21st Century upgrade of the Great Western Main Line

The upgrade programmes for the Great Western Main Line, its South Wales branch and other associated lines were announced at separate times but their development timescales overlap each other to represent a comprehensive upgrade to the Great Western and its associated lines during the second decade of the 21st Century. The upgrades include: electrification, resignalling, new rolling stock and station upgrades.

Historical background
At the start of the 21st Century, the Great Western Main Line was the last of the major main line routes in the UK to be using diesel trains as the main source of locomotive power. When the announcement was made in July 2009 to electrify the Great Western (along with the Liverpool-Manchester line), it represented the first big rail electrification project in the UK for 20 years. The South Wales Main Line branch of the GWML is set to be the first electrified cross-country railway line in Wales. The plan to upgrade the rolling stock on the Great Western was included in the Intercity Express Programme (IEP) announced in 2007, a Department for Transport (DfT)-led initiative to replace the ageing fleet of InterCity 125 and InterCity 225 train sets currently in use on much of the UK rail network.

Electrification
At present, the only electrified portion of the Great Western is between London Paddington and Airport Junction (west of Hayes and Harlington). This portion of the Great Western is equipped with a 25 kV AC overhead system which was implemented for the Heathrow Express service. The electrification will be extended from Airport Junction to Maidenhead under the Crossrail scheme. Further electrification west of Maidenhead was announced by the DfT separately.

July 2009 Announcement
The UK government first considered electrifying the Great Western between London and Bristol in a first phase, then electrifying the rest of the line between Swindon to Swansea at a later date. However, in July 2009, the Department of Transport under the then Labour Party (in the run-up to the 2010 UK General Election), announced that there would be a £1 billion programme to electrify the whole of the Great Western from London to Swansea as well as to Bristol. The Labour government claimed that the investment would pay for itself over a 40-year period. 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 proposed electrified route will include: Estimates showed that the Hitachi Super Express trains could reduce journey times from London Paddington to Swansea by 19 minutes. In an effort to minimise disruption during the electrification works, Network Rail is developing new "factory engineering trains" to facilitate the process of installing overhead lines. There will be three types of trains: the first train will be used to install pylons, followed by a train to hang the wires and finally there will be a train which will check the installation. The system is expected to be able to install 1.5 km of electrification in one eight hour shift. In its initial survey, Network Rail identified 113 structures - mainly bridges and tunnels - which require modification. One structure which could pose major difficulties is the Severn Tunnel with rail expert Christian Wolmar commenting "It's pretty wet and damp in there, and there might not be enough room to electrify it without digging out the tunnel somewhat, so it will be a big barrier." The experience gained by the constructors of the Simplon Tunnel and Gotthard Base Tunnel in Switzerland may help to solve the problems. These tunnels make use of twin overhead rails to supply the electric power rather than suspended catenary wire.
 * the Great Western Main Line between London Paddington and Bristol Temple Meads via Bath Spa;
 * the South Wales Main Line from Swindon to Swansea via the Severn Tunnel;
 * the connecting line from Bristol Parkway to Bristol Temple Meads stations;
 * the section of the Cherwell Valley Line connecting Didcot with Oxford; and
 * the section of the Reading to Plymouth Line connecting Reading with Newbury.

Review and announcements after May 2010 general election
After the 2010 UK General Election in May 2010, the coalition Conservative/Liberal Democratic alliance placed all major government capital expenditure, including the Great Western electrification scheme on hold pending a return-on-investment review. In November 2010, Transport Secretary Philip Hammond gave the go-ahead for the line from Oxford via Didcot and Newbury to London to be electrified in the next six years. Extension from Didcot to Swindon, Bath, Bristol and to South Wales would be dependent on a further assessment due in 2011 of the costs and implementation requirements of the Intercity Express Programme. On 1 March 2011, transport secretary Philip Hammond announced that rail electrification from Didcot Parkway to Bristol Temple Meads and Cardiff Central would go ahead. The section linking Bristol Parkway and Bristol Temple Meads would also be electrified.

