The Central London Railway (CLR) officially opened on 27 June 1900, with the railway opening to the public on 30 June 1900 and operating between Shepard‘s Bush and Cornhill, not far from modern day Bank, with 13 immediate stations. The railway quickly became known as the twopenny Tube after the single fare that was introduced across the line. The line was successful from the beginning and quickly began looking at ways of improving the passenger service. The railway proposed a series of extensions, such as the loop line which was rejected, however the railway was extended to Wood Lane in 1908, Liverpool Street in 1912 and Ealing over the GWR route in 1920. Despite the popularity of the route, the railway began to struggle and was taken over by the Underground Electric Railway Companies of London (UECL) in 1913. The railway was absorbed into the London Transport Passenger Board (LTPB) in 1933, when the railway was remaned the Central line along with a seires of extensions to the line which opened after the Second World War, and forms much of the line that we know today.

Proposing the Central London Railway

During November 1889 the Central London Railway (CLR) published notice that it was presenting a bill before parliament for the construction of an underground electric railway which would run from the junction of Queens Road (Queensway today) and Bayswater Road in Bayswater and King William Street in the clity, where an interchange would be provided with the, then still under construction, City and South London Railway (CSLR). The railway would run in a pair of tunnels running beneath Bayswater Road, Oxford Street, New Oxford Street, High Holborn, Holborn, Holborn Viaduct, Newgate Street, Cheapside and Poultry with stations constructed at Queens Road, Stanhope Terrace, Marble Arch, Oxford Circus, Tottenham Court Road, Southampton Row, Holborn Circus, St Martins Le Grand and King William Street.

The tunnels would be constructed using the tunnelling shield method with the tunnels lined in cast iron segments and with a diameter of 3.35m (11ft). The tunnels at stations would have a diameter of 6.71m (22ft) or 8.84m (29ft) depending on the layout of the station, passengers would access the underground platforms though hydraulic lifts, which would be provided at the stations. A depot and power generating station would be constructed west of Queens Road on a 0.61 hectare (1.5 acre) site.

The Metropolitan Railway and Metropolitan District Railway (MDR) strongly opposed the plans because the planned route paralleled the 'inner circle' route, which was currently under construction. There where objections from the City of London Corporation who where concerned with subsidence which had been an issue when constructing the City and South London Railway (CSLR), and the Dean and Chapter of St Pauls Cathedral also objected stating their concerns that the tunnelling could undermine the foundations of the cathedral. Despite the opposition the bill passed the House of Commons, but it was rejected by the House of Lords, who recommended that any derision to be made should take place after the compilation of the City and South London Railway (CSLR) and the railway was opened to be able to assess accurately.

The Central London Railway (CLR) entered a fresh bill into parliment in November 1890, with the City and South London Railway (CSLR) about to open, to extend the previous route eastwards to run underneath Nottling Hill High Street (Notting Hill Gate today) and Holland Park Avenue to end at the eastern corner of Shepard‘s Bush Green, the proposed depot and power generating station would be relocated to the northern terminus on the eastern side of Wood Lane. The route would also be extended westwards, inspired by the abandoned route of the London Central Subway, a subsurface railway was proposed briefly in 1890 which would run underneath the roadway following a similar route to the Central London Railway (CLR). An eastern terminus would be extended to Cornhill and the proposed station at Southampton Row would be replaced by a station at Bloomsbury, there would be immediate stations at Lansdowne Road, Notting Hill Gate, Davies Street (planned to be extended northwards to meet Oxford Street) and Chancery Lane. The plan to connect the railway to the City and South London Railway (CSLR) at King William Street was dropped and the diameter of the tunnels expanded to 3.51m (11ft 6in). This proposal was agreed by parliament and the bill received Royal Assent on 5 August 1891 as the Central London Railway Act 1891.

A further bill was entered to parliament during November 1891 by the Central London Railway (CLR) who proposed to reroute the north-eastern section of the railway and to extend beneath the Great Eastern Railway (Great Eastern Railway (GER)) terminus at Liverpool Street, the station at Cornhill would be relocated to the Royal Exchange. The proposed where approved and received Royal Assent on 28 June 1892 as the Central London Railway Act 1892.

The money needed to construct the Central London Railway (CLR) was obtained though a group of people who where financiers, the group incorporated a contractor to construct the railway, the Electric Traction Company Limited (ETCL), who had agreed to construct the railway for £2,544,000 (approximately £261 million today) plus £700,000 in a 4% credit note. The group offered 285,000 shares to the public for £10 each, however the public where cautions following the failure of other similar railway schemes. Some of the shares where sold in Europe and the United States of America, but the unsold shares where purchased by the group or Electric Traction Company Limited (ETCL).

