British Rail Class 84
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|British Railways AL4
British Rail Class 84
Preserved locomotive 84001 on display at Crewe Works open day on 11 September 2005
|Builder||North British Locomotive Company|
|AAR wheel arr.||B-B|
|Gauge||4 ft 8 1⁄2 in (1,435 mm) standard gauge|
|Wheel diameter||4 ft 0 in (1.219 m)|
|Length||57 ft 6 in (17.53 m)|
|Locomotive weight||76.60 long tons (77.83 t; 85.79 short tons)|
|Electric system(s)||25 kV AC Catenary|
|Traction motors||750 hp (560 kW) GEC WT501, 4 off|
|Top speed||100 mph (160 km/h)|
|Power output||3,100 hp (2,300 kW)|
|Tractive effort||50,000 lbf (220 kN)|
|Train heating||Electric Train Heating|
|65.5 long tons-force (653 kN)|
|Train brakes||Vacuum; Dual from 1972|
|Number||E3036–E3045; later 84001–84010|
|Axle load class||Route availability 6|
|Disposition||One preserved, remainder scrapped|
As part of the modernization of the West Coast Main Line, which included electrification, 100 locomotives of five types were acquired from different manufacturers. Ten Class AL4 locomotives numbered E3036 - E3045 were built in 1960 to a design by GEC by the North British Locomotive Company in Springburn, Glasgow.
The locomotives always worked on power provided by overhead catenary energized at 25,000 V AC. However, the main transformer, normally operated with the four windings in series, could be operated at 6250V AC with the transformer windings in parallel. This voltage was initially to be used where limited clearances gave concern over use of the higher voltage.
Problems with the mercury-arc rectifiers plagued this class and in 1962 E3036 was returned to GEC, the builder of the electrical equipment, in an attempt to find a solution.
Within a year, all ten were out of service for repair. The problems persisted and in 1967 they were once more placed into storage, using the former steam shed at Bury, along with Class AL3. During this time E3043 went to Rugby Testing Centre for testing.
The persistent problems could have been the end of the ten locomotives of Class 84, but the extension of the West Coast Main Line electrification to Glasgow meant that more electric locomotives would be needed. It was therefore decided that the stored Class AL3 and AL4 locomotives would be repaired and returned to service, with a lower number of Class 87 being built.
Rebuild 2 and renumbering
Between 1971 and 1972, all ten locomotives were rebuilt once more and were reclassified under TOPS as Class 84, being renumbered 84001 - 84010.
The second rebuild failed to overcome some of the more persistent problems and British Rail decided in 1976 to withdraw them from service. The first to be withdrawn was 84007 in 1977, the last 84003 and 84010 in 1980.
84003 and 84009 passed to the Research Division: 84009 was rebuilt as a load bank tester and 84003 was used for spares. They were given departmental numbers ADB968021 and ADB968022 respectively, although the latter was never applied. In 1995 84009 was broken-up following withdrawal from its load bank duties; one cab of this locomotive was saved together with a quantity of spares.
84002 and 84010 were purchased by GEC for experiments, but scrapped soon afterwards.
84001 was moved to the National Railway Museum in York on long-term loan. The original intention was to eventually swap it for a more representative Class 86, but in 1994 the locomotive was officially claimed for the National Collection. In the intervening years, the 84 had become important to the Museum as the sole-surviving post-steam, main line (i.e. not a small shunting locomotive) example of a North British Locomotive Company product. 84001 remained at the NRM until 2000 when it was loaned to the AC Locomotive Group for an initial period of three years, later extended by five years, in exchange for much-needed cosmetic restoration work being undertaken. It continues to carry BR blue livery, as expensive cosmetic modifications would be required to return to "as built" condition in electric blue livery.
Due to financial difficulties the AC Locomotive group have now ended their custodianship of 84001 but despite this the national railway museum have decided for the locomotive to remain at Barrow Hill Roundhouse and an appeal is due to be launched for a repaint of the locomotive by roundhouse volunteers.
|E3036||84001||1979||Preserved by the National Railway Museum
On loan to the AC Locomotive Group at Barrow Hill
|E3037||84002||1980||Scrapped at Texas Metals|
|E3038||84003||1980||To Research Department
Scrapped at Vic Berry, Leicester
|E3039||84004||1977||Scrapped at Birds, Long Marston|
|E3040||84005||1977||Scrapped at Birds, Long Marston|
|E3041||84006||1978||Scrapped by J Cashmore at Crewe Yard|
|E3042||84007||1977||Scrapped by J Cashmore at Crewe Yard|
|E3043||84008||1979||Scrapped at Crewe Works|
|E3044||84009||1978||To Research Department
Scrapped at Gwent Demolition, Margam
|E3045||84010||1980||Scrapped at Texas Metals|
- McManus, Michael. Ultimate Allocations, British Railways Locomotives 1948 - 1968. Wirral. Michael McManus.
- Railway World December 1967, p. 554.