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The 1972 Tube Stock was
developed from the Victoria Line's 1967 Tube Stock. It was originally ordered in two
separate batches for the Northern Line. It also operated on the Jubilee Line but now
operates only on the Bakerloo. Some of the trains have been scrapped. It has
had an interesting and varied history. This page outlines that history and describes
the trains.
|
Car | Weight | Seats | Equipment | ||||||
DM | 27.8 tons | 40 | Cab | Shoes | Traction Package | Auto couplerš | Batteries | ||
T | 18.1 tons | 36 | Motor Alternator | Compressor | |||||
ST˛ | 18.1 tons | 36 | Motor Alternator | ||||||
UNDM | 26.5 tons | 40 | Shunting controller | Shoes | Traction Package | Auto coupler | Batteries | ||
šEmergency coupler on DM cars in 3-car units. ˛ST (Special Trailer) is used only on 3-car units. It is standard apart from its two braking units in place of one. |
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The 1972 Stock is arranged so that each unit is self contained as far as equipment is concerned. The general arrangement of the equipment for a 3-car unit is shown in the diagram below. The equipment on a 4-car unit is similar except that the UNDM is replaced by a second trailer and another DM car. In effect, the 4 car unit comprises two DM-T pairs, back to back, making a DM-T-T-DM unit. The 3-car units have one trailer which is virtually the same as the trailers of the 4-car units, except that it has two separate brake units, one linked to the brake equipment of each of the adjacent motor cars. For this reason, the 3-car unit's trailer is sometimes referred to as a "Special Trailer".
Fig 7: Equipment schematic of 1972 Tube Stock 3-car unit showing simplified layout of systems. The 4-car unit is formed of two DM-T pairs, back to back.
Click on the image for the full size view.
The 1972 Stock traction equipment is a copy of the system used on the 1967 Tube Stock of the Victoria Line. It is equipped with DC traction motors and using a pair of pneumatically driven camshafts for resistance control. One camshaft operates the series contactors, while the other operates the parallel contactors. The traction circuit is arranged in a classic series-parallel configuration with two stages of weak field control. Each of the two motor cars in a unit has four 300 volt DC motors, giving 57% axles motored on a 7-car train. The two motors on one bogie are permanently connected in series. The motors are type LT 115, built by Brush and drive the axle through a gear ratio of 16:65. The low voltage traction control circuits are duplicated and arranged so that one set of control circuits operates one motor car of a unit, whilst the other set operates the other motor car. This set-up ensures that a low voltage control circuit failure will not disable the train. Only 50% of control will be lost. The cab is equipped with a special Fault Isolation Switch (FIS) which allows selection of the control circuits.
The double camshaft control traction system was adopted on the 1967/72 fleet to allow the introduction of rheostatic braking on London Underground. The additional contactors required forced the use of two camshafts. The rheostatic brake control is an essential feature of the traction system and is linked to the brake system by a complex series of relays. These detect that the rheostatic braking is working and holds off the electro-pneumatic brake on the motor cars as long as enough brake is being achieved relative to the brake demand. If any car fails to get rheostatic braking, the system cancels it on the whole train and allows the e.p brake to do all the braking. The lag between the two is sometimes the cause of overruns, as the e.p. can't quite match the lost rheostatic brake in time. This is not a nice feature of this train but the crews have got used to it.
Each trailer car has a single Westinghouse 3HC43 or Reavell TBC38Z air compressor supplying a main reservoir up to 105 psi. Air is used to power brakes, doors and to drive the pneumatic camshaft of the traction control system. Each trailer also has a motor alternator (MA) providing 230 volts AC at 850Hz for auxiliary services. Lighting is supplied at 115 volts AC. The MA recharges the battery on each motor car at 50 volts DC and supplies the control circuits at that voltage. It is unusual for a motor alternator to be located on a different car to the battery but the 1967/72 design is short of space under the motor cars because of the use of a double camshaft traction control system so the MA is located on the trailer. The battery remains in the standard position on the DM car because it was a requirement on London Underground that the end cars of the train always had a battery to supply the tail lights in case the last car became detached from the train. This is a legacy from the days of individually coupled stock and is not nowadays enforced. The 199x series of stocks don't have their batteries on end cars.
