Crossrail is the name for a plan to build several underground railways through Central London, thus linking the mainline railways which surround the capital. This would allow services similar to the existing Thameslink system to run straight through the heart of London, stopping at a handful of stations on the way. The first line to be built will be Crossrail 1, which will run east-west via Paddington and Liverpool Street and is scheduled to open no sooner than 2015. The project is run by Cross London Rail Links Ltd, a company owned by Transport for London and the Department for Transport.

Background

In 1846, Parliament banned the construction of railway lines above the surface in Central London. The London and Birmingham Railway's terminus at Euston station had already been open for nine years, and was soon followed by many other cavernous buildings each housing a multitude of platforms and offering a variety of destinations. Railway companies simply kept going until they neared the capital's centre and then simply stopped - there was no point in going any further.

However, this sort of situation still persists today, with only the London Underground linking the mainline termini together. Passengers wishing to travel by rail either into or through Central London have to change from the mainline services to the tube to continue their journey, and this leads to longer journeys and crowding on the Underground. So far, a few solutions to the problem of traversing Central London without blocking up local services have been thought up:

• The Thameslink Service - North-south services through Central London first became possible when Snow Hill tunnel was opened in 1865 between Farringdon and Blackfriars. The tunnel allowed mainline trains to run from King's Cross and St Pancras to London Bridge and Elephant & Castle via Blackfriars, but was closed between 1969 and 1988 due to lack of use. However, the tunnel is now used by the Thameslink service which runs from Luton and Bedford in the north to Streatham and Brighton in the south, thus providing a direct mainline rail service passing beneath the centre of the capital.

• The Victoria Line - Opened between 1968 and 1971, the Victoria Line was built to alleviate the pressure on the Piccadilly Line whilst also linking a series of mainline railway stations. The line thus provides an express link between the termini at Euston, King's Cross, St Pancras and Victoria.

• The London Overground - The London Overground network provides an alternative way of solving the problem by bypassing Central London. Once completed, the network will encircle the capital, linking stations such as Clapham Junction, Willesden Junction, Highbury & Islington, Stratford and New Cross.

However, many journeys via Central London are still difficult, with a journey from Stratford to Heathrow seemingly taking forever due to the lack of a quick way of crossing London from east to west. Meanwhile, London's public transport is often tested by the sheer number of passengers travelling during peak hours.

The Solution

According to the UK Government, the solution to both these problems is a series of mainline railway tunnels under Central London, allowing passengers to avoid using local transport while increasing the capacity of London's transport in general. Though this sort of idea has been around since the end of WWII, the Crossrail scheme itself was first proposed in the late 1980s and has been steadily altering ever since. The scheme is comparable to the RER in Paris, which supplements the Paris Metro by providing a mainline service through the centre of the French capital. If built, the scheme would be the largest ever undertaken in the UK with an estimated cost of £15 billion¹. However, the first scheme, Crossrail 1, has had many complaints and setbacks, has been subject to much alteration, and actual construction is yet to begin.

Structure

Like the existing Thameslink service, each Crossrail line would consist of a large tunnel underneath Central London connected to existing mainline railways, thus allowing Crossrail trains to run off one mainline railway, through Central London and onto another railway on the opposite side of the capital. Any tunnels built would have to successfully navigate past the extensive network of tunnels that already exists, and would be very difficult and costly to build due to both the consistency of London's subsoil layers and the fact that each Crossrail line would require up to ten miles of tunnelling. Each tunnel would have to be accompanied by a series of emergency exits as well as a handful of stations with connections to London Underground, Docklands Light Railway and mainline stations.

The electric trains serving Crossrail 1 are to be powered by 25kV overhead lines as trains will then be compatible with the Great Eastern and Great Western Main Lines either side of London. The tunnels will therefore be 6 metres in diameter, making them much bigger than the 3.8-metre tunnels used by deep-level Underground lines. The platforms are to be 245 metres long - decidedly bigger than those on the London Underground - and stations will have at least two exits each so that a larger area can be served by each stop, as is already the case at City Thameslink station. All the new underground platforms will include platform-edge doors similar to those already in place on the Jubilee Line extension between Westminster and North Greenwich.

Operation

Trains are intended to run at up to 60mph inside tunnels and 100mph elsewhere with up to 24 trains per hour serving the most important stretches of line during peak hours, with 12 trains per hour off-peak. Trains in Central London would thus run up to every two-to-three minutes, with each Crossrail line then splitting into branches with fewer trains per hour once outside the city centre.

