Pound lock

Pound lock

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

Indirect evidence suggests that pound locks may have been used in antiquity by the Ptolemaic Greeks and the Romans. [Frank Gardner Moore "Three Canal Projects, Roman and Byzantine." "American Journal of Archaeology", 54, (1950), 97-111 (99)]

Pound locks were created in medieval China during the Song Dynasty (960–1279 AD), pioneered by the government official and engineer Qiao Weiyo in 984,Needham, Volume 4, Part 3, 350-351] mentioned by the Chinese polymath scientist Shen Kuo (1031–1095) in his book "Dream Pool Essays" (published in 1088),Needham, Volume 4, Part 3, 351-352.] and fully described in the Chinese historical text "Song Shi" (compiled in 1345).Needham, Volume 4, Part 3, 351.]

In medieval Europe a type of pound lock was first built in 1373 at Vreeswijk, the Netherlands.Needham, Volume 4, Part 3, 357.] 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. 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.Needham, Volume 4, Part 3, 358.]

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

* [http://www.the-river-thames.co.uk/locks.htm Locks on the River Thames]
* [http://www.naviandes.com/ascensore_ad_acqua.html Locks in Governolo near Mantua (ITALY)]
* [http://archive.museophile.org/rrm/children/lock.html Interactive lock] from the original River and Rowing Museum website
* [http://terrax.org/sailing/locks/locksjs.aspx Interactive lock from terrax.org]


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