London Underground D78 Stock

The London Underground D78 Stock was a type of sub-surface rolling stock which operated on the District line of the London Underground, except on the Wimbledon to Edgware Road service. Following the withdrawal of the C Stock in June 2014, these were the oldest subsurface trains in service on the London Underground. The first units were withdrawn in January 2015 with the last withdrawn on 21 April 2017.

The D stock was ordered in 1976 to replace the pre-war CO/CP Stock and post-war R Stock on the District line. Seventy-five six-car trains were built by Metro-Cammell, Birmingham, the first entering service on 28 January 1980 with final delivered in 1983.

Usage
The stock was used on the District line, except the High Street Kensington to Edgware Road section, because the platforms are not long enough.[citation needed]

Between April 1985 and May 1987, the stock operated the East London line service in three-car formations, there being enough stock spare because of reduced services on the District line. This allowed A60/62 Stock to be sent for One Person Operation (OPO) conversion. The A60/62 stock took over the service again in 1987.

The stock started being replaced by S Stock in 2016. It was replaced about 15 years short of its intended lifespan, as a consistent new fleet will allow for frequencies to be increased and will reduce maintenance costs.

In July 2011, Harrogate Chamber of Commerce proposed to use the stock on the Harrogate line from York to Leeds via Harrogate to increase capacity. Stations in the Harrogate and Leeds urban areas are close together; the superior acceleration of the stock over the Class 150 diesel multiple units currently used is intended to cut journey times. It was proposed, the line would be electrified with third rail similar to the Docklands Light Railway, as opposed to the London Underground or the Southern region network.

On 24 July 2012, car 7007 was designated as the Olympic 2012 Train with London Underground Chief Operating Officer Howard Collins carrying the Olympic Torch from Wimbledon to Wimbledon Park. This is the only London Underground train to be an Olympic Torch train.

Refurbishment
The mid-life refurbishment was the first to be carried out under the PPP, by Metronet, and was delayed until contract negotiations were completed. A prototype unit of three cars (7008/17008/8008) was prepared by London Underground's Train Modification Unit at Acton Depot in 2001. This had some detail differences from the eventual refurbishment, and was later brought up to the standard of the rest of the stock. The refurbishment programme began in summer 2005 with the work undertaken by Bombardier Transportation's, Derby Litchurch Lane Works. After which, C151s were undergone refurbishment from 2006 to 2008. The programme was completed in 2008.

The refurbishment consisted of:


 * applying London Underground livery with anti-vandal paint and window film
 * restyling the interiors in green and white
 * replacing maple flooring with rubber
 * adding end-of-car windows
 * replacing hanging straps (bobbles on springs) with grab bars
 * covering the door buttons
 * adding dot matrix indicators showing the station and destination on the inside and exterior front and sides
 * adding an audio passenger information system guided by GPS and odometer, voiced by Emma Clarke: announcements for each station name include connecting lines, and provide warnings to *"mind the gap between the train and the platform"
 * adding two tip-up seats/disabled multi purpose area
 * fitting air conditioning to driver's cab
 * fitting CCTV

The refurbished D Stock were the first Underground trains to have electronic dot-matrix information displays on the sides of the cars; some pre-war trains had slot-in or reversible destination or non-stopping plates.

Withdrawal
Withdrawals commenced on 19 January 2015 when the first full 6-car train, formed of units 7510 and 7058, was withdrawn from service at Ealing Common Depot and loaded onto trucks for Long Marston for the driving motors to be converted into 230s and the other cars to be either scrapped or stored for future use. The last train, formed of units 7007 and 7032, ran on 21 April 2017.

A farewell heritage tour took place on 7 May 2017 operated by units 7007+7032.

In February 2016, four redundant D78 cars were used by the emergency services in a mock tube accident staged at Littlebrook Power Station.