British Rail Class 84

Last updated

British Railways AL4
British Rail Class 84
84001 at Crewe Works.JPG
Preserved locomotive 84001 on display at Crewe Works open day on 11 September 2005
Type and origin
Power typeElectric
Builder North British Locomotive Company
Order numberL91 [1]
Build date1960–1961
Total produced10
Specifications
Configuration:
​
 •  AAR B-B
 •  UIC Bo′Bo′
 • Commonwealth Bo-Bo
Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge
Wheel diameter4 ft 0 in (1.219 m) [2]
Wheelbase 39 ft 6 in (12.04 m) [2]
Length:
​
 • Over beams53 ft 6+1⁄2 in (16.32 m) [2]
Width8 ft 8+1⁄4 in (2.648 m) [2]
Height:
​
 • Pantograph13 ft 0+9⁄16 in (3.977 m) [2]
 • Body height12 ft 4+1⁄4 in (3.766 m) [2]
Loco weight76.60 long tons (77.83 t; 85.79 short tons)
Electric system/s 25 kV AC Catenary
Current pickup(s) Pantograph
Traction motors 4 × GEC WT501 [3]
Gear ratio25:74 [3]
Train heating Electric Train Heating
Train brakes Vacuum; Dual from 1972 [1]
Performance figures
Maximum speed100 mph (160 km/h)
Power output:
​
 • 1 hour4 × 890 hp (660 kW) [3]
 • Continuous4 × 750 hp (560 kW) [3]
Tractive effort 50,000  lbf (220  kN)
Brakeforce65.5 long tons-force (653 kN)
Career
Operators British Rail
NumbersE3036–E3045; later 84001–84010
Axle load class Route availability 6
Retired1979–1980
DispositionOne preserved, remainder scrapped

The British Rail Class 84 was a 25 kV AC electric locomotive that operated on the West Coast Main Line (WCML) of the London Midland Region.

Contents

The ten strong class was one of five prototype classes of electric locomotives built in the early stages of WCML electrification. Built between 1960 and 1961, the type was not a success, as they were beset by technical problems, and after several lengthy periods of storage, and unsuccessful attempts at resolving these problems, British Rail decided to withdraw the entire fleet between 1977 and 1980.

History

As part of the modernisation 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 by the North British Locomotive Company in Springburn, Glasgow, to a design by GEC. [4]

Locomotive E3040 worked the inaugural AC electric-hauled train from Manchester Piccadilly to Crewe on 12 September 1960. [2]

Power supply

The locomotives always worked on power provided by overhead catenary energised 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. Since the clearances were found to be adequate, the lower voltage connections were locked out of use. [5]

Service

Once in service a number of problems emerged with the class, including rough riding, flashovers in the transformer windings, short lifespans for the motor spring drives, and major problems with the mercury-arc rectifiers. In April 1963 the entire fleet was temporarily taken out of service, and was returned to GEC Dukinfield, the builder of the electrical equipment, in an attempt to find a solution, and remedial work was carried out. [6] [7]

When the class returned to service, the problems persisted, and in 1967 they were placed into storage, using the former steam shed at Bury, [8] along with Class AL3. [9] During this time E3043 went to Rugby Testing Centre for trials. [10]

Reprieve and rebuilding

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 which was conducted at Doncaster. [10]

After spending five years in storage, all ten locomotives were rebuilt with silicon rectifiers and dual brakes in 1972. [1] [11] and were reclassified under TOPS as Class 84, being renumbered 84001 - 84010.

