Great Western Mainline

The Great Western Main Line is a main line railway in Great Britain, that runs westwards from London Paddington station to the west of England and South Wales. The core Great Western Main Line runs from London Paddington to Temple Meads railway station in Bristol. A major branch of the Great Western, the South Wales Main Line, diverges from the core line west of Swindon and terminates in Swansea. The term “Great Western” is also used by Network Rail and other rail transport organisations in the UK rail industry to denote a wider group of routes, see Associated routes below.
 

The core London–Bristol Temple Meads line is the original route of the pre-1948 Great Western Railway which was subsequently taken over by the Western Region of British Railways and is now part of the Network Rail system.

 

It is planned to electrify the line by 2016. The South Wales Main Line, the Cherwell Valley Line and the Reading to Taunton Line as far as Newbury will also be electrified at later dates.

 

The line was built by the Great Western Railway and engineered by Isambard Kingdom Brunel as a dual track line using a wider 7 ft 0 1⁄4 in (2,140 mm) broad gauge and was opened in stages between 1838 and 1840. The alignment was so level and straight it was nicknamed ‘Brunel’s Billiard Table’. It was supplemented with a third rail for dual gauge operation allowing standard gauge 4 ft 8 1⁄2 in (1,435 mm) trains to also operate on the route in stages between 1854 and 1875. Dual gauge was introduced as follows: London to Reading (1 October 1861), Reading to Didcot (22 December 1856), Didcot to Swindon (February 1872), Swindon to Thingley Junction, Chippenham (June 1874), Thingley Junction to Bathampton (16 March 1875), Bathampton to Bristol (June 1874), Bristol station area (29 May 1854). The broad gauge remained in use until 1892. Evidence of the original broad gauge can still be seen at many places where bridges are a wider than usual, or where tracks are ten feet apart instead of the usual six.

 

The original dual tracks were widened to four track in various places between 1877 and 1899. Paddington to Southall (1 October 1877), Southall to West Drayton (25 November 1878), West Drayton to Slough (1 June 1879), Slough to east side of Maidenhead Bridge (8 September 1884), Maidenhead Bridge to Reading (4 June 1893(, Reading station (1899), Reading to Pangbourne (30 July 1893), Pangbourne to Cholsey and Moulsford (?), Cholsey and Moulsford to Didcot (27 December 1892), Various short sections between Didcot and Swindon, and at Bristol.

 

Following the Slough rail accident in 1900 when five passengers were killed improved vacuum braking systems were used on locomotives and passenger rolling stock and Automatic Train Control (ATC) was introduced in 1908.

 

At the outbreak of World War I in 1914, the Great Western Railway was taken into government control, as were most major railways in Britain and were reorganised after the war into the “big four” companies, of which the Great Western Railway was one. The railways returned to direct government control during World War II before being nationalised to form British Railways in 1948.

 

The line speed was upgraded in the 1970s to support the introduction of the InterCity 125 (HST).

 

In 1977 the Parliamentary Select Committee on Nationalised Industries recommmended considering electrification of more of Britain’s rail network, and by 1979 BR presented a range of options that included electrifying the GW Main Line from Paddington to Swansea by 2000. Under the 1979–90 Conservative governments that succeeded the 1976–79 Labour government the proposal was not implemented.

 

In August 2008 it was announced that a number of speed limits on the relief lines between Reading and London have been raised so that 86% of the line can be used at 90 miles per hour (140 km/h), however the time allowed between stations for trains running on the relief lines has been reduced in the December 2008 timetable to improve timekeeping.