British Rail Class 91

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British Rail Class 91
Kings Cross - LNER 91125 ecs.JPG
Type and origin
Power typeElectric
BuilderBREL Crewe Works
Build date1988–1991
Total produced31
Specifications
Configuration:
 • AARB-B
 • UICBo'Bo'
Gauge1,435 mm (4 ft 8 12 in) standard gauge
Length19.400 m (63 ft 7.8 in)[1]
Loco weight81.5 tonnes (80.2 long tons; 89.8 short tons)
Electric system/s25 kV AC Catenary
Current pickup(s)Brecknell Willis high speed pantograph
Traction motorsGEC G426 (1.175 MW or 1,576 hp peak/1.135 MW or 1,522 hp continuous)
Train heatingElectric Train Heating (index 95)
Loco brakePrimary, 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 brakesAir (axle-mounted triple-disc brakes; 140–0 mph or 225–0 km/h)
CouplersHook with drophead buckeye at both ends.
Performance figures
Maximum speedDesign: 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 output4,830 kW (6,480 hp)[1]
Tractive effortmax 190 kN (43,000 lbf)[1]
continuous 107 kN (24,000 lbf) @ 153 km/h (95 mph)[1]
BrakeforceDynamic 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
OperatorsLondon North Eastern Railway
Europhoenix[2]
Numbers91001–91031
later 91101–91122, 91124–91132
NicknamesElectras
Axle load classRoute availability 7
Scrapped2021[3]
Current ownerEversholt Rail Group

The British Rail Class 91 is a class of high-speed, 4,830 kW (6,480 hp) electric locomotive 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); they 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, therefore 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][4][5]

History[edit]

Background[edit]

The origins of the Class 91 are closely associated with the East Coast Main Line (ECML) that it has been primarily operated upon. During the 1950s, British Rail had considered electrification of the ECML to be of equal importance to the West Coast Main Line (WCML), but various political factors led to the envisioned electrification programme being delayed for decades; as an alternative, high-speed diesel traction, including the Deltic and InterCity 125, was introduced upon the route during the 1960s and 1970s.[6] During the 1970s, a working group of British Rail and Department of Transport officials determined that, out of all options for further electrification, the ECML represented the best value by far. Its in-house forecasts determined that increases in revenue and considerable reductions in energy and maintenance costs would occur by electrifying the line.[7]

Accordingly, between 1976 and 1991, the ECML was electrified with 25 kV AC overhead lines. The electrification was installed in two phases: The first phase between London (King's Cross) and Hitchin (including the Hertford Loop Line) was carried out between 1976 and 1978 as the Great Northern Suburban Electrification Project, using Mk.3A equipment,[8] covering 30 miles in total.[7][6] In 1984, the second phase commenced to electrify the Northern section to Edinburgh and Leeds. During the late 1980s, the programme was claimed to be the longest construction site in the world, spanning more than 250 miles (400 km).[7]

During 1989, the InterCity 225 was officially introduced to revenue service.[9][10] That same year, the ECML had been energised through to York;[7] two years later, electrification had reached Edinburgh, allowing electric services to begin on 8 July 1991, eight weeks later than scheduled. The ECML electrification programme was completed at a cost of £344.4 million (at 1983 prices), a minor overrun against its authorised expenditure of £331.9 million. 40 per cent of the total cost was on new traction and rolling stock and 60 per cent for the electrification of the line.[7]

Options and selection[edit]

The electrification of the ECML necessitated the procurement of new high speed electric traction. The options and requirements for this trainset were hotly deliberated for a number of years. On 7 June 1978, the electric-powered prototype Advanced Passenger Train (APT) was unveiled; it was at one point intended for the APT to be the next major intercity express train.[11] However, due to various factors including technical issues, the APT programme was curtailed during the summer of 1989. Shortly thereafter, two alternative options were explored, an electrified version of the InterCity 125 (known as the HST-E), and the Class 89 mixed-traffic locomotive; these were both intended to a peak service speed of 125 mph.[12]

Some officials within British Rail pushed for more demanding requirements for the future Intercity trainset; reportedly, BR's Director of Mechanical and Electrical Engineering (M&EE) was a strong proponent for increasing the top speed to 140 mph.[12] To facilitate this, tilting train technologies developed for the APT were explored. While BR's board had approved the ordering of a single Class 89 as a prototype, the Strategy Committee queried why the type had been favoured over a proposed 80-tonne Bo-Bo locomotive.[12] While the Class 89 was thought to be a low-risk option for multi-purpose traction, it offered little advantage over the existing Class 87 in terms of speed. At the time, the 1950s era Class 81 and Class 85 electric locomotives were nearing the end of their viable service lives and were quite unreliable, but their withdrawal had effectively ruled out by a national shortage of newer electric traction, in part caused by the APT's cancellation.[12]

