should, before leaving sheltered areas, allow time for additional tightening, as necessary, of all lashings by the crew prior to entering the open sea and an entry made in the ship's log-book.

Section 9 - HEIGHT OF CARGO 9.1 On a ship within a seasonal winter zone in winter, the mean height of the cargo above the weather deck should not exceed one-third of the extreme breadth of the ship.

For the purpose of this Sub-Section, the "weather deck" means the uppermost complete deck exposed to weather and sea, a deck which is stepped being taken to consist of the lowest line of the deck and the continuation of that line parallel to the upper part of the deck. 9.2 The height of the deck cargo should be so controlled that its weight does not exceed the designed maximum permissible load on weather decks and hatches. 9.3 Masters should be provided with such information as to comply with Sub-Section 9.2. 9.4 The height of the deck cargo should be restricted so that:

(i) visibility from the navigation bridge is not impaired;

(ii) any forward facing profile of the deck stow does not present overhanging shoulders to a head sea. Section 10 - PROTECTION OF CREW 10.1 A satisfactory and safe means of access to crew's quarters, and all parts used in the necessary working of the ship should be provided. This may take the form of guard lines or rails on each side of the deck cargo not more than 25 centimetres (13 inches) apart vertically and to a height of at least 1 metre (3 feet) above the walking surface. In addition a lifeline, preferably wire rope with a stretching device, set up taut situated as near as practicable to the centreline of the ship, should be provided. The stanchion supports to all guard rails and lifelines should be spaced so as to prevent undue sagging. Where the cargo is uneven a safe walking surface of not less than 60 centimetres (2 feet) width should be fitted over the cargo and effectively secured beneath or adjacent to the lifeline. 10.2 Fencing or closing should be provided for all openings in the stow such as masthouses, winches, etc. 10.3 Alternative to the provisions of Sub-Sections 10.1 and 10.2, or where uprights are not fitted, a walkway of substantial construction should be provided having an even walking surface and consisting of two fore and aft sets of guard wires or rails about 1 metre apart, each having a minimum of three courses of wires or rails to a height of not less than 1 metre (3.3 feet) above the walking surface. The lowest course should not exceed 23 centimetres (9 inches) above the walking surface and the other courses should be not more than 38 centimetres (15 inches) apart. Such guard wires or rails should be supported by rigid stanchions spaced not more than 3 metres (9.8 feet) apart and wire should be set up taut by stretching screws. 10.4 Properly constructed ladders or steps fitted with guard wires or handrails should be provided:

(a) from the top of the cargo to the deck; and

(b) where the cargo is stepped more than 68 centimetres (27 inches). ANNEX A TEXT OF REGULATION 44 OF THE INTERNATIONAL CONVENTION ON LOAD LINES, 1966 "Stowage General

(1) Openings in the weather deck over which cargo is stowed shall be securely closed and battened down. The ventilators shall be efficiently protected.

(2) Timber deck cargo shall extend over at least the entire available length which is the total length of the well or wells between superstructures. Where there is no limiting superstructure at the after end, the timber shall be stowed as far as practicable in the whole between superstructures. Where there is no limiting superstructure at the after end, the timber shall be stowed as far as practicable in the whole between the standard height of the superstructure.

(3) On a ship within a seasonal winter zone in winter, the height of the deck cargo above the weather deck shall not exceed one-third of the extreme breadth of the ship.

(4) The timber deck cargo shall be compactly stowed, lashed and secured. It shall not interfere in any way with the navigation and necessary work of the ship. Uprights

(5) Uprights, when required by the nature of the timber, shall be of adequate strength considering the breadth of the ship; the spacing shall be suitable for the length and character of timber carried, but shall not exceed 3 metres (9.8 feet). Strong angles or metal sockets or equally efficient means shall be provided for securing the uprights. Lashings

(6) Timber deck cargo shall be efficiently secured throughout its length by independent overall lashings spaced not more than 3 metres (9.8 feet) apart. Eye plates for these lashings shall be efficiently attached to the sheer strake or to the deck stringer plate at intervals of not more than 3 metres (9.8 feet). The distance from an end bulkhead of a superstructure to the first eye plate shall be not more than 2 metres (6.6 feet). Eye plates and lashings shall be provided 0.6 metre (2¾ inches) and 1.5 metres (4.9 feet) from the ends of timber deck cargoes where there is no bulkhead.

