canals...canal from Utrecht with the Lek River. Outer and inner gates contained a basin, the water level of which was controlled by alternatively winding up and lowering the gates. In the 15th century the lock-gate system was much improved with the addition of paddles to control the flow of water in and out of the lock chamber through sluices in the gates or sides of the lock.Movable gates must be strong enough to withstand the water pressure arising from the level difference between adjacent pounds. The most generally used are mitre gates consisting of two leaves, the combined lengths of which exceed the lock width by about 10 percent. When opened, the leaves are housed in lock wall recesses; when closed, after turning through about 60°, they meet on the lock...Lock gate renewal is normally planned to ensure that a predetermined number of gates are replaced annually; special vessels equipped with heavy lifting tackle are needed for transport and site handling.
Simply begin typing or use the editing tools above to add to this article.
Once you are finished and click submit, your modifications will be sent to our editors for review.