On April 26, 2016, the wooden railway trestle bridge over the Little Paddle River near the community of Mayerthorpe, located about 120 km northwest of Edmonton, Alberta, was deliberately set on fire. The bridge was destroyed within a few hours, crippling the railway network owned by Canadian National Railway (CN).
The bridge is an important link in the rail line that carries freight, including oil, lumber, and gravel supplies, to Edmonton from Whitecourt and beyond. CN committed to have a new bridge in service within three weeks. Klohn Crippen Berger (KCB) worked closely with CN Engineering and other contractors to complete the investigation, design and construction monitoring to meet CN’s timeline, and manage the risks associated with the execution of this type of project. Suspected weak foundation soils prompted the design of the embankment fills using the observational approach to adjust the design during the build.
The new bridge was constructed in just 20 days, quickly re-establishing rail service for the communities and resource industries affected by the disruption. On May 15, 2016, the rail line was back in service.