Video: Explosive demolition of Campbell River hydro dam tower
Published Friday, July 12, 2019 12:55PM PDT Last Updated Friday, July 12, 2019 4:46PM PDT
One of three surge towers at the John Hart dam in Campbell River was felled in a controlled demolition Friday.
Incendiary devices were placed on the girders at the base of the 90-metre tower, causing it to carefully crash down like a large tree.
A 450-metre safety zone was established around the towers prohibiting entrance to the surrounding public trails and two access roads.
To maximize a safe fall, some of the eight supporting legs were cut using linear shaped charges, with kicker charges used to ensure full metal separation.
The tower is in the process of being removed and the steel recycled, with a second tower's demolition scheduled for some time next week.
A third tower to the south will remain in place. While not part of the hydro-electric facilities, the tower holds valuable communication equipment, serves as a beacon for the local airport and has heritage value.
The 90-metre towers were once the highest towers on Vancouver Island. They’re visible from certain areas of Campbell River and from boats on the surrounding water.
In operation from 1947 to 2018, they protected the 1.8-kilometre penstocks that led from the dam to the generating station from short duration water pressure changes that happen when water flow is increased or decreased.