21st Century upgrade of the Great Western Main Line

Network Rail plans to spend £5 billion on modernising the Great Western and its South Wales branch plus other associated lines like the North Cotswolds which was completed in 2011. The modernisation plans were announced at separate times but their development time-scales overlap each other to represent a comprehensive modernisation plan for the Great Western and its associated lines during the second decade of the 21st Century. The modernisation include: electrification, resignalling, new rolling stock and station upgrades. According to Network Rail, the modernisation started in June 2010 and will end in 2017.

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, other than the Midland Main Line. 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
In 2009, the only electrified portion of the Great Western was 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, though the electrification west of Airport Junction (to take Crossrail to Maidenhead) and west of Maidenhead is likely to be done as one scheme.

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 Government (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:
 * the Great Western Main Line between London Paddington and Bristol Temple Meads via Bath Spa, Chippenham/Swindon;
 * 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 Taunton line connecting Reading with Newbury.

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. The vehicles are to be supplied by German firm Windhoff.

In its initial survey, Network Rail identified 113 structures - mainly bridges and tunnels - which require modernisation. One structure which some people suggest could pose major difficulties is the Severn Tunnel with rail writer 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."

Review and announcements after May 2010 general election
After the 2010 UK general election in May 2010, the coalition Conservative/Liberal Democrat 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.

In March 2012 Amey plc announced it had been awarded a £700 million contract to undertake the electrification works.

In July 2012, the UK Government announced that the final portion of the Great Western from Cardiff to Swansea would 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 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. Signalling Solutions is to resignal the 12 miles from Paddington to West Drayton, including the Airport branch, as part of the Crossrail project.

Thames Valley
In November 2008, Westinghouse (subsequently known as Invensys Rail, and now part of Siemens Rail Automation) was awarded a £20 million contract for a 30 month programme of signalling enabling work. Over a series of 12 commissionings, Invensys Rail will re-lock the existing Reading Station and Spur interlockings to three new WESTLOCK Interlocking 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 in the entire English Western region. The London area is due to switch over at the end of 2011, followed by the old Slough PSB (Power Signal Box) area. Attention will then be given to abolishing Oxford, Swindon A, Bristol PSBs and the 1990s Swindon B IECC. This will be followed by the elimination of the 1980s PSBs at Westbury and Exeter, and the 1970s Plymouth PSB, the 1960s PSB at Gloucester as well as substantial semaphore signalling in Cornwall.

The signalling is due to be overlaid with ERTMS control system level 2 from 2016.

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 148 mph but limited to 125 mph as are all trains in the UK except those on High Speed One. The new Super Express trains will have a 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 planned for the Great Western inter-city services will now be predominantly electric units instead of the planned diesel units. Although capable of 140 mph these new trains will be limited to 125 mph until pending operational improvements in track and signalling. Despite an absence of increased speed, increased acceleration and operational efficiency are expected to decrease the journey time from London to Bristol Temple Meeds by 22 minutes. 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, to which electrification does not extend under the current electrification proposals, like Carmarthen, Worcester, Gloucester, Cheltenham and the regions to the south west of Bristol and Newbury. The new Super Express trains will bring about an estimated 15% increased capacity during the morning peak hours.

New servicing facilities for the new fleet of Inter-City Express trains will be developed at the London North Pole Depot, the Filton Triangle rail depot in Stoke Gifford and at Maliphant sidings in Swansea.

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" three-car DMUs which are capable of operating at 90 mph. These trains will be replaced by the Class 319 four-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 renovation and enhancements
Several stations along the Great Western like London Paddington and Reading are undergoing redevelopment or have recently been upgraded to cope with growing passenger numbers and to ease rail traffic congestion.

Bristol Temple Meads
Bristol Temple Meads will be expanded into Digby Wyatt's 1870s extension to the original train shed built by Isambard Kingdom Brunel in 1840 as the terminus for the Great Western Main Line. This part of the 'Old Station' building is currently in use as a car park, but will be remodelled as terminating platforms for services to London Paddington. To achieve rail access to the existing old platforms the Bristol power box, opened in 1970 and controlling 114 route miles of track, will need to be decommissioned and demolished.

