Dødvekt

Dødvekt, or deadweight tonnage (DWT), is a measure of the maximum weight a ship can safely carry when loaded. It is defined as the difference between the vessel’s full-load displacement and its lightship displacement, and is expressed in metric tons. This weight represents cargo, fuel, freshwater, provisions, crew, passengers, and other consumables; it does not include the ship’s own hull and machinery weight.

In practice, DWT serves as a key indicator of a vessel’s carrying capacity. It is used in ship design and classification, as well as in chartering, port planning, and regulatory or fee calculations that depend on the size or payload of a ship. When comparing ships, operators often use DWT to assess how much cargo a vessel can transport within given draft and stability constraints.

Calculation and interpretation are straightforward: DWT = full-load displacement minus lightship displacement. Equivalently, it equals the total weight of cargo, fuel, stores, crew, and other consumables the ship can carry. The actual payload at sea depends on factors such as draft restrictions, stability, ballast, and operational conditions.

Typical DWT values vary by vessel type. Small coastal vessels may have a few thousand tonnes, while large container ships or tankers can exceed hundreds of thousands of tonnes. It is important to distinguish DWT from the ship’s displacement or from lightship weight, as these terms describe different aspects of a vessel’s size and weight.

See also displacement, lightship, and ship tonnage.