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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)).^[1] It opened in 1876.^[2]^[3] The tunnel was daylighted in 1983 due to rock falls which blocked the tunnel from time to time.^[4]^[5]
- 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.^[6]
- The Arncliffe Tunnel on the NSW South Coast Line was daylighted and replaced with a road bridge when the track was quadruplicated in 1921^[7]
- The Waterfall Tunnel on the NSW South Coast Line was daylighted in 1914 when the line was duplicated.^[8]
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).^[9]
- The Macgregor Tunnel on the Main South Line was daylighted in 1971 to allow for container freight.^[10]
- Tunnels No. 22 and 23. were daylighted in 1981 and 1979 respectively on the Main North Line.^[10]
- The Mercer Tunnel was daylighted in 1956 on the North Island Main Trunk.^[10]
- The Makohine Tunnel was daylighted in 1984 on the North Island Main Trunk.^[10]
- The Kiwi Tunnel was daylighted in 1972 on the North Island Main Trunk. This alignment has since been bypassed in 1985 however.^[10]
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.

United States of America
- Auburn Tunnel on the Schuylkill Canal, daylighted in 1857
- Tunnel No. 5 on the Alaska Railroad's Seward-Anchorage line^[11]
- Tunnel No. 5 on the Virginia & Truckee Railroad at Nevada S.R. 341 near Virginia City
- The Gwynedd Cut on the North Pennsylvania Railroad, near North Wales, Pennsylvania, built as a tunnel between 1853 and 1856, daylighted in 1930 when the Reading Railroad electrified the line
- A number of tunnels were open cut for the National Gateway project including:
  - Shoo Fly Tunnel (2012)
  - Pinkerton Tunnel (2012)
  - Benford Tunnel (2012)

References

^ "Duaringa (front)" (Map). Queensland Government. 1943. Retrieved 25 April 2024.
^ "ROCKHAMPTON". Morning Bulletin. Vol. LXIV, no. 11, 650. Queensland, Australia. 4 April 1903. p. 5. Retrieved 25 April 2024 – via National Library of Australia.
^ "On the Northern Railway". The Brisbane Courier. Vol. XXXIII, no. 3, 461. Queensland, Australia. 21 June 1878. p. 3. Retrieved 25 April 2024 – via National Library of Australia.
^ "The Morning Bulletin, ROCKHAMPTON". Morning Bulletin. Vol. XXIII, no. 3495. Queensland, Australia. 25 June 1879. p. 2. Retrieved 25 April 2024 – via National Library of Australia.
^ "A Banana Tree Growing Vigorously in the Wet – Joh Bjelke-Petersen and the Queensland Railways 1960s to 1980s: Part 2". Under The Clocks. 2021-12-07. Retrieved 2024-04-25.
^ "Pinera Tunnel", Wikipedia, 2024-06-04, retrieved 2024-08-20
^ "Arncliffe Tunnel". www.nswrail.net. Retrieved 2024-09-01.
^ "Waterfall Tunnel". www.nswrail.net. Retrieved 2024-09-01.
^ The Encyclopedia of New Zealand: Daylighting a Manawatū Gorge tunnel
^ ^a ^b ^c ^d ^e "NZR Tunnels - Railway Knowledge Base for New Zealand". rkbnz.nz. Retrieved 2024-10-04.
^ F. C. Weeks et al., "Tunnel 'Daylighting' on the Alaska Railroad," Transportation Research Record No. 1119, Geotechnology (1987).