The arrangement of doorways on the 1972 Stock is the standard used by most tube cars. As the small body profile required by tube tunnels restricts the floor height, the wheels intrude into the underframe construction over the bogies. Doors cannot be located at these positions so the openings for the wheels are covered by longitudinal seats. Doorways are positioned either side of the bogie positions. Each car has four doorways on each side with a single leaf sliding door at each end and two double doorways between. The double doorway opening is the standard 1372mm (4ft 6ins) or 2ft 3ins for single doorways.
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There were a number of differences between the two batches of 1972 Stock. When the trains were first delivered, both batches had the door controls in the then usual position at the trailing end of the driving car. The Mk IIs had an ATO position on the selector switch, and the FOR 1/ FOR 2 facility was positioned on the side control panel. There was a motorised destination blind and the train number bracket was mounted on the offside console. There was no train number slot in the centre (M) door. An electronic train number display box was eventually mounted on the offside console. The number and blind were operated from thumbwheels mounted on the train number box. Both these electrically operated displays were soon removed as they were both a lot of trouble. They also had door control buttons and switches for lights and heaters in the end cabs, very like those provided for the C Stock The additional features of the Mk IIs were to allow easy conversion to ATO on the Jubilee (Yes, really). These controls were only provided on the end motor cars, not the middle ones.
The Mk IIs converted to OPO for the Jubilee Line had new door controls added in the cab (and the existing ones remained) to allow the driver to operate them without having to turn round. The new controls were mounted on the leading edge of the front desk.
Fig 8: 1972 Tube Stock cab as refurbished.
Click on this image for the full size view of this picture and a page showing the old and new cab layouts of the 1972 Tube Stock.
Another difference between the original Mk Is and the Mk IIs was the livery. Mk Is had the plain unpainted aluminium body finish standard between the early 1960s and late 1980s but the Mk IIs were the first trains to appear with red painted side doors and a 17 inch plain red roundel on each car side. The Mk I trains had only the word UNDERGROUND on the driving cars. Inside the Mk I cars, the seating upholstery was originally red/black/grey with red armrests but green/blue with blue armrests in the Mk II cars. In later years, the upholstery was replaced by newer patterns with a theme indicating some element of the line colour on which the btrains operated.
The traditional "NO SMOKING" roundel sign seen on Mk I cars was replaced by a simple blue bar on Mk IIs. It was so difficult to see that the remaining bits of the red roundel were added soon after
The red doors were the idea of the late Dr Misha Black, leader of what was to become the "Design Research Unit", the company now known as DRU. He had been involved in much of the design work for the Victoria Line and was considered by the London Transport management of the day as something of a "guru" in design matters. The red doors survived much criticism in the early days and is now part of the Underground's corporate image but the horrible, solid red roundel did not.
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In addition to its wanderings and transfers over the years, the 1972 Stock has been subjected to a number of modifications and trials. Trial fans were fitted to Mk I car 4209 in 1975 but these were removed a couple of years later. Trial bogies were fitted to the DM car 3363 in the last 4-car unit to be built. These had aluminium frames and Metacone air suspension units fitted. The bogies were replaced with the standard design in 1982.
Experimental flooring was fitted to cars 4205 (Dunlop tiles) and 4517 (Vamac tiles) in 1984 and car 3305 was fitted with self-steering bogies. Frame mounted motors were fitted to car 3230 with special bogies in 1985.
When 1972 Mk II trains were first transferred to the Bakerloo, they were equipped with radio and step plates and grab rails were provided on the end driving cars, i.e. except the 33xx DMs which were to operate only in the middle of Bakerloo trains. the step plates and grab rails were mounted on the front of the cabs to allow drivers to get out of the cab without using the passenger saloon. This was a particular problem at Baker Street, where the leading car was often full of passengers blocking the exit door between the cab and the saloon.
