Encyclopedia  |   World Factbook  |   World Flags  |   Reference Tables  |   List of Lists     
   Academic Disciplines  |   Historical Timeline  |   Themed Timelines  |   Biographies  |   How-Tos     
Sponsor by The Tattoo Collection
London Underground
Main Page | See live article | Alphabetical index

London Underground


The London Underground is a public transport network, composed of electrified railways (that is, a metro system) that run underground in tunnels in central London and above ground in the city's suburbs. The oldest metropolitan underground network in the world, first operating in 1863, the London Underground is usually referred to as either simply "the Underground" by Londoners, or (more familiarly) as "the Tube."

Table of contents
1 Background
2 Layout
3 History
4 Tickets
5 Station access
6 Safety, reliability and cost
7 Iconography
8 The future
9 See also
10 External links


. Note the brown signage indicating the Bakerloo Line.]]

Since 2003, the Tube has been part of Transport for London (TfL), which also schedules and lets contracts for the famous red double-decker buses. Previously London Transport was the holding company for London Underground.

There are currently 275 open stations and over 253 miles (408 km) of active lines, with three million passenger journeys made each day (927 million journeys made 1999-2000; there are a number of stations and tunnels now closed).

Lines on the Underground can be classified into two types: sub-surface and deep level. The sub-surface lines were dug by the cut-and-cover method, with the tracks running about 5 metres below the surface. Trains on the sub-surface lines have the same loading gauge as British mainline trains. The deep-level or "tube" lines, bored using a tunnelling shield, run about 20 metres below the surface (although this varies considerably), with each track running in a separate tunnel lined with cast-iron rings. These tunnels can have a diameter as small as 3.56m (11ft 8.25in) and the loading gauge is thus considerably smaller than on the sub-surface lines, though standard gauge track is used. Lines of both types usually emerge onto the surface outside the central area, the exceptions being the Victoria Line which is in tunnel for its entire length save for a maintenance depot, and the Waterloo & City Line; which, being very short, has no non-central part and no surface line.


The table below describes each of the lines, giving the colour presently used to represent the line on the ubiquitous Tube maps, the date the first section opened and the type of tunnel used.

London Undergound lines
Line Name Map colour Opened Type Length Notes
Bakerloo Line Brown 1906 Deep level 23 km / 14 miles  
Central Line Red 1900 Deep level 74 km / 46 miles  
Circle Line Yellow 1884 Sub-surface 22 km / 14 miles 1
District Line Green 1868 Sub-surface 64 km / 40 miles 2
East London Line Orange 1869 Sub-surface 8 km / 5 miles 3a
Hammersmith & City Line; Pink 1864 Sub-surface 14 km / 9 miles 3b
Jubilee Line Grey 1979 Deep level 36 km / 23 miles  
Metropolitan Line Purple 1863 Sub-surface 67 km / 42 miles  
Northern Line Black 1890 (part) Deep level 58 km / 36 miles 4
Piccadilly Line Dark Blue 1906 Deep level 71 km / 44 miles  
Victoria Line Light Blue 1969 Deep level 21 km / 13 miles  
Waterloo & City Line; Teal 1898 Deep level 2 km / 1.5 miles 5

1 The Circle Line became known as such in 1949 although a long-established service on the system. The Circle line was not built as a separate line, but was instead created as a service using parts of the District and Metropolitan Lines.
2 Originally called the Metropolitan District Railway
3a Originally a separate line operated by a consortium of companies including the Metropolitan. The line was owned by London Underground from
1948 but British Railways goods trains continued to run on it until 1966. It was for many years regarded as a branch of the Metropolitan Line, and was shown on the map as a purple and white striped line. The line gained its own identity in the late 1980s.
3b Originally part of the Metropolitan Line, the line became known as the Hammersmith & City Line in 1990.
4 The busiest line on the system, with two branches in central London.
5 Came under control of London Transport in 1994.

The Piccadilly Line now runs to Heathrow Airport. Although it is slow (52 minutes nominal to Green Park) and often crowded, it is a far cheaper way to travel to the city centre than the Heathrow Express, which is not part of the tube network.

