Daylighting a tunnel is to remove its "roof" of overlying rock and soil, exposing the railway or roadway to daylight and converting it to a railway or roadway cut. Tunnels are often daylighted to improve vertical or horizontal clearances—for example, to accommodate double-stack container trains or electrifying rail lines, where increasing the size of the tunnel bore is impractical.

List of daylighted tunnels

Australia

  • The Moocomonga Tunnel carried the Central Western railway line through the Gogango Range in Queensland, Australia (23°42′06″S 149°55′27″E/23.70164°S 149.92430°E/ -23.70164; 149.92430(Moocomonga railway tunnel)). It opened in 1876. The tunnel was daylighted in 1983 due to rock falls which blocked the tunnel from time to time.
  • The Coromandel and Pinera Tunnels on the Belair line in Adelaide, South Australia, both built as a single track tunnel with the line in 1883, were daylighted in the 1920s when the line to Belair was duplicated.
  • The Arncliffe Tunnel on the NSW South Coast Line was daylighted and replaced with a road bridge when the track was quadruplicated in 1921
  • The Waterfall Tunnel on the NSW South Coast Line was daylighted in 1914 when the line was duplicated.

New Zealand

  • The railway line through the Manawatū Gorge, when constructed in 1891, had five tunnels. Three of these(Tunnels No. 3, 4 and 5) were daylighted in 2008 to allow for the carriage of large containers (the other two tunnels had their floors lowered).
  • The Macgregor Tunnel on the Main South Line was daylighted in 1971 to allow for container freight.* Tunnels No. 22 and 23. were daylighted in 1981 and 1979 respectively on the Main North Line.
  • The Mercer Tunnel was daylighted in 1956 on the North Island Main Trunk.
  • The Makohine Tunnel was daylighted in 1984 on the North Island Main Trunk.
  • The Kiwi Tunnel was daylighted in 1972 on the North Island Main Trunk. This alignment has since been bypassed in 1985 however.

United Kingdom

  • Liverpool Lime Street station was originally approached through a 1.13-mile (1.82 km) twin-track tunnel completed in 1836. The tunnel was daylighted in the 1880s, and replaced with a deep four-track cutting, with only the eastern 50 metres (55 yd) approaching Edge Hill railway station remaining as a tunnel.
The short remaining portion of Liverpool's Lime Street Station tunnel can be seen west of Edge Hill Station.

United States of America

See also