This page was last modified on 16 July 2008.
In the late 1950s the Central Line’s fleet of Standard Stock was life-expired and in need of urgent replacement. By way of prototyping, twelve Driving Motor (DM) cars were ordered from Cravens of Sheffield; these were marshalled with pre-1938-stock trailer cars (T) to produce three 8-car trains (formed DM-T-T-DM+DM-T-T-DM). These became the prototype/experimental 1960 tube stock.
The Cravens DM cars carried some innovations: the most notable visible one concerned the bodyside windows. These were rectangular and metal-framed (previously they had been square-ish and wooden-framed), and of twin-pane construction throughout, the space between the panes serving as the door pocket.
On the technical side, the Motor cars’ bogies were arranged differently to the accepted norm. 1938/59/62-stock had been designed with one 600-Volt motor mounted on the inboard axle of each bogie; the motors would be connected across the traction supply first in series and then, as more speed was attained, in parallel. This arrangement of asymmetric bogie trucks may have simplified maintenance through only having the single motored wheelset, but it did nothing to reduce tendency of wheelspin. Back in Sheffield, Cravens designed symmetrical bogies with both axles each carrying a 300-Volt motor; the two motors on each bogie were permanently wired in series, and so the control equipment remained exactly the same — it treated each bogie as having one 600-Volt motor, and connected the bogies first in series and then in parallel. This arrangement of all-axles-motored on each Motor car proved very satisfactory and was immediately adopted as the absolute standard throughout the entire Underground service fleet.
The Piccadilly Line already had new stock built for it (1959 stock), but the urgent need for new stock on the Central Line gave insufficient time for testing the 1960 prototypes, and so further 1959-type stock was ordered instead: this order became known as the 1962 tube stock. In this way, the 1960 stock remained just a prototype, and it was not until the Victoria Line’s purpose-built 1967 stock that the innovations described could be introduced into a production train.
Within a couple of years of entering service, these three prototype trains were converted into Automatic Train Operation (ATO) test trains for the Victoria Line which was being built at that time. They were fitted with the Safety and Auto-Driving equipment which was being developed for use on the 1967 stock; the testing took place on the Hainault to Woodford shuttle service on the Central Line, which had likewise been fitted with ATO equipment under test. Following completion of the testing programme, the extra cab-equipment was largely removed, but the under-seat Auto Driver Boxes and Safety Boxes still remain, although of course out of use.
The 1960-stock trains were unsuited to being amalgamated with any of the main fleets, because of differences in equipment; so the experimental vehicles remained an oddity throughout their lives. Latterly, the pairs of decaying “Standard” stock trailer cars were removed, and a single 1938-stock trailer put in their place; the trains became permanently separated into their constituent units, with some of the twelve Cravens DMs being scrapped along the way. This left four 3-car trains (formed DM-T-DM), which continued to be used on the Chigwell Loop (Hainault to Woodford), and the Epping to Ongar shuttle. By and by, one of the trains became the Track Recording Train (a substituted 1973-stock trailer being kitted out with the requisite equipment), and another was withdrawn to provide spares to keep the other two in service.
These last two trains just worked the Ongar shuttle, peak hours only, with three trips in the morning and four in the evening. In 1990 they were painted red to commemorate the 125th anniversary of the Loughton — Ongar line; following closure of the Epping to Ongar line on 30 September 1994, they were withdrawn from service.
The train that worked that last Ongar service was bought by a specially-formed company, the Cravens Preservation Group; this was subsequently renamed Cravens Heritage Trains, and in 1999 became [Cravens Heritage Trains Limited] (CHTL). The train, 3906-4927-3907, is maintained in full working order and can be used on the London Underground network for special occasions. The wholehearted support of London Underground’s Central Line management (and subsequently Infraco BCV and then Metronet BCV) has greatly facilitated the Cravens preservation project.
In the very early hours of Sunday 30 July 2000, the Cravens unit operated a once-in-a-lifetime railtour covering all parts of the Central Line, to celebrate the line’s 100th birthday. Run 100 years to the day since the first train entered service on the Tuppenny Tube, the tour had to be operated entirely during engineering hours (0130-0550) because the Cravens unit is not fitted with Central Line ATP equipment (see 1992 stock pages). It was a truly unique event, no such tour is ever likely to take place again!
In recent years the train has been “stopped” with some mechanical problems; since March 2006 it has been living at Northfields Depot, where it is set to have the faults put right so that it can resume its outings.
This event, on Saturday 3 October 1998, involved the freshly-repainted unit replacing the more usual Metropolitan Line A stock 4-car unit for the middle of the Saturday service: the unit is seen arriving at the bay platform (3) at Chalfont & Latimer, prior to returning to Chesham at 11:21. The destination blinds were intended for use on the Central Line and so, in the spirit of the occasion, the unlikely destination of Grange Hill is being displayed. Note that the Train Number (107) is displayed in the window of the ‘M’ door, and not in the location provided (see the other end, below); this is because poorly-sited public-address equipment was blocking the proper aperture at the time, but this has since been re-sited.
The pipe fastened to the front of the unit and passing close to the headlights contains the tripcock-reset cord, the top of which can be seen dangling from the mouth of the pipe. This provision obviates the need for the driver whose train has been “tripped” to get down onto the track, astride the negative rail, and feel for a filthy cord at solebar level near the live rail! In fact, the use of a pipe to extend the reset cord to within reach of the cab was a special modification, made when this train was doing ATO testing as described above: there was a fear that, if the driver had to get down onto the track after being tripped, he could be run over by his own automatically-restarting train when he pulled the reset cord! All passenger stock now has a means of resetting the tripcock without leaving the cab.
In June 1999 the train worked the all-day Northern Heights railtour from Uxbridge, via King’s Cross (Piccadilly Line) to the Northern Line, where it visited most of the destinations: I was particularly amused to have been through all four platforms of Leicester Square station that day without once changing trains!
Before the above tour had even finished, Allan Hoare (then Cobourg Street Control Room Manager, who has greatly assisted in coordinating these events) was discussing the possibility of repeat. This duly happened, on Sunday 24 October 1999; on that occasion we visited every one of the 50 stations on the Northern Line, plus Highgate and Morden depots!