The Tube interchanges with the Docklands Light Railway (DLR) at several stations, including Bank, Canary Wharf and Stratford, and with the Croydon Tramlink system at Wimbledon. The Tube interchanges with international Eurostar trains at Waterloo.

The lack of lines in the south of the city is because of the geology of that area, the region almost being one large aquifer. Additionally, it is impossible for cut and cover lines to go under the River Thames. This is made up for, however, by a large number of suburban rail services run by the South West Trains, Southern and South East Trains franchise holders (see Rail transport in the United Kingdom).


As the oldest and one of the most complicated rapid transit systems in the world, the London Underground has a long history.

The first half of the 19th century saw rapid development in train services to London, but most mainline termini were constructed a long way away from the central business district to avoid damage to historic buildings. As a result, reliance on buses increased until London was gridlocked. The solution came in the form of yet another railway. In 1854 it was decided that the Metropolitan Railway Company would be allowed to build a short stretch of underground railway between Paddington and Farringdon. This would link the mainline termini of King's Cross, St. Pancras, Euston and Paddington to a point near the edge of the City of London. The relatively simple cut-and-cover method was used, because deep-level tunnel construction methods were not sufficiently advanced to construct anything more than covered trenches. This first part of the Metropolitan Railway was opened in 1863 using steam locomotives to haul trains, which meant that ventilation shafts had to be built at regular intervals.

Expansion was rapid. The Metropolitan quickly branched out into the suburbs, even creating whole villages from nothing in a region of countryside which came to be known as "Metroland". The railway bought up extra land adjacent to the railway and built houses in a spectacularly practical example of demand creation and by 1880 the 'Met' was carrying 40 million passengers a year.

Meanwhile, a second railway company began construction further south. The Metropolitan District Railway first opened a stretch from Westminster to South Kensington in 1868, taking advantage of the construction of the Thames embankment to expand towards the city, reaching Tower Hill and linking the termini of Victoria, Charing Cross, Blackfriars, Cannon Street and Fenchurch Street. Having conquered the city, the District Railway turned its attention to commuters even more so than the Metropolitan Railway had, reaching Wimbledon, Richmond and Ealing.

Although the Circle Line didn't get its own identity until 1949, the "District" and the "Metropolitan" had linked up with each other to provide an "Inner Circle" service starting in 1884.

Advances in deep-level tunnel design came thick and fast. Tunnelling shields allowed stable tunnels to be constructed deep underground, and the world's first underground tube railway was the Tower Subway beneath the River Thames south of Tower Hill in 1870. While this was soon discontinued as a rail service, better shields and electric locomotive traction appealed to engineers for more ambitious schemes.

The result was the City and South London Railway, which linked King William Street (close to today's Monument Station) and Stockwell. The ride was unpleasantly rough and the lack of windows seemed to have a detrimental psychological effect. However, people learned from these mistakes and over the next 25 years six independent deep-level lines were built.

The presence of six independent operators running different Tube lines was inconvenient. In many places passengers had to walk some distance above ground to change between lines. Also, the costs associated with running such a system were heavy, and as a result many companies looked to financiers who could give them the money they needed to expand into the lucrative suburbs.

One such financier was Charles Yerkes, an American tycoon whose companies (first the Metropolitan District Traction Company, then Underground Electric Railways of London) initially took over the District, Piccadilly and Bakerloo lines. The Underground Group, as this second company was known, gradually absorbed the rest of the tube lines, save the Waterloo & City; (which remained separate until 1994) and Metropolitan lines. The company also owned many tram lines and proceeded to buy the London General Omnibus Company, creating an organisation colloquially known as the Combine. In 1933, a public corporation called the London Passenger Transport Board was created. The Underground Group, the Metropolitan line and all the independent bus and tram lines were placed under the Board, an organisation which approximated the scope of the current Transport for London.

Between the wars, expansion took place at a rapid pace, driving the Northern and Bakerloo Lines out into the suburbs of northern London. Architect Charles Holden's memorable station designs have brightened the commuters' journey both on these lines and elsewhere with a style which still looks fresh today.

