Fabricated Overshot Gates

Overshot gates are designed for use in open-channel flows where upstream level control is required. Armtec’s unique design includes a bottom hinge and a channel-floor recess that enables the fully opened gate to lie flat on the channel floor. The premise of the design is that of a moveable weir. Overshot gates are operated by single or tandem cable hoists, specifically designed by Armtec for these applications.

An overshot gate consists of a gate leaf, hinge, and hoist mechanism. The 600 series is a self-contained unit that includes side plates and a hoist support. The action of this gate can be likened to a drawbridge hinged across the bottom of a vertical walled channel. When the gate position is horizontal (fully open), water flows through the channel end of the gate and over the lip while the channel sides restrict it. Water backs up behind the gate as it reaches an angle of 60 degrees, as excess water flows over the end of the gate leaf. The overshot gate can be set to any position between 0 and 60 degrees (0 degrees being flat or open), therefore establishing upstream level control.

Typical Applications

• Irrigation canals
• Flood control
• Dam spillways

Features

• Intuitive control - changes in upstream water level are achieved with gate adjustments of the same amount and direction
• Precise control - minimum gate movement is 0.25 inches; increment or control with a stop log style of structure is limited by the depth of the flow
• Inherent safety - surge flows and debris pass over and carry on downstream
• Large selection of models available depending on installation; contact your Armtec Sales Representative for more information