Daylighting a

tunnel A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ve ...

is to remove its "roof" of overlying rock and soil, exposing the

railway Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of ...

roadway A carriageway (British English) or roadway (North American English) is a width of road on which a vehicle is not restricted by any physical barriers or separation to move laterally. A carriageway generally consists of a number of traffic lane ...

daylight Daylight is the combination of all direct and indirect sunlight during the daytime. This includes direct sunlight, diffuse sky radiation, and (often) both of these reflected by Earth and terrestrial objects, like landforms and buildings. Sunlig ...

and converting it to a railway or roadway

cut Cut or CUT may refer to: Common uses * The act of cutting, the separation of an object into two through acutely directed force ** A type of wound ** Cut (archaeology), a hole dug in the past ** Cut (clothing), the style or shape of a garment ** ...

. 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 The Central Western railway line is a railway line in Queensland, Australia. It was opened in a series of sections between 1867 and 1928. It commences at Rockhampton and extends west to Winton. History Following the separation of Queensl ...

through the Gogango Range in

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

, Australia (). 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 The Belair line is a suburban rail commuter route in greater Adelaide, South Australia, that runs from the Adelaide railway station to Belair in the Adelaide Hills via the Adelaide-Wolseley line using diesel 3000/3100 class railcars. This pa ...

Adelaide Adelaide ( , ; ) is the list of Australian capital cities, capital and most populous city of South Australia, as well as the list of cities in Australia by population, fifth-most populous city in Australia. The name "Adelaide" may refer to ei ...

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

, both built as a single track tunnel with the line in 1883, were daylighted in the 1920s when the line to

Belair Belair or Bélair may refer to: People *Bianca Belair, wrestler *Sanité Bélair (1781–1802), Haitian freedom fighter *Anne Liger-Belair, Belgian writer known as Anne Duguël Places Historic locations *Belair (Nashville, Tennessee), United Sta ...

was duplicated. ** The Arncliffe Tunnel on the NSW

South Coast Line The South Coast Line (SCO) is an Regional rail, intercity rail service that services the Illawarra region of New South Wales, Australia. The service runs from , and runs the entire length of the eponymous South Coast railway line, New South W ...

was daylighted and replaced with a road bridge when the track was quadruplicated in 1921 ** The Waterfall Tunnel on the NSW

was daylighted in 1914 when the line was duplicated. * New Zealand ** The railway line through the

Manawatū Gorge The Manawatū Gorge () is a steep-sided gorge formed by the Manawatū River in the North Island of New Zealand. At long, the Manawatū Gorge divides the Ruahine and Tararua Ranges, linking the Manawatū and Tararua Districts. It lies to the ...

, 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 Encyclopedia of New Zealand: Daylighting a Manawatū Gorge tunnel
/ref> ** The Macgregor Tunnel on the

Main South Line The Main South Line, sometimes referred to as part of the South Island Main Trunk Railway, is a railway line that runs north and south from Lyttelton, New Zealand, Lyttelton in New Zealand through Christchurch and along the east coast of the ...

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 North Island Main Trunk (NIMT) is the main railway line in the North Island of New Zealand, connecting the capital city Wellington with the country's largest city, Auckland. The line is long, built to the New Zealand rail gauge of and ser ...

. ** The Makohine Tunnel was daylighted in 1984 on the

. ** The Kiwi Tunnel was daylighted in 1972 on the

. This alignment has since been bypassed in 1985 however. * United Kingdom ** Liverpool Lime Street station was originally approached through a twin-track tunnel completed in 1836. The tunnel was daylighted in the 1880s, and replaced with a deep four-track

cutting Cutting is the separation or opening of a physical object, into two or more portions, through the application of an acutely directed force. Implements commonly used for wikt:cut, cutting are the knife and saw, or in medicine and science the sca ...

, with only the eastern approaching

Edge Hill railway station Edge Hill railway station is a Train station, railway station that serves the district of Edge Hill, Liverpool, England and is one of the oldest railway stations in the world. There have been two stations of that name. The first stood a shor ...

remaining as a tunnel. Lime Street Station tunnel remnant seen from Edge Hill Station

* United States of America ** Auburn Tunnel on the

Schuylkill Canal The Schuylkill Canal, or Schuylkill Navigation, was a system of interconnected canals and slack-water pools along the Schuylkill River in the U.S. state of Pennsylvania, built as a commercial waterway in the early 19th-century. Chartered in 1815 ...

, daylighted in 1857 ** Tunnel No. 5 on the

Alaska Railroad The Alaska Railroad is a Class II railroad that operates freight and passenger trains in the state of Alaska. The railroad's mainline runs between Seward, Alaska, Seward on the southern coast and Fairbanks, Alaska, Fairbanks, near the center of ...

's Seward-Anchorage lineF. C. Weeks et al., "Tunnel 'Daylighting' on the Alaska Railroad," ''Transportation Research Record'' No. 1119, ''Geotechnology'' (1987). ** Tunnel No. 5 on the Virginia & Truckee Railroad at Nevada S.R. 341 near

Virginia City Virginia City is a census-designated place (CDP) that is the county seat of Storey County, Nevada, United States, and the largest community in the county. The city is a part of the Reno– Sparks Metropolitan Statistical Area. Virginia City dev ...

** Th
Gwynedd Cut
on the

North Pennsylvania Railroad North Pennsylvania Railroad was a railroad company which served Philadelphia, Montgomery County, Bucks County and Northampton County in Pennsylvania. It was formed in 1852, and began operation in 1855. The Philadelphia and Reading Railway, pr ...

, near

North Wales, Pennsylvania North Wales is a Borough (Pennsylvania), borough in Montgomery County, Pennsylvania. It is a suburb of Philadelphia and is one of the three historic population centers that make up the North Penn Valley, which is centered on the borough of Lans ...

, built as a tunnel between 1853 and 1856, daylighted in 1930 when the

Reading Railroad The Reading Company ( ) was a Philadelphia-headquartered railroad that provided passenger and freight transport in eastern Pennsylvania and neighboring states from 1924 until its acquisition by Conrail in 1976. Commonly called the Reading Railr ...

electrified the line ** A number of tunnels were open cut for the

National Gateway National Gateway is a multi-stage railroad construction project in the United States promoted by CSX Transportation, a unit of CSX Corporation. It is designed to improve rail connections between ports in the U.S. mid-Atlantic seaboard and the Midwe ...

project including: **
Shoo Fly Tunnel
(2012) **
Pinkerton Tunnel
(2012) **
Benford Tunnel
(2012)

References

Tunnel construction {{civil-engineering-stub

List of daylighted tunnels

See also

References