Using Snow Nets for Avalanche and Rock Mitigation

The Advantages of Snow Nets 

Snow nets offer several key benefits that made them the ideal choice for this project. Their lightweight components can be installed using helicopters, allowing access to areas that would otherwise be unreachable. Unlike rigid structures, snow nets are also visually less obtrusive, an important consideration in a national park where preserving the natural landscape is crucial for tourism. 

In regions prone to rockfall, snow nets can be effectively adapted to the terrain. Their flexible nature is particularly advantageous in permafrost areas or on slopes with creeping unconsolidated rock. The nets can move with the terrain, thanks to their floating base plates and adjustable structure, ensuring stability and effectiveness even when the ground shifts beneath them. 

The project utilized Geobrugg SPIDER® Avalanche nets, and despite the challenging conditions, over 2,000 meters of nets were successfully installed. 

A Decade of Reliable Protection 

For nearly a decade, these Geobrugg Spider snow net systems have reliably protected the Trans-Canada Highway through Glacier National Park in Rogers Pass. Their resilience is due to spec from GeoBrugg. Since leading the design and layout of the project in 2016, Alpine Solutions, in collaboration with GeoBrugg and McElhanney, has been responsible for the annual inspection and maintenance of these systems, integrating our engineering, rope access, and inspection services to ensure they continue to perform optimally. 

This year, Alpine Solutions deployed a team of IRATA/SPRAT certified rope access technicians and engineers. The engineering team was responsible for inspecting the structural components of the Geobrugg SPIDER® Avalanche nets, while the maintenance team performed concrete pad repair to ensure the durability of the posts’ anchor. The adaptability of the snow nets continues to be a key factor in their long-term success, allowing them to adjust to changes in the terrain and maintaining their protective capabilities. 

Safety and Precision in a High-Risk Environment 

The Cougar Corner project also posed significant safety risks to personnel due to the steepness of the terrain and the constant threat of rockfall from above. To mitigate these dangers, extensive rope access and rockfall management systems were employed across approximately 75% of the project site. While these safety measures slowed the project’s progress, they were essential in ensuring a secure work environment for the drillers, installers, and engineers on site. 

Once in place, the Geobrugg SPIDER® Avalanche nets themselves are excellent protection against rockfall to protect workers and provide multiple anchor points for rope access system to be installed. This enables faster progress during construction and ensures a safe environment during inspection and maintenance for years to come. 

The project required helicopter access and involved complex logistics to ensure the delivery of a quality product in a timely manner. Glacier Helicopter has been a major contributor to this project’s ongoing success, providing access to workers and performing longlining of tools and materials professionally. 

Commitment to Ongoing Maintenance 

The sustained performance of the Cougar Corner snow nets over the past nine years underscores the importance of regular maintenance and inspections. The Geobrugg SPIDER® Avalanche nets continue to serve as reliable avalanche mitigation structures, effectively protecting the Trans-Canada Highway. These nets have replaced the previously challenging and less reliable avalanche control methods that relied primarily on explosive control via helicopter deployment. As these systems continue to protect one of Canada’s most vital transportation routes, Alpine Solutions remains committed to ensuring their effectiveness through meticulous care and expert services.