Current systems
The Great Western Main Line is currently equipped with colour light signalling common to the rest of the United Kingdom. At the time of the Ladbroke Grove rail crash, the ATP (Automatic Train Protection) warning system was under trial. In response to the Ladbroke Grove crash, it became a requirement for First Great Western trains to have all their trains to be fitted with ATP.

Future systems
When the Department for Transport first released the train specification for the new trains for the Intercity Express Programme in November 2007, it was stated that the Great Western Main Line would be upgraded to ETCS level 2 and ERTMS Level 2 in-cab signalling. Some or all of the resignalling work will be carried out alongside the electrification work.

Thames Valley
In November 2008, Westinghouse was awarded a £20 million contract for a 30 month programme of signalling enabling work. Over a series of 12 commissionings, Westinghouse will re-lock the existing Reading Station and Spur interlockings to three new WESTLOCK units, re-control the remaining 18 relay interlockings and move signalling and telecommunications control from Reading Station to the new Thames Valley Signalling Centre at Didcot. The work culminates in a final commissioning, scheduled for 5 December 2010 and paves the way for future stages of the remodelling programme. The Thames valley signalling centre will eventually replace older signalling control: The 1960s/70s PSBs at Oxford, Reading, Slough and the 1990s Swindon B and Slough IECCs. The centre could also take over control of the Cotswold line and interface with the West Midlands Signalling centre on both the Cotswold and Banbury lines.

South Wales
The first phase of a £400m, 10-year resignalling scheme in South Wales by Network Rail was carried out on a 22 mi stretch between Port Talbot and Bridgend (termed Port Talbot East) in 2006/2007. The works provided a new turnback facility in both directions at Port Talbot Parkway if required. The renewals replaced an old British Railways Western Region NX panel installation, dating from 1963. Railway technology has evolved somewhat since 1963 and the renewals will make some signalling facilities redundant. Further signalling renewals are programmed for the Newport area (which will be implemented in two phases), Cardiff and Port Talbot West. The first phase of the Newport Area remodelling and resignalling began in 2009 and is expected to be completed by the end of 2010. The first phase covers the stretch of line between Patchway and Marshfield to the west of Newport. A new control centre for south Wales, the South Wales Control Centre, built on the eastern end of Canton Depot in Cardiff opened in Spring 2009. The signals implemented in Newport Area resignalling phase 1 will be the first have control transferred to the South Wales Control Centre and once Phase 2 of the Newport Area resignalling is complete in 2011, the Newport signalbox will be closed. Control will pass to the South Wales Control Centre for other parts of the south Wales network as resignalling progresses.

Long distance inter-city services
Services from London Paddington to south west England and south Wales are currently served by Class 43 "InterCity 125" train sets. The Intercity 125 trains were built between 1975 and 1982 and due to their age are set to be replaced by new Hitachi Super Express train sets. The "Intercity 125" trains are the fastest trains on the Great Western, capable of 125 mph. The new Super Express trains will have the same top speed of 125 mph but are capable of 140 mph with minor modifications. The upgrading of the signalling on the Great Western to in-cab signalling is one pre-requisite to allow the new Super Express trains to run at 140 mph. In the 2010 GWML RUS Network Rail stated that linespeeds in excess of 125 mph west of Reading would be "reviewed in line with electrification and resignalling opportunities as ERTMS becomes deployed across the RUS area" after Control Period 4 (2014–2019). The new Hitachi Super Express trains are to be delivered from 2013. The new Hitachi Super Express trains planned for the Great Western inter-city services will now be predominantly electric units instead of the planned diesel units. However, a proportion of the fleet will be using dual power source electro-diesel bi-mode trains, which will enable services to operate to Swansea before line electrification reaches Swansea. The bi-mode trains will allow inter-city services to operate from London directly to places in South Wales and south west England, which electrification does not extend to under the current electrification proposals, like Carmarthen, Worcester, Gloucester, Cheltenham and the regions to the south west of Bristol. The new Super Express trains will bring about an estimated 15% increased capacity during the morning peak hours.