The required legislation to construct the railway came with time limits for the compulsory purchase of land and for the rising of capital. The original date specified for the compleation for the construction was at the end of 1896, however the time needed to raise the required finances and to purchase station sits meant that the construction of the railway had not began. To obtain additional time the Central London Railway (CLR) obtained a time extension to 1899, with the Central London Railway Act 1864.

The construction works where let by the Electric Traction Company Limited (ETCL) as three subcontracts, Shepard's Bush to Marble Arch, Marble Arch to St Martins Le Grand and St Martins Le Grand to Bank. The construction works began with the demolition of buildings at Chancery Lane in April 1896, and the construction shafts had been started at Chancery Lane, Shepard‘s Bush, Stanhope Terrace and Bloomsbury between August and September 1896.

The woks beneath the Great Eastern Railway (GER) terminus at Liverpool Street where still in negotiations and where proving unsuccessful, a short final section beyond Bank was constructed for stabling. In order to reduce the risk of subsidence the railway was constructed beneath the road infrastructure and followed these to avoid passing beneath buildings, the tunnels where normally bored 18-34m (60-110ft) beneath the surface, however where the roads where too narrow to allow this the tunnels where constructed on top of each-other therefore some stations have platforms on different levels. To assist with deceleration and acceleration of trains at stations the station tunnels included a series of slight inclines.

The tunnelling had been completed by the end of 1898 however a planned concerete linking cast iron tunnel rings had not been installed and the internal diameter of the tunnels was generally 3.56m (11ft 8.25in). The Central London Railway (CLR) negotiated with the City of London Corporation to construct its ticket hall underneath the roadway and pavements at the junction of Threadneedle Street and Cornhill for Bank station. This involved diverting pipes and cables into ducts underneath the subways which linked the ticket hall to the street, these works became delayed and the works where costly and nearly bankrupted the company. Another time extension was needed to complete these works and this was obtained though the Central London Act 1900.

The station at Bank was the only station to be completely submerged, the rest of the stations where constructed with a single story station building, designed by Harry Bell Measures. The stations where constructed with the intention of expanding above the single story for commercial developments and had elevations which where faced with in a beige terracotta. Every station was supplied with lifts, each lift was configured for the passenger flow though the station which where operated in sets of two or three in a shared shaft. The tunnel walls in the station white finished with white ceramic tiles and lit using electric arc lamps. The electricity required to run the trains and stations was supplied by a power generating station located at Wood Lane which provided 5,000v AC and was converted using electrical substations along the railway converting the power to 550v DC to power the trains though the third rail.

Opening the Central London Railway

The Central London Railway (CLR) was opened by the Prince of Wales, later Edward VII, on 27 June 1900, one day before the time lapsed under the Central London Railway Act 1899, however the railway did not open to the public until 30 June 1900. The railway operated a single faire of 2d to travel between any two stations, giving the Central London Railway (CLR) the nickname ‘Twopenny Tube‘ from the Daily Mail in August 1900.

The service proved popular from the outset, and by the end of 1900 the railway had carried 14,916,922 Passengers. The railway attracted Passengers from the bus services along its route and the slower steam-hauled services of the Metropolitan Railway and Metropolitan District Railway (MDR). Within its first few years of operating the railway had attracted 45 million passengers per year, which generated a high turnover that was twice the operational costs of the railway.

The original plan was to haul the trains with a pair of small electric locomotives at each end of the trains, however these plans where rejected by the Board of Trade who insisted that a larger locomotive could be designed and was able to haul up to seven cars on its own. As a result 28 locomotives where manufactured in America by the Great Electric Company and assembled in the deport at Wood Lane. A further fleet of 168 carriages where constructed by the Ashbury Railway Carriage and Iron Company and the Bush Electrical Engineering Company.

Passengers would board the trains though a lattice gate located at the end of each carriage, where the gates would be operated by gate-men who rode on the outside platform. The Central London Railway (CLR) had originally planned on having two classes of travel, however this was dropped prior to opening this lead to the carriages being constructed to different qualities and differing interior fittings for this purpose.

Complainants about vibrations from passing trains where made by the occupiers of surrounding buildings began soon after the railway opened. The vibrations where caused by the heavy, largely unsprung locomotives which weighed 44.7 tonnes (44 ton) and the Board of Trade quickly set up a committee to investigate the problems, with the Central London Railway (CLR) exclaiming two solutions. The first solution was to modify three locomotives to use a lighter motor and to provide suspension to reduce the weight to 31.5 tonnes (31 ton) which would reduce vibrations because this was more sprung. The second solution was to form two six-carriage trains formed of two end carriages converted and provided with a drivers cabin and their own motors to allow them to operated as a multiple unit without a separate locomotive.