World War II

The outbreak of World War II, and especially The Blitz, led to the use of many Tube stations as air-raid shelters. They were particularly suited to this purpose, but sadly a small number of horrific accidents occurred, notably at Bethnal Green. Other stations and sections of line were given other uses:

Post-war developments

Following the war, travel congestion continued to rise. The construction of the carefully planned
Victoria Line on a diagonal northeast-southwest alignment beneath central London attracted much of the extra traffic caused by expansion after the war. It was designed so that almost all of the stations along its length allowed interchange with other lines, and it was the first underground line to use automatic train operation (ATO).

Remarkably, steam locomotives continued to be used on the Underground (as engineering trains) until as late as 1971, several years after steam had been phased out on the national railway network.

In 1977, the Piccadilly Line was extended to Heathrow Airport.

The Jubilee Line was named in honour of Queen Elizabeth's Silver Jubilee in 1977, but did not open until two years later. During design and into initial construction it had been known as the Fleet Line as the route was planned to follow much of London's hidden River Fleet along the Strand and Fleet Street to Bank. During the 1990s it was diverted from the original route through Charing Cross to a new tunnel via Westminster and extending through the Docklands to Stratford in East London. The stations on the Jubilee Line Extension are particularly spacious and stylish, each designed by a leading architect. London Underground states that North Greenwich station, for example, "is large enough to contain 3,000 double-decker buses or an ocean liner the size of the RMS Queen Mary within its walls." Canary Wharf station is larger in volume than 1 Canada Square, one of the huge towers that dominates the Docklands area; it was built on a barge that was then sunk into the Thames to move it to its final position. Canary Wharf is also notable for being the first London Underground station to play host to a wedding; this event took place in 2003. All platforms between North Greenwich and Westminster incorporate automated platform-edge doors which are designed to minimise the wind resistance of the train and for noise abatement purposes; as a side benefit they also assist in the prevention of suicides. They are a predominant feature of the Jubilee Line Extension, and there are no plans at present to extend their installation to the rest of the Line or overall system. These modern stations include lifts (US: elevators) to ease access to all parts of the station complex and were the first stations on the London system to be fully wheelchair accessible.

Flooding is an increasing problem for the system. The ground water of London has been rising since the 1960s, after the closing of industries such as breweries and paper mills that had previously extracted large volumes of water. By mid 2001, London Underground was pumping 30,000 cubic metres of water out of its tunnels each day.

Until the completion of the Thames flood barrier in 1986, there was also a strong danger of flooding from the Thames itself. A series of floodgates were erected in the tunnels such that they would seal the affected sections of tunnel closed, allowing services to continue to run elsewhere on the line. The floodgates were no longer necessary once the Thames flood barrier came into service, but they remain in place and are tested three times a year.


Transport for London (and local National Rail franchisees) use a zonal pricing scheme where zone 1 is the most central, with a boundary just outside the Circle Line. After number 6, the zones are named A, B, C and D; zone D is the most remote and consists of Amersham and Chesham out in the Chiltern Hills on the Metropolitan Line. These lettered zones cater for the rural extremities of the tube and do not encircle the capital. Since 2004 buses treat the entire city as a single zone.

In general, the more zones travelled through, the higher the fare. Journeys through zone 1 are more expensive than those only involving outer zones. The zone system works well because most of the stations where lines cross are in zone 1, meaning that most journeys over similar distances will cost the same.

There are assistance booths open for limited periods and ticket machines usable at any time. The machines will accept coins and fresh English paper money — though not Northern Irish or Scottish notes — and usually give change. Most machines now accept major credit and debit cards. A small number of cash machines dispensing all-zone bus passes have appeared.

In 2003 London Underground launched the Oyster Card, a proximity card that a traveller swipes over a reader on the automatic gates rather than feeding it through a card ticket reader. Unlike the card tickets, the Oyster Card is not disposable, but intended to be topped up at the ticket machines.

