Carrying capacity

Carrying capacity is the maximum cargo a vessel can lift, set by whichever limit binds first: weight (cargo deadweight) or volume (grain or bale cubic). On a dense cargo such as iron ore the ship loads to its deadweight and leaves hold space empty; on a light cargo such as grain or containers it fills the cube before reaching deadweight. Cargo deadweight is total summer deadweight less bunkers, fresh water, stores, and constant. The freight earned per voyage turns on which constraint controls, so charterers match cargo stowage factor to the ship’s deadweight-to-cube ratio.