Connaught Tunnel is an underground passageway.
Connaught Tunnel . The Connaught Tunnel is a railway tunnel under the Selkirk Mountains in southeastern British Columbia , Canada , near the city of Revelstoke . 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 . Compressed air equipment and narrow gauge locomotives were used inside the tunnel . A tunnel is an underground passageway , dug through the surrounding soil/earth/rock and enclosed except for entrance and exit , commonly at each end .