British Rail Class 91

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British Rail Class 91
91111 at Kings Cross 1.jpg
Specifications
Power type Diesel Electric
Builder BREL Crewe Works
Build date 1988–1991
Total produced 31
UIC classification Bo'Bo'
Gauge 1,435 mm (4 ft 8 12 in) standard gauge
Length 19.400 m (63 ft 7.8 in)[1]
Locomotive weight 81.5 tonnes (80.2 long tons; 89.8 short tons)
Electric system(s) 25 kV AC Catenary
Current collection
method
Pantograph
Traction motors GEC G426 (1.175 MW or 1,576 hp peak/1.135 MW or 1,522 hp continuous)
Top speed Design: 140 mph (225 km/h)
Service: 125 mph (201 km/h)
Blunt-end first: 110 mph (177 km/h)
Power output 4,830 kW (6,480 hp)[1]
Tractive effort max 190 kN (43,000 lbf)[1]
continuous 107 kN (24,000 lbf) @ 153 km/h (95 mph)[1]
Locomotive brake Primary, rheostatic (140–30 mph or 225–48 km/h); secondary friction (pneumatic single-cardan shaft-mounted disc and tread brakes; 30–0 mph or 48–0 km/h)
Locomotive
brakeforce
Dynamic braking:
83 kN (19,000 lbf) max @100 to 200 km/h (62 to 124 mph)[1]
50 kN (11,000 lbf) max @200 to 240 km/h (120 to 150 mph)[1]
Train brakes Air (axle-mounted triple-disc brakes; 140–0 mph or 225–0 km/h)
Career
Railroad(s) East Coast
Number 91001–91031
later 91101–91122, 91124–91132
Axle load class Route availability 7

The British Rail Class 91 is a class of 140 mph (225 km/h), 6,300 hp (4,700 kW) electric locomotives ordered as a component of the East Coast Main Line modernisation and electrification programme of the late 1980s. The Class 91s were given the auxiliary name of InterCity 225 to indicate their envisaged top speed of 225 km/h (140 mph). The other end of the InterCity 225 train set is formed of a Driving Van Trailer, built with a similar body shell to the Class 91 locomotives. The locomotive body shells are of all-steel construction. Unusually, the motors are body mounted and drive bogie mounted gearboxes via cardan shafts. This reduces the unsprung mass and hence track wear at high speeds. The locomotive also features an under-slung transformer so that the body is relatively empty compared to contemporary electric locomotives. Much of the engineering was derived from the research and operational experience of the APT-P.[2][3]

History[edit]

In 1985, ASEA, Brush and GEC tendered for the design and construction of the Class 91s.[4] GEC subsequently won the bid and the fleet was built by sub-contractors BREL in Crewe between 1988 and 1991.

The Class 91s began passenger service on 3 March 1989 when 91001 worked 1P26 17.36 London Kings Cross to Peterborough train. This train was formed of InterCity 125 Mark 3 coaches and a Class 43 power car converted for use as a DVT as the Mark 4 coaches were not yet ready. The Class 91s then began service on King's Cross to Leeds trains on 11 March 1989 when 91008 with a rake of Intercity 125 Mark 3 coaches and power car 43068 worked the 1D32 06:50 Kings Cross to Leeds service. The set then worked 1A12, the 10:00 Leeds to London Kings Cross service.

In the early 1990s, after the Treasury failed to provide funding for the InterCity 250, British Rail examined the option of ordering a further set of ten Class 91s to operate on the West Coast Main Line. Limited funding meant that the procurement of the Class 365, Class 465 and Class 466 EMU Networker stock was taken forward instead of these.

91115 running flat end first at London King's Cross

The asymmetric body style is streamlined at one end to allow high-speed operation with the fixed sets of Mark 4 coaches in normal push-pull passenger operation. An additional requirement of the design was that they could operate as normal locomotives. This led to a second cab being incorporated into the unstreamlined 'blunt end'; operating with the blunt end first limits the maximum speed of the locomotive to 110 mph (180 km/h) due to aerodynamic stability.

The fleet, previously operated by InterCity and then GNER (Great North Eastern Railway), and National Express East Coast, it is currently run by the nationalised operator East Coast. Since privatisation, the fleet has been owned by HSBC Rail who lease it to the operators. Between 2000 and 2003, the whole fleet underwent a refit to improve reliability. This has resulted in the renumbering of the fleet from 910xx to 911xx. During this time, GNER hired in Class 90 locomotives to provide cover.[5]

A Class 91, 91010 (now 91110) holds the British locomotive speed record at 162 mph (261 km/h), set on September 17, 1989, just south of Little Bytham on a test run down Stoke Bank with the DVT leading. Although both Class 370s and Class 373s have run faster, both types are EMUs, which means that the Electra is officially the fastest locomotive in Britain. Another loco (91031, now 91131), hauling five Mk4s and a DVT on a test run, once ran between London King's Cross and Edinburgh Waverley in 3 hours, 29 minutes and 30 seconds, still the current record. The set covered the route in an average speed of 112.5 mph (181.1 km/h), and reached the full 140 mph (225 km/h) several times during the run.