A key advantage of the InterCity 225 concept over a Class 89-hauled consist was the lower weight of the former, resulting in less slippage and greater acceleration over the latter.[12] Appraisals also determined that the Class 89 was comparatively inferior in financial terms, in part due to the InterCity 225's prospective compatibility with WCML traction, reducing its development costs. A further cost-saving measure was the decision to base the InterCity 225's technologies on the APT, BR reportedly stated that it had derived 90% of the former's engineering from the latter.[12] Thus, the study group recommended that the InterCity 225 be pursued as the preferred option, while the Class 89 and HST-E initiatives serve as back-ups. Despite this, the HST-E effort was promptly aborted, while Brush Traction decided to de-prioritise work on the Class 89 after learning that it was unlikely to lead to volume production.[12]

By spring 1984, favour was being given towards the adoption of a tilting carriage, tentatively designated as the Mk 4; this was viewed as superior to the existing Mk 3 and enabled a single design to be shared between the ECML and WCML.[12] At one point, it was envisaged that the InterCity 225 would be extremely ubiquitous, even potentially having the capability built into it to operate over the southern third-rail network and within the Channel Tunnel; by mid 1984, such fanciful ideas were curtailed. Furthermore, it was decided to reduce the freight haulage capabilities of the InterCity 225, as traction for this sector was instead intended to be served via other platforms.[12] The emergence of the Class 90, derived from the existing Class 87, somewhat reduced the pressure for the InterCity 225, reducing the prospective numbers to be built of the latter. Without tilting carriages, it had little speed advantage over the Class 90 on the WCML.[12]

It was decided to hold a competitive tender for the InterCity 225 programme; this measure was aimed at avoiding the difficulties experienced with the APT programme.[12] A pre-qualification document was formalised, in which various requirements for the type were laid out; these included the need to perform mixed-traffic duties (day and night passenger, parcel and mail, and overnight heavy freight services), the haulage of both tilting and conventional rolling stock, a top speed of 225 km/h, a maximum cant deficiency of 9° without the provision of tilt equipment, and that the maximum unsprung mass could not exceed 1.8 tonnes. Furthermore, BR stated its readiness to sub-contract with the successful bidder for the supply of technical information, advice and testing.[12] The prequalification document was issued to BREL, Brush Traction and the General Electric Company (GEC), as well as the French firm Alsthom and Germany's Krauss Maffei. The inclusion of foreign manufacturers was in part due to the limited domestic experience with trainsets capable of such high top speeds.[12] A total of three companies, ASEA, Brush Traction and GEC, submitted tenders for the design and construction of the Class 91 locomotive.[13]

On 14 February 1985, the BR board approved the substitution of the Class 91 for Class 89 for the ECML programme.[12] The tendering process was relatively complex, but a decisive move appeared to have been GEC's offer of a sub-contracting arrangement to BREL for the construction of the locomotive's mechanical elements. It would be GEC's submission that would be selected as the winner; after which a contract for the construction of 31 Class 91 locomotives, along with an option for 25 more for the WCML, was awarded during February 1986.[7][12] Shortly thereafter, BREL established a production line for the type at its Crewe Works.[12]

Post-introduction developments[edit]

The Class 91 entered service with InterCity on the East Coast Main Line (ECML) in 1989.[10] In service, as a part of the InterCity 225 sets, it was used alongside other rolling stock, including Class 90 locomotives and Class 317 electric multiple units. The displaced diesel trains were reallocated predominantly to the Midland Main Line.[7] The InterCity 225's introduction correlated with a significant increase in passenger numbers using the ECML within two years; one station recorded a 58 per cent increase in passengers.[7]

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.[14] and led to the electric Networker Classes 365, 465 and 466 EMU Networker stock's procurement being taken forward.[citation needed]

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).

As a consequence of the privatisation of British Rail, the Class 91 fleet was entirely acquired by the Eversholt Rail Group, which had leased it to various train operating companies. Between 2000 and 2003, the whole fleet underwent a refit (Project Delta) to improve reliability. The Class 91 units were refurbished at Bombardier Transportation at its Doncaster Works. 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.[15]

Speed record[edit]

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,[16] just south of Little Bytham on a test run down Stoke Bank with the DVT leading. Although Class 370s, Class 373s and Class 374s have run faster, all 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.

The Class 91 was designed to achieve a peak service speed of 140 mph (225 km/h); the upper range of its high speed capabilities facilitated a 3hr 29mins non-stop run between London and Edinburgh on 26 September 1991.[7] However, British regulations have since required in-cab signalling on any train running at speeds above 125 mph (201 km/h) preventing such speeds from being legally attained in regular service.[17] Thus, except on High Speed 1, which is equipped with cab signalling, British signalling does not allow any train, including the InterCity 225, to exceed 125 mph (201 km/h) in regular service, due to the impracticality of correctly observing lineside signals at high speed.

