Tainter gate

A segment weir is an adjustable weir.

The weir consists of a plate which is rotatably attached to a support structure at one point. Tie rods or chains of the shield can be lowered into the water and pulled out again. If the point around which the plate rotates, above the weir, one speaks of a Zugsegmentwehr; otherwise of a pressure defense segment. A segment weir is generally flows through below. The better controlled raid operation is only possible if one is installed on the plate an additional fish belly flap. In this case, the two operating modes are possible.

Sketch of a Zugsegmentwehrs with optional fish-belly flap

Pressure segment weir at the John H. Kerr Dam, Boydton, Virginia

• Weir Type ( Hydraulic )