(7) Lashings shall be not less than 19 millimetres (¾ inch) close link chain or flexible wire rope of equivalent strength, fitted with shackles and turnbuckles, which shall be accessible at all times. Wire rope lashings shall have a short length of long link chain to permit the length of lashings to be regulated.

(8) When timber is in lengths less than 3.6 metres (11.8 feet) the spacing of the lashings shall be reduced or other suitable provisions made to suit the length of timber.

(9) All fittings required for securing the lashings shall be of strength corresponding to the strength of the lashings. Stability

(10) Provision shall be made for a safe margin of stability at all stages of the voyage, regard being given to additions of weight such as those due to absorption of water and icing and to losses of weight such as those due to consumption of fuel and stores. Protection of Crew, Access to Machinery Spaces, etc.

(11) In addition to the requirements of Regulation 25(5) of this Annex guard rails or lifelines spaced not more than 33 centimetres (13 inches) apart vertically shall be provided on each side of the deck cargo to a height of at least 1 metre (39½ inches) above the cargo. Steering Arrangements

(12) Steering arrangements shall be effectively protected from damage by cargo and, as far as practicable, shall be accessible. Efficient provision shall be made for steering in the event of a breakdown in the main steering arrangements." ANNEX B

(This Annex and its Appendices I to IV reproduce the text of the Recommendation on Intact Stability for Passenger and Cargo Ships under 100 Metres in Length, adopted by the 4th Extraordinary Session of the IMCO Assembly (Resolution A.167(ES.IV)), as amended with respect to ships carrying deck cargoes by Resolution A.206(VII), adopted by the 7th Ordinary Session of the IMCO Assembly.) RECOMMENDATION ON INTACT STABILITY FOR PASSENGER AND CARGO SHIPS UNDER 100 METRES IN LENGTH AS AMENDED WITH RESPECT TO SHIPS CARRYING DECK CARGOES 1.

SCOPE 1.1 The provisions given hereunder are recommended for new decked sea-going passenger and cargo ships (other than fishing vessels*) under 100 metres in length. * A separate recommendation is issued for fishing vessels. 1.2 Administrations are invited to adopt, for all conditions of loading, the stability criteria given in paragraph 5 unless they are satisfied that operating experience justifies departures therefrom. 2.

GENERAL PRECAUTIONS AGAINST CAPSIZING 2.1 Compliance with the stability criteria does not ensure immunity against capsizing regardless of the circumstances.

Masters should therefore exercise prudence and good seamanship having regard to the season of the year, weather forecasts and the navigational zone and should take the appropriate action as to speed and course warranted by the prevailing circumstances. 2.2 Care should be taken that the cargo allocated to the ship is capable of being stowed and secured properly.

If necessary the amount should be limited to the extent that ballast weight may be required.

If necessary the amount should be limited to the extent that ballast weight may be required. 2.3 Before a voyage commences care should be taken to ensure that the cargo and sizeable pieces of equipment have been properly stowed or lashed so as to minimize the possibility of both longitudinal and lateral shifting while at sea, under the effect of acceleration caused by rolling and pitching. 3.

CALCULATION OF STABILITY CURVES The methods and procedures employed for calculating stability righting arms should be in accordance with Appendix I and the degree of accuracy obtained should be acceptable to the Administration. 4.

