Bagged cargo handling various considerations

Bagged cargo handling various considerations

Bagged cargo

Handling bagged cargo on board need careful considerations. The commodity itself has to be robust to withstand outside pressure and compression, for the bags will only hold the contents in one place and will not provide protection against external damage. Such commodities might typically be fertilizers, grain (rice, maize, wheat, etc.), seeds, dried fruit, sugar, coconut, coffee, fresh vegetables, frozen offal (meat from carcasses), flour, copra, small items such as shells, raisins, etc., mail, salt, mineral sands and ores, meal (fish, seed, copra, etc.), dried blood, dried milk etc.

Handling bagged cargo

Materials

The material from which a bag is made will depend on a number of factors, i.e. the commodity, its physical composition and its properties, e.g. moisture content, sensitivity to contamination, etc. The commonest materials used are single or multi-ply paper, plastic, woven polypropylene (possibly with a sealed polythene liner), open mesh plastic fibre and, much less commonly today, jute and hessian. Bags may be sown, glued or welded depending on the material.

Commodities

Bagged commodities need to be sufficiently robust to withstand external pressure and compression, as the bag is designed to contain the contents rather than provide any substantial protection against external damage. Such commodities might normally be carried in bulk or mini-bulk operations but for particular markets are shipped bagged in smaller quantities and include fertiliser, grain, seed, dried fruit, sugar, cement, coffee, flour, salt, mineral sand, fish meal, dried milk, etc.

Characteristics

Bag sizes vary although it is standard practice to use a size which, when filled with the particular product, can be readily handled by stevedores, i.e. about 50kgs. A secondary advantage is that this weight allows rapid calculation of the total weight loaded into a cargo space or container. Care must be taken when loading large quantities of bagged cargo to allow in calculations for gross, nett, and tare (bag) weights.

The shape of a bag, and therefore the ease with which it can be stowed, made up into a sling, pallet load, etc., varies with the commodity and the construction of the bag. The bag may be "shaped" (usually those of paper or plastic construction) and form a near rectangle which is stable and has flat surfaces. However, jute bags, for example, are usually sewn flat at each end and tend to have no flat surfaces, although these may be induced by pressure during the storage or stowage cycle. If the contents are powdery (e.g. cement) the package is more likely to conform to outside pressures around it, such as weight on top or pressure on the sides. On the other hand, if the contents are hard and bulky (e.g. frozen offal) then the bag will be of irregular shape and will be unlikely to respond to outside influences.

Commodities in hessian and woven polypropylene bags may be subject to contamination from powder or small granular cargoes stowed beside or above them while the contents, if of a powder or granular nature, may themselves sift through the bags with resultant loss and contamination of other cargo (see Part 4). Recently filled bags tend to settle and spread outwards and this can affect stowage arrangements, e.g. in containers (see "Unitised Cargoes"). Woven polypropylene bags, because of their non-absorbent characteristics, may be more suitable for moisture inherent/sensitive cargoes (e.g. rice, sugar, coffee, etc.) than traditional hessian.

"Jumbo" bags are normally of woven polypropylene with lifting slings sewn into the bag. They vary in size but may weigh several tonnes when full. In `tween deck ships they are most suitable for hatch square stowage where they can be clean lifted upon discharge. In such ships, wing and end stowage is only suitable when there is sufficient headroom for forklifts to operate.

Handling

Different bagging materials and different commodities lend themselves to different handling methods; a jute bag with good "ears" on it may be more easily lifted by the human hand than a heavy fully filled plastic sack with nothing to grip. Thus, there is a great temptation for stevedores to use hand hooks to manhandle bags in and out of their stowage positions in holds, containers, etc. Since most bagged commodities easily spill and some of them are very valuable (e.g. coffee), as a general rule, hand hooks should not be used for bagged cargoes.

