Deck cargo handling technics - general cargo ship procedure

Deck cargo handling technics - general cargo ship procedure

Deck cargo

A large variety of goods, because of their inherent properties (length, height, weight, etc.) may be carried on deck. "On deck" means an uncovered space and includes deck houses having doors which can be continuously open (except in heavy weather). Deck houses and mast houses may be considered suitable for either on or under deck stowage, depending on their structure and closing arrangements.

Deck cargo

Bills of lading for cargo carried on deck must be claused accordingly and suitable provision made for the securing of the cargo. It is prudent for the Master to check the bill of lading to establish under which cargo convention the goods are being carried.

Goods often carried on deck include: Dangerous Goods (e.g. compressed gases, flammable liquids, substances giving off inflammable vapours, corrosive substances) for which on deck stowage is prescribed in the IMDG Code; heavy logs, sleepers, props, sawn timber exceeding that which can be stowed under deck as per charter-party ; long structural steel and other forms of steel, heavy bridge girders or sections, pipes; heavy unpacked machinery and vehicles, boilers and pontoons; crated machinery; small vessels; etc.

When planning a deck cargo the following points need consideration:

a. the weight of individual pieces and the total weight of the cargo, its location and distribution on the deck;
b. the strength of the deck (by reference to the point loading or maximum permissible weight expressed in tonnes per square metre from the ship's plans) and consequent consideration of the necessity for any underdeck shoring;
c. the stability of the ship at the time of loading or discharging a particular heavy lift.

While deck cargo is usually carried at shipper's risk, liability for loss or damage may rest with the ship in certain circumstances, e.g. if due diligence and practical measures are not observed in securing and preserving the cargo or the stowage is negligent or improper, such as by overstowing weak packages with heavier goods.

Precautions

Dangerous Goods carried on deck must comply with the IMDG Code in all respects and the packaging should not exceed a size or weight that can be conveniently handled should the necessity arise to jettison that cargo. Containers laden with Dangerous Goods that are particularly sensitive and could require jettisoning in extreme circumstances, should be stowed at deck level so that access to them is clear and doors or other fastenings can be opened readily.

Deck cargo must be stowed so that it does not obstruct access to the steering gear, life saving or fire fighting equipment, sounding pipes, pilot ladder access, etc. Additionally, properly constructed and protected means of access for safe movement about the ship must be provided for the crew over or through deck cargo.

Securing

Additional ring bolts and eye plates may be necessary to facilitate the securing of deck cargo and they should be welded to the deck, bulwarks, coamings or hatch cover and closely spaced. Chocks or beds on which packages are to rest should be positioned over beams. When particularly heavy items are carried on deck they should, if possible, be placed so that the heavy part is over an underdeck bulkhead. If necessary, deck beams should be given additional support by shores placed under the beams in the `tween deck.

Dunnage under heavy cargo should be of sufficient size and appropriate material to adequately distribute the weight, and spread diagonally over the deck (at an angle of 45°) to avoid depressing deck plating between frames.

Timber deck cargo

As laid down in SOLAS Chapter II-1, timber deck cargo is subject to the provisions of the IMO Code of Safe Practice for Ships Carrying Timber Deck Cargoes, 1991, where timber is defined as lumber, cants (logs which are ripped lengthwise resulting in thick pieces with two opposing, parallel flat sides), logs, poles, pulpwood and other types of timber in loose or packaged form. It does not include wood pulp or similar cargo. A timber deck cargo is defined as a cargo of timber which is carried on an uncovered part of a freeboard or superstructure deck. Ships that comply with certain construction requirements set out in the International Convention on Load Lines may have a timber load line assigned which may be used when the cargo is stowed and secured in compliance with the Timber Deck Cargo Code.

Prior to loading a timber deck cargo, reference should be made to the Code which lays down specific requirements for the stability of the ship, as well as the stowage and securing of the cargo. Requirements are also given for the protection and safety of personnel, the actions to be taken during the voyage (including action in case of listing, water ingress and taking an angle of loll), together with advice on stowage and lashing for the different types of timber that may be loaded.

In addition to the precautions mentioned in the previous section, before loading timber on deck, hatch covers and other openings must be securely closed and battened down, air pipes and ventilators protected and examined to ensure that they are effective against the entry of water. Uprights and lashings should normally be in place before loading begins. The Code specifies the maximum height and extent to which the cargo may be loaded, together with the basic principle of constant supervision to ensure a solid stowage is achieved at all stages of loading, thus providing for safe carriage.

Every lashing must pass over the deck cargo and be shackled to eyeplates attached to the deck stringer plate or other strengthened points. The interval between lashings may vary with the particular cargo loaded. If wire rope clips are used to make a wire eye, not less than four should be used at intervals of at least 15cm. The saddle of the clip must be used on the live load part of the wire and the U-bolt on the shortened end part. Rope clips should be tightened initially so that they visibly penetrate into the wire with subsequent re-tightening after the lashing has been stressed.

Summarized below some more details on general cargo ship cargo handling procedure and operational info:

Cargo handling procedure for general cargo ship

Deck cargo handling technics - general cargo ship procedure

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