Great Western Main Line

Great Western Main Line
Maidenhead Railway Bridge, which the GWML crosses
Overview
Status	Operational
Owner	Network Rail
Locale	Greater London, South West England
Termini	London Paddington Bristol Temple Meads
Stations	25
Service
Type	Commuter rail, InterCity, heavy rail
System	National Rail
Operator(s)	First Great Western Heathrow Connect Heathrow Express Chiltern Railways CrossCountry South West Trains
Depot(s)	Reading TMD Old Oak Common TMD
Rolling stock	Class 43 HST Class 57 Class 150 "Sprinter" Class 158 "Express Sprinter" Class 159 "Express Sprinter" Class 165 "Network Turbo" Class 166 "Network Turbo" Class 220 "Voyager" Class 221 "Super Voyager" Class 332 Class 360 "Desiro"
History
Opened	30 June 1841 (complete line)
Technical
Line length	119 mi (192 km)
Track gauge	1435
Operating speed	125 mph (201 km/h) maximum

Great Western Main Line
miles Circle and Hammersmith & City lines via Liverpool Street Elizabeth line to Abbey Wood and Stratford 0⅓ London Paddington Paddington Goods Royal Oak ( ) Mileage Yard Goods & Coal Subway Junction Westbourne Park ( ) Portobello Junction Notting Hill Sidings Circle and Hammersmith & City lines to Hammersmith Kensal Green Gasworks siding Westway (A40) West London Line North Pole depot West London Junction Old Oak Common TMD Old Oak Common Goods Old Oak West Junction Acton–Northolt line Willesden & Acton Brick Co. siding Central line via Liverpool Street North London line Central line Western Avenue (A40) 4¼ Acton Main Line Central line District and Piccadilly lines 5¾ Ealing Broadway 6½ West Ealing Greenford branch line Plasser works 7¼ Hanwell Wharncliffe Viaduct over River Brent Brentford branch line 9⅓ Southall Grand Union Canal 11⅓ Hayes & Harlington Airport Junction to Heathrow Airport stations 14⅓ West Drayton River Colne Greater London boundary Uxbridge (Vine Street) branch line Staines and West Drayton Railway to Colnbrook Cargo Centre M25 motorway 14¾ Iver Western Rail Approach to Heathrow to Heathrow Terminals 2 & 3 and Terminal 5 (proposed) 16¼ Langley 18½ Slough Slough–Windsor & Eton line 21⅓ Burnham 22½ Taplow Jubilee River Maidenhead Railway Bridge over River Thames 24¼ Maidenhead Marlow branch line 31⅓ Twyford Henley branch line River Loddon Sonning Cutting 1 mile (1.6 km) long 60 feet (18 m) deep River Kennet Waterloo–Reading line North Downs Line Reading East Junction 36⅓ Reading Reading–Basingstoke line and Reading–Taunton line 38¾ Tilehurst Purley Cutting 41½ Pangbourne Gatehampton Railway Bridge over River Thames 44¾ Goring & Streatley Moulsford Railway Bridge over River Thames Moulsford 48½ Cholsey Cholsey & Wallingford Railway (bank holidays and weekends only) Didcot, Newbury and Southampton Railway 53⅓ Didcot Parkway Didcot Railway Centre Cherwell Valley line to Oxford, Birmingham and the Cotswold Line Didcot power stations Milton Park estate Steventon Wantage Tramway Wantage Road Challow Uffington Faringdon branch Shrivenham Stratton Park Halt Highworth branch line 77¼ Swindon Golden Valley line to Cheltenham Spa and Birmingham Midland & South Western Junction Railway M4 motorway Wootton Bassett Junction South Wales Main Line Dauntsey Malmesbury branch line Christian Malford Halt Calne branch line 94⅓ Chippenham Thingley Junction Wessex Main Line to Melksham, Bradford-on-Avon and Salisbury Corsham Box Tunnel 2939 yd 2687 m Box (Mill Lane) Halt Box Bathford Halt Bathford Bridge over River Avon Wessex Main Line to Weymouth, Southampton and Brighton Bathampton Junction Bathampton Hampton Row Halt 107⅓ Bath Spa 108⅓ Oldfield Park Somerset & Dorset Joint Railway Twerton-on-Avon Twerton Tunnel Saltford Tunnel Saltford 113¾ Keynsham St Anne's Park No 3 Tunnel 1017 yd 930 m St Anne's Park No 2 Tunnel 154 yd 141 m St Anne's Park River Avon North Somerset Junction Bristol & North Somerset Railway St Philip's Marsh TMD Cross Country Route to Gloucester & Birmingham New Street to Mangotsfield to Ashton Gate Platform 116½ Bristol Temple Meads Bristol West Junction Temple Meads Goods Bristol–Exeter line

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.