Fleet[edit]

Class 91/1, no. 91118 "Bradford Film Festival" at Peterborough on 27 July 2003. This locomotive is painted in GNER blue livery

When British Rail was privatised, the white Intercity livery was progressively removed. New operator GNER applied their corporate livery of blue and red. When GNER lost their franchise in 2007, the red stripe was replaced by a white stripe containing the words National Express and East Coast. National Express East Coast originally planned to repaint all of their InterCity 225 sets in the white and silver NXEC corporate livery within two years. However, the collapse of NXEC in 2009 and its replacement with East Coast saw this repainting programme cancelled. As a result, 91111 was the only Locomotive to receive the full National Express livery.[6]

In June 2010, a new silver livery with purple stripe was unveiled by East Coast.[7] As of February 2011, locomotives 91101,[8] 91106, 91107 and 91109 being the first to carry this livery. Locomotive 91101 has since been given maroon vinyls, with Flying Scotsman branding. Locomotive 91107 was given James Bond theme vinyls as 'Skyfall' for promotional purposes but this has since been removed and the locomotive returned to conventional EC silver livery.[citation needed] Locomotive 91110 carries 'BBMF' Battle Of Britain Memorial Flight livery. All locomotives now carry the standard East Coast livery of silver/grey with a purple stripe apart from one locomotive, 91118. Locomotives 91113, 91114, 91121 and 91119 were the most recent repaints. All Mark 4 coaches and DVTs have since been repainted.

The Class 91 fleet has carried various nameplates applied in various batches and themes. Immediately after repainting into GNER colours in the late 1990s, all locomotives were briefly nameless. Having initially been applied to only a few locomotives in the early 1990s using cast-iron plates, eventually the whole fleet was named, many multiple times, until all were removed in 2008. In 2011, in response to customer requests, East Coast resumed the practice. It began by naming No. 91109 as Sir Bobby Robson with cast-iron plates, unveiled in a ceremony at Newcastle Central Station on 29 March by his widow Elsie and Alan Shearer.[9][10]

Locomotive 91023 was involved in both the Hatfield rail crash and the Great Heck rail crash. After refurbishment in 2001 it was renumbered 91132 (rather than 91123).

In November 2012, unit 91114 had a second pantograph added as a pilot project operated jointly by Eversholt Rail Group, East Coast, ESG, Wabtec Rail and Brecknell-Willis. The new design uses the same mounting positions as a conventional pantograph but pairs two pantograph arms in an opposing configuration. If there is an ADD (Automatic Dropping Device) activation or the pantograph becomes detached, the train can keep going, so the system provides redundancy in the event of a pantograph/OLE failure.[11][12]

Subclass Number built (year) TOPS number range Operators Comments
91/1 31 (1988–1991) 91101–91122
91124–91132
East Coast Originally classed as 91/0
(91001–91031)

See also[edit]

References[edit]

  1. ^ a b c d e f Jean-Marc Allenbach, "BoBo BR 91 (Spec Sheet)", documents.epfl.ch (in French) 
  2. ^ "The Design and Development of the Class 91 Locomotive", P J Donnison and G R West, Main Line Railway Electrification Conference 1989 - Proceedings of the Institute of Electrical Engineers, 1989.
  3. ^ "The design, manufacture and assembly of the British Rail Class 91, 25kV 225km/h locomotive", M L Broom and G W Smart, Proceedings of the Institute of Mechanical Engineers Vol. 205, 1990.
  4. ^ Ford, Roger (April 1988). "Managing Electra". Modern Railways. ISSN 0026-8356. 
  5. ^ Pritchard, Fox & Hall (2007). British Railways Locomotives & Coaching Stock 2007. Sheffield, UK: Platform 5 Publishing Ltd. ISBN 978-1-902336-55-8. 
  6. ^ 91111 East Coast Newcastle Central. Flickr. Retrieved 5 November 2010
  7. ^ Cover, Ron (9 August 2010). "East Coast goes silver and purple!". In Tuplin, Richard. Railway Herald (223): 3. ISSN 1751-8091. Retrieved 12 August 2010. 
  8. ^ "91101 at Leeds". 5 October 2010. 
  9. ^ "Sir Bobby Robson name given to train". BBC News. 29 March 2011. Retrieved 29 March 2011. 
  10. ^ "East Coast Names Train Sir Bobby Robson" (Press release). East Coast. 29 March 2011. Archived from the original on 29 March 2011. Retrieved 29 March 2011. 
  11. ^ "Second pantograph fitted to '91' in bid to cut failures". Rail (Peterborough). 28 November 2012. p. 6. 
  12. ^ "Duplex pantograph prototype unveiled", www.railwaystrategies.co.uk, 1 February 2013, retrieved 12 November 2013 

Literature[edit]

External links[edit]