During 1989-90, all remaining Mk I trains on the Northern (24˝, the others had been converted for use on the Bakerloo and Victoria Lines) were sent to Acton Works for a modification programme which involved replacing the original passenger alarm system (which automatically stopped the train) with one which operated an alarm in the driver's cab. The original, manually operated, hydraulically actuated parking brake was replace by a fully automatic spring applied parking brake, similar to the type first introduced on the D Stock.
4-car unit 3203 was withdrawn for spares in June 1985 to allow overhauls of the 1972 fleet to begin at Golders Green. It wasn't re-instated until 1989. LU had decided that centralisation of overhauls was too expensive in its present form and that the work was better done at depots where specialist knowledge of individual stocks was always available. It was also an excuse to shut down the works and get rid of the numerous restrictive practices which had arisen over the years. Now a rebuilt Acton workshop complex specialises in modification programmes and specialist overhaul of components.
During 1987, two cars of 1972 Mk II Stock were equipped with pneumatically retractable shoegear. One set, by AEG, appeared on 3259 and was the type subsequently adopted for the 1992 Tube Stock for the Central Line. The other set was by Brecknell Willis and appeared on 3557.
Fig
9: 1972 Tube Stock as repainted in a test colour scheme in 1989. The cars had
blue doors and a plain white body. Photo by Kim Rennie
Click on this image for the full size view of this picture.
In 1989, three trains of Mk I stock on the Northern Line were painted in special liveries in an attempt to find a suitable body colour scheme for the corporate standard. All trains had the red front now seen on most trains. One train had a white body with blue doors, one had a blue upper body and white lower body and one had the now standard red, white and blue scheme (Fig 9).
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OPO conversion of the 1972 Stock was confined to the Mk II cars and, later, a few Mk I cars which were transferred to the Bakerloo to enhance the fleet or replace damaged cars. OPO conversion work began at Acton in 1987 and was continued slowly until the changeover of the Bakerloo to OPO in November 1989. 1972 Stock trains working on both the Jubilee and Bakerloo Lines during this period were converted but the Jubilee Line trains were done first.
The original OPO conversion of Mk II Stock included the provision of electronic train number displays and a window wiper for the offside cab window. There were no door controls on the driver's desk. The door control panels originally provided on the rear cab walls were wired in for use from the cab and the panels on the trailing ends of the driving motor cars were panelled over. During the period when converted train and unconverted trains were running with two-person crews, the guards had to operate the doors from the rear cabs of converted trains. Trains were also provided with electrical passeniger alarm buttons and passenger alarm indicator lights over the end communicating doors. Operation of the alarm stopped the trains while they were operated in 2PO mode but was modified to sound an alarm in the cab after the introduction of OPO.
Fig 10: 1972 Tube Stock guard's position before conversion to OPO.
Click on this image for the full size view of this picture and a page showing the
guard's controls of the 1972 Tube Stock.
OPO was introduced to the Jubilee Line in March 1988 with a mixed fleet of 1983 and 1972 Mk II Stocks. Most of the 14 1972 Mk II Stock trains used on the Jubilee then were transferred to the Bakerloo once the delivery of 1983 Tube Stock trains to the Jubilee was completed. They were temporarily used in 2PO mode until the Bakerloo was converted to OPO in November 1989. Some of the 1972 Mk II trains on the Bakerloo were still awaiting conversion at the end of 1988 and the work was not finished until March 1989 when the last unit converted was sent from Acton to Stonebridge Park.
Fig 11: Refurbished 1972 Tube Stock at Harrow & Wealdstone. Photo by Kim Rennie.
Click on the image for the full size view and
description.
