Annex 2 of CSS Code deals with safe stowage and securing of portable tanks.
Annex 3 deals with the safe stowage and securing of portable receptacles.
Annex 4 is about safe stowage and securing of wheel-based (rolling) cargoes.
Annex 5 deals with the safe stowage and securing of heavy cargo items such as locomotives, transformers, etc.
Annex 10 is Safe stowage and securing of flexible intermediate bulk containers.
Annex 11 recommends the safe practices for the under-deck stowage of logs.
Annex 12 recommends the safe practices for carriage of pallet; or pallet box; or
General factors to consider in respect of these cargoes:
- sufficiency of securing devices;
- adequate factor of safety;
- non slippery deck area;
- structural strength of the deck or hatch;
- no load is imposed on the cargo or fittings;
- no blocking of sounding pipes, walk space, etc;
- particularly, if tender or heavy, the distribution of accelerations on the ship should be kept in mind.
- provision for tightening lashings, during voyage;
- prevent weakening through chafing, etc during voyage;
- securing method must consider resisting sliding and shifting;
- stow should be fore-and-aft with dunnage athwartship or supporting the securing; and
- where practicable, wires can be laid athwart ships prior to loading.
General details to be provided to Master, in respect of portable tanks or receptacles:
- Dimensions, gross weight, diagram or relevant details if that would help;
- IMDG related details if applicable;
- securing provision, etc.
Let us first understand the meaning of some of the cargoes covered under above annexes. A portable tank, basically is a large tank not permanently fixed to ship. It means a tank with a capacity of more than 450 lit and a shell fitted with external stabilizing members and items of service equipment and structural equipment necessary for the transport of liquids, solids or gases. Thus, the provisions do not apply to smaller tanks though, may be transporting liquids, solids or gases. The capacity for portable tanks for gases usually is 1000 lit or more. Portable tanks should be liftable with structural equipment when loaded. The requirements of Safe Containers, 1972, and relevant section of the General Introduction to the IMDG Code should be met, if applicable. A portable receptacle on the other hand means, a receptacle not being a portable tank, which is not permanently secured on board the ship and has a capacity of 1,000 lit or less and has different dimensions in length, width, height and shape and which is used for the transport of gases or liquids. They can be divided into three types:
- cylinders of different dimensions without securing points and having a capacity not exceeding 150 lit; and
- receptacles of different dimensions other than the above type having a capacity of not less than 100 lit and not more than 1,000 lit. (hoisting devices of sufficient strength may or may not be there).
- The cylinders of the first type above, interconnected within the frame and held firmly together by metal fittings. The frames are equipped with securing and handling devices of sufficient strength.
Flexible intermediate bulk container (FIBC), on the other hand means, a flexible portable packaging to be used for the transport of solids with a capacity of not more than 3 m³ (3,000 l) designed for mechanical handling and tested for its satisfactory resistance to transport and transport stresses in a one-way type or multi-purpose design.
Paletised cargo means a number of packages either: placed or stacked, and secured by strapping, shrink-wrapping or other suitable means, on a load board such as a pallet; or placed in a protective outer packaging such as a pallet box; or permanently secured together in a sling.
Portable tanks should not have liquid level that will cause dangerous sloshing. In case of the transport of dangerous goods due certification, as per IMDG Code, by the competent authority must be done.
The external stabilizing members of a portable tank may consist of skids or cradles or a framework of ISO or non-ISO. Tanks should be stowed in the fore-and-aft direction on or under deck. Tanks should be stowed so that they do not extend over the ship’s side. Tanks should be stowed so as to permit safe access for personnel in the necessary operation of the ship. The tanks should not overstress the deck or hatches. The securing against sliding and tipping must be done withstanding the transverse and longitudinal forces. The lashing angles against sliding should not be higher than 25° and against tipping not lower than 45° to 60° as shown below.
Dunnage should be used to increase friction. If stowage under deck is permitted, the stowage should not involve dragging. Caution must be observed regarding; securing points; lashing methods if such points are not given; and the area in contact with the deck.
The wires are tightened to make a compact stow by using appropriate tightening devices. During loading, wedges may be necessary to prevent cylinders rolling. Cylinders should, whenever practicable, be stowed upright with their valves on top and with their protective caps firmly in place. Where possible, the hoisting devices on receptacles should be used to lash them.
Wheel-based Cargoes are covered under Annex 4. These are provided with wheels on tracks, including those which are used for the stowage and transport of other cargoes, except trailers and road trains, but including buses, military vehicles with or without tracks, tractors, earth-moving equipment, roll trailers, etc.
When in stowage position, the brakes of a wheel-based unit, if so equipped, should be set. Lashings should be made of material having strength and elongation characteristics at least equivalent to steel chain or wire. Where possible, wheel-based cargoes, carried as part cargo, should be stowed close to the ship’s side or be block stowed from side to side of the cargo space. Sufficient securing points of sufficient strength are very important particularly when stowed on deck.