Fleet[edit]

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 of a Class 91
The normal cab of a Class 91

When British Rail was privatised, the InterCity livery was progressively removed and 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.

In June 2010, a new silver livery with a purple stripe was unveiled by East Coast.[18] By February 2011, locomotives 91101,[19] 91106, 91107 and 91109 carried this livery. Locomotive 91101 was soon 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. By 2013, all locomotives carried the standard East Coast livery of silver/grey with a purple stripe. 91118 was the last locomotive to carry GNER/NXEC livery. 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 I livery and named 'For The Fallen'.[20]

The Class 91 fleet has carried 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.[21][22]

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). It was scrapped on 2nd of April, 2021 at Sims Group, Beeston scrapyard.[23]

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.[24][25] This has since been removed, but the extended lower roof is still visible.

Class Operator No. of locos Locomotive Numbers Status
Class 91/1 London North Eastern Railway 12 91101, 91105-91107, 91109-91111, 91114, 91119, 91124, 91127, 91130 Originally numbered 91001-91031.
Europhoenix 2 91117, 91120
D.A.T.S 2 91122, 91128
Off Lease/Storage 15 91102-104, 91108, 91112, 91113, 91115-116, 91118, 91121, 91125-91126, 91129, 91131
Scrapped 1 91132[26]
Table of withdrawals
Year Quantity in
service at
start of year
Quantity
withdrawn
Numbers
2019 31 4 91103/108/117/120
2020 27 15 91102/104/112/113/115/116/118/121/122/125/126/128/129/131/132

Operators[edit]

Operator Years Livery Image
InterCity 1988—1996 Intercity Swallow 91021 at Peterborough in 1992.
Great North Eastern Railway 1996—2007 Navy blue with red detailing 91101 "City of London" at King's Cross in July 2007.
National Express East Coast 2007—2009 National Express corporate grey 91111 at Kings Cross in March 2009.
East Coast 2009—2015 East Coast silver with purple stripe 91106 at King's Cross in August 2012.
Virgin Trains East Coast 2015—2018 Virgin Trains corporate red and white 91124 at York in April 2015.
London North Eastern Railway 2018— LNER red and white (VTEC red/white with LNER branding) 91125 at King's Cross in July 2018.
Europhoenix 2019— Europhoenix grey, silver and red (with a phoenix motif branding) 91117 at Leicester TMD in October 2019.

Current operations[edit]

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.

In July 2019, 91108 was the first of the class to be withdrawn.[27] Following the withdrawal of the InterCity 125 fleet in December 2019, it was previously thought that the InterCity 225 fleet would be fully withdrawn by June 2020.[28] However, LNER announced on 29 January 2020 that they would be retaining a limited number of the InterCity 225 fleet to deliver all of the benefits of their December 2021 timetable.[29] LNER later confirmed that they would be keeping 10 sets in service.[30]

In September 2020, Eversholt Rail Group and London North Eastern Railway extended their lease to 10 by 2023. In addition, there are options to make it operational until 2024. It will be overhauled at the Wabtec Doncaster plant.[31][32]

At the end of service on 15 January 2021, the remaining serviceable InterCity 225 sets went into storage and are currently not in service. The sets are planned to return to service in summer 2021 after engineering works at King's Cross station have been completed as part of the East Coast Upgrade.[33]

Future operations[edit]

Europhoenix purchased 91117 and 91120 in September 2019. They were repainted at Bounds Green TMD before moving to UK Rail Leasing's Leicester depot. They are to be re-geared for freight operation in Europe.[34]

Rail Operations Group have taken a pair of Class 91s for use in testing of the newly electrified Midland Main Line prior to the introduction of regular electric services between Bedford and Corby.[35] The company has also expressed interest in using the Class 91s on high speed logistics trains.[36]

Grand Union is proposing to operate InterCity 225s on London Paddington to Cardiff Central and London Euston to Stirling services.[37][38]

Withdrawal[edit]

91132 electric locomotive in scrapyard

Class 91 91132 was the first Class 91 to be officially scrapped. It was scrapped at Sims Metals Scrapyard in Nottingham.[26]

Preservation[edit]

Upon retirement, 91110 will be preserved as part of the National Collection, having been nominated by the Railway Heritage Committee.[39]

References[edit]