The lighter locomotives reduced the vibrations that where felt on the surface, but the multiple units removed the vibrations almost completely and the Central London Railway (CLR) chose to adopt that as a solution. The committee published its report in 1902 which identified the Central London Railway (CLR) decision to use a 49.6kg/m (100lb/yard) bridge rail for its tracks was much stiffer than the bullhead rail that was used on cross sleepers contributed to the vibrations.

Following the publication of the report, the Central London Railway (CLR) purchased 64DM carriages to be used with its existing rolling stock, which would be formed into six-or-seven carriage trains. The change to a multiple electric unit had been completed by June 1903 and all but two of the original locomotives where destroyed with the two remaining used for shunting in the depot.

Extending the Central London Railway

The Central London Railway (CLR) had managed its high passenger demand, however the service was constrained by the service interval it could achieve by the turn-around time at terminal stations because the locomotive had to be disconnected from the leading end of the train and ran around the rear to be reconnected to the other end to allow the train to proceed in the opposite direction, this took a minimum of 2.5 minuets. In order to reduce the interval the Central London Railway (CLR) entered a bill into parliament in November 1900 to construct loops at each end of the railway to allow the trains to be turned around without being disconnected. The loop at the western end would run anti-clockwise underneath three sides of Shepard's Bush Green. The eastern end loop had a series of proposals to run a loop underneath Liverpool Street mainline station or for a larger loop running beneath Threadneedle Street, Old Broad Street, Liverpool Street, Bishopsgate and then returning to Threadneedle Street. The estimated costs for constructing the two loops was £800,000 (approximately £78.1 million today) with most of the cost being for the eastern loop costing the most in way-leaves.

The Central London Railway (CLR) was one of many bills discussed for underground railways at the time. To review the bills, parliament established a committee, however by the time the committee had published its report it was too late for the session of parliament and the bills would have to be resubmitted. The committee recommended the withdrawal of the Central London Railway (CLR) city loop and that a quick tube route from Hammersmith to the City of London would be beneficial to commuters.

The Central London Railway (CLR) did not resubmit its bill, however the railway proposed a more ambitious alternative for the following parliamentary session. The railway had dropped the reversing loops, and the Central London Railway (CLR) proposed to turn the whole railway into a single large loop by constructing a southern section between the two end points adopting the committees recommendations for a route from Hammersmith to the City of London. New tunnels would be constructed at the western end of the railway from a dead-end reversing siding, the depot would be accessed though an access tunnel, the new route would pass beneath Shepard's Bush Green and run underneath the Goldhawk Road to Hammersmith Grove where the railway would tun south. The southern end of Hammersmith Grove station would be provided on the corner of Brook Green Road (Shepard‘s Bush Road today) which would provide an interchange for the three existing stations.

The Central London Railway (CLR) route from Hammersmith would run eastwards underneath Hammersmith Road and Kensington High Street with an interchange with the Metropolitan District Railway (MDR) station at Addison Road (Kensington Olympia today) and High Street Kensington stations. The route would then continue along the southern side of Kensington Gardens underneath Kensington Road, Kensington Grove and Knightsbridge with immerdiate stations constructed at Royal Albert Hall and the junction of Knightsbridge and Slone Street, where the Brompton and Piccadilly Circus Railway (B&PBR), later absorbed into the Great Northern Piccadilly and Brompton Railway (GNPBR), already had permission to construct a station. The railway would then continue following the approved route of the Brompton and Piccadilly Circus Railway (B&PBR) under its eastern portion of Knightbridge, underneath Hyde Park Corner and along Piccadilly to Piccadilly Circus, the Central London Railway (CLR) station at Hyde Park Corner would be sited close to the B&PBR and the Central London Railway (CLR) station at St James Street would be situated close to the Brompton and Piccadilly Circus Railway (B&PBR) station at Dover Street. The Central London Railway (CLR) planned an interchange station with the Brompton and Piccadilly Circus Railway (B&PBR) and partially constructed Baker Street and Waterloo Railway at Piccadilly Circus. The railway would then continue turning south-east underneath Leicester Square to a station at Charing Cross, then running north-east underneath the Strand to Norfolk Street where an interchange station was planned with the terminus of the Great Northern & Strand Railway, later absorbed into the Great Northern Piccadilly and Brompton Railway (GNPBR).

The railway would then continue eastwards beneath Fleet street to Ludgate Circus where an interchange station would be provided with the South Eastern and Chatham Railway (SECR) station at Ludgate Hill. The railway would then continue southwards underneath New Bridge Street tuning east into Queen Victoria Street where an interchange station would be provided with the Metropolitan District Railway (MDR) Mansion House station, the railway would then continue under Queen Victoria Street to the Central London Railway (CLR) station at Bank where separate platforms would be provided beneath the existing platforms.

