The different types of steel cargo are dealt in various annexes as follows:
Annex 6: Coiled sheet steel stowed on the round side.
Annex 7: Safe stowage and securing of heavy metal products like bars, pipes, rods, plates, wire coils, etc.
Annex 8: Safe stowage and securing of anchor chains
Annex 9: Safe stowage and securing of metal scrap in bulk.
Annex 6 deals only with coiled sheet steel stowed on the round. Vertical stowage is not dealt with because this type of stowage, normally strapped onto wooden grating does not create any special securing problems. These coils are of upto about 5 tonnes.
Normally, a coil of sheet steel, not in the wooden grating, has a gross mass in excess of 10 tonnes. Such coils, when loaded should be given bottom stow and, whenever possible, be stowed in regular tiers from side to side of the ship. Coils should be stowed on dunnage laid athwartships and their axes in the fore and aft direction. The cylindrical heavy objects, like the sheet rolls in this case, strictly speaking, cannot be held in position by any amount of lashings. Unless of course, the wire ropes can take the weight of the cylindrical cargo and relevant shocking loads. Adequate amount of choking may help. Though, if the cargo is loaded from shipside to shipside would actually be effective. Each coil should be stowed against its neighbour. Wedges should be used as stoppers, particularly where there may be possibility of play as shown below.
The coils in any row should normally rest on the two coils below or rest on coil on one side and ship side on the other. The mass of coils on upper tiers lock the coils in the lower tier. Any void space between coils in the topmost tier should be adequately secured. The continuous play caused during the passage is likely to damage the cargo and loosen the lashings.
A large, immovable block of coils is prepared in the hold, with minimum or no play, by lashing them together. This is done by group or Olympic lashings. In case the top tier has bare-wound coils, group-lashing should not be applied due to their fragile nature. In such case, the end row of a top tier should be secured by dunnage and wires, which are to be tightened from side to side, and by additional wires to the bulkhead.
The lashings can be of a conventional type consisting of wire ropes having sufficient tensile strength. It should be possible to re-tighten the lashings during the voyage. Wire lashings should be protected against damage from sharp edges. If there are few coils, or a single coil only, the stow cant be left in the middle of the hold and unsupported. A heavy cylindrical object, free to move is like a live torpedo. These coils should be adequately secured to the side, by placing them in cradles, by wedging, or by shoring and then lashing to prevent transverse and longitudinal movement. Coils carried in containers, railway wagons and road vehicles should be stowed in cradles or specially made beds and should be prevented from moving by adequate securing.
Annex 7 deals with Safe stowage and securing of heavy metal products like bars, pipes, rods, plates, wire coils, etc. The stress concentration over a certain deck area and maximum allowable weight for the compartment must always be considered. Thus, a cargo plan prepared by the shore people must always be checked prior agreeing to the loading plan. The possibility of relocating of a consignment containing heavy cargoes like steel skids etc should always be considered. A very stiff vessel too is not desirable.
A poor securing of steel cargo directly jeopardizes the safety of ship, much more than any other type of cargo. Following recommendations in respect of heavy steel cargoes are worth noting:
The cargo spaces in which heavy metal products are to be stowed should be clean, dry and free from grease and oil. The cargo items should be stowed compactly from one side of the ship to the other leaving no voids between them and using timber blocks between items if necessary. The cargo should be stowed level whenever possible and practicable. The surface of the cargo should be secured as and where required. The shoring should be made of strong, non-splintering wood and adequately sized to withstand the acceleration forces. One shoring should be applied to every frame of the ship but at intervals of not less than 1 m. In the case of thin plates and small parcels, alternate fore-and-aft and athwartships stowage has proved satisfactory. The friction should be increased by using sufficient dry dunnage or other material between the different layers. Pipes, rails, rolled sections, billets, etc., should be stowed in the fore and-aft direction to avoid damage to the sides of the ship if the cargo shifts. The cargo, and especially the topmost layer, can be secured by having other cargo stowed on top of it or lashing by wire, chocking off or similar means.
