levels out, is . The contract was awarded to the Vancouver engineering firm of MacDonnell, Gzowski and Company and work started in 1907. The labour force amounted to about 1000 and the cost was about $1.5 million. Regardless of the opening of the spiral tunnels, Field Hill remained a significant challenge and it was necessary to retain the powerful locomotives at Field locomotive depot. Even after the introduction of modern locomotives with dynamic braking and continuous pneumatic brakes, accidents were not eliminated. There were 64 derailments between Calgary and Field between 2004 and 2019. On February 4, 2019, two of the three locomotives and 99 grain hopper railcars of westbound Canadian Pacific train 301 derailed at Mile 130.6, just outside of the western portal of Upper Spiral Tunnel. The three crew members were killed in the accident. See also Spiral (railway) Spiral tunnels and tunnels on a curved alignment References Further reading Rail infrastructure in British Columbia Columbia Valley Canadian Pacific Railway facilities Railway tunnels in British Columbia Tunnels completed in 1909 Hills of British Columbia