BC Hydro update #7: Fraser River Transmission Infrastructure
6:30 p.m. PDT; Friday, July 8
VANCOUVER – As BC Hydro’s work continued today near the Port Mann Bridge in Surrey to stabilize a 500-kilovolt transmission tower on the south side of the Fraser River, operations were temporarily halted between 2 and 5 p.m. after a crane laying riprap made contact with one of the multiple piles supporting the tower, causing it to shift down by four centimetres.
As per site safety procedure, BC Hydro workers, contractors and WorkSafeBC staff were evacuated immediately, to allow geotechnical engineers to inspect the tower. On-site engineers conducted structural inspections and determined that the stability had not been compromised and no structural damage had occurred. At 5 p.m. the engineers deemed the site safe to continue the work, with modifications to the riprap installation to avoid similar incidents moving forward. Work has resumed according to the tower restoration plan.
Summary of recent activity and background
BC Hydro is now on day four of 24-hour operations for the repair and stabilization of the transmission lines across the Fraser River near the Port Mann bridge. On July 4, a 230-kilovolt tower fell into the Fraser River after it appears to have been damaged by high water flows and erosion. BC Hydro crews have been working to stabilize a 500-kilovolt transmission tower on the south side of the river by laying 900 cubic metres of rip rap (approximately 18 truckloads) along the riverbed and bank closest to the foundation of the tower to increase stability and prevent further erosion.
After the riprap has been installed and further erosion is prevented, crews will drive steel piles into the bed of the Fraser River that will surround the tower and provide extra support and stability.
Earlier this week, BC Hydro successfully installed additional guy wiring (support wiring) on the 500-kilovolt tower on the south side of the river, as a precautionary measure, and repositioned existing wiring to enhance stability. Crews also installed guy wiring as a precautionary measure to the 500-kilovolt tower on the north side of the river. This was done to further enhance safety and prevent potential disruption to the public should the tower on the south side fall.
For further background, please visit www.bchydro.com/mediabulletins.
For more information
BC Hydro Media Relations
p. 604.928.6468