London Underground 1973 Tube Stock

The 1973 Tube Stock fleet was ordered to replace the mixture of 1938, 1959 and 1962 Tube Stock which operated on the Piccadilly Line in the early 1970s. A large fleet was ordered so that more trains could be provided, they were also needed for the extension of the Piccadilly Line to Heathrow Airport in the late 1970s [1]. The trains entered service from 1975 and are now the second oldest stock in operation on the London Underground.
235 at Acton Town

Eighty six 6-car units were ordered with an extra three-car unit for the Aldwych branch, seventy six of these are needed for peak time operation. The trains usually operate with two Uncoupling Non Driving Motors in the middle though twenty units can operate as a complete three-car unit with a Driving Motor at either end however service trains usually contain six cars. When the Aldwych branch of the Piccadilly Line was still operating a single three-car unit was used on it [2].

Information
Number built: 519 (86.5 6-car units)
Built: 1974-77
Builder: Metro-Cammell
Engine: 4 LT118 traction motors per motor car (630v DC fourth rail)
Power: 260 hp / 196 kW per motor car
Formation: Driving Motor (DM)+Trailer (T)+Uncoupling Non Driving
Motor (UNDM)[+UNDM+T+DM] (some as DM+T+DM)

At eighteen metres in length the 1973 Tube Stock cars were longer than previous tube stock (which were usually around sixteen metres in length) this allowed for six-car trains instead of seven as was the case before with earlier tube stock but with virtually the same capacity. This resulted in a reduced operating cost due to smaller number of bogies, car bodies et cetera needed [3]. The 1973 Tube Stock was refurbished by Bombardier in the late 1990s and has regularly been London Underground's most reliable fleet of rolling stock [4].

The 1973 Tube Stock is due to be replaced in the Deep Tube Upgrade Programme in the mid 2020s. Originally replacement of the 1973 Tube Stock was planned much earlier and indeed at one time they were considered the preferred and natural replacement for the 1938 Tube Stock / Class 483 on the Isle of Wight. However now they are planned to remain in service until 2026 when they will be replaced by the 2025 Tube Stock, and the Isle of Wight had to make other plans!
Arriving at Holborn


198 at Acton Town

Arriving at Ealing Common

Approaching Acton Town

Passing through Ravenscourt Park

[1] John Glover, London Underground Rolling Stock in Colour (Ian Allan, 2009) p. 8
[2] Anthony Badsey-Ellis and Mike Horne, The Aldwych Branch (Capital Transport, 2009) p. 72
[3] J. Graeme Bruce, The London Underground Tube Stock (Ian Allan, 1988) p. 114
[4] John Hawkins, "LU Train Reliability", Underground News No. 644 (August 2015), p. 458