New Road and Bridge enables access to construction site of new commercial oil sands mining and processing facility

Steel girder erection, McKay Bridge

Canadian Natural Resources Ltd. (CNRL) is constructing Horizon, a new commercial oil sands mining and processing facility north of Fort McMurray. Previously, the only access to CNRL’s new Horizon mine site was across the Athabasca River using an ice bridge in the winter or by road through the native hamlet of Fort McKay. To facilitate mine access, CNRL required a new road and bridge over the McKay River.

Following an intensive evaluation process, CNRL engaged the design/build team of Kiewit Management Co. with Lead Consultant Associated Engineering to complete their first design/build contract for the Horizon oil sands development. AMEC Earth and Environmental and AMEC Infrastructure Ltd. provided subconsultant services to Associated Engineering.

The team’s mandate was to design and construct a safe, durable, cost-effective road and bridge in an environmentally responsible manner within a very short time period - only ten months. CNRL required the road and bridge to be designed and constructed to Alberta Transportation specifications. In addition, the bridge had to accomodate 800 tonne over-load vehicles and be wide enough to transport major mining and process equipment to the site.

CNRL McKay River Bridge

By analysing the comparative costs of bridge length and resulting road earthworks, the Team was able to produce a balanced river crossing that met both budget and schedule.

Bridge design had to consider the difficult access to the site, due to the steepness of the McKay River Valley and access restrictions through Fort McKay. The design allowed for bridge erection by conventional crane lift or launching from the south abutment, once the southern six kilometres of road through boreal forest and muskeg was complete.

Girders were designed in short, 21 metre lengths to facilitate access to and manoeuvering on site. Smaller girder lengths enabled simple lifts from the riverbanks without encroaching into the active McKay River channel. The bridge span arrangement enabled the piers to be located outside the 1:100 year flood level on the McKay River and therefore minimized environmental impacts to the river.

“Due to the short construction period and long lead-in time for manufacture and delivery of plate girders, preliminary design of the steel girders was fast-tracked so that the steel could be ordered two days after award of the contract,“ advised Project Manager Robin Clee. “The bridge layout, coupled with the flexible construction approach significantly shortened the construction schedule, thereby allowing the project to be completed on time and within budget.”

The bridge was opened for vehicle traffic in December 2003, successfully meeting the tight schedule constraints. The total cost of the project was approximately $18 million. Other Associated Engineering personnel involved in the project included John Fussell, Julien Henley, Helen Du, David Harvey, Alfred Kao, Steve Croxford, and James Nikolai.