Helicopters place towers on the Northwest Transmission Line
BC Hydro crews install new towers along the Northwest Transmission Line using a helicopter on July 15.
About 1,000 towers called "guyed Y lattice structures" are being installed along the right of way for the new line. Each tower is about 27 metres high. Using a helicopter for installation is quicker than using cranes.
After a structure has been picked up from one of the "fly yards" where the towers have been pre-assembled, the helicopter sets it in place. Each structure is lowered onto the foundation that is constructed ahead of time. Then, long cables, which are attached to the cross arm of the tower, are connected to anchors on the ground by ground crews. The helicopter then releases the tower and returns to the fly yard to pick up the next one.
As many as 20 structures can be installed in a single day. In a number of locations, the sites can only be accessed by helicopter.