The final section developed on the propped loop, with the tunnels winding underneath the City's winding narrow streets. The tunnels would tun eastwards, one above the over, underneath Cornhill and Leadenhall street, northwards underneath St Mary Axe to Liverpool Street station, where the railway would then run southwards underneath Blomfield Street, eastwards underneath Great Winchester Street, southwards underneath Austin Friars and Old Broad Street and westwards underneath Threadneedle Street where the tunnels would connect with the existing sidings at Bank station. This route would have two immediate stations constructed along its route, at the southern end of St Mary Axe and another at Liverpool Street.

To allow for the additional rolling stock the depot would be extended northwards and the electrical power generating station would be enlarged to allow for an increase in electrical supply. The Central London Railway (CLR) estimated that the works would cost £3,781,000 (approximately £370 million today), approximately £2,110,000 for construction, £873,000 for land acquisitions and £798,000 for electrical equipment including additional rolling stock.

The Central London Railway (CLR) was one of many bills presented to parliament, including several for the Hammersmith and City route, and was sent to another committee. The route received support from many mainline railway companies that the route interchanged with and the the City and South London Railway (CSLR) who operated the station at Bank, the London County Council and City of London Corporation also supported the proposal. The Metropolitan Railway opposed the plans, foreseeing competition between the companies and its services on the 'inner circle'. The Central London Railway (CLR) withdrew its proposal for the city loop, without the main part of the Central London Railway (CLR) proposed route, a few improvements to the existing railway where approved and received Royal Assent on 31 July 1902 as the Central London Railway Act 1902.

The plans for the Piccadilly, City and North East London Railway (PC&NELR) collapsed late 1902 after a falling out with the projects promoters which led to a critical part of the planned route becoming under the control of a rival company, the Underground Electric Railway Companies of London (UECL), who withdrew their propoasal from parlimentry consideration. Once the Piccadilly, City and North East London Railway (PC&NELR) had been withdrwan, the Central London Railway (CLR) resubmitted its bill, although the progress of the bill was once again held up because parliament established a Royal Commission on London Traffic which was tasked to assess the manner that the transport infrastructure should be developed in London. While the commission deliberated the bill and any reviews of any bills for any new railways or any extension of a railway, therefore the Central London Railway (CLR) withdrew its bill. The bill was breifly represented in 1905 but the Central London Railway (CLR) withdrew the bill again, before making an agreement with the Underground Electric Railway Companies of London (UECL) in October 1905 that neither company would submit a bill to develop an east-west route in 1906. The plan was quickly abandoned and new trains allowed for driving positions to be located on each end of the train which allowed the Central London Railway (CLR) to reduce their service interval at terminal stations to two minuets without the need to construct a loop.

The government announced plans in 1905, to hold an international exhibition to celebrate the Entente cordiale signed by France and Britain in 1904. To exploit the opportunity to carry the visitors to the exhibition the Central London Railway (CLR) announced a bill in November 1906, this was to construct a loop from Shepard's Bush station and back, a new station would be constructed at Wood Lane close to the entrance of the exhibition. These new works where approved and received Royal Assent on 26 July 1907 as the Central London Railway Act 1907.

The new loop section of the railway would be formed by constructing a section of tunnel which would join the end of the dead-end reversing tunnel at the west of Sheppard's Bush station and the northern side of the depot. Trains would run anti-clockwise around the single track loop from Sheppard's Bush, the first section though the depot access tunnel, then passing through the northern side of the depot and through the new station before entering the new section and returning to Sheppard's Bush. There where also alterations made to the layout of the deport to accommodate the new station and looped operations. The construction work for the exhibition had began in January 1907 with the exhibition and new station being opened on 14 May 1908. The station was constructed on the surface between two tunnel openings and was a basic design, the platforms where located both sides of the curving track and passengers alighted onto one and boarded from another.

The Central London Railway (CLR) revised its plans for an eastwards extension, after the successful opening of Wood Lane, with an extension from Bank to Liverpool Street. The Great Eastern Railway agreed to allow the Central London Railway (CLR) to construct a station beneath the mainline terminus at Liverpool Street, provided no further extensions would be made northwards or north-east from there. The bill was announced in November 1908 and the bill received Royal Assent on 16 August 1909 as the Central London Railway Act 1909. Construction began in July 1910 and the new underground station at Liverpool Street opened on 28 July 1912, following the successful introduction of escalators at the Metropolitan District Railway (MDR) Earls Court station, four escalators where provided, two for the underground station and a further two where installed at the adjacent North London Railway Broad Street station.