ASSESSMENT OF COMPLIANCE WITH CRITERIA 4.1 For the purpose of assessing in general whether the criteria are met, stability curves should be drawn for the main loading conditions intended by the owner in respect of the ship's operations. 4.2 If the owner does not supply sufficiently detailed information regarding such loading conditions, calculations should be made for the standard conditions given in Appendix II. 4.3 In all cases calculations should be based on the assumptions shown in Appendix II. 5.

RECOMMENDED CRITERIA 5.1 The following criteria are recommended for passenger and cargo ships:

(a) The area under the righting lever curve (GZ curve) should not be less than 0.055 metre-radians up to θ = 30° angle of heel and not less than 0.09 metre-radians up to θ = 40° or the angle of flooding θf, if this angle is less than 40°. Additionally, the area under the righting lever curve (GZ curve) between the angles of heel of 30° and 40° or between 30° and θf, if this angle is less than 40°, should not be less than 0.03 metre-radians.

(b) The righting lever GZ should be at least 0.20 m at an angle of heel equal to or greater than 30°.

(c) The maximum righting arm should occur at an angle of heel preferably exceeding 30° but not less than 25°.

(d) The initial metacentric height GM₀ should not be less than 0.15 m. 5.2 For ships loaded with timber deck cargoes and provided that the cargo extends longitudinally between superstructures** transversely for the full beam of ship after due allowance for a rounded gunwale not exceeding 4 per cent of the breadth of the ship and/or securing the supporting uprights and which remains securely fixed at large angle of heel, an Administration may apply the following criteria in substitution for criteria given in 5.1 above:

(a) The area under the righting lever (GZ curve) should not be less than 0.08 metre-radians up to θ = 40° or the angle of flooding if this angle is less than 40°. ** θf is an angle of heel at which openings in the hull, superstructures or deckhouses which cannot be closed weathertight immerse. In applying this criterion, small openings through which progressive flooding cannot take place need not be considered as open. ** Where there is no limiting superstructure at the after end, the timber deck cargo shall extend at least to the after end of the aftermost hatchway).

(b) The maximum value of the righting lever (GZ) should be at least 0.25 m.

(c) At all times during a voyage the metacentric height GMₒ should be positive after correction for the free surface effects of liquid in tanks and, where appropriate, the absorption of water by the deck cargo and/or ice accretion on the exposed surfaces. Additionally, in the departure condition the metacentric height should not be less than 0.10 m. 5.3 The following additional criteria are recommended for passenger ships:

(a) The angle of heel on account of crowding of passengers to one side as defined in Appendix II 2(11) should not exceed 10°.

(b) The angle of heel on account of turning should not exceed 10° when calculated using the following formula: MR = 0.02 v₀²/L Δ(KG - d/2) Where MR = heeling moment in metre-tons.

V₀ = service speed in m/sec.

L = length of ship at waterline in m. Δ = displacement in metric tons. d = mean draught in m.

KG = height of centre of gravity above keel in m. 5.4 The criteria mentioned in 5.1, 5.2 and 5.3 fix minimum values, but no maximum values are recommended.

It is advisable to avoid excessive values, since these might lead to acceleration forces which could be prejudicial to the ship, its complement, its equipment and to the safe carriage of the cargo. 5.5 Where anti-rolling devices are installed in a ship the Administration should be satisfied that the above criteria can be maintained when the devices are in operation. 5.6 A number of influences such as beam wind on ships with large windage area, icing of topsides, water trapped on deck, rolling characteristics, following seas, etc. adversely affect stability and the Administration is advised to take these into account so far as is deemed necessary. 5.7 Regard should be paid to the possible adverse effects on stability where certain bulk cargoes are carried.

In this connection attention should be paid to the Code of Safe Practice for Bulk Cargoes.

Ships carrying grain in bulk should comply with the criteria mentioned in 5.1 in addition to the stability requirements in Chapter VI of the International Convention for the Safety of Life at Sea, 1960. 6.

INCLINING TEST 6.1 When construction is finished, each ship should undergo an inclining test, actual displacement and co-ordinates of the centre of gravity being determined for the light ship condition. 6.2 The Administration may allow the inclining test of an individual ship to be dispensed with, provided basic stability data are available from the inclining test of a sister ship. 7.

