Definitions for "Gross tonnage"
Keywords:  tonnage, cubic, ton, cargo, ship
This is not a measurement of weight as we traditionally think of it. It is a measurement of the amount of vessel space: a ton is 100 cubic feet. A ship's gross tonnage is all the cubic feet in its enclosed spaces: cargo holds, engine room, and deck house divided by 100. See net tonnage.
Applies to vessels, not to cargo. Determined by dividing by 100 the contents, in cubic feet, of the vessel's closed-in spaces. A vessel ton is 100 cubic feet.
Abbreviation: GRT The measure of the overall size of a vessel determined in accordance with the provisions of the international convention on measurement of vessels usually expressed in register ton.