pound lock

A plan and side view of a pound lock.

An example pound lock.

An older lock on the Kennet and Avon Canal in England.

A pound lock is type of lock that is used almost exclusively nowadays on canals and rivers. A pound lock has a chamber (the pound) with gates at both ends that control the level of water in the pound. In contrast, an earlier design with a single gate was known as a flash lock.

History

Pound locks may have been used in antiquity by the Ptolemaic Greeks and the Romans as indirect evidence suggests.^[1]

Pound locks were innovated in medieval China during the Song Dynasty (960—1279 AD). It was pioneered by the government official and engineer Qiao Weiyo in 984,^[2] mentioned by the Chinese polymath scientist Shen Kuo in his book Dream Pool Essays (1088),^[3] and fully described in the Chinese historical text of the Song Shi (compiled in 1345).^[4]

In medieval Europe a type of pound lock was first built in 1373 at Vreeswijk, Holland.^[5] This pound lock serviced many ships at once in a large basin, yet the true pound lock (i.e. one for a small basin) came in 1396 with the one built at Damme near Bruges.^[5] A famous civil engineer of pound locks in Europe was the Italian Bertola da Novate (c. 1410-1475), who constructed 18 of them on the Naviglio di Bereguardo (part of the Milan canal system sponsored by Francesco Sforza) between the years 1452 and 1458.^[6]

Notes

References

• Needham, Joseph (1986). Science and Civilization in China: Volume 4, Physics and Physical Technology, Part 3, Civil Engineering and Nautics. Taipei: Caves Books Ltd.

See also

• Locks (water transport)
• Sluice
• Flash lock

External links

• Locks on the River Thames
• Locks in Governolo near Mantua (ITALY)
• Interactive lock from the original River and Rowing Museum website

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