The trains used will be fully air-conditioned mainline trains consisting of ten carriages each, making them 200 metres long with a capacity of 1,500 passengers each. As all Crossrail platforms are to be made 245 metres long, two more carriages could be added to each train once the demand for a particular Crossrail service increases. However, shorter five-carriage trains would be used after 9pm and during weekends and bank holidays. The trains will be carefully designed with large doors and large internal standing areas to allow passengers to board and alight quickly, with trains stopping for just 45 seconds at each station except for Paddington and Liverpool Street, where a whole minute will be allowed.

Crossrail 1

So far, Crossrail 1 has been the crux of the scheme and is the only line to have gone through the planning steps and then finally reached Parliament. The central section of the line has remained more or less the same since its conception during the late 1980s, and the course of the tunnels between Paddington and Liverpool Street has so far been safeguarded from building works.

Western Section

From Paddington, Crossrail 1 is to take over a pair of Great Western tracks towards Maidenhead, thus replacing the stopping services along that part of the route. Crossrail 1 trains will also provide a stopping service from Paddington to Heathrow Central and Heathrow Terminal 4, thus replacing the Heathrow Connect service.

Central Section

The central section of Crossrail 1 is to lie mostly underground, with interchanges being made at existing Underground stations. The tunnels would begin near Royal Oak on the Great Western Mainline, diving underground a short way before Paddington station to call at a stop underneath Eastbourne Terrace. The tunnels would then pass underneath Bayswater Road and the Central Line to skim the northeast corner of Hyde Park before heading eastwards parallel to Oxford Street. The line would then run below some tube lines and above others while calling at Bond Street and Tottenham Court Road, with both stations being expanded to cope with the increase in passengers. No station will be built at Oxford Circus due to the fact that the station is already quite crowded and an exit will be provided from Bond Street station in the nearby Hanover Square.

Next, the line would pass underneath New Oxford Street and High Holborn to reach Holborn station, where no Crossrail stop is to be built but a shaft will be sunk to reach the line. After this the line will head towards Farringdon where an interchange will be made with the Underground and Thameslink stations at Farringdon and Barbican, with the Crossrail line then running underneath the Circle Line to reach Liverpool Street. The station at Liverpool Street has already been built and will be situated underneath the Moorhouse office development, allowing links to be built to both Liverpool Street and Moorgate Underground stations. After this the line would head straight for a stop at Whitechapel and would then run underneath Mile End Road and Stepney Green before splitting into two branches.

Eastern Section

Current plans have the first branch heading northeast towards Mile End Stadium and then running via Bow to Pudding Mill Lane, with the tunnels surfacing right next to the DLR station there. Trains would then run onto the mainline out of Liverpool Street, with the Crossrail 1 trains replacing the Liverpool Street - Shenfield stopping service.

Meanwhile, the other branch is destined to head south-east to reach the Limehouse Basin, following which it will call at a station towards the north end of the Isle of Dogs. The Isle of Dogs station will actually be situated underneath and upon its own little island in the middle of the North Dock, with footbridges providing access from West India Quay. The line would then take over the disused North London Line station at Custom House, and would then pass under the Thames to reach Abbey Wood station on the North Kent Line (Woolwich to Dartford). However, there are no longer any plans to run Crossrail trains along the line towards Dartford or Ebbsfleet, with the Abbey Wood station acting as an interchange with mainline service instead. At one stage, Crossrail also pushed for a station at Woolwich, but this was deemed to be too expensive by the government.

Alternative Branches

In 2002, six 'corridors' which Crossrail 1 might follow outside of Central London were proposed, with the public being consulted on each one to determine which of the schemes might be the most favourable with local residents.

• Corridor 1 - The Watford Junction Line (Euston - Watford Junction)
• Corridor 2 - The Aylesbury Line (Marylebone - Aylesbury)
• Corridor 3 - The Great Western Main Line (Paddington - Maidenhead/Reading)
• Corridor 4 - The Great Eastern Main Line (Stratford - Shenfield)
• Corridor 5a - The North Kent Line via Royal Docks
• Corridor 5b - The North Kent Line via Charlton

While Corridors 3, 4 and 5a will now be included in Crossrail 1, Corridors 1 and 2 will either become part of later Crossrail lines or will simply never be included. Due to the busy nature of Corridor 4, this leaves the plans for Crossrail 1 lopsided, with more trains running to the east than to the west.

However, in 2003 a Corridor 6 between Turnham Green and Kingston was proposed, with plans having Crossrail take over the District Line between Turnham Green and Richmond, following which trains would follow the suburban mainline via Strawberry Hill. This made the plan very unpopular with the residents of Richmond, who would lose their tube service into Central London and would also lose a few of their houses to the line development required. Corridor 6 was thus dropped despite its popularity with Kingston residents.

In 2004, a proposal was made by Hounslow Council to run trains out of Paddington along a Corridor 7 towards Hounslow via Acton Central. This route would not require any extra tunnelling work, and is thus a better candidate for an extra western corridor that the rejected Corridor 6. Despite this, neither scheme is to be included in the Crossrail 1 scheme.

