Friday, May 22, 2015

the Connaught Tunnel on the Canadian Pacific








The Connaught Tunnel under the Selkirk Mountains in southeastern British Columbia near the city of Revelstoke replaced the railway's previous routing over Rogers Pass, which had been struck by several deadly avalanches since its completion in 1885.

The 5.022-mile (8.082 km) tunnel takes the CPR main line under Mount Macdonald and at the time was the longest railway tunnel in North America. It was named for the Governor General of Canada–the Prince Arthur, Duke of Connaught – who in turn was named after the province of Connaught in Ireland.

Announced in February 1913, the contract was awarded on 1 July 1913, to Foley Bros. Welch and Stewart. A small tunnel was built from which cross cuts were made to the main tunnel so work could carry on at a number of headings. The sub-contractor guaranteed to drill 900 feet (270 metres) of the tunnel per month and started on 2 April 1914. Compressed air equipment and narrow gauge locomotives were used inside the tunnel. The company town housed some 300 workers. The tunnel was completed before the original deadline, with operation beginning 16 December 1916. It had a grade of only 0.95 % westward and was straight; light at one end can be seen at the other.

The tunnel enabled 14.5 miles (23.3 km) of track to be bypassed including the Loops and over 4 miles (6.4 km) of snow sheds. Overall, the route was shortened by 4.3 miles (6.9 km).

Problems were encountered with ventilation, loose rocks and wet rails, which caused trains to stall. The tunnel was later lined with reinforced concrete and equipped with a better ventilation system. Originally double tracked as in the pictures, it was realigned with a single track in 1959 to accommodate higher freight cars.

In the late 1980s, the Mount Macdonald Tunnel was built to supplement the Connaught Tunnel and to lessen the grade on the eastern approach to the pass. Trains now predominantly travel east through the Connaught Tunnel and west through the Mount Macdonald Tunnel. (edited from Wikipedia)

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