BC Hydro’s project contractor, InPower BC, has successfully achieved another significant milestone in the John Hart Generating Station replacement project.
The most recent accomplishment is the competition of the drilling and blasting for what’s called the tailrace tunnel.
The tunnel, at 10.7 metres in height and about six metres wide, runs about 600 metres from the underground powerhouse to the tailrace outlet where the water will re-enter the Campbell River. The excavation milestone was achieved at the end of April.
“We are very pleased and proud to see this tunnel competed,” says project and BC Hydro spokesperson, Stephen Watson. “It’s very impressive to stand within a tunnel of that size. It was excavated in two stages by removing an upper rock heading and then the lower bench. The last section of the upper heading broke through at the end of March, and the lower rock bench was fully excavated by the end of April. And of course it nicely aligned with the concrete tailrace outlet works that were already in place.”
The concrete form work at the tailrace outlet was completed months ago and includes the steel stop logs that were placed in position. Looking ahead, the solid rock plug that keeps the Campbell River water from entering the tunnel work area, is planned to be removed with one controlled blast towards to the end of 2017.
“SNC-Lavalin and their subcontractors Aecon and Frontier-Kemper continue to progress well and it’s rather amazing to see the changes at the site from month to month,” said Watson. “It’s visually impressive and the project has been quickly transitioning from a rock removal and a concrete placement process to an electrical and mechanical focus with turbine/generator supplier General Electric.”
Watson said the current schedule shows the nearly 1.6 kilometre long power tunnel, from the John Hart dam to the powerhouse, fully excavated by July.
“When that happens, the underground rock removal process will be complete.”
The John Hart project remains on schedule for the new facility to be in-service in fall 2018. While people are unable to get into the tunnel, the tailrace outlet area is part of the site tour during the John Hart project community site event on July 9.