The Connaught Tunnel shortly after completion of East Portal in 1916. Courtesy of Library and Archives Canada.
The Connaught Tunnel was built between 1913 and 1916. At 5.02 miles long, it is the longest tunnel in Canada. It was officially opened on December 16, 1916 and is named for the Duke of Connaught, who was Governor-General of Canada at the time.
Prior to construction of the Connaught Tunnel, the Canadian Pacific mainline twisted around the base of the mountain through Rogers Pass.
Construction of the 20 foot wide, concrete-lined tunnel eliminated 200 degrees of curves and clipped 4.52 miles off the transcontinental mileage. It also reduced hazards due to 30-foot average yearly snowfalls. There were some problems at first, such as inadequate ventilation, wet rails causing wheels to slip and dangerous loose rocks.
The original dual track has been reduced to a single track. This change has increased clearance and made maintenance easier and safer. This tunnel contributed to development of the railway as an effective east to west connecting link which could be used throughout the year.