The company reported no injuries nor apparent significant damage to the ship.
The terminal is a key shipping point for coal from Teck Resources' (TSX:TCK.B) mines in B.C.
Westshore said there was no damage to Berth 1 itself, but that it would be out of commission due to the damage to the trestle.
"The main priority is to restore power to Berth 1 to secure the shiploader," the company said.
Berth 1, the outer dock at the terminal, can handle vessels up to 260,000 deadweight tonnes, while Berth 2 handles ships up to 180,000 tonnes.
Westshore is the operator of the largest coal-handling terminal on the west coast of the Americas.