The rapidly growing Town of Cochrane partnered with PCL to connect the north and south sides of the community with a three-span bridge over the Bow River. In addition to relieving traffic, the new crossing features bike lanes, a multi-use pathway and a large lookout area above the eastern pier for bridge users to enjoy. The 160-meter bridge is the largest infrastructure project in the Town of Cochrane and rests 14 meters above the water level.
The project involved substantial temporary in-stream work (berms and cofferdams) to accommodate the structure, earthworks, foundation construction up to 8 meters below the river, substructure (bridge abutments and two piers), structural steel girders, a cast-in-place concrete deck, underground utilities, street lighting and landscaping.
The construction of the in-stream and shoreline piers required extensive work within the Bow River, including two berms and two cofferdams. Strict environmental regulations protected the river’s fish and habitats and prohibited in-river work for five months of the year (the “fish window”). Not only was there a fish window, but there were also restrictions determined by high flow periods in the spring and ice damming in the winter. Because of these complexities surrounding in-stream work, strategic scheduling was crucial to completing the project on time and as planned.
Project completion weighed heavily on early engagement with the Town of Cochrane, consultant teams, and key subcontractors to allow the critical in-stream work to be concluded before restrictions began. To do this, the project team worked with the client and consultants and entered an early-works contract with a design-assist approach. This enabled the team to develop early work packages to accelerate essential work items and create a strategic procurement schedule for long-lead items that accounted for market fluctuations and helped mitigate supply challenges.
The success of the design-assist and early-works approach became evident when the initial in-stream berms were completed just days before the fish window restrictions were imposed and again when the berm was partially removed the day before the high-flow period in the spring. The work completed between restriction windows included installing and removing the cofferdam, piling, pier foundations, earthworks, piers, pier caps, and erection of steel girders.
Despite schedule complexities, strict timelines, and various restrictions, PCL completed the Jack Tennant Memorial Bridge on time and within budget while increasing travel options, reducing congestion and promoting healthier lifestyles in the community.