Central Line

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See also Central Line (Tanzania) for the Tanzanian railway, and central venous catheter for the medical concept.
Central Line
Colour on map Red
Year opened 1900
Line type Deep Tube
Rolling stock 1992 Tube Stock
Stations served 49
Length (km) 74
Length (miles) 46
Depots Ruislip
Hainault
White City
Journeys made 183,512,000 (per annum)
Rail lines of
Transport for London
London Underground lines
  Bakerloo
  Central
  Circle
  District
  East London
  Hammersmith & City
  Jubilee
  Metropolitan
  Northern
  Piccadilly
  Victoria
  Waterloo & City
Other lines
  Docklands Light Railway
  Tramlink
  Overground (starts November 2007)

The Central Line is a line of the London Underground and coloured red on the tube map. It is a deep-level "tube" line, running east-west across London, and has the greatest total length of track on the Underground (but is not the longest continuous line). Until the closure of the Epping-Ongar section, the terminus at Ongar was the furthest point from London on the network.

Contents

[edit] History

[edit] The beginnings

Although the Central London Railway was incorporated in 1891 for a line between Shepherd's Bush and Bank (with an extension to Liverpool Street authorised in 1892) the time for completion had to be extended twice (1894, 1899); and it was not until 27 June 1900 that it was formally opened, a month before public traffic began to use the railway on 30 July, to Bank station. The railway was initially operated by electric locomotives hauling a train of trailer cars. The distinctive station buildings, few of which survive, were designed by the architect Harry Bell Measures.

The railway has had a chequered history. Although the tunnels were bored with the unusual diameter of 3.56 metres (11 feet 8¼ inches), they were not well aligned and it was discovered that the rolling stock, which was already smaller than would be expected for this size of tunnel, would not fit. It is rumoured that the engineers forgot to take into account the height of the rails above the tunnel floor. The problem was remedied by a combination of replacing the bullhead running rails with lower profile bridge rails, and shortening the springs on the rolling stock. The locomotives caused considerable problems with vibration as they weighed 48 long tons (49 tonnes), most of which was unsprung.

In the late 1930s the tunnels were expanded and realigned and the stations lengthened. In 1940, the line was converted to the standard tube 4 Rail electrification. Because of the manner in which tunnel had been enlarged, it was no longer round and for clearance reasons the positive rail within the original tunnels had to be of an unusual shape with the top contact surface 40 mm (1½ inches) higher than normal. This is still the situation today, and the extra height can be observed at most deep-level stations, where the insulating 'pots' stand on small cement mounds. Trains between Liverpool Street and White City must have special positive collectors that can lift higher than normal. In turn the current Central Line stock cannot run on any other line, partly because they are operated by Automatic Train operation, have no trip-cocks, and would interfere with other signalling equipment. There are also clearance problems with the gearboxes.

One legacy of the line's building is that the sections under the City were built to follow the geography of the streets above, rather than underneath buildings, to take advantage of the free wayleave offered by the government. As a result there are many sharp bends and curves between Chancery Lane, Bank and Liverpool Street, leaving this section of the line particularly prone to derailments. At Bank station, the Central Line platform stations are so tightly curved it is not possible to see one end of the platform from the other and the traditional "Mind The Gap" message is particularly stressed here.

For several years from the outset a uniform fare of two pence was adopted: the railway was popularly known as the "Twopenny Tube". In July 1907 and graduated fares of two pence and three pence were introduced: a one penny fare was added in 1909.

[edit] Former rolling stock

When opened in 1900, the railway was operated by electric locomotives hauling coaches. The coaches were fitted with gates at each end, similar to those used on the City and South London Railway and the Glasgow Subway. The locomotives, with a large unsprung weight, proved highly unsatisafactory and the cause of considerable vibration. They were replaced as early as 1903 with motor cars, with the existing coaching stock being adapted to run as trailers within newly formed electric multiple units.

By the 1920s the rolling stock was in need of modernisation or replacement. Given that the then-new Standard Stock was too large to work in the line's tunnels, it was decided to modernise the existing fleet. The end gates were removed and replaced by an extension to the passenger accommodation. Two air operated single-leaf sliding doors were inserted into both sides of each carriage. Reconstruction work was carried out by the Union Construction Company at Feltham.

Additional trains were purchased for the opening of the Wood Lane to Ealing Broadway extension in 1920. These were also temporarily used on the Watford extension of the Bakerloo Line.

The 1900/03 stock and 1920 stock were finally withdrawn from service in 1939. With the enlargement of the tunnels and modification of the electrical supply, Standard Stock (displaced from the Northern Line by new 1938 Stock) was operated - eventually as 8-car trains following platform extensions.

The Standard Stock became increasingly unreliable during the 1950s. Some had been stored during World War II pending the opening of extensions. Plans for replacement (using a production version of the prototype 1960 Stock) were abandoned; new trains of 1962 Stock (virtually identical to the tried and tested 1959 Stock) were ordered instead. These operated until their replacement by 1992 Stock in the early 1990s.

The Epping-Ongar branch was not electrified until 1957, prior to which the service was operated on behalf of London Transport by British Railways using steam hauled coaches. Upon electrification, two-car sets of 1935 Stock were initially used, later replaced by 4-car sets of 1962 Stock specially modified to cope with the limited current. The section closed in 1994 - see Epping Ongar Railway.

