In the winter, many of our construction engineering services staff who typically work very long hours during the summer take a break and search for sunnier climes. For our staff who work in the northern regions of Canada, the inverse is true. Winter brings new construction opportunities in the North that can make it a very busy time of the year. The increase in activities is mainly due to improved accessibility to remote regions during the winter season.
A close inspection of a map of the northern Territories shows a landscape dotted with lakes. Where the surface is not covered with lakes, exposed Precambrian igneous and high-grade metamorphic rocks of the Canadian Shield are commonly found, making it very difficult to find overland access routes in this terrain. Also, overland routes can result in irreversible damage to the delicate ecosystem and permafrost.
In the very cold winter, the snow-covered landscape freezes and access becomes possible. The best example of a northern access road is the Tibbitt to Contwoyto Winter Road, a 405 kilometre lifeline to Canada’s diamond mines north of Yellowknife. Annually, upwards of 300,000 tonnes of freight are transported over a two-month period to provide an annual supply of fuel, equipment, infrastructure, and other commodities to the operating mines. Each winter, a team of seven to nine staff work long hours on site to ensure that the ice road remains safe for users.
Recently, Associated Engineering was the Independent Engineer on the construction of the Inuvik to Tuktoyaktuk Highway, which took advantage of the benefits of winter construction. The road was constructed in a region where suitable gravel sources are scarce. However, we needed a large volume of material to achieve the minimum embankment fill heights necessary to protect the underlying permafrost.
The high moisture content of some of the local gravel made handling and placing the material in the summer season impossible. However, placing the same ice-rich material during the winter time was possible. With the fill in place, construction activities could continue throughout the year. As can be expected, the poor embankment material settled significantly in the following summer season and will result in higher maintenance requirements in the years to come. This is a reasonable trade-off considering the lack of suitable alternative construction methods available.
Winter access has made possible the construction of large northern bridges. Recently, the superstructure of the 1.1 kilometre long Deh Cho Bridge near Fort Providence was assembled and launched in the extremely cold Northwest Territories winter, after which work continued throughout the year. Leslie Mihalik, who served as the Project Manager of the final phase of the Deh Cho Bridge project, says, “Our staff worked long hours in the cold and dark environment to help make this project successful.”
Our success in these northern projects stems from our corporate experience working in these extreme and harsh environments. Al Fitzgerald, National Practice Leader, Ice Engineering, tells us, “A deliberate approach to safety, and our understanding of the logistical and engineering challenges of working in the North enables our team to manage risks and contribute to the overall success of projects in the North.” We combine this expertise with dedicated and robust staff who are excited to work in tough and breathtaking landscapes.