  1. ^ a b c d e f g h Jean-Marc Allenbach, "BoBo BR 91 (Spec Sheet)" (PDF), documents.epfl.ch (in French)
  2. ^ https://www.railmagazine.com/news/network/europhoenix-earmarks-91s-for-european-freight-use
  3. ^ "Hatfeild and Great Heck "91" is first to be scrapped". Rail. No. 928. 7 April 2021. p. 28.
  4. ^ "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.
  5. ^ "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.
  6. ^ a b Stanton, Peter. "ECML Power Supply Upgrade." Rail Engineer, 23 November 2017.
  7. ^ a b c d e f g h i Shirres, David. "ECML: Electrification as it used to be". Rail Engineer. Retrieved 10 January 2018.
  8. ^ "Your NEW Electric Railway, The Great Northern Suburban Electrification" (PDF). British Railways. 1973. Retrieved 18 March 2014.
  9. ^ Semmens, P.W.B. (March 1991). Electrifying the East Coast Route: Making of Britain's First 140m.p.h. Railway. Patrick Stephens Ltd. ISBN 978-0850599299.
  10. ^ a b "Back to the future as history made with east coast rail icons". National Railway Museum. Retrieved 10 January 2018.
  11. ^ "First impressions of ATP-P". Modern Railways. Vol. 35 no. 359. Ian Allan. August 1978. pp. 354–358. ISSN 0026-8356.
  12. ^ a b c d e f g h i j k l m n o p "FROM THE ARCHIVES: Class 91s...promise unfulfilled". railmagazine.com. 27 July 2019.
  13. ^ Ford, Roger (April 1988). "Managing Electra". Modern Railways. ISSN 0026-8356.
  14. ^ Vincent, Mike (2013). InterCity Story 1964-2012. Oxford Publishing Company. ISBN 978-0860936527.
  15. ^ Pritchard, Fox & Hall (2007). British Railways Locomotives & Coaching Stock 2007. Sheffield, UK: Platform 5 Publishing Ltd. ISBN 978-1-902336-55-8.
  16. ^ "Class 91 hits 162 mph". Rail. No. 106. EMAP National Publications. 5–18 October 1989. p. 5. ISSN 0953-4563. OCLC 49953699.
  17. ^ Heath, Don (August 1994). "Electrification of British Rail's East Coast Main Line". Paper No. 105. Proceedings of the Institute of Civil Engineers (Transportation): 232. Cite journal requires |journal= (help)
  18. ^ 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.
  19. ^ "91101 at Leeds". 5 October 2010. Archived from the original on 27 September 2011.
  20. ^ "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.
  21. ^ "Sir Bobby Robson name given to train". BBC News. 29 March 2011. Retrieved 29 March 2011.
  22. ^ "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.
  23. ^ "First Class 91 goes for the chop". RMweb. 19 April 2021. Retrieved 19 April 2021.
  24. ^ "Second pantograph fitted to '91' in bid to cut failures". Rail. Peterborough. 28 November 2012. p. 6.
  25. ^ "Duplex pantograph prototype unveiled", www.railwaystrategies.co.uk, 1 February 2013, retrieved 12 November 2013
  26. ^ a b "First LNER Class 91 locomotive set to be scrapped in Nottingham". RailAdvent. 19 March 2021. Retrieved 6 April 2021.
  27. ^ First Class 91 withdrawn from traffic by LNER Rail issue 884 31 July 2019 page 28
  28. ^ "FROM THE ARCHIVES: Traction transition: HST to Azuma". www.railmagazine.com. Retrieved 17 January 2020.
  29. ^ Railway, London North Eastern (29 January 2020). "If you're a fan of our IC225 trains, you can continue to enjoy them for a bit longer. We are retaining a number of them in order to deliver all of the benefits of our Dec 2021 timetable plans. Here is our favourite, For the Fallen, at York Station.pic.twitter.com/ry89sQ45JE". @LNER. Retrieved 30 January 2020.
  30. ^ Railway, London North Eastern (5 February 2020). "18 currently and we are keeping 10 till the end of 2021. ^SM". @LNER. Retrieved 5 February 2020.
  31. ^ IC225 Fleet Lease Extension and Overhaul - Eversholt Rail Limited. Retrieved 2020-12-25.
  32. ^ LNER to retain 10 Class 91s up to 2023, as overhaul contracts awarded - RailAdvent. Retrieved 2020-12-25.
  33. ^ Horne, David (15 January 2021). "Last day in service for our speed record-breaking #Class91 locomotives today... for a while". Twitter.
  34. ^ Europhoenix earmarks ‘91s’ for European freight use Rail 10 October 2019
  35. ^ Clinnick, Richard (5 February 2020). "ROG to use Class 91s for Midland Main Line electrification testing". Rail Magazine. Bauer Media. Retrieved 27 July 2020.
  36. ^ Clinnick, Richard (24 April 2019). "May start for withdrawal of LNER's redundant trains". Rail Magazine. No. 877. Peterborough: Bauer Media. p. 32. ISSN 0953-4563.
  37. ^ Cardiff - London open access plan Railway Gazette International 19 June 2019
  38. ^ - Notification to the Office of Rail and Road of a Proposed service that may be subject to the economic equilibrium Office of Rail and Road
  39. ^ Class 60 to be saved for preservation Rail issue 678 7 September 2011 page 33

Literature[edit]

External links[edit]