London Transport also sell daily, weekend, weekly, monthly and annual "LT cards", allowing unlimited rides in one or more zones on buses or on the London Underground; these are a good deal for commuters and anyone else who rides the trains or buses daily. Travelcards are similar, although they also permit travel on National Rail. Daily Travelcards are only sold from machines after 9:30 am, but a peak hour inclusive version is available at a much higher price. Many shops, usually newsagents, sell bus passes and Travelcards; these are identified by a "Pass Agent" sign, usually in a door panel or front window. A day pass is valid until 4:30 am the next morning. Passes can be bought from these agents during a day prior to travel.

Station access

Not all Underground stations are accessible by people with mobility problems. Many have some of the 408 escalators and 112 lifts, but not all of them. New stations are designed for accessibility, but retrofitting accessibility features to old stations is considered prohibitively expensive.

The escalators in London Underground stations are both an asset and a liability. They are among the longest escalators in Europe and all are custom-built for each station. Because of their age and heavy usage, they tend to break down rather frequently, causing long delays at stations.

London Transport now produces a map specifically indicating which stations are accessible and more recent line maps are noting which stations provide step-free access to street level. However, step height from platform to train is often as high as 20 cm on older lines, and there can be a large gap between the train and some curving platforms. Only the Jubilee Line Extension is completely usable by the unassisted wheelchair-using traveller.

Safety, reliability and cost

The London Underground has an excellent passenger safety record. Suicides are unfortunately common, at roughly one per week across the network. Surprisingly few accidents are caused by overcrowding on the platforms; one explanation suggested for this — presumably by people who have never actually visited London or the Tube — is that Londoners are too polite to push!

For its employees, however, the record is less good. In January 2002 London Underground was fined 225,000 for breaching safety standards for workers. In court the judge said the company was "sacrificing safety" to keep the trains running "at all costs." He continued that the company, "despite the lip service they paid to health and safety issues, fell lamentably short of the proper safety standards and, objectively, simply ignored their obligations in this respect." Workers had been ordered to work in the rain, in the dark, while the track current was still switched on. [1]

Smoking was banned on the trains in July 1984. The ban was extended to all subsurface stations in February 1985 after the Oxford Circus fire.

The worst recent incident was a fire at King's Cross station on November 18, 1987, caused by a burning match falling onto a wooden-tread escalator panel. Thirty-one people died in the fire, which prompted the phasing out of wooden escalators and improved safety training for staff.

However, there have also been a number of high profile de-railings in recent years; mostly on the Central Line.

The system has suffered from significant under funding in the past two decades and consequently has far older carriages and signals compared with its contemporaries in such cities as Barcelona, Madrid, Paris and Geneva.


London Transport's roundel logo (right) and tube map are instantly recognisable by any Londoner, almost any Briton, and many people around the world.

The logo, as well as London Transport's distinctive sans-serif typeface, were designed by Edward Johnston, the former in 1913, the latter in 1916. Much of the reason for the widespread recognition of the London Transport logo is its ubiquitous usage on London Transport documents and signage. It is used for all tube station signs (where the station name appears on the horizontal bar), for example, as well as on in-carriage maps.

Since TfL took control of London's transport the roundel has been applied to other transport types within the city (bus, taxi, tram, DLR etc) in different colour pairs. The roundel has become a symbol for London itself.

Station identification

Each station displays the Underground logo containing the station's name instead of the word "Underground", both at entrances to the station and repeatedly along the station walls so that they can easily be seen by passenengers on arriving trains. In addition, many stations' walls are decorated in tile motifs that are unique to the station, such as profiles of Sherlock Holmes' head at the Baker Street station or a cross containing a crown at the King's Cross station.

Tube map

The tube map was designed by Harry Beck in 1931. See Tube map for an in-depth analysis of its history and its topological nature.

London Transport is known for taking legal action against unauthorised use of its trademarks, in spite of which unauthorised copies of the logo continue to crop up worldwide.

The future


The London Underground is currently part way through partial privatisation, where all the infrastructure is maintained by private companies but the Underground is still owned and controlled by Transport for London.