One final possibility is the extension of Crossrail 1 along the North Kent Line to reach Dartford and Northfleet, thus allowing a link with the Channel Tunnel Rail Link (CTRL) and thus a through-route from Paris to Maidenhead². However, this seems unlikely due to the fact that the CTRL already allows trains to reach London St Pancras, which lies quite near to Euston and King's Cross and from which trains towards the north can easily be caught.

Services

As mentioned above, trains will run at up to 24 tph³ in Central London during peak times. This would mean 24 trains per hour split evenly between the Shenfield and Abbey Wood branches, in other words 12 tph each. However, due to the higher requirements of the eastern section compared to the western branches, all trains from Shenfield and two trains per hour from Abbey Wood will terminate at Paddington, thus leaving only 10tph to continue west towards Hayes & Harlington. From here, 4tph will head for Heathrow and 6 tph will head to West Drayton, with two terminating at the latter to give 4 tph to head on from West Drayton towards Maidenhead.

As mentioned above, Crossrail 1 trains will replace the local stopping services along the Liverpool Street - Shenfield and Paddington - Maidenhead routes, with a semi-fast Great Western service running along the latter to serve Ealing Broadway, Maidenhead, Twyford and Reading. However, the fact that Crossrail 1 will take over the so-called 'Relief' tracks along the Great Western Mainline up to Maidenhead will force all other trains onto the intercity line, possibly resulting in slower services to places such as Oxford, Reading, Bristol and Cardiff. Finally, Crossrail 1 trains to Heathrow are to replace the Heathrow Connect service from Paddington, as opposed to the Heathrow Express service.

Beneficial Effects

Once fully up and running, Crossrail 1 will alleviate the pressure on the London Underground and will reduce crowding at Liverpool Street and Paddington. Many passengers travelling from east to west through London will no longer need to use the northern half of the Circle line, and the Piccadilly line towards Heathrow will experience similar relief as passengers use the Crossrail service instead. Crossrail will be able to provide much faster services than the tube, with a journey from East London to Heathrow taking just 43 minutes. Crossrail 1 will make travelling from one side of London to the other much easier, while also making areas such as Oxford Street more accessible to those living near the Great Eastern and Great Western mainlines. The scheme will also improve London's financial prospects by bringing businesses into the capital.

Opposition, Controversy and Other Issues

• As mentioned above, the priority to be given to Crossrail trains between Paddington and Maidenhead could result in disruptions to intercity services to Reading and beyond. Meanwhile, the Rail Freight have complained that Crossrail 1 will interfere with freight running along the lines out of Liverpool Street and Paddington, and that Crossrail will take over goods yards which are badly needed by freight operators. They fear that if Crossrail 1 is built, it will force freight traffic back onto the roads.

• Original plans involved Crossrail taking over the much faster Heathrow Express between Paddington and Heathrow, with Crossrail running all the way to Terminal 5. However, this would have reduced the frequency of fast trains to the airport and would also have prevented the construction of the Airtrack scheme to allow trains to run from Terminal 5 to Waterloo via a link line underneath Staines. Also, the replacement of Heathrow Express rolling stock, which is designed to transport passengers with heavy luggage, with Crossrail's commuter trains would cause further problems. The plans were therefore opposed by BAA, and the plans were therefore changed so that Crossrail would take over the Heathrow Connect service to Terminal 4, thus keeping Terminal 5 free for the Heathrow Express and Airtrack.

• Although some iterations of Crossrail 1 have excluded stations at Forest Gate, Manor Park and Maryland from the service, complaints from organisations such as the London Transport Users Committee (LTUC) have led to their inclusion. Although the platforms at Maryland are too short to properly serve ten-carriage trains, Crossrail trains are now planned to serve the stop by using selective door opening⁴.

• Meanwhile, it remains slightly unclear as to whether Crossrail 1 trains running between Paddington and Ealing Broadway will call at Acton Main Line station, although not doing so would upset local residents through the removal of an important rail service.

• Though supported by the LTUC, stations at Woolwich and Silvertown are not to be included in Crossrail 1, although provisions will be made to facilitate their construction at a later date. The cost of the stations has so far been the limiting factor for the Woolwich station, but its rejection by the government as too costly is seen by some as a sign that they are taking Crossrail seriously.

• Plans for the construction of new entrances to Tottenham Court Road tube station to allow for integration of Crossrail 1 and possibly Crossrail 2 include the demolition of the Astoria Theatre on Charing Cross Road. This move will require the support of the local council, who have so far remained unsatisfied as to the need for the demolition of the theatre.

