A Tight Spot

Inspecting wicket gates sounds like just another maintenance task, but it's not a job for the claustrophobic. A while back in my tenure with an electrical utility, my partner and I were assigned the task of inspecting the wicket gates on a small hydro-electric turbine the utility owned.

A small log was thought to have gone through the gates, and the plant supervisor wanted to check if any damage had been done. The first thing that had to be done before we entered the scroll case, was to close the ten foot diameter butterfly valve that supplied water to the turbine.

After the valve was closed and locked out, we proceeded into the pipe which rapidly got smaller as it transitioned into the scroll case. Soon we were on our hands and knees, and then stomachs as we arrived at the wicket gates which were about sixteen inches high.

During our short trip in the pipe, I noticed that some water was leaking by the rubber seal on the large butterfly valve. As we were looking for damage, I kept hoping the valve wouldn't fail somehow, and allow the full 100' plus head of water to force us through the gates like the log.

Fortunately the engineer that designed the valve knew what he was doing and we finished our inspection without incident. That was one time when I was really in a "tight spot."