Thames Valley commuter services
Thames Valley commuter services, from London Paddington to Reading and to Oxford are currently served by a combination of Class 165 "Network Turbo" and Class 166 "Network Express Turbo" 3 car DMUs which are capable of operating at 90 mph. These trains will be replaced by the Class 319 4-car 100 mph trains currently used on Thameslink, after refurbishment. The UK Government's plans are to replace the Network Turbo trains with the Class 319 trains from the end of 2016. The Network Turbo/Network Express Turbo trains would then be transferred for use for services in the Bristol and South West area (see Bristol Metro scheme below).

Crossrail
It is planned that 65 new trains are to be constructed for use on Crossrail. These will be electric multiple units and are planned to have speeds up to 100 mph on the surface parts of the route and up to 60 mph in the tunnels. It is envisaged, as part of the government's rolling stock plan, that the stock for Crossrail will be similar to the new rolling stock planned for the Thameslink Programme and will displace other types of multiple unit currently used on the Great Eastern and Great Western routes for use elsewhere on the network.

Station upgrades
Several stations along the Great Western are under going redevelopment or have recently be upgraded to cope with growing passenger numbers and to ease rail traffic congestion.

Bristol Parkway
Bristol Parkway had a new third platform (Platform 4) completed in 2007 to provide a new platform for trains departing to London and Birmingham and to make services more reliable between London and south Wales. A new fourth platform is planned on the south side of the station.

Reading
On 10 September 2008, Network Rail unveiled a £400 million regeneration and reconfiguration of Reading railway station and surrounding track incorporating an overpass system to the West of the station; with freight and passenger trains able to transit from the Reading to Plymouth Line and Reading to Basingstoke Line to the 'slow' lines without crossing the 'fast' lines via an underpass beneath the 'fast' lines, rather than the conventional points in place. This is planned to help alleviate current delays, due to slow moving freight service passing through the station. As well as the reconfiguration of the track, five additional platforms are planned to be added; the terminal platforms for services to/from London Waterloo will be altered and the Cow Lane bridge under the tracks will be made two-way and include a cycle path. There will be improvements that will allow the capacity for at least four extra trains in each direction every hour. The station will receive: These plans provide for possible future Crossrail and Airtrack services at Reading station, building a railway that will be fit for at least the next thirty years. Network Rail are also examining options to: Also, the improvements will allow six new freight trains each day - this could take around 200 lorries a day off the roads. Rail freight has only a quarter of the carbon footprint of moving freight by road, meaning this project will contribute to reductions in carbon and congestion.
 * Five new platforms to ease overcrowding
 * A new foot-bridge between platforms
 * New escalators and lifts
 * A new northern entrance for the station will improving the link through the station between Reading town centre to the Thames (Caversham).
 * Improve the station concourse
 * Provide new facilities such as improved ticketing
 * Enhance cycle facilities.

Newport
In 2009, an upgrade to Newport railway station was started to enable the station to cope with the expected passenger traffic associated with the 2010 Ryder Cup. A new passenger bridge and two new terminal buildings were constructed with each platform being served by a lift. The new bridge is clad in Ethylene tetrafluoroethylene (ETFE), the material which protects the Eden Project in Cornwall. The new development at the station includes a new multi-story car park and a new bus station will be developed outside, replacing the existing Newport bus station.

Cardiff Central
Extra platform capacity at Cardiff Central will be introduced in the form of a new bay platform (platform 5 ) for services between Cardiff and Maesteg along the GWML and two new through platforms to the south of the station (platforms 8 & 9) for the Cardiff urban services to cater for up to 16 trains per hour. This will bring the total number of platforms from 7 to 10. Redevelopment of Cardiff Central bus station outside the railway station commenced in 2008.

London Paddington
Between 2009 and 2015, a new Crossrail station will be built under London Paddington, serving as both a connection to National Rail services, as well as London Underground. Services are due to start in 2018. Network Rail had planned to demolish the arched section to the northeast of Paddington station, known as Span 4. Span 4 was an extension which was completed in 1916 but has since fallen into disrepair. An internal blanket was erected in the 1990s to protect people from falling glass. Span 4 was to be replaced by an office block over the rails. It was later decided that Span 4 would be restored. The restoration of Span 4 is taking place between 2009 and 2010.

