Long ton (
weight ton or
imperial ton) is the name for the unit called the "
ton" in the
avoirdupois or
Imperial system of measurements, as used in the
United Kingdom and several other
Commonwealth countries. It has been mostly replaced by the
tonne, and in the
USA by the
short ton. It is equal to or of salt water with a density of 1.025 g/ml. It has some limited use in the United States, most commonly in measuring the
displacement of
ships, and was the unit prescribed for
warships by international agreements between the
world wars, for example
battleships were limited to 35,000 long tons.
The tonne is equal to . The standard ton in the
U.S. measurement system is the "
short ton", equal to . Both long and short tons are defined as 20
hundredweights, but a hundredweight is in the Imperial system (long or gross hundredweight) and in the U.S. system (short or net hundredweight).
See also
- Tonnage, volume measurement used in maritime shipping. Originally based on .
- Tonne, also known as a metric ton (t). .
