Deadweight is a shipping term used to denote the number of long tons of 2,240 pounds that a vessel can transport of cargo, stores and bunker fuel. It is the difference between the number of tons of water a vessel displaces when unladen ("light") and the number of tons it displaces when submerged to the "load line."
A Deadweight Cargo is a long ton of cargo that can be stowed in less than 40 cubic feet.[1]