Freight units. When charging freight for the carriage of goods and the rate of freight is to be based on weight, a distinction can be made between:
short ton = 2000 pounds = 907.18 kilogrammes
long ton = 2240 pounds = 1016.06 kilogrammes
metric tons =1000.00 kilogrammes
Freight in the liner trades can be based on cubic measurement. The “revenue ton” was 40 cu. ft. before metrication and is now 1 cubic metre, which is approximately 35.3 cu. ft. In the liner trades freight rates may be assessed on weight or measurement basis at ship’s option, the freight will be on the weight or measurement of the individual packages, whichever produces the greatest revenue. In these trades, the freight rates can also be based on other units, e.g., per container (the “box rate”) or a uniform freight for all cargo, “freight all kinds” (FAK), in a particular unit, be it a box or a tonne weight.
In order to ensure safe carriage, valuable cargo, which requires special attention, will attract freight at a certain percentage of the value (ad valorem rates). Weight and measurement are not taken into account when computing freight on the basis of the value.
The expression “freight ton” or “shipping ton” or “revenue ton” relates to the tons upon which freight charges have been based, either measurement or weight.
