British Rail Class 91

British Rail Class 91
Virgin Trains East Coast Class 91 Locomotive at King's Cross
Type and origin
Power type Electric
Builder BREL Crewe Works
Build date 1988–1991
Total produced 31
Specifications
Configuration:
 ​
 • UIC Bo'Bo'
Gauge 1,435 mm (4 ft 8 1⁄2 in) standard gauge
Length 19.400 m (63 ft 7.8 in)[1]
Loco weight 81.5 tonnes (80.2 long tons; 89.8 short tons)
Electric system/s 25 kV AC Catenary
Current pickup(s) Pantograph
Traction motors GEC G426 (1.175 MW or 1,576 hp peak/1.135 MW or 1,522 hp continuous)
Loco 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)
Train brakes Air (axle-mounted triple-disc brakes; 140–0 mph or 225–0 km/h)
Performance figures
Maximum speed Design: 225 km/h (140 mph)
Service: 125 mph (201 km/h)
Blunt-end first: 110 mph (177 km/h)
Lok (Overspeed): 240 km/h (149 mph)[1]
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]
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]
Career
Operators London North Eastern Railway
Numbers 91001–91031
later 91101–91122, 91124–91132
Nicknames Electras
Axle load class Route availability 7

The British Rail Class 91 is a class of 225 km/h (140 mph), 4,830 kW (6,480 hp) 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), and were also referred to as Electras by British Rail during their development, and throughout the electrification of the East Coast Main Line. The other end of the InterCity 225 train set is formed of a Mark 4 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 underslung transformer so that the body is relatively empty compared to contemporary electric locomotives. Much of the engineering specification for the locomotive was derived from the research and operational experience of the APT-P.[1][2][3]

History

In 1985, ASEA, Brush and GEC Transportation Projects tendered for the design and construction of the Class 91s.[4] GEC subsequently won the bid and the fleet was built by sub-contractors British Rail Engineering Limited's Crewe Works 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 then 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 cancellation of InterCity 250, British Rail examined the option of ordering a further set of ten Class 91s to operate on the West Coast Main Line with UK Treasury support, however the business case for these failed to prove sufficiently worthwhile,[5] and led to the electric Networker Classes 365, 465 and 466 EMU Networker stock's procurement being taken forward.

91115 running blunt-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 the aerodynamics of the pantograph's knuckle creating excessive uplift force on the OLE.

Speed record

A Class 91, 91010 (now 91110) holds the British locomotive speed record at 161.7 mph (260.2 km/h), set on 17 September 1989,[6] 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, ran between London King's Cross and Edinburgh Waverley in 3 hours, 29 minutes and 30 seconds on 26 September 1991. This is 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.

Current operations

The fleet, which was previously operated by InterCity and then GNER, National Express East Coast, East Coast and Virgin Trains East Coast, is currently run by London North Eastern Railway. Since privatisation, the fleet has been owned by Eversholt Rail Group who lease it to the operators. Between 2000 and 2003, the whole fleet underwent a refit (Project Delta) 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.[7]

Future operations

Great North Western Railway (GNWR) is seeking rights to operate services between London Euston and Blackpool using Class 91s with seven Mk 4 coaches and a driving van trailer. The class 91s would require route and vehicle acceptance on the West Coast Main Line prior to the service starting. GNWR says capacity would be around 400 seats, although could be increased by adding further vehicles. The trains would initially be limited to 110 mph, as they do not tilt and any trains operating at the 125 mph line speed require this facility. The luggage area in the driving van trailer would be used to provide rescue couplings and point clips for use in emergencies. Fitment of on-train equipment to monitor the reliability of the rolling stock and the infrastructure is planned. Maintenance would involve two sets being serviced overnight at Arriva TrainCare in Crewe, with one serviced at Wembley and a spare set kept at Crewe depot, although GNWR says discussions with other maintenance providers are ongoing.[8]

Fleet

Class 91/1, no. 91118 "Bradford Film Festival" at Peterborough on 27 July 2003. This locomotive is painted in GNER blue livery
the blunt end cab
the normal cab of a class 91

When British Rail was privatised, the 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.[9]