Whenever heavy metal products are not stowed from side to side of the ship, special care should be taken to secure such stowages adequately. Whenever the surface of the cargo is to be secured, the lashings should be independent of each other, exert vertical pressure on the surface of the cargo, and be so positioned that no part of the cargo is unsecured.
Wire coils should be stowed flat so that each coil rests against an adjacent coil. The coils in successive tiers should be stowed so that each coil overlaps the coils below. Wire coils should be tightly stowed together and substantial securing arrangements should be used. Where voids between coils are unavoidable or where there are voids at the sides or ends of the cargo space, the stow should be adequately secured. When securing wire coils stowed on their sides in several layers like barrels, it is essential to remember that, unless the top layer is secured, the coils lying in the stow can be forced out of the stow by the coils below on account of the ship’s motions. Any probability of initiation of transverse movement should be ruled out. A negligence in ensuring that there is no play between steel skids can cause havoc in a compartment. One must assume a tilt of say 400-500, before feeling happy about the securing.
Annex 8 and 9 deal with Safe stowage and securing of anchor chains; and metal scrap in bulk respectively.
Anchor chains by itself is not of a shifting type cargo owing to its nature of construction. It is like a bulk cargo of reasonable angle of repose. However, owing o its weight and possibility of shift in heavy rolling adequate securing must be done. Chains are usually carried in bundles or in continuous lengths. Provided certain safety measures are followed prior to, during and after stowage, anchor chains may be lowered directly onto the place of stowage in bundles without further handling, or stowed longitudinally either along the ship’s entire cargo space or part thereof. If the cargo plans given in the ship’s documentation contain no specific requirements, the cargo should be distributed over the lower hold. Bundles may also be distributed in tween decks, partly to avoid stiffness but load density must also be considered. Cargo spaces in which chains are stowed should be clean and free from oil and grease. Chains should only be stowed on surfaces which are permanently covered either by wooden ceiling or by sufficient layers of dunnage or other suitable friction-increasing materials. Chains should never be stowed directly on metal surfaces.
Chains in bundles, which are lifted directly onto their place of stowage without further handling, should be left with their lifting wires attached and should preferably be provided with additional wires around the bundles for lashing purposes. It is not necessary to separate layers of chain with friction-increasing material such as dunnage because chain bundles will grip each other. The top layer of chain bundles should be secured to both sides of the ship by suitable lashings. Bundles may be lashed independently or in a group, using the lifting wires. If chains are stowed longitudinally, stowage of each layer of chain should, whenever possible and practicable, commence and terminate close to the ship’s side. Care should be taken to achieve a tight stow. The top layer of each stow should be secured by lashings of adequate strength crossing the stow at suitable intervals and thus holding down the entire stow.
Precautions and hazards in respect of the metal scrap is also discussed in IMSBC Code. Metal scrap is difficult to stow compactly because of its size, shape and mass. Metal scrap such as metal borings, shavings or turnings, etc can be of varying nature. The hazards involved in transporting metal scrap include. It must be treated like a bulk cargo with a reasonable angle of repose but having high unit weight that can cause damage upon shifting. Additionally, the heavy stress on loaded decks and causing a stiffness in stability can be the serious areas of concern. Before loading, the lower battens of the spar ceiling should be protected by substantial dunnage to reduce damage and to prevent heavy and sharp pieces of scrap coming in contact with the ship’s side plating. Air and sounding pipes, and bilge and ballast lines should be duly protected. When loading, care should be taken to ensure that the first loads are not dropped from a height which could damage the tank tops. If light and heavy scrap is to be stowed in the same cargo space, the heavy scrap should be loaded first. Scrap should never be stowed on top of metal turnings, or similar forms of waste metal. Scrap should be compactly and evenly stowed with no voids or unsupported faces of loosely held scrap.
Heavy pieces of scrap, which could cause damage to the side plating or end bulkheads if they were to move, should be overstowed or secured by suitable lashings. The use of shoring is unlikely to be effective because of the nature of the scrap. Guidance from the P & I write ups owing to the rich experience in the specific trade can be of great importance.
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