Severn Tunnel Junction
Severn Tunnel Junction serves as a Park and Ride station for commuters from southern Monmouthshire to Bristol, Newport and Cardiff and there is a local action group - the Severn Tunnel Action Group (STAG) who are campaigning to enhance Severn Tunnel Junction's status as a transport hub for the southern Monmouthshire area. As of January 2010, Network Rail have remodelled the tracks around the station, re-opened Platform 4 and modernised the parking and passenger facilities. The junction where the Gloucester to Newport Line joins the South Wales Main Line has moved west of the station and now joins the main line with high-speed turnouts.

Crossrail
Crossrail is a major rail scheme to develop new railway connections under Central London. The western portion of line will connect with the Great Western Main Line near London Paddington. The current plans are for Crossrail services to terminate at Maidenhead in the west. However with the rail electrification of the Great Western now being extended westwards beyond Maidenhead, past Reading, the Department of Transport is now considering extending the service to terminate at Reading from the outset. Some of the suburban services which traverse the GWML into London Paddington will be transferred to the new Crossrail service, which will in turn free up some capacity at the surface level station at London Paddington.

Connections to Heathrow Airport
Heathrow Airtrack is a new service proposed by Heathrow Airport's operator BAA. If the proposals are realised Heathrow Airtrack would mostly use existing railway lines which would connect Heathrow Terminal 5 with Reading railway station via a southerly route on the disused southern portion of the former West Drayton to Staines railway line. The scheme would also provide direct services to Guildford and London Waterloo. However, the Heathrow Airtrack scheme faces opposition in several of the settlements which trains will cross. (see main article for more details and references) The Windsor Link Railway is a proposed scheme which would provide an additional or alternative route to the one defined in the Heathrow Airtrack proposal to link Reading with Heathrow Airport. If Heathrow Airtrack does go ahead, the link between Heathrow Terminal 5 and Staines could be used. Otherwise an alternative link can be provided by building a new bridge over the M25. (see main article for more details and references) With the confirmed electrification of the Great Western Main line west of Airport Junction, local authorities in the Thames Valley identify a case to be made for introducing a service to Heathrow Airport from Reading via the Great Western, which would also serve Maidenhead and Slough.

Greater Bristol Metro scheme
The Greater Bristol Metro scheme is a proposal to improve the rail services in Bristol and the surrounding region first proposed at First Great Western's Stakeholder Event in March 2008. The aim of the project is to develop half hourly services through central Bristol which will also serve the surrounding West of England region. Transport campaigning group, Transport for Greater Bristol are actively supporting the proposal.

Swindon-Kemble redoubling
The Golden Valley Line serves as a diversionary line for several other lines in the area as well as serving its normal traffic. It will be a major diversionary route during the electrification of the Great Western Main Line. The portion of line between Swindon and Kemble is currently a single track line which limits capacity. On the 23rd March 2011 in his Budget Speech the Chancellor of the Exchequer, George Osborne MP approved the project after several years of campaigning by local politicians to re-double this section of line.

Controversies
Some press reports state that passengers face six years of disruption from the electrification work. Over 100 bridges and tunnels face demolition or modification work to accommodate the new overhead lines. There are railway experts who are doubtful about the feasibility of electrification being deployed in the Severn Tunnel, stating that the tunnel may need to be enlarged and that the tunnel may be too wet and damp. The announcement to electrify the Great Western led to the government changing their plans to purchase a new fleet of diesel trains consisting of 202 locomotives and 1,300 train carriages. The RMT union called for assurances that the plans will not have an adverse impact on jobs at the UK's only train maker Bombardier. In February 2010, it was announced the Intercity Express Programme (for long distance express services) was suspended pending an independent report, with a decision on its viability to be given after the 2010 UK General Election.

Developments timeline

 * 2007
 * November - DfT publishes specification for Inter City 125 HST replacement trains
 * 2009
 * 23 July - Electrification west of Maidenhead announced by Labour Government
 * 2010
 * 26 February - Plans for electrification (announced in 23 July 2009) west of Maidenhead suspended until after 2010 General Election
 * 25 November - Electrification from Maidenhead to Newbury and to Oxford announced
 * 2011
 * 1 March - Electrification from Maidenhead to Bristol and Cardiff announced