Experience in reconstructing the radial gate of the spillway at the Vilyui hydroelectric station

Conclusions

• 1. Reconstruction of the radial gate of a spillway by installing an additional gate on the sill under the existing gate is an effective method of increasing the height of the gate, especially when the gate height is increased by 1.5–2 m and more.

• 2. The capacity of the gate hoisting gear can be increased by increasing the mechanical advantage of the block and tackle with the installation of additional blocks and by increasing the capacity of the cable drum; such reconstruction increases the lifting capacity by 15–20%.

• 3. A sectional strut-braced flashboard permits even under winter conditions draining the spillway sill and reliably protecting the zone of works on the sill.

• 4. The use of hot water with a temperature of 50–60° is an effective method of removing surface icing and fast ice on the perimeter of the gate if it is necessary to lift it in the winter, especially under conditions of the Far North.

• 5. When installing a sectional strut-braced flashboard in front of a radial gate at temperatures of minus 40–50° it is necessary to heat the water in the intergate space (for example, by steam) to preclude the formation of a thick ice cover and ice attached to the gate.