Thursday, 28 September 2017

LU 1992 Tube Stock (Central Line)

The 1992 Tube Stock (1992TS) was built for the Central Line in the early 90s to replace ageing 1962 Tube Stock. As well as the Central Line an order of stock was added for the Waterloo & City Line too, then still British Rail owned, as the Class 482. The 1992TS is based on the 3 1986 Prototype Tube Stock trains which ran a series of trials in the late 1980s [1]. They were the first production stock fitted with solid state traction equipment [2].

Information
Number built: 680 cars (8-car sets)
Built: 1991-94
Builder: BREL Derby / ABB Derby
Engine: 4 Brush LT130 traction motors per car (630v DC fourth rail)
Power: 1, 984 hp (1, 472 kW)
Formation: Driving Motor (DM)+Non Driving Motor (NDM)+NDM+NDM+NDM+NDM+NDM+DM

Eighty five 8 car sets were built for the Central Line making up 680 cars in total, 175 being Driving Motors and the rest Non Driving Motors. Some NDMs are also fitted with de-icing equipment. The make-up of an 8-car formation can vary though DMs are always at the outer ends of course. The NDMs lack cabs but do have shunting controls accessible via an external cabinet.

The 1992TS has not been a trouble-free design for London Underground, despite the fact it was based on years of work with the prototype fleet there were a number of teething problems that delayed and hindered the entry into service. In 2003 a train of 1992TS derailed at Chancery Lane, after a traction motor became detached from one of the bogies following a sheered bolt, injuring 32 passengers [3][4]. The entire fleet was taken out of service (both Central and Waterloo & City fleets) for bolts to be checked and faulty ones replaced. In 2010-11 the bogies were replaced by a new design by Siemens [5]. However the 1992TS is the worst performing fleet on LU in terms of reliability and availability [6].

The 1992 Tube Stock fleet will be replaced as part of Deep Tube Upgrade in the 2020s, under current plans the 92TS fleet will be replaced near the end of the decade or early in the next [7]. To keep the fleet going until then the Central Line Improvement Programme (CLIP) will be carried out in the next few years by Bombardier. The upgrade includes replacing the DC traction system with a Mitrac AC system [8], on board computer, communication system and refreshing and updating the interior to make it RVAR compliant.
91013 at Leytonstone

Aboard a DM

Departing Mile End heading West

91289 at White City

[1] John Glover, ABC London Underground (Ian Allan, 1997) p. 64
[2] Piers Connor, The London Underground Electric Train (Crowood Press, 2015)  p. 105
[3] "Thirty hurt after Tube crash" BBC News <http://news.bbc.co.uk/1/hi/england/2694361.stm>
[4] John Glover, London's Underground 12th Edition (Ian Allan, 2015) p. 76
[5] Connor p. 105
[6] Central Line Heavy Overhaul Programme Lift (TfL Paper) <http://content.tfl.gov.uk/rup-20150212-part-1-item10-central-line-overhaul.pdf>
[7] Kim Rennie, Underground and Overground Trains (Capital Transport, 2017) p. 19
[8] "Bombardier for Central Line retractioning", Modern Railways (October 2017) p. 83