Onderwerp: Bezoek-historie

667 Containers and Cargoes - Safe practices on board bulk carriers
Geldigheid:22-12-1994 t/m Status: Geldig vandaag

Dit onderwerp bevat de volgende rubrieken.

The Maritime Safety Committee, at its sixty-fourth session (5 to 9 December 1994), agreed that in the interests of promoting safe practices on board bulk carriers, the relevant advice promulgated by the Nautical Institute and the International Federation of Shipmasters' Associations is relevant. The advice, which is reproduced at annex, is circulated to Member Governments for information and action as appropriate.

Annex Safe practices on board bulk carriers

Minimize corrosion within holds by maintaining paint coatings. The areas most liable to suffer from corrosion are the frames and adjoining areas against the ship`s sides, and the transverse bulkheads. These areas are less exposed to scouring by cargo or cargo-handling equipment than are tank tops and lower hopper sides, so paint coatings, if properly applied, can last reasonably well. Paint coatings should be maintained. Holds which have been routinely washed with seawater should, where possible, be given a final rinse with fresh water. Ships which are continuously employed carrying the same corrosive cargo, where holds are not cleaned between cargoes, have a higher risk of corrosion. A procedure of pumping bilges regularly during the voyage will reduce corrosion at tanktop level and within the bilge system, but will not stop corrosion which occurs as a result of sweat. Extra precautions should be taken when the cargoes are corrosive.

Minimize corrosion within ballast tanks by maintaining coatings. The touching up of mechanical damage and local corrosion is suitable work for a ship's crew, but a complete descaling and recoating probably requires shore labour and equipment.

Prevent stevedores' damage by close supervision of the stevedores to prevent bad practices, and by holding them responsible for any damage done.

Prevent hull contact damage by proceeding carefully when berthing, unberthing, manoeuvring and passing through ice.

Report damage, and have it surveyed and properly repaired: Ensure that damage, when found, is reported to owners. All except minor damage should be reported to class and surveyed by a class surveyor. It should be properly repaired by a competent person.

Avoid local overloading: Ensure that maximum permissible hold tonnages are known, and are not exceeded. Do not exceed maximum tanktop loadings. Avoid block loading.

Monitor loading and prevent delivery of excess tonnage to hold. Distribute closeweight cargo evenly over the length of the hold.

Provide accurate, accessible stability information: Ensure that the ship's stability and loading information is readily available, accurate and easy for the officers to use.

Prepare a full loading/deballasting or discharging/ballasting plan: Use The Nautical Institute's form or a similar one and make sure that every stage is within permitted longitudinal bending stress and shear force limits.

Keep strictly to loading/deballasting or discharging/ballasting plan: Accept changes to the plan only when an amended plan has been fully calculated and found to be safe.

Reduce loading rates when starting an empty hold: While the cargo is being poured directly on the tanktop the loading rate should be reduced. Cargoes which can cause damage require special care. The first grabloads of scrap should be lowered close to the tanktop before being released. When pig iron is being loaded the tanktop should be shielded from the first pour by temporary sheathing such as pallets.

Ensure that discharging and ballast changes are planned and executed with the same care as loading: High values of longitudinal bending stresses and shear forces can be reached by unplanned or careless operations. They should be avoided.

Reject cargo with excessively high moisture content: Insist on being provided with a certificate of transportable moisture limit, and follow the guidelines laid down in the Code of Safe Practice for Solid Bulk Cargoes.

Ensure that ship is not twisted whilst loading or changing ballast: Twisting can occur if two loaders do not operate exactly in tandem, or if a single loader distributes cargo unevenly between port and starboard sides. This damage can also be caused by uneven changing of ballast.

Close dump valves immediately deballasting is completed: Ensure damp valves are well maintained and do not leak and have a routine to ensure that they are closed when deballasting is completed.

Trim cargo reasonably level to the boundaries of the cargo space: Cargo should be trimmed in accordance with the Code of Safe Practice for Solid Bulk Cargoes.

Ensure that cargoes such as steel are well secured: Cargo which breaks adrift can damage the ship's structure. Securing should be in accordance with the Code of Safe Practice for Cargo Stowage and Securing.

All hatch covers should be well maintained and carefully secured: The hatch covers must be in sound condition, with a cleating system which is well maintained and correctly operated.

All deck openings should be in sound condition and properly secured: This applies upon sailing, at night, during adverse weather and any time when there is no need for them to be open.

Speed should be substantially reduced in adverse weather: When adverse weather causes a speed reduction of 25% (for example, from 12 knots to 9 knots) with constant engine speed, the rpm should be substantially reduced to avoid damage from forcing the ship into the weather.

Avoid continuous heavy rolling: Heavy rolling results in the repetitive heavy loading (panting) of the side shell plating as the pressure of seawater is applied and removed. Ships are built to withstand this treatment, but can be harmed when rolling is excessive and prolonged.

Sloshing of ballast water in part-filled tanks should not be allowed to occur: As far as possible ballast tanks should be filled or emptied before bad weather is met, this precaution being particularly important in the case of ballast holds and topside ballast tanks, both of which have large open areas which allow sloshing.

Prevent springing by adjustment of course, speed or ballast: Springing, otherwise known as whipping, flexing or wave-excited hull vibration, can be prevented by adjustment of course, speed or ballast. It will disappear with change of loading.

Aboard OBOs follow strict procedures to avoid the possibility of gas explosions: When carrying dry bulk cargoes all compartments, including void spaces, empty ballast tanks, duct keels, pump-rooms, pumps and pipelines must be scrupulously gas freed. Thereafter they must be regularly rechecked for gas to detect any unsuspected gradual build-up.
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