The government approved a scheme from the Great Western Railway (GWR), obtaining parliamentary approval to construct a railway from Ealing to the West London Railway (WLR) Sheppard's Bush station, calling the proposal the Ealing and Sheppard's Bush Railway (ESBR) in 1905. The new railway from Ealing was to curve north-east though the mostly rural North Acton, turning eastwards to follow the existing Great Western Railway (GWR) High Wycombe line before the railway curved south-east. The railway would then run along an embankment south of Old Oak Common and Wormwood Scrubs before connecting with the West London Railway (WLR) a short distance from the Central London Railway (CLR) depot at Wood Lane.

Construction work on the railway did not begin immediately, in 1911 the Central London Railway (CLR) and Great Western Railway (GWR) agreed the running powers of the railway with the Central London Railway (CLR) taking over its services to Ealing Broadway. To enable this a connection would have to be constructed to the Ealing and Sheppard‘s Bush Railway (ESBR) and the Central London Railway (CLR) obtained parliamentary consent for a short extension from Wood Lane receiving Royal Assent on 18 August 1911 as the Central London Railway Act 1911. The Great Western Railway (GWR) opened the Ealing and Sheppard‘s Bush Railway (ESBR) as a steam-hauled freight railway on 16 April 1917, however the outbreak of the First World War postponed electrifying the track for the Central London Railway (CLR) and the service began on 3 August 1920 with an immediate station at East Acton opening.

The station at Wood Lane was modified and extended to accommodate the northwards extensions which linked the Ealing and Sheppard‘s Bush Railway (ESBR), the existing loop platforms where retained and used by trains what where truing back to central London, with two new additional platforms constructed at the station to allow for services running to or from Ealing on a lower level on the new tracks connecting each side to the loop. The station at Ealing Broadway was modified to allow for additional platforms for the Central London Railway (CLR) to use between the existing but separate sets of platforms used by the Great Western Railway (GWR) and Metropolitan District Railway (MDR).

The new extension would run for a total of 6.97km (4.33 miles) and require additional rolling stock, these where commissioned from the Brush Company who delivered 24 additional DM carriages in 1917, these where borrowed from the Baker Street and Waterloo Railway who intended to use them on their Watford Junction extension. The new carriages featured train doors which where fully enclosed, without lattice gates at the ends of the carriages and where instead provided with hanging doors on the sides of the carriages to speed up loading times, the first tube-sized rolling stock to feature this. To enable the new rolling stock to operate on the Central London Railway (CLR) 48 existing carriages where converted, which provided 72 carriages for twelve six-car trains, additional modifications to the stock while they where used on the Baker Street and Waterloo Railway Watford Junction extension meant the carriages where not compatible with the rest of the Central London Railway (CLR) fleet and the trains became known as the 1915 or Ealing stock.

The Ealing and Sheppard‘s Bush Railway (ESBR) was owned by the Great Western Railway (GWR) until its nationalisation at the beginning of 1948, when it was transferred to the London Transport Executive, with the exemption of Ealing Broadway station which remained a part of British Railways as a successor of the Great Western Railway (GWR).

The Central London Railway (CLR) announced plans to extend south-westwards from Shepard's Bush in November 1912. The planned tunnels would run beneath Goldhawk Road, Stamford Brook Road and Bath Road to Chiswick Common where the railway would surface and turn east of the London and South Western Railway (L&SWR) Gunnersbury station. A connection would be constructed to allow the Central London Railway (CLR) trains to run south-west to Richmond over the London and South Western Railway (L&SWR) and Metropolitan District Railway (MDR) tracks which where electrified in 1905. Stations where planned for Goldhawk Road at its junctions with The Grove, Paddenswick Road and Rylett Road, another located at Emlyn Road on Stamford Brook Road, Turnham Green Terrace for a connection to the London and South Western Railway (L&SWR) and Metropolitan District Railway (MDR) services from Turnham Green and at the junction of Chiswick High Road and Heatfield Terrace. The Central London Railway (CLR) saw opportunities beyond Richmond to continue over the London and South Western Railway (L&SWR) tracks to the towns of Twickenham, Sunbury, Shepperton, however these tracks would have to be electrified. Permission was granted for the extension and Royal Assent was granted on 15 Augusts 1913 as the Central London Railway Act 1913. The outbreak of the First World War prevented the works from beginning and the permission expired.