Withdrawal

The second rebuild overcame some of the previous problems, however new problems emerged involving traction motor failures, caused in part by the long period they had spent in storage, and the class continued to give trouble in service. By the mid-1970s, having already spent a substantial amount of money on them, British Rail could not justify any further investment in the fleet, especially since the recently introduced Class 87s allowed them to be sidelined. The decision was taken to withdraw them from service, with 84005 and 84007 being the first to be withdrawn in April 1977, the last to be withdrawn were 84003 and 84010 in 1980. [6] [7] [12]

After withdrawal

ADB968021 (ex 84009) load bank tester (1987) 19870830-BritishRail ADB968021.jpg
ADB968021 (ex 84009) load bank tester (1987)

Several of the locomotives were saved from scrap: 84001 was donated to the National Railway Museum for preservation. 84002 and 84010 were returned to GEC for a proposed scheme to use them as new-technology test bed locomotives, however this project never materialised, and both were scrapped in December 1982. [12]

84009 saw further use in a new guise; it passed to the British Rail Research Division, and was rebuilt as an unpowered mobile load bank tester, to test the power supply to new and upgraded overhead line equipment, and was renumbered as ADB968021. In 1992 it was withdrawn from service and broken up. [6] 84003, was saved to be used as a source of spares for 84009 and for possible conversion to departmental use, but was scrapped in 1986. [12]

Preservation

One locomotive (84001) has been preserved by the National Railway Museum: This was initially meant to be temporary; the locomotive was to be exchanged at a later date for a more representative example of WCML electric traction such as a Class 86 or Class 87. [12] It was later on loan to the Scottish Railway Museum, Bo'ness. [13]

Fleet details

Key:PreservedScrapped
Numbers [1] Date Introduced [1] Withdrawn [14] [15] Disposal
Pre-TOPSTOPSNBL Works No.
E30368400127793March 196022 January 1979 [1] Preserved by the National Railway Museum. [13]
E30378400227794May 1960September 1980Scrapped at Texas Metals
E30388400327795June 1960November 1980To Research Department
Scrapped at Vic Berry, Leicester
E30398400427796July 196012 November 1977 [1] Scrapped at Birds, Long Marston
E30408400527797August 196020 April 1977 [1] Scrapped at Birds, Long Marston
E30418400627798October 1960January 1978Scrapped by J Cashmore at Crewe Yard
E30428400727799October 1960April 1977Scrapped by J Cashmore at Crewe Yard
E30438400827800December 1960October 1979Scrapped at Crewe Works
E30448400927801December 19603 August 1978 [1] To Research Department
Scrapped at Gwent Demolition, Margam
E30458401027802March 1961November 1980Scrapped at Texas Metals

References

  1. 1 2 3 4 5 6 7 8 9 Webb & Duncan 1979, p. 59
  2. 1 2 3 4 5 6 7 Webb & Duncan 1979, p. 58
  3. 1 2 3 4 Webb & Duncan 1979, p. 54
  4. ↑ Marsden & Fenn 2001 , p. 82
  5. ↑ Allan 1968, p. 11.
  6. 1 2 3 Marsden, Colin J. (2007). The AC Electrics. Ian Allan Publishing Ltd. pp. 38–41. ISBN   978-0-86093-614-5.
  7. 1 2 Morrison, Colin (2014). AC Electric Locomotives. Ian Allan Publishing Ltd. pp. 16–18. ISBN   978-0-7110-3505-8.
  8. ↑ Railway World December 1967, p. 554.
  9. ↑ Longhurst 1979 , Class AL4–84
  10. 1 2 Marsden & Fenn 2001 , p. 83
  11. ↑ Webb & Duncan 1979 , p. 55
  12. 1 2 3 4 "Class History - AL4 / 84". The AC Locomotive Group. Archived from the original on 29 January 2023. Retrieved 29 January 2023.
  13. 1 2 @RailwayMuseum (26 January 2023). "Class 84, 84001, made the short trip from Holgate Engineering Works to the NRM via platform 11" (Tweet) – via Twitter.
  14. ↑ "The Class 84 Fleet". Rail Blue. Archived from the original on 3 July 2016. Retrieved 11 February 2016.
  15. ↑ "Class 84". RAIL . No. 88. EMAP National Publications. January 1989. p. 42. ISSN   0953-4563. OCLC   49953699.

Sources

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.