• Earlier plans for the Crossrail 1 involved the construction of a boring hole in the middle of the East End, thus allowing the tunnels to be bored both towards and away from the City of London at the same time. However, the idea of six years of non-stop work in Hanbury Street, just off Brick Lane, did not please the borough of Tower Hamlets, who successfully petitioned to have the tunnel built end-to-end instead. Hanbury Street will now instead be home to a much smaller ventilation shaft.

• There are fears that the tunnelling under Central London will cause uneven subsidence, thus endangering many Victorian, Edwardian and Georgian houses along with 47 different listed buildings. Those at risk include Paddington station, the Barbican Centre, Centre Point, the London Palladium and Smithfields meat market. Crossrail engineers are to inspect around 300 buildings before construction begins, and measures will be put in place to minimise damage due to settlement.

• Up to 35 families in Shenfield may have to leave their houses for several months while construction work takes place, with over a hundred houses in total qualifying for sound-proofing grants if the scheme goes ahead. Meanwhile, residents of Clerkenwell have been warned that they will face 'sleepless nights' due to extended work on the Thameslink/Crossrail interchange at Farringdon, and many other areas are also likely to be affected by building works.

• Plans for construction of a maintenance depot at Romford led to the formation of the Romford Crossrail Action Group, who are now successfully fighting its construction. The depot would cause much disruption to the local area and would take over part of some nearby playing fields.

SuperCrossRail and Superlink

In 2002, GB Railways proposed an alternative route for Crossrail 1 between Paddington and Isle of Dogs entitled SuperCrossRail. The plans included several changes to expand the line outside Central London, but the most interesting changes made were to the central section. From Paddington, this alternative line would head southeast via Park Lane to reach Charing Cross, with a station being constructed there beneath the River Thames. From there the line would run underneath the river bed to call at Blackfriars and London Bridge, and would only come out from beneath the Thames for the final section next to Isle of Dogs. The line and stations would be constructed using coffer dams, which would allow efficient access via the river bed. However, Cross London Rail Links Ltd rejected the plan, stating that it would have too great an environmental impact, and that the location of stations beneath the river would make access difficult for passengers and emergency services alike.

However, in December 2004 Superlink Ltd put forward another alternative entitled Superlink due to the belief that Crossrail 1 won't make the best use of the corridor between Paddington and Liverpool Street. Their first proposal involved the line calling at King's Cross instead of Tottenham Court Road, with many extra branches being added outside Central London in order to serve Northampton, Reading, Basingstoke, Guildford, Cambridge, Ipswich, Southend and Tilbury. The most recent Superlink plans now consist of the planned Crossrail 1 route between Paddington and Liverpool Street, but with a hub at Canary Wharf providing links to mainline services towards Cambridge, Stansted, Ipswich, Southend and Pitsea. Meanwhile, trains to Maidenhead would continue all the way to Reading, while a link between Heathrow and Staines would allow trains to run from Paddington to Woking and onwards to Basingstoke and Guildford. Cross London Rail Links Ltd have so far rejected Superlink, partially due to the fact that running Crossrail/Superlink trains onto more and more congested local lines would make the system too difficult to handle and would result in many delays.

Crossrail 2

Though it is unlikely that any further Crossrail lines will be built until Crossrail 1 has proven itself, provisions for a second scheme already exist. Crossrail 2 was first proposed in the form of the Chelsea to Hackney tube in 1970, an Underground line which would link the only areas of inner London which are not currently served by a tube line. The original proposal involved a line passing from Victoria to King's Cross via Tottenham Court Road, which once outside the city centre would take over the District Line between Wimbledon to Parsons Green along with the Leyton to Epping section of the Central line. The proposed tunnel route between Parsons Green and Leytonstone was safeguarded from construction in 1991, but is now likely to be discarded in favour of Crossrail 2.

Crossrail 2 would consist of a tunnel between Victoria and King's Cross, with the route extending to Clapham Junction to the south, possibly via Battersea, and to Dalston and Hackney to the north. In Central London, stops would be constructed at Victoria and King's Cross along with a station at Tottenham Court Road to allow interchange with Crossrail 1. The service might also include a link between Heathrow Airport and Clapham Junction via Staines along with a link to Stansted Airport via Epping and Harlow. One further possibility would be the extension of Crossrail 2 from King's Cross to Finsbury Park and then along what is now the Parkland Walk to reach Highgate, thus allowing Crossrail 2 to take over parts of the Northern Line.

Crossrail 3

A third Crossrail scheme has also been mentioned in passing by the Mayor of London, but so far no plans have been made for its construction. Crossrail 3 would most likely run from Euston to Waterloo, thus connecting Corridor 1 (Euston to Watford Junction) with a variety of services towards the south. It is possible that Crossrail 2 and Crossrail 3 will be considered as mutually exclusive due to the fact that they both share the same north-south concept, thus making one of them superfluous.