In 1989, a programme for the refurbishment of the whole Underground rolling stock fleet was begun. Following the Kings Cross fire of November 1987, there was a panic driven, media fueled anti fire frenzy across London Underground. All inflammable materials had to be removed, whatever the cost and regardless of how low the risk. All the 1967/72 Stock on the Victoria Line, the 1972 Mk Il stock on the Bakerloo Line, and the remaining 1972 Mk l Stock on the Northern Line was mechanically modified and given an alI-over face-lift to make them brighter, cleaner and more pleasant to ride in. It was originally anticipated that the trains would be refurbished at the rate of one each fortnight and that the work will be finished in the Spring of 1994. However, following a prototype refurbishment completed in September 1989, the first train (of 1967 Stock) was dispatched in June 1990 and took 18 months to do. The Mk II fleet was sent to Tickford's of Rosyth in Scotland for a complete refurbishment. The first train went in 1990 and work continued slowly unitl 1995. One train of Mk I Stock was converted to OPO and transferred to the Bakerloo in 1989 to provide a float for the trains being sent away for refurbishment. This train was also refurbished for the Bakerloo.
Fig 12: Refurbished 1972 Tube Stock interior.
Click on the image for the full size view and
description.
The opportunity was taken to update the car interiors and to build in some engineering modifications at the same time. The manually operated hydraulic handbrakes which caused so much trouble with leaking hoses and pumps were replaced with spring-applied parking brakes. Cabs were improved and some operational changes were made like new door control panels and door buttons on the drivers desk. Each car had new fire resistant ceilings and waIl panelling. The maple wood floors were replaced by a coloured ribbed rubber surface which is fire retardant and low in smoke emission.
Trains were painted in the corporate livery in high durability two-pack paint. It was supposed to be graffiti resistant and make removeal of vandalism easier. Seats were replaced by a more vandal-resistant design with removable removable covering for easier cleaning and with locking devices for better security. The flexible grab handles were replaced by modular grab poles throughout the car length to reduce maintenance and replacment costs, and to provide a more comfortable environment for standing passengers. Some of the new fittings (such as flooring, grab poles, arm rests and seat moquette coverings are in the identity colour of the Bakerloo Line on which the trains run. Lights were fitted with diffusers, a "designer" addition which reduced the interior lights levels and increased maintenance costs but which were said to enhance the interior appearance. Drivers cabs were given air conditioning because of the need to seal the cabs to comply with new noise at work regulations. Cabs have been tidied up and some improvements made to seats and controls (Photos). The original shunting controls provided on the UNDM cars were replaced by a redesigned set in a smaller cabinet.
Only three trains of Mk I Stock working on the Northern Line were refurbished before money was promised to allow replacement of the whole Northern Line fleet with new trains, the 1995 Tube Stock. These three 1972 Stock trains were eventually modified for OPO, given interior Bakerloo colours in place of the Northern Line colours and sent to the Bakerloo to increase the fleet to 35˝ trains.
Stock | Original Total | Conversions | Withdrawals | Date | Comments |
1972 Mk I | 30 x 7 cars | 5 x 4-cars, 4 x 3 cars |
4 cars | 1987-89 | Created 28 additional cars for the Victoria Line |
1 x 7 cars | 1991 | Converted to OPO for use with 1972 Mk II Bakerloo fleet | |||
3 x 7 cars | 1995-6 | Ex Northern Line refurbished trains now on Bakerloo | |||
150 cars | Replaced by 1995 Tube Stock | ||||
1972 Mk II | 33 x 7 cars | 5 cars | Collision damage |
Fig 13: Refurbished 1972 Mk II Tube Stock showing the inter-car safety barrier at Queens Park.
Click on the image for the full size view.
One recent modification on the 1972 Tube Stock, which has also been applied to other lines, is the provision of inter-car safety barriers. These first appeared on the Piccadilly Line in 1997 and were a response to the occasional accidents where passengers - usually those suffering from the effects of alcohol or drugs - have fallen between cars. The barriers are made of black canvas and are hung on brackets fitted to the outer corners of the car body. They are coupled between cars on sprung attachments to allow transition on curves without creating a gap or tearing. They look dreadful and have become something of a maintenance problem.
After the refurbishment programme was started, the trains were also equipped with "Correct Side Door Enable" (CSDE), to prevent the train doors being opened on the wrong side of the train, a problem which became much more frequent after the introduction of OPO.
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To the Top of this Page or to the Home Page This page created 12 March 2003 Copyright © Tubeprune 2001, 2002. If you have comments or if you would like to use any part of this site for publishing or commercial reasons, please e-mail me |