The Central London Railway (CLR) entered a new bill into parliament during November 1919 to revive the plans to extend the railway to Richmond, however the route had been altered to allow for a short section on tunnelling the proposal saw the tunnels constructed southwards from Sheppard's Bush station and coming to surface to connect with the disused London and South Western Railway (L&SWR) line north of Hammersmith Grove Road station which had closed in 1916. Beyond Hammersmith the disused London and South Western Railway (L&SWR) tracks continued westwards over the same viaduct as the Metropolitan District Railway (MDR) line though Turnham Green to Gunnersbury and Richmond. This plan required the electrification of the disused route but avoided the costs of tunnelling and would share existing stations with the Metropolitan District Railway (MDR). The plan received Royal Assent on 4 August 1920 as the Central London and Metropolitan District Railway Companies (Works) Act 1920. Despite the authorisation from parliament to construct the railway the Central London Railway (CLR) had made no attempt to complete the works, and the disused L&SWR line was eventually used to extend the Great Northern Piccadilly and Brompton Railway (GNPBR) westwards from Hammersmith in 1932.

Integrating the Central London Railway

The Central London Railway (CLR) began to experience a decline in passenger demand for their railway from 1906, this was because of increasing competition between the Metropolitan Railway and Metropolitan District Railway (MDR), who had just electrified the Inner Circuit, and from the Great Northern Piccadilly and Brompton Railway (GNPBR) with a new rival route from Hammersmith in 1906. There were also improvements in road transport with the slower horse-drawn being replaced by motor-buses, which was increasing the competition between the modes of transport within London. To attempt to improve the finances of the company, the 2d flat faire was increased to 3d in July 1907 and a reduced faire for short journeys of 1d in March 1909. Booklets of tickets, which where previously sold at face value, where offered with discounts and season tickets where introduced from July 1911.

The Central London Railway (CLR) also planned to reduce its expenditure by investing in technological developments. Dead-man's handles where introduced in 1909, these where added to the controls of the train, in addition to this ‘trip cocks‘ where introduced on the signalling which removed the requirement of an assistant driver as a safety measure. The automation of the signalling allowed for the closure of 16 signal boxes and a reduction in staff for the signalling. The Central London Railway (CLR) operated a parcel service from 1911, making modifications to the DM of four trains to provide a compartment where parcels could be sorted, these where then collected at the relevant station and distributed to their final destination by a team of tricycle riding delivery boys. The service ended in 1917 because of wartime labour shortages despite the service making a profit.

The declining passenger revenues where not limited to the Central London Railway (CLR), but affected all the operators of transport in London. The decline in revenue made it difficult for the companies to pay back the money they had borrowed to construct their railways and the companies where unable to pay a dividend to their shareholders. The dividends payments for the Central London Railway (CLR) had reduced by 3% from 1905, a contrast to the 0.75% by the railways operated by the Underground Electric Railway Companies of London (UECL). The Underground Electric Railway Companies of London (UECL), Central London Railway (CLR), City and South London Railway (CSLR) and Great Northern Piccadilly and Brompton Railway (GNPBR) began to introduce fare arrangements in 1907 and began to present themselves as a single brand from 1908, called the 'UndergrounD'.

The Underground Electric Railway Companies of London (UECL) announced that it would be taking over the Central London Railway (CLR), after a series of secret take over talks, in November 1912. The take over was effective from 1 January 1913, however although the Central London Railway (CLR) was an entity of the Underground Electric Railway Companies of London (UECL) it remained a separate legal entity to the other railways operated by the Underground Electric Railway Companies of London (UECL).

The Underground Electric Railway Companies of London (UECL) took steps to integrate the Central London Railway (CLR) with its other railways, after their take over, the Central London Railway (CLR) power generating station was closed in March 1928 with the power for the railway being supplied from the Underground Electric Railway Companies of London (UECL) power generating station at Lotts Road in Chelsea. The busier stations on the railway where modernised, Bank and Sheppard's Bush stations received escalators in 1924, with Tottenham Court Road and Bond Street receiving escalators in 1926 along with new entrances designed by Charles Holden. The stations at Chancery Lane and Marble Arch where reconstructed to allow for escalators in the early 1930s.

Two new stations where opened on 5 November 1923 on the Ealing extension of the Central London Railway (CLR) at North Acton and West Acton. The new stations where built to serve the local residential communities and industrial developments around Park Royal and East Acton, the stations where constructed as a basic structures with simple timber shelters on the platforms.

The location of the station at British Museum was poorly located and lacked an interchange with the Great Northern Piccadilly and Brompton Railway (GNPBR) station at Holborn, which had been considered a problem since the opening of the Great Northern Piccadilly and Brompton Railway (GNPBR) in 1906. A pedestrian subway was considered to connect the stations in 1907, however no works where carried out. The Central London Railway (CLR) in November 1913 entered a proposal to parliament to enlarge the tunnels at Holborn beneath High Holborn to construct platforms to be used by the Central London Railway (CLR) and to abandon the existing station at British Museum, consent was given by parliament during 1914, however the outbreak of the First World War prevented the works from being carried out. The new platforms along with a new ticket hall was opened at Holborn on 25 September 1933, the station at British Museum closed the day before.

