Quick, there’s a train coming

Speed is often the most critical factor when engineering for the railways. UMA Engineering of Edmonton had to act quickly, for example, to restore a timber trestle bridge in northern Alberta last May. The client, RailLink, had taken over the former CN line only four days before, when the 81-metre long bridge scanning the Saulteaux River near Slave Lake was destroyed by forest fire.

The line links Smith, Alberta to the Hay River terminal. The bridge had to be immediately repaired because it serves the forestry industry and is the seasonal resupply route of the western Northwest Territories. All 11 approach spans as well as the 36-metre long centre timber deck were destroyed. Fortunately the centre steel span could be reused.

UMA organized getting materials, equipment and a work force to the remote site. Site surveys and detailed design drawings were done over the weekend, and pile driving started on Monday May 9. The bridge’s timber trestles were reconstructed at the same time as the deck panels were being prefabricated.

The first train (with seven engines and a heavy load) travelled across the reconstructed bridge just 13 days after the fire struck.