Device to prevent water leaving a canal at high tide comprises tube of two halves of equal diameter and plates covering hollows in the lower tube half which move to upright position to prevent water escaping

摘要

Device includes a water-tight rigid hollow tube (1) placed along the canal bank. It is made of top and bottom halves, the bottom of which stays permanently on the bank. The upper half's diameter corresponds to that of the lower. They contain plates, some of which are placed permanently on the bank, covering small hollows on the lower half in their normal position. The plates, attached to the other bank by holding parts, are placed flat on the bank and have devices to put them into an upright or oblique working position preventing water overflowing.