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 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 Taunton Line and Reading to Basingstoke Line to the 'slow' lines via an underpass beneath the 'fast' lines, rather than the conventional at-grade crossing of the 'fast' lines via points as at present. 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 has been made two-way and now includes 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:


 * Five new platforms to ease overcrowding
 * A new foot-bridge between platforms
 * New escalators and lifts
 * A new northern entrance for the station, to serve the north side of the town and Caversham, and provide a link through the station between Reading town centre and the Thames.

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. Also, the improvements will allow six new freight trains each day - this could take around 200 lorries a day off the roads.

While the engineering work was carried out in 2010, First Great Western InterCity services had to be diverted. Trains to Devon and Cornwall ran from London Waterloo instead of London Paddington, using the South Western Main Line to Basingstoke, where the trains called to allow passengers to travel to Reading, then the West of England/Wessex Main Lines to Bristol Temple Meads, where it continued to Taunton and then along the normal route. Trains to Bristol, South Wales and Cheltenham still ran from London Paddington, but were diverted via the Chiltern Main Line and made an additional stop at Reading for passengers travelling to Oxford.

Newport
In 2009, an upgrade to Newport 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. The new north and south concourses opened on 13 September 2010. The development was criticised by RAIL magazine columnist Barry Doe for being at the wrong end of the station, having a leaking roof, a lack of seating and generally poor design.

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 one new through platform to the south of the station (platforms 8) 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 a connection to National Rail services and London Underground. Services are due to start in 2018.

Network Rail had planned to demolish the arched section to the north-east of Paddington station, known as Span 4. Span 4 was an extension completed in 1916 and the roof had since become dangerous. 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 took place between 2009 and 2010, and it re-opened in late 2011, looking notably brighter than the other three spans of the station.

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 been moved west of the station and now joins the main line with high-speed turnouts.

Swansea
A £7.6M Modernisation of Swansea station began in 2011 and was completed in June 2012. The renovation work included enlargement of the concourse, cleaning of the front of the station with a new entrance, replacement of the partition wall between concourse and platforms with a glazed wall, a new café and more shops.

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

Connections to Heathrow Airport
Heathrow Airtrack was a proposed new service by Heathrow Airport's operator BAA. If the proposals had been realised Heathrow Airtrack would have mostly used existing railway lines which would have connected Heathrow Terminal 5 with Reading station via a southerly route on the disused southern portion of the former West Drayton to Staines railway line. The scheme would have also provided direct services to Guildford and London Waterloo. However, the Heathrow Airtrack scheme faced opposition in several of the settlements which trains would cross. (see main article for more details and references) Many objections were because the line has many level crossings on main roads and the effect that additional trains would have on road congestion.

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 had gone ahead, the link between Heathrow Terminal 5 and Staines could have 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.

On 12 July 2012 Transport Secretary Justine Greening announced that a new rail link connecting Slough and Heathrow had been given the go-ahead and would be operational by 2021.

Greater Bristol Metro
This Greater Bristol Metro is a project to improve the rail services in Greater Bristol. It was first proposed at First Great Western's Stakeholder Event in March 2008. On 5 July 2012, the UK government and councils in and around Bristol agreed a City Deal whereby Bristol would have more funding for investment in the area. As a result of the City Deal, around £100M is expected to be invested in rail services under the Greater Bristol Metro scheme. As part of the work, the Cross Country Route between Bristol Parkway and Bristol Temple Meads, commonly known as Filton Bank, will be expanded from two to four tracks.

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 line between Swindon and Kemble is currently a single track line which limits capacity. On 23 March 2011 in his Budget Speech the Chancellor of the Exchequer, George Osborne, approved a project to re-double this section of line, after several years of campaigning by local politicians.

Further electrification in south Wales
During his announcement on the Great Western electrification on 1 March 2011, transport secretary Phillip Hammond stated that a good business case existed for the electrication of several south Wales commuter lines. In July 2012, the UK Government announced that the south Wales commuter lines would be electrified. The lines which would be electrified are: all Valleys & Cardiff Local Routes, the Ebbw Valley Railway and the Maesteg 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.

Some railway experts doubt the feasibility of electrification in the Severn Tunnel, stating that the tunnel may need to be enlarged and that the tunnel may be too wet and damp. However, experience from the Simplon Tunnel and the Gotthard Base Tunnel in which overhead conductor rails are used in place of overhead catenary wire may offer a solution to this.

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.