Deadweight Tonnage - Wikipedia

Measure of how much weight a ship can carry Not to be confused with vessel displacement.

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.[1][2][3] It is the sum of the weights of cargo, fuel, fresh water, ballast water, provisions, passengers, and crew.[1]

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.

Definition

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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,[a] but is now usually given internationally in tonnes (metric tons).[4] 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.[5][6]

See also

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• Transport portal

Notes

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1. ^ One long ton (LT) is 1,016 kilograms (2,240 lb).

References

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1. ^ a b Turpin, Edward A.; William A. McEwen (1980). Merchant Marine Officers' Handbook (4th ed.). Centreville, Maryland: Cornell Maritime Press. pp. 14–21. ISBN 0-87033-056-X.
2. ^ Hayler, William B. (2003). American Merchant Seaman's Manual (7th ed.). Centreville, Maryland: Cornell Maritime Press. p. G-10. ISBN 0-87033-549-9.
3. ^ Gilmer, Thomas C. (1975). Modern Ship Design (2nd ed.). Naval Institute Press. p. 25. ISBN 0-87021-388-1.
4. ^ McNicholas, Michael (29 August 2011). Maritime Security: An Introduction. Butterworth-Heinemann. p. 30. ISBN 9780080919539. Retrieved 25 August 2014.
5. ^ SOLAS Consolidated Edition 2009. London: International Maritime Organization. 2009. p. 33. ISBN 978-92-801-1505-5.
6. ^ MARPOL Consolidated Edition 2011. London: International Maritime Organization. 2011. p. 44. ISBN 978-92-801-1532-1.

v t e Ship measurements
Length	Length overall Length between perpendiculars Length at the waterline
Breadth	Beam
Depth	Draft Moulded depth Freeboard Load line (Plimsoll Line) Under keel clearance
Height	Air draft
Volume	Worldwide Tonnage Gross tonnage Compensated gross tonnage Net tonnage Underdeck tonnage Specialized Panama Canal/Universal Measurement System Thames measurement tonnage Archaic Gross register tonnage Net register tonnage
Capacity	Current Deadweight tonnage Twenty-foot equivalent unit (Intermodal containers) Archaic Builder's Old Measurement Moorsom System
Weight	Displacement Loaded displacement Standard displacement Light displacement Normal displacement
Stability	Inclining test List Angle of loll Metacentric height (GM)
Limits	Aframax Baltimax Capesize Chinamax Handymax/Supramax Handysize Malaccamax Panamax and § Neopanamax Péniche Q-Max (Qatar-max) Seawaymax Suezmax VLCC and ULCC Yamalmax