Down it Goes

The mission: to lower a 34 tonne hydro generator 110 meters (about 360 feet) underground. Certainly no easy task, but it was accomplished with precision and grace recently at our Aishihik facility. The seven megawatt unit, commonly referred to as Aishihik 3, is being added to the two existing hydro generators at the plant to help us manage our available water in the most efficient way possible.

The generator has had quite a journey. It was manufactured in India, travelled to Vancouver by boat, and was trucked up the Alaska Highway to Aishihik on a large flatbed. A heavy duty crane lowered it to its final resting place in our hydro plant through an underground tunnel. The lowering took close to two hours; with a clearance of only about 15 centimetres (six inches) on each side of the generator, the unit had to be carefully positioned and monitored so that it would not hit the rough rock blasted walls of the service shaft. In preparation for the lowering, crews spent about a month doing planning and preparation, including carrying out detailed inspections and engineering work to ensure the installation would go smoothly.

The next step is to finalize placement, and bolt and cement the unit and associated equipment in place. The penstock pipe (the pipe that carries water to the turbine) must also be tied in.

Aishihik 3 is scheduled to be operating by late this year.

Photos: 1) getting ready to lower the generator down into the tunnel; 2) in its final resting place.