[edit] Extensions of the line

1908
Extended in the west by means of a loop to Wood Lane Exhibition Station in 1908 for the Franco-British Exhibition.
1912
Extended eastwards to Liverpool Street.
1920
In the west, a short connecting link was made from Wood Lane station to join the Great Western Railway (GWR)-operated line, the Ealing and Shepherd’s Bush Railway, allowing trains to run to Ealing.
1935
As part of the New Works Programme 1935–40, announced in June 1935, London Transport proposed works to extend the Central Line as follows:
  • "to construct and electrify two additional GWR tracks from North Acton to Ruislip, allowing Central Line trains from Wood Lane to use the line;

An extension beyond West Ruislip to Denham was also planned (and shown on tube maps of the period) but abandoned for the same reasons (relating to the Green Belt) as the Northern Heights extensions of the Northern Line.

Although the works of the latter were completed by the outbreak of war the opening was delayed, and the section, safer as it was from bombing, was used as a long, narrow, munitions factory. The branch opened in December 1946 as far as Stratford (with trains continuing empty through the new tube tunnels to a temporary reversing facility at Drapers Field, in the cutting south of Leyton), with the line beyond Stratford opening to passengers in 1947, and the link to Ilford closed. BR trains continued to access the line via a link from Temple Mills East to Leyton. These included the BR locomotives and stock for the Epping - Ongar shuttle (until electrification in 1957), freight trains to sidings (including Fairlop, Barkingside, Buckhurst Hill, Theydon Bois, South Woodford, Loughton, North Weald, and Ongar) until the mid-1960s, and early-morning and late-night trains between Liverpool Street and Epping (latterly formed by DMUs, and last running on 31 May 1970). This section of line now forms a loop and there are some through services to Woodford via Hainault.
1949
Extended to Epping, when London Transport took over the line from British Railways.
1957
Extended from Epping to Ongar, taking over from British Railways.

[edit] Epping to Ongar branch

Although electrification of this section had begun under the 1935/40 New Works Programme (see above), the line remained steam-hauled (though from 16-27 June 1952 an experimental ACV/BUT three-car lightweight railcar set operated part of the shuttle service Monday-Friday) until 18 November 1957. From that date two-and three-car tube trains were used on the branch. The power supply being limited, it was not possible to work through trains to and from London, and the line remained a branch, though the shuttle service initially operated between Ongar and Loughton. Expected levels of passenger use never materialised, and the line became a heavy loss maker, and was closed on 30 September 1994 and sold to the Pilot Group. The direct connection to Epping was lifted soon after closure, but the remaining section of the branch stayed intact.

A heritage passenger service started operation in October 2004. A train runs between North Weald and Ongar (not stopping at the old Blake Hall station, because it is in private residence) on Sundays, with a possible extension to Epping in the future. At present, a bus service provides connections between trains and Epping Tube station. See Epping Ongar Railway.

[edit] 2003 derailment and closure

A Central Line train derailed at Chancery Lane on 25 January 2003, injuring 32 passengers, after a traction motor became detached from the train and fell onto the track. The entire line was closed whilst the cause of the failure was determined and appropriate modifications made to the trains. The line was then re-opened in stages. By late March 2003 a limited service was running on the eastern and western extremities of the line, with the central section still closed. Services resumed over that central section on 3 April and to all stations (albeit at a reduced frequency) on 12 April, with a full service by the end of the month. The initial closure also extended to the Waterloo & City Line which uses the same "1992 tube stock" trains, but this line, being far shorter - with only two stops and far fewer trains - reopened quickly.

A more minor derailment occurred on a set of points at the London end of the westbound platform at White City on 11 May 2004, but there were no reported injuries.

[edit] Current trains

A train of 1992 tube stock approaching Roding Valley station on the Central Line.
Enlarge
A train of 1992 tube stock approaching Roding Valley station on the Central Line.
A 1992 tube stock train terminating at Loughton Station.
Enlarge
A 1992 tube stock train terminating at Loughton Station.

In common with virtually all other Underground lines, the Central Line is worked by a single type of rolling stock. The 1992 Tube Stock was introduced gradually from April 1993 to 17 February 1995, and was the first in London to introduce automated announcement of the next station and connections available. The 1992 stock is painted in the standard red, white and blue Underground livery. The 1992 stock on the line runs in 8-car sets.

In 1996 the line was fitted with Automatic Train Operation, and this was brought into service in sections over the next few years.

[edit] Map

Geographical layout of the Central Line

[edit] Stations

In order from west to east. Note that the station names in italics are no longer on the Central line

[edit] West Ruislip branch

branch joins at North Acton:

[edit] Ealing Broadway branch

this was the main line until the post-war extensions

branch joins at North Acton, using ex GWR tracks:

Splits into two branches.

[edit] Woodford branch

The Greater London boundary with Essex is at Grange Hill

Terminates at Woodford [see Ongar Branch] (except for rush hours)

[edit] Ongar branch (now Epping Branch)

The Greater London boundary with Essex is between Woodford and Buckhurst Hill

Note: the remaining stations to Ongar were served by a shuttle service from Epping.

[edit] External links

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