Bulging plastic bags may be difficult to make up in a pallet load because of their shape and consequent tendency to slide. Similarly, multi-ply paper sacks may not be safely lifted by rope slings or snotters without the possibility of rupturing the bags. Flat webbed slings of man-made fibres are most suitable for slinging bags, and the "clover leaf" sling arrangement can be used to advantage with bags that are difficult to handle because of shape or material. Such slings are very suitable for pre- slinging requirements and unit loads (see "Unitised Cargoes"). Canvas or heavy-duty plastic holdalls may be required for loading and discharging high-value commodities such as flour, coffee, cocoa, etc., when the nature of the bagging material and the value of the commodity are likely to make any damage the source of a high value claim. Great care is required when handling bagged cargo with mechanical equipment (cranes, winches, fork lift trucks, etc.) so that damage is not caused by swinging or rubbing against obstructions such as beams, hatch coamings, etc.

Stowage

Most bagged cargoes are liable to damage if stowed with moist cargo or cargo liable to sweat and should be well protected against obstructions such as beams, brackets, stringers, etc. Otherwise, as the cargo settles, pressure on an unsupported or projecting part of the bag may result in tearing and spilling of the contents. Bags should be protected by mats, heavy-duty paper, etc., from bare steel work and sources of moisture running down bulkheads, pillars, etc. Such protection also helps to save the bags from discolouration by rusty metal.

If two types of bagged cargo are carried in the same space and there is a risk of one contaminating the other (e.g. plastic granules over rice), then plastic or similar sheeting should be laid between the different commodities. Similarly, sheeting should be laid where sifting or loss of cargo might be expected, particularly with a valuable cargo such as coffee. Any such protective separation must be carefully handled at discharge, with any spillage collected and landed before moving to the cargo below .

Careful tallying is essential and for ease of counting, slings and pallets should always be made up of the same number of bags. Bagged cargo bills of lading should be endorsed "weight and quantity unknown" or at the very least "said to contain..." Slack or damaged bags must be rejected for loading. Damp or stained bags, particularly of sugar, cocoa and coffee, should also be rejected.

Some commodities are liable to rot a natural fibre bag, e.g. some manures and chemicals, and with such cargoes the bill of lading should be claused to protect the ship from having to bear the cost of re-bagging. The ship should also be protected against any claim for loss of contents due to leakage from bags of insufficient strength or quality to prevent such loss.

Bleeding of Bags

A practice largely consigned to the past is that of cutting and bleeding bags into the hold from the edge of the open hatch. If this practice should be encountered there are a number of points that should be monitored by the ship's officers. Care must be taken to see that bags are fully emptied of their contents before being discarded to avoid subsequent claims of short-delivery. Bags may be bled through a wire or rope grill in order to ensure that the bags themselves do not end up in the hold which, in practice, frequently occurs. It is also quite common for foreign or "field matter" to be mixed with the contents. Should the presence of bags and foreign matter be observed in the stow, loading should be stopped and the contamination drawn to the attention of the stevedores and the charterer.

The mates' receipts should be claused accordingly. It will be appreciated that the presence of foreign material and bags in the cargo will cause problems during discharge and may result in claims. The shipper will inevitably want clean bills of lading but if foreign material has been noted every endeavour should be made to have this noted in the bill of lading. The ship should not accept the offer of a letter of indemnity from the shipper as it is the owner who will be sued by the receiver, not the shipper, and the likelihood of recovery from the shipper is remote.

Discharging

Slings of bagged cargo should not be dragged out from wings or ends of holds as this will result in bags tearing on plate butts and landings, rough wooden tank top ceilings or other obstructions. If the cargo warrants, facilities should be available for rebagging of spilt cargo bags both when loading and discharging. All torn, slack or empty bags and packages should be carefully inspected while discharging is in progress and delivered (against tally) along with the cargo, otherwise a claim for short delivery is likely to follow.

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

Cargo handling procedure for general cargo ship

Bagged cargo handling various considerations

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