Deadweight tonnage
Measure of how much weight a ship can carry
Deadweight tonnage (also known as deadweight; abbreviated to DWT, D.W.T., d.w.t., or dwt) or tons deadweight (DWT) 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 (i.e. when it is fully loaded so that its Plimsoll line is at water level), although it may also denote the actual DWT of a ship not loaded to capacity.
01Definition
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 (weight of water displaced), which includes the ship's own weight, or the volumetric measures of gross tonnage or net tonnage (and the legacy measures gross register tonnage and net register tonnage).
Deadweight tonnage was historically expressed in long tons, but is now usually given internationally in tonnes (metric tons). 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 (corresponding to average density of sea water of 1,025 kg/m3 or 1,728 lb/cu yd) at the draft corresponding to the assigned summer freeboard and the light displacement (lightweight) of the ship.
Sources and credits
This article is adapted from the Wikipedia article “Deadweight tonnage”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Draft scale at the ship bow (PIC00110).jpg by Wikisearcher, Public domain
- Echelle Port en lourd.jpg by No machine-readable author provided. Clipper assumed (based on copyright claims)., CC BY 2.5
Fathomly is not affiliated with or endorsed by the Wikimedia Foundation. Spotted a problem? Tell us.