The Spiral Tunnels are one of the most bizarre feats of engineering to get the grade of a train line to be at or below 2.2%. They are located on the Big Hill just beyond the crossing of the Continental Divide just inside British Columbia on the transcontinental line of the Canadian Pacific Railway that united the Dominion of Canada together. The current two spiral tunnels where the railroad forms two spirals, crossing beneath itself twice, almost forming a figure eight, before continuing in the proper direction down the mountain were completed in 1909. The tunnels are referred to as the Upper and Lower Tunnels and since the massive VIA Rail cuts of 1990 have only seen passenger train service from the seasonal biweekly Rocky Mountaineer First Passage to the West. The tunnels were built to replace a railway that had grades of up to 8% and used the equivalent of runaway truck ramps for trains (by having various switches a train could be switched onto to go up the sides of the valley to slow it down) safety.
The Spiral Tunnels have never served as a passenger rail station but there is an overlook on the Trans-Canada Highway of the Lower Tunnel. This highway pull-off is a must stop (even if you don't get luckily and see a train coming through) on a tour of Yoho National Park and most Rocky Mountaineer Packages (like my Golden Circle via Whistler) include it. The overlook includes some signs about the history of the railway and a model of the tunnels in relation to highway since their quite hard to visualize
All photos in this section were taken on 3 October, 2011
Last Updated: 15 November, 2011