The Adam Viaduct is a grade II

listed Listed may refer to: * Listed, Bornholm, a fishing village on the Danish island of Bornholm * Listed (MMM program), a television show on MuchMoreMusic * Endangered species in biology * Listed building, in architecture, designation of a historical ...

concrete underbridge in Wallgate,

Wigan Wigan ( ) is a large town in Greater Manchester, England, on the River Douglas, Lancashire, River Douglas. The town is midway between the two cities of Manchester, to the south-east, and Liverpool, to the south-west. Bolton lies to the nor ...

. The bridge, constructed in 1946, is the earliest

prestressed concrete Prestressed concrete is a form of concrete used in construction. It is substantially "prestressed" (Compression (physics), compressed) during production, in a manner that strengthens it against tensile forces which will exist when in service. Post ...

railway bridge in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

, with only some examples in Switzerland being earlier. It is bridge number 54 on the Kirkby branch line and is at a line distance of .

History and construction

The bridge was constructed as a

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, to see if prestressed concrete construction was feasible for rail projects in the UK, by the LMS railway company, and designed by their chief civil engineer

William Kelly Wallace William Kelly Wallace (1883–1969) was an Irish railway engineer who joined the Northern Counties Committee and later became Chief Civil Engineer of the London Midland and Scottish Railway (LMS). He was awarded a civil CBE in the 1946 New Yea ...

. The beams used were prestressed using the Freyssinet system, in which concrete is precast with stressed high-tensile-strength metal tendons, which consist of multiple steel wires, running down the length of them. In construction, the beams internal rods are tightened and tied together so, under live load, they act as one. The LMS developed this system in the 1930s, and prestressed beams were first used for emergency repairs during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, but the Adam Viaduct first to use them for a full-scale project. The benefits of the system were found to be that it was quicker to install, more economical and longer-lasting, and with the bridge being less lively than traditional designs. The bridge has six

I-beams An I-beam, also known as H-beam (for universal column, UC), w-beam (for "wide flange"), universal beam (UB), rolled steel joist (RSJ), or double-T (especially in Polish, Bulgarian, Spanish, Italian and German), is a beam with an or -shaped ...

for each track and two beams for each

parapet A parapet is a barrier that is an extension of the wall at the edge of a roof, terrace, balcony, walkway or other structure. The word comes ultimately from the Italian ''parapetto'' (''parare'' 'to cover/defend' and ''petto'' 'chest/breast'). ...

, and they are deep. It was erected in 1946 on the foundations of an earlier

Victorian Victorian or Victorians may refer to: 19th century * Victorian era, British history during Queen Victoria's 19th-century reign ** Victorian architecture ** Victorian house ** Victorian decorative arts ** Victorian fashion ** Victorian literature ...

bridge, created as part of the Liverpool & Bury Railway in 1847, which was made from

timber Lumber is wood that has been processed into dimensional lumber, including Beam (structure), beams and plank (wood), planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as fini ...

with masonry

abutments An abutment is the substructure at the ends of a bridge span or dam supporting its superstructure. Single-span bridges have abutments at each end which provide vertical and lateral support for the span, as well as acting as retaining walls ...

. The earlier bridge was strengthened three times in: 1869, 1888 and 1906.

Southgate

Southgate, a bypass of the A49 from Pottery Road and Saddle Junction, passes underneath the bridge and next to the River Douglas. The road, which officially opened in March 2013, was constructed to reduce traffic in the area.

References

External links

Pre-stressed Concrete Railway StructuresHistory of Concrete Bridges
{{Authority control Grade II listed bridges in Greater Manchester Buildings and structures in Wigan