Deadweight tonnage


Deadweight tonnage or tons deadweight is a measure of how much weight a ship can carry. It is the sum of the weights of cargo, fuel, fresh water, ballast water, provisions, passengers, and crew.
DWT is often used to specify a ship's maximum permissible deadweight, although it may also denote the actual DWT of a ship not loaded to capacity.

Definition

Deadweight tonnage is a measure of a vessel's weight carrying capacity, not including the empty weight of the ship. It is distinct from the displacement, which includes the ship's own weight, or the volumetric measures of gross tonnage or net tonnage.
Deadweight tonnage was historically expressed in long tons but is now usually given internationally in tonnes. In modern international shipping conventions such as the International Convention for the Safety of Life at Sea and the International Convention for the Prevention of Pollution From Ships, deadweight is explicitly defined as the difference in tonnes between the displacement of a ship in water of a specific gravity of 1.025 at the draft corresponding to the assigned summer freeboard and the light displacement of the ship.