STABILITY INFORMATION 7.1 The master of any ship to which the present Recommendation applies should receive information which will enable him to assess with ease and certainty the stability of his ship in different service conditions.

A duplicate of this information should be communicated to the Administration. 7.2 Stability information should comprise:

(i) Stability characteristics of typical loading conditions;

(ii) Information in the form of tables or diagrams which will enable the master to assess the stability of his ship and verify whether it is sufficient in all loading conditions differing from the standard ones. This information should include, in particular, a curve or table giving, as a function of the draughts, the required initial metacentric height GM₀ (or any other stability parameter) which ensures that the stability is in compliance with the criteria given in 5.1 above;

(iii) Information on the proper use of anti-rolling devices if these are installed in the ship;

(iv) Additionally, information enabling the ship's master to determine the initial metacentric height GM₀ by means of rolling test as described in the Annex to the Memorandum to Administrations reproduced at Appendix III would be desirable;

(v) Notes on the corrections to be made to the initial metacentric height GM₀ to take account of free surface liquid effects;

(vi) For ships carrying timber deck cargoes the Administration may deem it necessary that the master be given information setting out the changes in deck cargo from that shown in the loading conditions, when the permeability of the deck cargo is significantly different from 25 per cent.

(vii) For ships carrying timber deck cargoes conditions should be shown indicating the maximum permissible amount of deck cargo having regard to the highest stowage rate likely to be met in service. APPENDIX I CALCULATION OF STABILITY CURVES 1. General

(1) Hydrostatic and stability curves should normally be prepared on a designed trim basis. However, where the operating trim or the form and arrangement of the ship are such that change in trim has an appreciable effect on righting arms, such change in trim should be taken into account.

(2) The calculations should take into account the volume to the upper surface of the deck sheathing. In the case of wood ships the dimensions should be taken to the outside of the hull planking. Superstructures, Deckhouses, etc. which may be taken into account

(3) Enclosed superstructures complying with Regulation 3(10)(b) of the 1966 Load Line Convention may be taken into account.

(4) The second tier of similarly enclosed superstructures may also be taken into account.

(5) Deckhouses on the freeboard deck may be taken into account, provided that they comply with the conditions for enclosed superstructures laid down in Regulation 3(10)(b) of the 1966 Load Line Convention.

(6) Where deckhouses comply with the above conditions, except that no additional exit is provided to a deck above, such deckhouses should not be taken into account; however, any deck openings inside such deckhouses shall be considered as closed where their means of closure comply with the requirements of Regulations 15, 17 or 18 of the 1966 Load Line Convention.

(7) Deckhouses, the doors of which do not comply with the requirements of Regulation 12 of the 1966 Load Line Convention should not be taken into account; however, any deck openings inside the deckhouse are regarded as closed where their means of closure comply with the requirements of Regulations 15, 17 or 18 of the 1966 Load Line Convention.

(8) Deckhouses on decks above the freeboard deck should not be taken into account, but openings within them may be regarded as closed.

(9) Superstructures and deckhouses not regarded as enclosed can, however, be taken into account in stability calculations up to the angle at which their openings are flooded. (At this angle, the statical stability curve should show one or more steps, and in subsequent computations the flooded space should be considered non-existent.)

(10) In cases where the ship would sink due to flooding through any openings, the stability curve should be cut short at the corresponding angle of flooding and the ship should be considered to have entirely lost her stability.

(11) Small openings such as those for passing wires or chains, tackle and anchors, and also holes of scuppers, discharge and sanitary pipes should not be considered as open if they submerge at an angle of inclination more than 30°. If they submerge at an angle of 30° or less, these openings should be assumed open if the Administration considers this to be a source of significant flooding.

(12) Trunks may be taken into account. Hatchways may also be taken into account having regard to the effectiveness of their closures. 3. Effect of Liquid