26.5 km, 36 stations (serving Edgware Road twice, and two different Paddington stations)
Until 13 Dec 2009, the Circle Line was a real circular line (20.5 km), but now it is operated from Hammersmith to Edgware Road via Paddington, Edgware Road, Liverpool Street, Embankment, Victoria and High Street Kensington. On almost its entire route, the Circle Line shares tracks with other subsurface lines.
65.3 km, 34 stations
The Metropolitan Line's four western branches are operated as follows during off-peak hours (all trains stopping all stations), with a complex pattern of fast and semi-fast services during peak hours:
1) Aldgate - Uxbridge (4t/h)
2) Baker Street - Uxbridge (4t/h)
2) Baker Street - Watford (4t/h)
3) Baker St - Amersham (2t/h)
4) Aldgate - Chesham (2t/h)
Hammersmith & City Line
25.4 km, 28 stations
On almost its entire route, the Hammersmith & City Line shares tracks with other subsurface lines, although until Dec. 2009, the section between Hammersmith and Edgware Road had been exclusively served by the H&C for many decades.
64.5 km, 60 stations
What is known as the District Line is actually a network made of five lines:
1) Richmond - Upminster (the Richmond - Gunnersbury section is shared by London Overground trains)
2) Ealing Broadway - Tower Hill
3) Wimbledon - Upminster
4) Wimbledon - Edgware Road
5) Kensington Olympia - High Street Kensington
59. 1 km, 52 stations
The central segment of the Northern Line incorporates what was the world's first electric underground railway, opened in 1890 between Stockwell and King William Street (near the present Monument station). The Northern Line probably has the most unconventional route layout worldwide, with three northern termini and one in the south, plus two different routes through the city centre, resulting in complex service pattern. From the northern branches, southbound trains continue through the city on alternating routes (indicated "via Bank" or "Via Charing Cross"), with some trains terminating at Kennington.
There are recent plans to extend the Northern Line from the Kennington loop to Battersea Park with an intermediate station at Nine Elms.
73.3 km, 50 stations
Opened in 1900, the Central Line is a cross-city tube line right through the heart of London, with two branches at the western end, and two at the eastern, where the Hainault loop is served frequently by trains via Newbury Park to Hainault, but on the Hainault - Woodford section there is a train only every 20 minutes.
Waterloo & City Line
2.4 km, 2 stations
The Waterloo & City Line is a non-stop shuttle service between Waterloo railway station and the City of London. It only became part of the London Underground system in 1994.
23.6 km, 25 stations
The Bakerloo Line is a typical tube line on its route through the city centre, opened in the first decade of the 20th century, but north of Queen's Park it shares tracks with London Overground services (Euston to Watford Jn), so the tube trains have to stop at platforms which have a height between the typical tube platforms and those of mainline railways.
65.6 km, 52 stations
The Piccadilly Line is a typical tube line from the early 20th century, although some of the western sections date back to 1877, when they were opened as part of the District and Metropolitan Railways. It runs from the north towards the west, where it splits into two branches. On the Uxbridge branch, tracks are shared with the Metropolitan Line between Rayners Lane and Uxbridge. Between South Kensington and Turnham Green, the Piccadilly Line runs parallel to the District Line, but on separate tracks. On the Heathrow branch, trains either run around the Terminal 4 loop in an anti-clockwise direction or go directly to Terminal 5.