History

The first section of the Great Western Railway was opened from London to a temporary station on the east side of the Thames at Maidenhead on 4 June 1838. The remaining line was opened in stages as the engineering works were completed:

• Maidenhead to Twyford — 1 July 1839
• Twyford to Reading — 30 March 1840
• Reading to Steventon — 1 June 1840
• Steventon to Faringdon Road — 20 June 1840
• Faringdon Road to Wootton Bassett Road — 17 December 1840
• Wootton Bassett Road to Chippenham — 31 May 1841
• Chippenham to Bath — 30 June 1841
• Bath to Bristol — 31 August 1840

The original 84 broad gauge was supplemented in various stages between 1854 and 1875 by a third rail to allow standard gauge 4 ft 8+1⁄2 in (1,435 mm) trains to operate over the route, but the broad gauge rail was retained until the last empty trains had been worked back from Penzance on 21 May 1892. The dates that the sections were mixed were:

• 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 original two tracks have been widened to four at several places:

• 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

Services

Main line and local services are provided by First Great Western (FGW). The stations served by express trains between London Paddington and Bristol Temple Meads are: Slough, Reading, Didcot Parkway, Swindon, Chippenham, Bath Spa and Keynsham. Not all trains call at all of these stations, especially Slough, Didcot and Keynsham.

Fast trains from Paddington to London Heathrow Airport are operated by BAA as the Heathrow Express. Local services on this route are jointly operated by FGW and BAA under the Heathrow Connect name.

CrossCountry operate trains between Reading and Oxford, using the Great Western Main Line as far as Didcot and South West Trains operate a limited number of trains between Bath and Bristol.

First Great Western also operate a train between London Paddington – Cardiff Central (South Wales) every 30 minutes, with hourly extensions to Swansea. Additionally, 2–3 trains continue to Pembroke Dock on weekends during the Summer season to connect with ferry services to Ireland.

Infrastructure

The line speed is 125 miles per hour (201 km/h), having been upgraded during the 1970s to support the introduction of the Intercity 125 (HST). The relief lines from Paddington to Didcot are currently limited to 90 miles per hour (140 km/h) as far as Reading, and then 100 miles per hour (160 km/h) to Didcot. Lower restrictions apply at various locations.

It is one of only two Network Rail-owned lines to be equipped with the Automatic Train Protection (ATP) system, the other being the Chiltern Main Line. Network Rail intends to replace the ATP system with ETCS – Level 2 from 2017 to 2035 along with the introduction of the new IEP trains.

Approximately 12 miles of the line is currently electrified at 25 kV AC overhead between Paddington and Airport Junction, the junction with the line to London Heathrow Airport near Hayes.

Signalling Solutions is to resignal the 12 miles from Paddington to West Drayton, including the Airport branch, as part of the Crossrail project.

Associated routes

Trains on the Great Western Main Line are sometimes diverted from Reading along the Reading to Taunton line as far as Westbury, from where they can use the Wessex Main Line to reach either Chippenham, or Bath Spa.

Beyond Bristol, some trains continue on the Bristol to Taunton Line to Weston-super-Mare or beyond.

The 2007 Network Rail Business Plan includes the following routes as part of their Great Western Main Line (Route 13):

• Didcot to Oxford and Worcester via the Cherwell Valley Line and Cotswold Line
• Swindon to Cheltenham Spa via the Golden Valley Line
• Swindon to Cardiff Central and Swansea via the South Wales Main Line
• Cross Country Routes south of Birmingham
• All connecting branch lines.

Plans

Main article: 21st Century upgrade of the Great Western Main Line

Traffic levels on the Great Western Main Line are rising faster than the national average, with continued increases predicted. The now defunct Strategic Rail Authority produced a Route Utilisation Strategy (RUS) for the Great Western Main Line in 2005 to propose ways of meeting this demand. Network Rail planned to publish a new RUS by summer 2009; publication has been postponed to a scheduled date of early 2010, though a draft was issued for consultation in September 2009. In the meantime, their 2008 Business Plan highlights the large number of delays that can be reduced by improving the quality of the track, to which end a major renewal programme is underway from bases at Reading and Taunton. Further capacity improvements are also scheduled at Swindon, adding to recent changes and the new Platform 4.

Other more distant aspirations include resignalling and capacity improvements at Reading; the provision of four continuous tracks between Didcot and [Swindon (including a grade-separated junction at Milton, where the down (westbound) relief line switches from the north side of the line to the south); and resignalling between Bath and Bristol to enable trains to run closer together.

By 2016, there are plans for a direct rail link from Swindon to London Heathrow Airport. There are also calls for the reintroduction of a station at Corsham due to recent growth of the town. The original station was closed to passengers in 1965.

