Builders Old Measurement

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A system of measuring a ship's tonnage adopted in Britain by Act of Parliament passed in 1773. As a system of measurement it gradually replaced the burthen method of calculating a ship's carrying capacity and was the method by which a ship's port and harbour dues etc. could be calculated. The formula was where L equals the length of the ship measured from the aft end of the keel to the fore side of the stem at the deck and B equals its maximum beam, the result giving its measurement in tons. This formula remained in force until the mid-19th century when the introduction of iron as the most efficient material for shipbuilding, and steam propulsion, meant a new method of calculation had to be devised.

See also thames measurement.

See also thames measurement.

Subjects: Maritime History.

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