When creating the railway corridor through Kicking Horse Pass, the steep grade posed a serious challenge as the engineers of the time were not in a position to carve a gradual descent. Eventually one of the railway's assistant chief engineers named J.E. Schwitzer came up with a solution for a more gradual grade by modelling the Spiral Tunnels after a system used in Switzerland, and in 1909 the tunnels were finally completed. The gentler grade and descents became safer and slower, and spur lines and rear pushers for the trains were no longer necessary. The tunnels were a great improvement in the safer use of the rail; however, rockfalls, mudslides, and avalanches are still challenges that are being faced today.