The Central London Railway (CLR) began to convert its remaining 1906 or gated stock carriages in phases between March 1926 and September 1928. The platforms on the ends of the carriages where the lattice gates where located where enclosed, with two doors being inserted on each side, this allowed for an increase in passenger capacity. These conversions allowed the Central London Railway (CLR) to remove its gate-men, transferring the responsibility of operating the doors to the guards on the trains who managed half the train each, diver and guard communications where introduced in 1928 and allowed the railway to reduce the train crew to a single guard and driver.

The introduction of sliding doors caused problems at Wood Lane where the length of the platform on the inside of the curve into the depot was restricted, the solution was to create a section of platform which pivoted and sat above the track to allow passengers to board the trains and normal, this section could be removed to allow access to the depot.

The underground railways continued to struggle, despite working closely together and improvements to the network. The Underground Electric Railway Companies of London (UECL) ownership of the London General Omnibus Company (LGOC) since 1912 and their profits where used to subsidise the underground railways. However, competition between the modes of transport remained fierce during the 1920s and the introduction of smaller bus operating companies eroded the prifitability of the London General Omnibus Company (LGOC) which had a negative impact on the whole Underground Electric Railway Companies of London (UECL) group.

To protect the revenues of the Underground Electric Railway Companies of London (UECL) group, the chairman Lord Ashfield lobbied the government for the regulation of transport service within London. A series of legislative initiatives where made following this direction, however a series of debates where conducted regarding the level of public control that the transport companies should be subjected to. The Underground Electric Railway Companies of London (UECL) group was lobbying for protections from competitors in the area and to allow the company to take over the London County Councils tram system, however the opposition wanted to bring the companies into complete public ownership. After a series of false starts over seven years, a bill was announced during the end of 1930 for the formation of a public board who would take control of the Underground Electric Railway Companies of London (UECL), Metropolitan Railway and all the bus and tram operators within a designated area called the London Transport Area. The formation of the London Transport Passenger Board (LTPB) was a system of public ownership but not full nationalisation, the board came into existence on the 1 July 1933 and the ownership of the companies assets where transferred to the board.

New Works Programme on the Central line

The formation of the London Transport Passenger Board (LTPB) on 1 July 1933 amalgamated the transport companies that operated within an area called the London Transport Area into a single entity which became known as London Transport. The board renamed the Central London Railway (CLR) the Central line in 1937, further to a major expansion to the railway under the 1935-1940 New Works Programme.

The railway would be extended westwards over a series of new tracks to be constructed paralell to the Great Western Railway (GWR) New North Mainline to Debden. Eastward the railway would be extended with new tunnels to run just beyond Stratford station where the railway would be extended over the London and North Eastern Railway (LNER) suburban branch to Epping and Ongar along with a new underground line between Leytonstone and Newbury Park mostly underneath Eastern Avenue to serve the new suburbs of northern Ilford and along the Hanault Loop. The platforms within central London where lengthened to allow for 8-car services to operate.

The construction began with the tunnels though central London being expanded and realigned to allow for the longer 8-car trains, however the modifications at Wood Lane station proved impossible and a new station at White City was authorised in 1938. The railway was converted to the London Underground 4-rail electrical system in 1940, however the positive outer rail is 40mm (1.6in) higher than other railways on the network because the reconstruction works led to the tunnels being slightly smaller than other railways on the network. The majority of the works to extend the tunnelling had been completed by 1940, however the outbreak of the Second World War prevented the works from continuing and they where suspended in June 1940.

During the Second World War the disused tunnels between Laytonstone and Newbury Park where equip for an aircraft components factory which opened in March 1942 and employed 2000 people. Other sections of the underground network where used as shelters during the air raids, the unopened station at Bethnal Green had enough space for 10,000 people, however during March 1943, 173 people where killed when a woman who was entering the station to shelter fell at the bottom of the stairs and those following fell on top of her ensuing a crush.

After the Second World War construction resumed on the railway with the western extension opening to Greenford in 1947 and West Ruislip in 1948. The railway was initially intended to be constructed to Debden however this was never completed because the post-war establishment of the Green Belt around London prevented the required developments along this section.