In June 2010, a new silver livery with purple stripe was unveiled by East Coast.[10] As of February 2011, locomotives 91101,[11] 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 promotional "Skyfall" vinyls for a time during 2012/3. The locomotive later returned to conventional Virgin Trains East Coast livery. 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. 91118 the last locomotive to carry GNER/NXEC livery has now been repainted. All Mark 4 coaches and DVTs have since been repainted. On 14 October 2014 at Newcastle station, locomotive 91111 was unveiled in a commemorative World War One livery and named 'For The Fallen'.[12]

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 station on 29 March by his widow Elsie and Alan Shearer.[13][14]

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.[15][16]

Subclass Number built (year) TOPS number range Operators Comments
Class 91/1 31 (1988–1991) 91101–91122
91124–91132		 London North Eastern Railway It is originally Class 91/0. (91001–91031)

Operators

Operator Years Livery Image
InterCity 1988—1996 Intercity Swallow
Great North Eastern Railway 1996—2007 Navy blue with red detailing
National Express East Coast 2007—2009 National Express corporate grey
East Coast 2009—2015 East Coast silver with purple stripe
Virgin Trains East Coast 2015—2018 Virgin Trains corporate red and white
London North Eastern Railway 2018— LNER red and white
Great North Western Railway 2019— Great North Western Railway corporate brown

See also

References

  1. 1 2 3 4 5 6 7 8 Jean-Marc Allenbach, "BoBo BR 91 (Spec Sheet)" (PDF), 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, 25 kV 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. ↑ Vincent, Mike (2013). InterCity Story 1964-2012. Oxford Publishing Company. ISBN 978-0860936527.
  6. ↑ "Class 91 hits 162 mph". RAIL. No. 106. EMAP National Publications. 5–18 October 1989. p. 5. ISSN 0953-4563. OCLC 49953699.
  7. ↑ Pritchard, Fox & Hall (2007). British Railways Locomotives & Coaching Stock 2007. Sheffield, UK: Platform 5 Publishing Ltd. ISBN 978-1-902336-55-8.
  8. ↑ "BLACKPOOL OPEN ACCESS BATTLE LOOMS" Modern Railways July 2017 Volume 74 Number 826 page 9
  9. ↑ 91111 East Coast Newcastle Central. Flickr. Retrieved 5 November 2010
  10. ↑ Cover, Ron (9 August 2010). Tuplin, Richard, ed. "East Coast goes silver and purple!" (PDF). Railway Herald (223): 3. ISSN 1751-8091. Archived from the original (PDF) on 15 July 2011. Retrieved 12 August 2010.
  11. ↑ "91101 at Leeds". 5 October 2010. Archived from the original on 27 September 2011.
  12. ↑ "East Coast unveils tribute "For the Fallen"" (Press release). East Coast. 14 October 2014. Archived from the original on 19 December 2014. Retrieved 5 January 2015.
  13. ↑ "Sir Bobby Robson name given to train". BBC News. 29 March 2011. Retrieved 29 March 2011.
  14. ↑ "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.
  15. ↑ "Second pantograph fitted to '91' in bid to cut failures". Rail. Peterborough. 28 November 2012. p. 6.
  16. ↑ "Duplex pantograph prototype unveiled", www.railwaystrategies.co.uk, 1 February 2013, retrieved 12 November 2013

Literature

  • P.J. Donnison; G.R. West (25–28 September 1989), Institution of Electrical Engineers, ed., "The design and development of the class 91 locomotive", IEE conference publication (312): 294–298, ISBN 0-85296-384-X
  • P.C. Bennett (25–28 September 1989), Institution of Electrical Engineers, ed., "Aspects of the design, construction and testing of BRB's Class 90 and 91 locomotive transformers", IEE conference publication (312): 279–283, ISBN 0-85296-384-X
  • R. Dettmer (12 May 1998), "The Class 91 locomotive. Learning from the APT", IEE Review, 34 (5): 188–189, ISSN 0953-5683
  • Broom, M. L.; Smart, G. W. (1990). "The design, manufacture and assembly of the wheelset for the British Rail Class 91, 25 kV, 225 km/h locomotive". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit. 204 (26): 141. doi:10.1243/PIME_PROC_1990_204_200_02.
  • Dave Coxon, "IC225 and Class 91 commissioning", www.traintesting.com, archived from the original on 15 November 2005
  • "Running to Time", www.youtube, Channel 4 / Equinox (series), 1998
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