The network was split into three parts - JNP (Jubilee, Northern and Piccadilly Lines), BCV (Bakerloo, Central and Victoria Lines) and SSR (the sub-surface lines - District, Metropolitan, East London, Circle and Hammersmith & City Lines). One company, Metronet, has taken over maintenance on both BCV and SSR, while another, Tube Lines, has taken over maintenance on JNP. These companies are known as Infracos - Infrastructure Companies - and are made up of consortia of different companies.

The aim of this "Public-Private Partnership" (PPP) is to accelerate investment in the sadly neglected aspects of the London Underground, commissioning new trains and installing safety features such as ATP, automatic train protection. The Mayor of London, Ken Livingstone, was sceptical about the practicality of the PPP plan. However, he dropped a legal challenge against PPP, and refurbishment works were expected to be carried out from the end of 2002 onwards.

The UK government has promised 16 billion of funding over the years until 2030, with early priorities to cut delays and improve reliability including refurbishments of lifts and elevators, more thorough cleaning and a new station serving the new Wembley Stadium. The Victoria line will receive new signalling systems and seven new trains, along with renewal of track and equipment on many other lines. The Jubilee line will receive 160 million for new signalling equipment and new trains, bringing the total to 63 seven car sets built by Alstom, although they will not be built in the UK. The Victoria and sub-surface lines will receive 1,738 new cars between 2008-2015, to be built in Derby. The Bakerloo line will not receive new trains until 2019. The Metropolitan, District, Circle and Hammersmith & City lines will receive 190 new trains, built by Bombardier, meaning all sub-surface trains will be of the same design giving easier maintenance. The trains will feature inter-car gangways enhancing passenger safety, and improved acceleration and braking allowing an increase in train frequency, in the case of the Victoria line from 28 trains per hour to 33. The last trains to be replaced, 75 District line trains, will get interim refurbishments.

Westinghouse will continue to supply signalling equipment; already 75% of installed control equipment has been supplied by Westinghouse.


Plans are underway to extend the East London Line to both the North and the South; to the North, Shoreditch station will be abandoned, and, in a move that will bring the Underground to Hackney for the first time, the line will run on the old Broad Street viaduct through Hoxton to Dalston, then to Highbury & Islington station; to connect with the Victoria Line. To the South, two branches are planned, running to Clapham Junction and West Croydon over existing railway lines. These will transform the line from a small stub in the network to a major transport artery. A link to Crystal Palace has also been proposed.

A new station will be built on the Piccadilly Line to serve Terminal 5 of Heathrow Airport, which is due to be completed in 2007 At present the plan is to lay tracks beside the existing rails along the Heathrow branch to provide a fast nonstop service between Acton Town and Heathrow 1, 2, 3.

TfL, together with Hertfordshire county council, also plans to connect the Watford branch of the Metropolitan Line to the disused Croxley Green railway branch. This will bring the Underground back to central Watford and the important main line station Watford Junction, but the current Metropolitan Watford station will probably close.


In the summer weather, temperatures on the Tube can become very uncomfortable for passengers. Normal air conditioning has been ruled out because of the lack of height to install units on trains and the problems of dispersing the heat generated. Heat pumps were proposed several years ago to overcome this, and following a successful demonstration in 2001 funds were given to the School of Engineering at London's South Bank University to develop a prototype; work began in April 2002. A cash reward of 100100,000 was offered by the Mayor of London in 2003 for a solution to the problem.

The new fleet of trains for the sub-surface lines (Circle, District, H&C, Metropolitan and East London lines) will come with air-cooling. The first air-cooled trains are due to arrive in 2009.

Underground stations

London Underground currently serves 275 stations, which are listed, along with DLR stations, at List of London Underground stations. Stations formerly served by the Underground or its predecessor companies can be found at List of closed London Underground stations.

See also

External links

Metros of the United Kingdom:
True Metros:
Docklands Light Railway | Glasgow Underground | London Underground | Tyne & Wear;
Modern Tramways:
(Croydon) Tramlink | Manchester | Midland Metro | Nottingham | Sheffield