The eastern section of the extension opened to Stratford in December 1946 with the trains continuing without passengers to reverse in a cutting south of Leyton, the section to Leytonstone opened in 1947 with Woodford and Newbury Park opening in quick succession. Beyond Newbury Park to Woodford via Hainult and Woodford to Loughton where served by underground services from 1948. The westwards facing junction with the mainline south of Newbury Park where closed in the same year to enable the depot at Ilford to be expanded, the depot was transferred when the railway was extended to Epping. A single line operated between Epping and Ongar, which where served by steam-hauled trains operated by British Rail (BR) until 1957 when the route was electrified. Trains operated by British Rail (BR) gained access to the line by a link from Temple Mills East to Leyton.

The stations east of Stratford kept their goods services, being worked from Temple Mills and the Hainault Loop being served via Woodford. The line south of Newbury Park, which was operated by British Rail (BR), closed in 1956 with the stations on the Hainault Loop loosing their goods services in 1965, followed by the reminder of the section following in 1966.

Passenger trains early in the morning from Stratford or Liverpool Street on Sundays, ran to Epping or Loughton until 1970. The section from Epping to Ongar remained a single track and was electrified in 1957, which then operated as a shuttle from Epping, however the section carried 100 passengers a day and lost money, the section was closed in 1994 and is operated by the Epping Ongar Railway as a heritage line.

Following 32 passengers being injured when a train derailed at Chancery Lane station due to a traction motor falling onto the tracks, the Central line was closed between January and March 2003. A full service was not restored until June 2003, the infrastructure was partially privatised in a public-private partnership, managed by Metronet, however the company went into administration and Transport for London took over its responsibilities.

Central line today

The Central line remains the longest line on the London Underground network spanning 74km (46 miles) and serving 49 stations, until the Elizabeth line opens in 2018. The railway is predominantly made of double tracks however some sections have been widened and have three sets of tracks south of Leytonstone and west of White City. The Central line does not share its tracks with another railway but some routes are parallel to the tracks. The total track length is 147.1km (91.4 miles) with 52.8km (32.8 miles) in tunnels.

The section between Leyton and south of Loughton is the oldest railway alignment on the London Underground network, being opened by the Eastern Counties Railway (ECR) on 22 August 1865, the section between Loughton and Epping was opened on 24 April 1865 by the Great Eastern Railway (GER) along with the section to Ongar. The Hainault Loop was a part of the larger Fairlop Loop which was opened by the Great Eastern Railway (GER) on 1 May 1903.

There are three junctions that are currently in use on the line, the Woodford Junction which is a flat junction, north of Leytonstone the Newbury Park branch descends into tube tunnels beneath the other route to Woodford, and west of North Acton there is a burrowing junction to separate the lines to Ealing Broadway and West Ruislip.

Stratford station is where the shortest escalator on the London Underground network is installed and the escalators at Stratford and Greenford are the only stations where passengers ascend to the platforms. The last escalator with wooden treads was replaced from Greenford station during March 2014, this was except from the fire regulations because the station is not located in a tunnelled section.

The shallowest platforms are located at Redbridge at 7.9m (26ft) between the road and the sharpest curve on the network is located between Shepard's Bush and White City, called Caxton Curve.

The services for the Central line, off-peak is:

Totalling 24 Trains Per Hour between White City and Leytonstone, with an average wait of 2 minuets and 30 seconds between trains.

During September 2013 the frequency on the Central line was increased to 34 Trains Per Hour, giving the railway the most intensive service in the UK, previously the Victoria line held the record at 33 Trains Per Hour.

The Central lime crosses the Uxbridge Branch, which is currently shared by the Metropolitan and Piccadilly lines, near West Ruislip depot and a single track was laid in 1973 connecting the lines. There has been lobbying for Central line trains to serve this route to Uxbridge because the depot at West Ruislip is located in a quiet suburb and Uxbridge is more densely populated, Transport for London has specified that this would be impossible because of the signalling used the Metropolitan line.

The line was refurnished in the early 1990s and was the first to be completely refurnished including the introduction of new rolling stock.

The proposal of Crossrail 2, a new railway line that would cross the city running from south-west to north-east London is planned to open in approximately 2030. The current plan involves transferring the Epping branch between Leytonstone and Epping to the new railway, the latest preferred route, published in 2013, no longer includes this as a proposal.

A station between Liverpool Street and Bethal Green, the longest continual section of railway without a station in central London, has been proposed with a connection and interchange with Shoreditch High Street station since the station opened in 2010. However, the interchange would bring benefits, but has been ruled out because the costs exceed the benefits because the new station and the platforms would be located too close to the existing sidings at Liverpool Street.

The developers of the First Central Business Park in Park Royal where planning a new station between North Acton and Hanger Lane to better serve their business park and to provide a walking distance interchange with the existing station at Park Royal on the Piccadilly line. This has not been pursued because the transport benefits of an additional station at Park Royal on the Central line would not be significantly high enough to justify the costs of construction.