Fishbelly Flap Gates (Variable Weirs)

This type of gate is designed as a torsionally-rigid structure suitable for one sided operation over long spans. A speciality of KGAL's, these gates have become increasingly popular as a means of controlling flows and levels in rivers. Operation is normally by hydraulic cylinder from one side.

Advantages
- Torsionally rigid, can be operated from one side only.
- Gate installation is unobtrusive.
- Good overflow discharge characteristics.
- Large spans include more pivots to reduce gate deflection.
- Economical design.
Disadvantages
- Sill recess which could be a problem where there is high silt content.
- Hoist capacity high as lifting water load.
- Pivots submerged so maintenance limited.