Deadweight Tonnage (DWT)
F5. The Reference Layer: Glossary, Units, Signals and Information SourcesDefinition
Maximum mass of cargo, fuel, stores, water, and crew a vessel can carry.
Deadweight tonnage is the total mass in tonnes a vessel can carry when loaded to her summer load line: cargo, fuel, fresh water, stores, crew, and effects. It equals loaded displacement minus lightship. DWT is a weight, not a volume, and is the headline size figure for tankers and bulk carriers, where cargo dominates. It is distinct from gross and net tonnage, which are volumetric measures under ITC69 used for dues, manning, and survey scope, not carrying capacity.