Ship Cargo Handling

Loading of bulk cargo can be by a variety of methods, ranging from modern sophisticated facilities capable of loading through conveyor belts, chutes, or spouts, at rates of thousands of tonnes per day: whilst in a few backward areas, it may still be necessary to load by the labor intensive system of slitting bags and emptying the contents over the side of hatch coamings into the holds beneath. Discharging of cargo can be effected by similarly varied methods, free-flowing cargoes such as grains lending themselves to fast, sucker discharge where available, or in extreme cases, bagging in in holds, filled bags then being raised and lifted ashore by slings secured to ship or shore gear.
Much research has taken place in recent years into methods of fast, efficient bulk cargo discharge, operated in many cases from alongside the ship, but sometimes by means of self-discharging equipment built into the carrying vessel. Much bulk cargo discharging however, is accomplished by grabs fitted to either ship or to shore cranes or derricks, and often charterers and/or receivers will require an entry in the shipping contract to the effect that the ship is suitable for grab discharge. Such a clause can be quite extensive, an example drawn up for a tween-deck vessel reading: “Vessel to be guaranteed suitable for grab discharge and the cargo to be loaded in lower holds only. No cargo to be loaded in tweendecks, deeptanks or other places not accessible to grabs. If in loading and/or discharging any extra expenses incurred for cargo not accessible to grabs, Owners to be responsible for all extra expenses and time not to count. Wooden-ceilings to be in proper condition’ for grabs and trimming machines. Deeptanks, tunnels and all other projections within vessel’s holds are to be sheltered against grab-discharge damage, failing which Owners to be responsible for all consequences, but grabs to be operated in a serviceable fashion. Vessels to have cargo battens, tweendeck hatchcovers and hatch beams removed, and holds to be cleared of all timber, hatch covers, hatch beams etc. If such materials stored in holds, same to be stowed away with due regard to discharging by grabs and trimming by apparatus. Any extra expenses due to failure to comply with this stipulation and time lost thereby to be for Owners’ account”. Some general cargo and short sea vessels have tank tops protected by wooden sheathing. particularly over double bottom bunker tanks, above shaft tunnels and directly beneath hatch openings, and this protection is itself liable to damage when discharging cargo by grab. As a bulk-cargo discharging operation nears completion, it may well be that bulldozers are placed in cargo holds to shift remaining cargo to piles and locations for grabs to collect and lift. These bulldozers will move in a variety of ways, ranging from rubber tvres to steel caterpillar tracks, and most owners being naturally anxious to avoid possible damage to the tank tops of their vessels, will thus specify in charterparties that where possible, only rubber tyred bulldozers may be utilised.