Deadweight capacity. The deadweight is the tonnage of the cargo and other items the vessel can carry at different draughts. Thus, at the statutory summer draught, the deadweight is called the “summer deadweight”.
The deadweight of a vessel is the total weight of cargo, bunkers, dunnage, provisions, fresh water, ballast (if any), stores and spare parts, expressed in tonnes of 1,000 kilogrammes, which a vessel can lift when loaded in salt water to her maximum draught, either winter, summer or tropical loadline, as the case may be. The deadweight is equal to the difference between the vessel’s displacement on her loaded draught and the displacement on her light draught .
The deadweight capacity is related to the cargo the vessel can carry under a charter. For commercial reasons the word can be divided into:
“DWAT” or “Deadweight all told” – the total deadweight, usually to the summer, salt water draught, and
“DWCC” or “Deadweight cargo capacity” – the mass of cargo only that the vessel is capable of carrying.