Fore and aft stow is best but if wheel-based cargoes are inevitably stowed athwart ships, additional securing of sufficient strength may be necessary. The wheels of wheel-based cargoes should be blocked to prevent shifting. Any movable external components attached to a wheel-based unit, such as derricks, arms or turrets should be adequately locked or secured in position.
Annex 5 deals with the safe stowage and securing of heavy cargo items such as locomotives, transformers, etc. When heavy items are to be stowed on deck, the expected “weather side” of the particular voyage should be taken into account if possible. The weight of the item should be distributed in such a way as to avoid undue stress on the ship’s structure. Particularly with the carriage on hatch covers, suitable beams of timber or steel of adequate strength should be used to transfer the weight of the item onto the ship’s structure.
Cargo Stowed in Open Containers, on Platforms or Platform-based Containers, ISO platforms or platform-based containers (flatracks) on a containership or a ship fitted or adapted for the carriage of containers should follow the information for that system. The stowage and securing of the cargo in such containers should be carried out in accordance with the IMO/ILO Guidelines for Packing Cargo in Freight Containers or Vehicles. When heavy cargo items are carried on ISO platforms or platforms-based containers (flat racks) the provisions of this annex should be followed. The ISO standard platform, etc., used should be of a suitable type with regards to strength and MSL of the securing points. The optimum lashing angle against sliding is about 25°, while the optimum lashing angle against tipping is generally found between 45° and 60° as shown below:
Dragging underdeck should be avoided but if grease was used then additional lashings must be used to prevent sliding. Timber shoring is a very good additional option. Welded fittings is even better if possible. Hot work would be done only with extreme safety. Lashings attached to items without securing points should pass around the item, or a rigid part thereof, and both ends of the lashing should be secured to the same side of the unit as shown below.
Securing devices should be arranged in such a way that each device takes its share of load according to its strength. Mixed securing arrangements of devices with different strength and elongation characteristics should be avoided. The integrity of the securing arrangements should be maintained throughout the voyage. Particular attention should be paid to the need for tight lashings, grips and clips and to prevent weakening through chafing. Timber cradles, beddings and shorings should be checked. Greasing the tread of clips and turnbuckles increases their holding capacity and prevents corrosion. The securing arrangements for heavy cargo items should be verified by an appropriate calculation in accordance with annex 13 to the Code.
The ideal ship for the carriage of FIBCs is one with wide hatches so that the FIBCs can be landed directly in the stowage positions without the need for shifting. The cargo spaces should, where practicable, be rectangular in shape and free of obstructions. Suitably adapted forklift trucks should only be used. When FIBCs are stowed in the hatchway only, the space in the wings and the forward and aft end of the cargo space should be loaded with other suitable cargo or blocked off suitably. If there will be a void space, the stowage of the FIBCs should start from both sides to the centre, so that any void space will be in the centre of the hatchway. Any void space should be chocked off. Fore and aft lashings are of no good with unblocked stow of FIBCs. Sufficient gratings or plywood sheets placed against the FIBCs prevents chaffing of cover. A batton tightened polypropylene lashing taken against plywood sometimes, helps securing smaller cluster.
Annex 11 recommends the safe practices for the under-deck stowage of logs and other operational safety measures designed to ensure the safe transport of such cargoes.
Prior to loading, following precautions should be taken:
- Each cargo space configuration (length, breadth and depth), the cubic bale capacity of the respective cargo spaces, the various lengths of logs to be loaded, the cubic volume (log average), and the capacity of the gear to be used to load the logs should be determined;
- Using the above information, a pre-stow plan should be developed to allow the maximum utilisation of the available space; the better the under-deck stowage, the more cargo can safely be carried on deck;
- The cargo spaces and related equipment should be examined to determine whether the condition of structural members, framework and equipment could affect the safe carriage of the log cargo. Any damage discovered during such an examination should be repaired in an appropriate manner;
- The bilge suction screens should be examined to ensure they are clean, effective and properly maintained to prevent the admission of debris into the bilge piping system;
- The bilge wells should be free of extraneous material such as wood bark and wood splinters;
- The capacity of the bilge pumping system should be ascertained. A properly maintained and operating system is crucial for the safety of the ship. A portable dewatering pump of sufficient capacity and lift will provide additional insurance against a clogged bilge line;
- Side sparring, pipe guards, etc., designed to protect internal hull members should be in place; and
- The master should ensure that the opening and closing of any high ballast dump valves are properly recorded in the ship’s log. Given that such high ballast tanks are necessary to facilitate loading and bearing in mind regulation 22(1) of the International Convention on Load Lines, 1966, which requires a screw-down valve fitted in gravity overboard drain lines, the master should (ensure that the dump valves are properly monitored to preclude the accidental readmission of water into these tanks. Leaving these tanks open to the sea could lead to an apparent inexplicable list, a shift of deck cargo and potential capsize.
