Lock

Lock

1) Structure at each end of a short stretch of canal (inland waterway) comprising gates and sluices that are opened and closed to change water levels.

Operated by boatmen to raise or lower the water level as required. (There are 1,549 locks on British waterways, the longest flight of narrow locks is at Tardebigge on the Worcester & Birmingham Canal, the longest flight of wide locks is at Devizes on the Kennet & Avon Canal). See also Staircase.

Source: David Lowe. The Dictionary of Transport and Logistics. Kogan Page, 2002. – P.147 (288 p.)