Reading station is currently undergoing a major redevelopment. Access to Heathrow Airport from the west remains an aspiration and there is a proposed future link to Heathrow Airport directly from Reading under the Heathrow Airtrack scheme which would use a route south of the Great Western Main Line. Under the plans for electrification of the Great Western announced in July 2009, it would make it easier to access Heathrow from Reading via the Great Western since the lack of electrification between Reading station and Heathrow Airport Junction near West Drayton station was a limiting factor.

Electrification

The line is electrified only between London Paddington and Airport Junction, which allows Heathrow Express and Heathrow Connect trains to operate. This electrification will be extended as far as Maidenhead as part of the Crossrail project. On 23 July 2009 it was announced that the Government planned to electrify the entire line to Bristol and also the line from Swindon to Swansea within the next eight years. This would coincide with the introduction of new Super Express trains. These would be electric trains, rather than diesel version previously planned. This was expected to lead to a decrease in journey times and would also potentially allow Crossrail services to be extended to Reading in the future.

The scheme announced by the Government on 23 July 2009 stated that, "work will begin immediately on the electrification of the Great Western Main Line between London, Reading, Oxford, Newbury, Bristol, Cardiff and Swansea, to be completed within eight years" (2016/2017). The electrified route would include the whole of the Great Western Main Line, the South Wales Main Line from Swindon to Swansea via the Severn Tunnel, and the connecting line from Bristol Parkway to Bristol Temple Meads stations. It was unclear if any parts of the line would be upgraded to a higher speed at the same time.

Network Rail plans to install European Rail Traffic Management System (ERTMS) in-cab signalling on the Great Western line, which is a pre-requisite to allowing the new Super Express trains to run at 140 mph (225 km/h). Some or all of the resignalling work will be carried out alongside the electrification work.

As of July 2010, the whole Great Western electrification scheme was put on hold pending a return on investment review by the new government. Rail improvement plans announced by the new government on 25th November 2010 did not confirm this electrification plan. The plan to replace the Intercity 125 fleet, which dominates this line included the possibility of continuing with diesel traction, implying electrification could be delayed indefinitely.

Transport Secretary Philip Hammond announced on 1 March 2011 that electrification would go ahead between London and Cardiff but that the business case for electrification to Swansea had not been made. Trains will switch to diesel power as they leave Cardiff .

Route

Communities served: West London (including Acton, Ealing, Hanwell – Southall – Hayes – Harlington – West Drayton) – Iver – Slough – Langley – Burnham – Taplow – Maidenhead – Twyford – Reading – Tilehurst – Goring-on-Thames – Streatley – Cholsey – Didcot – Swindon – Chippenham – Bath – Keynsham – Bristol

The main line was designed by Isambard Kingdom Brunel and opened in stages by the Great Western Railway between 1838 and 1841. It was originally a 84 broad gauge railway. Evidence of this can be seen at many places where bridges are a little wider than usual, or tracks ten feet apart instead of the usual six.

From London to Didcot, the line follows the Thames Valley, crossing the River Thames three times, including on the famous Maidenhead Railway Bridge. On this section, there are four tracks, grouped by speed with the "relief" lines on the north side of the "main" lines. Most smaller stations only have platforms in use on the relief lines. In August 2008, it was announced that a number of speed restrictions 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.

Didcot is home to the Didcot Railway Centre, a working steam railway museum. Soon after leaving Didcot, trains pass Didcot Power Station, a major source of freight traffic on the route with heavy coal trains running from Avonmouth near Bristol. Between Didcot and Wootton Bassett, there are a series of loop lines to allow fast trains to overtake slower ones. This section is also signalled for bi-directional running on each line but this facility is usually only used during engineering working or due to significant disruption to traffic in one direction.

Swindon, the next station, was the centre of the Great Western Railway and is still the headquarters for First Great Western. Leaving the station, trains pass the Swindon railway works on the north side of the line, now home to Steam - the Museum of the Great Western Railway. On the opposite side of the line is the "Railway Village", an area of industrial housing laid out for the employees of the railway workshops and a good example of early social housing.

At Wootton Bassett, the two different routes to Bristol — via Box Tunnel and via Bristol Parkway — allow flexibility. A third arrangement is to run via the Wessex Main Line but this involves a reversal at Bradford Junction so is only really suitable for multiple unit trains. A further diversionary route is available from Reading to Bath via Newbury.

• 
  London Paddington station
• 
  Didcot Power Station seen from a train
• 
  Challow, between Didcot and Swindon
• 
  Bristol Temple Meads

Further reading

• Pre-grouping Atlas and Gazetteer. Shepperton: Ian Allan Limited. 1976. ISBN 0-71100-320-3.
• MacDermot, E T (1927). History of the Great Western Railway, volume I 1833-1863. London: Great Western Railway.
• MacDermot, E T (1931). History of the Great Western Railway, volume II 1863-1921. London: Great Western Railway.