During loading operations the following must be remembered:
- Minimize Each lift of logs should be hoisted aboard the ship in close proximity to the ship to any potential swinging of the lift;
- The possibility of damage to the ship and the safety of those who work in the cargo spaces should be considered. The logs should not be swinging when lowered into the space. The hatch coaming should be used, as necessary, to eliminate any swinging of the logs by gently resting the load against the inside of the coaming, or on it, prior to lowering;
- The logs should be stowed compactly, thereby eliminating as many voids as is practicable. The amount and the vertical centre of gravity of the logs stowed under deck will govern the amount of cargo that can be safely stowed on deck. In considering this principle, the heaviest logs should be loaded first into the cargo spaces;
- Logs should generally be stowed compactly in a fore-and-aft direction, with the longer lengths towards the forward and aft areas of the space. If there is a void in the space between the fore and aft lengths it should be filled with logs stowed athwartships so as to fill in the void across the breadth of the spaces as completely as the length of the logs permits;
- Where the logs in the spaces can only be stowed fore-and-aft in one length, any remaining void forward or aft should be filled with logs stowed athwartships so as to fill in the void across the breadth of the space as completely as the length of the logs permits;
- Athwartship voids should be filled tier by tier as loading progresses;
- Butt ends of the logs should be alternately reversed to achieve a more level stowage, except where excess sheer on the inner bottom is encountered;
- Extreme pyramiding of logs should be avoided to the greatest extent possible. If the breadth of the space is greater than the breadth of the hatch opening, pyramiding may be avoided by sliding fore-and-aft loaded logs into the ends of the port and starboard sides of the space. This sliding of logs into the ends of the port and starboard sides of the space should commence early in the loading process (after reaching a height of approximately 2 m above the inner bottom) and should continue throughout the loading process;
- It may be necessary to use loose tackle to manoeuvre heavy logs into the under-deck areas clear of the hatchways. Blocks, purchases and other loose tackle should be attached to suitably reinforced fixtures such as eyebolts or padeyes provided for this purpose. However, if this procedure is followed, care should be taken to avoid overloading the gear;
- A careful watch by ship’s personnel should be maintained throughout the loading to ensure no structural damage occurs. Any damage which affects the seaworthiness of the ship should be repaired;
- When the logs are stowed to a height of about 1 m below the forward or aft athwartship hatch coaming, the size of the lift of logs should be reduced to facilitate stowing of the remaining area; and
- Logs in the hatch coaming area should be stowed as compactly as possible to maximum capacity.
After loading, the ship should be thoroughly examined to ascertain its structural condition,
bilges should be sounded to verify the ship’s watertight integrity. During the voyage, the ship’s heeling angle and rolling period should be checked, in a seaway, on a regular basis; wedges, wastes, hammers and portable pump, if provided should be stored in an easily accessible place; and the master or a responsible officer should ensure that it is safe to enter an enclosed cargo space by:
- Ensuring that the space has been thoroughly ventilated by natural or mechanical means;
- Testing the atmosphere of the space at different levels for oxygen deficiency and harmful vapour where suitable instruments are available; and
- Requiring self-contained breathing apparatus to be worn by all persons entering the space where there is any doubt as to the adequacy of ventilation or testing before entry.
Annex 12 deals with palletized cargoes. The slings should be identified by specific means, e.g., colour coding, batch number or otherwise. The decks, including the tank top, should be flush all over. The cargo spaces should preferably be of a rectangular shape, horizontally and vertically. Cargo spaces of another shape in forward holds or in ‘tweendecks should be transformed into a rectangular shape both athwartships and longitudinally by the use of suitable timber. The unit loads should be stowed in such a way that securing, if needed, can be performed on all sides of the stow.
The unit loads should be stowed without any void space between the loads and the ship’s sides to prevent the unit loads from racking. When unit loads have to be stowed on top of each other, attention should be paid to the strength of pallets and the shape and the condition of the unit loads. Precautions should be taken when unit loads are mechanically handled to avoid damaging the unit loads. Block stowage should be ensured and no void space be left between the unit loads. When stowed athwart ships, and stowed in a lower hold or in a ‘tween-deck against a bulkhead from side to side, gratings or plywood sheets should be positioned vertically against the stack of the unit loads. Wire lashings should be fitted from side to side keeping the gratings or plywood sheets tight against the stow.
Where the wires can damage the unit loads (particularly on the corners of the stow), gratings or plywood sheets should be positioned in such a way that no damage can occur on corners.
Special attention should be paid to the corners of the stow to prevent damage to the unit loads by the wire lashings.
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