British Rail Class 432

British Rail Class 432 (4-REP)
In service	1966–1992
Manufacturer	British Rail
Built at	York Works
Family name	BR Mark 1 EMU
Constructed	1966–1967, 1974
Number built	15 Sets
Formation	4 cars: DMSO-TRB-TBFK-DMSO
Capacity	24 First, 128 Standard, 23 buffet seats
Operators	British Rail
Depots	Bournemouth TMD
Specifications
Car length	DMSO: 19.75 m (64 ft 10 in) TRB/TBFK: 19.65 m (64 ft 6 in)
Width	2.82 m (9 ft 3 in)
Maximum speed	90 mph (145 km/h)
Weight	DMSO: 52.5 t (51.7 long tons; 57.9 short tons) TRB: 34.6 t (34.1 long tons; 38.1 short tons) TBFK: 35.7 t (35.1 long tons; 39.4 short tons) Total: 175.3 t (172.5 long tons; 193.2 short tons)
Traction system	EE546 traction motors of 300 kW (400 hp), 8 off
Braking system(s)	Air (Auto and Electro-Pneumatic)
Safety system(s)	AWS Automatic Warning System
Track gauge	1,435 mm (4 ft 8+1⁄2 in)

The British Rail 4-REP electric multiple units were built by BR at York Works from 1966-1967 and 1974. The units were built to power the 4-TC trailer units on services on the South Western Main Line. Fifteen four-car units were built. The motor coaches were new build, but the trailers were converted from Mk1 hauled stock. They were initially classified as Class 441 and numbered 3001-3015. This was later changed to Class 430, under which they spent the majority of their working lives. Shortly before withdrawal they were reclassified Class 432 and the units were renumbered to 2001-2015.

History

With the withdrawal of steam services and the electrification of the line to Bournemouth in 1967 there was insufficient financial justification to electrify between Bournemouth and Weymouth. This resulted in a quandary of how to maintain through services and the solution devised was novel. Tests in the mid 1960s had proved that high speed main line push-pull operation was both feasible and safe. The result was to have a high powered EMU at the London end pushing trailer units to Bournemouth where the trailers would be detached and then pulled to Weymouth by a push-pull equipped diesel electric locomotive. The operation in the up direction was would be the reverse.

The high powered EMU tractor units were classified 4-REP (Restaurant Electro-Pnuematic brake), the trailer units 3-TC and 4-TC (Trailer Control) and the push pull equipped diesel locomotives were converted from 19 of the Southern's native BRCW type 3 fleet (eventually to become designated class 33/1).

Initially eleven 4-REP units were built to propel the TC units to Bournemouth and pull them back to Waterloo. The 4-REPs were of the contemporary 1963 BR(S) EMU design and were formed of two driving motor second/standard saloons (DMSO) sandwiching a trailer brake first corridor (TBFK) and a trailer buffet (TRB). The DMSOs were new-builds but otherwise the TBFK was converted from a loco-hauled Mark 1 corridor composite and the TRB from Mark 1 loco-hauled Restaurant Buffets (1966–67) or Restaurant Unclassifieds (1974). Each of these restaurant/buffet cars were given names, the decorative panel behind the buffet counter carried the name of that particular car. The 4-REPs were the most powerful EMUs on the Southern Region, with a total of 3,200 hp (2,400 kW) available, in order to be able to provide the traction for up to eight trailer cars – just 100 horsepower (75 kW) less than the famous "Deltic" Class 55 diesel locomotives. Each REP had eight traction motors and because of this to avoid an overload a REP could only work with another powered EMU or Electro-Diesel Locomotive (EDL) if sufficient traction motors in the overall formation were first isolated. Each power bogie had a shoe beam with two pick up shoes since there were two power circuits. In 1974 an additional four units were introduced to increase the frequency of the service and to provide cover for extended maintenance of the fleet. Even at this late stage, the by-then obsolescent Mk1 design was adhered to, and a lack of Mk1 stock fit for conversion meant these last units were built from scratch – thus they were among the very last Mk1 cars built. The 1974 build units were fitted with double-glazed windows (except for the sliding toplights) as fitted to contemporary CIG/BIG stock.

When first introduced the REPs appeared in overall rail blue livery with small yellow warning panels and small aluminium BR arrows below their side cab windows. The yellow warning panels were subsequently enlarged to cover the whole cab front. They were repainted during the early 1970s into blue and grey, losing their aluminium arrows in the process; the 1974 builds emerged in blue and grey livery from new. Surviving REPs saw an application of Network SouthEast flashes from 1986 onwards, while the Class 442 “Wessex Electrics” were being built.

The REPs were good performers in service, their maximum permitted speed of 90mph being easily exceeded especially when loaded with only a single 4-TC or on their own. During the late 1970s speed tests were carried out between Woking and Basingstoke with a view to upgrading the permitted maximum to 100mph, but this was never undertaken mainly due to the increased braking performance required. On occasion 9 trailer cars were hauled, when the General Manager's Saloon DB975025 was added to a 4-REP/8-TC formation.

Replacement

In the mid 1980s the decision came to replace the Bournemouth line stock – not only because finance had become available to electrify the line between Bournemouth and Weymouth using new low-cost technology but also because the unpowered REP and TC cars were originally built in the 1950s, thus by the late 1980s they needed replacement. However the long-established Southern practice of re-using equipment took place for the traction motors and control gear, not being life-expired, were re-used. Various solutions to this stock shortage were found. In 1990 the South Hampshire Electrification Project (SHEP) was completed involving the Portsmouth to Eastleigh/Southampton lines. New stock was not allocated due to financial constraints but the service had to be kept running using existing resources. Originally it had been planned to retain three 4-REPs which had earlier been stripped of asbestos, however unit No. 2003 was partially written off following the Clapham Junction rail crash in 1988, so a change of plan was needed. Instead a new formation of four 6-REP units (numbers being 1903 to 1906) was considered and finally implemented on the route. Spare TC trailers formed in the middle had their leading ends repainted and their driver compartment doors locked out of use. Shoe gear was fitted, and all coaches in blue/grey were repainted into NSE colours. The 6-REPs also saw protracted use on the Weymouth line during the testing of Class 442s. In extreme cases, to keep services running, 4-REPs had a motor coach replaced by a Class 73 locomotive. The new stock was to be the Class 442, based on the Mark 3 bodyshell. This required REP units to be reformed and withdrawn to allow the equipment to be recovered before new 442s could become available. Reconfigured REPs and TCs soldiered on the Bournemouth line to cover for unavailable 442 units from mid 1988 until 1991. The final use of a REP was in the last week of September 1991, units 1901 and 1904 being the last.

Preservation

As the electrical equipment was salvaged for use in the Class 442s, only the two driving motors from unit no. 2015 have survived (without traction equipment), both in departmental service.

Both vehicles are used for ultrasonic testing. 62482, since renumbered 999605, is formed in a locomotive hauled test train usually in the care of two Class 31 locomotives. 62483 became 999602 and currently runs sandwiched between Class 101 DMU vehicles.

(The 4Rep Appreciation Society) are looking at saving the remaining carriages and converting back to REP.

References

• Marsden, Colin J. (1983). Southern Electric Multiple-Units 1948–1983. Shepperton, Surrey: Ian Allan Limited. pp. 73–84. ISBN 0-7110-1314-4.