British Rail Class 43 (HST)

In the early 1970s, the British Railways Board made the decision to replace its main-line express diesel traction. Financial limitations were tight, so mass electrification was not possible. As a result, a new generation of high-speed diesel trains had to be developed.

Experience with the high-speed Class 55 Deltic locomotives had shown that a low axle weight was essential to avoid damage to the track at sustained high speed, and that high-speed engines were the only way to provide a good enough power-to-weight ratio for diesels. To power the HST at up to 125 mph (201 km/h), each power car had a new diesel engine, the 12-cylinder Paxman Valenta, running at 1,500 rpm and developing 2,250 bhp (1,680 kW). The 70-tonne weight of the power car gave it a 17.5-tonne (per-)axle loading.

The HST, having been in operation since the late 1970s, is due for replacement by the Hitachi Super Express. The development cycle for the replacement series is such that the existing fleet may be required to operate through to 2019 or beyond.

• During 2005, two Class 43 power cars (43004 and 43009) operated by First Great Western were fitted with new MTU V16 4000 engines before being tested in passenger operation on the Great Western Line. In December 2005, First announced that all its power cars would receive the MTU engine. The MTU engine offers improvements over the existing Paxman 12RP200 'Valenta' engines, with reduced noise, smoke and exhaust emissions, improved reliability and fuel efficiency.[16]
• East Coast also re-engined its fleet with MTU engines, a process begun under its predecessor GNER. East Coast's fleet of re-engined power cars have been renumbered into the 432xx and 433xx series by adding 200 to the existing power car number.
• East Midlands Trains stated that it would install Paxman VP185 engines in all its powercars before the end of its franchise. It has since completed this operation, though the re-engined power cars retain their original numbers
• Grand Central had fitted their HST fleet with MTU engines, with the first pair entering service on 21 September 2010; they have also been repainted with an orange stripe to match Grand Central's Class 180s.[17] 43123 was the final Valenta powercar; it now carries a plaque reading "Valenta 1972-2010". The final passenger service of a Valenta engined power car was on 19 December 2010. On 22 December 2010 the Valenta was used in four farewell tours between York and Sunderland using 43123. All power cars have been re-engined by Brush Traction, Loughborough, and have been renumbered in the 43/4 range.
• CrossCountry's first CrossCountry-liveried HST powercar, 43301 (formerly 43101) was released from its overhaul at Brush Traction, Loughborough on 16 July 2008. To identify its fleet, CrossCountry is renumbering all its HST units by adding an extra 200 to the old number.
• Network Rail's New Measurement Train is a specially converted InterCity 125. It can check the condition of railway lines over a 13-week cycle. On the West Coast Main Line, care is taken so tilting trains can safely run. It measures contact between wheels, rails and overhead power lines and is equipped with lasers, video cameras and other instruments. It was launched in 2003, but the vehicles used for it are older. Its yellow livery has earned it the nickname "The Flying Banana", which was previously used for older High Speed Trains with a similar livery.

An eight-car East Coast Main Line set in 1979

A seven-car Cross Country set in the 1980s

When Crewe Works built them, the InterCity 125 units were considered to be diesel multiple units, and were allocated Classes 253 and 254 for Western and Eastern Region services respectively. The locomotives were introduced in the Midland region later.

Until the HST's introduction, the maximum speed of British trains was limited to 100 mph (160 km/h). The increased speed and rapid acceleration and deceleration of the HST made it ideal for passenger use, and it slashed journey times around the country. The prototype InterCity 125 (power cars 43000 and 43001) set the world record for diesel traction at 143 mph (230 km/h) on 12 June 1973. An HST also holds the world speed record for a diesel train carrying passengers. On 27 September 1985, a special press run for the launch of a new Tees-Tyne Pullman service from Newcastle to London King's Cross, formed of a shortened 2+5 set, briefly touched 144 mph (232 km/h) north of York.

During 1987, eight HST power cars were converted for use as driving van trailers (DVTs) with Class 91 locomotives during trials on the East Coast Main Line. The power cars were fitted with buffers and Time Division Multiplex equipment that allowed them to directly control a Class 91, and were moved over to the ECML where they were used on workings with Class 89 and then Class 91 locomotives from London to Leeds. After the Mk 4 stock had been delivered, the HST power cars had the TDM equipment removed, and then reverted to their normal duties. The power cars used for this project can be easily identified as they are still fitted with buffers. They were then transferred to Virgin Cross Country, and put in storage when Virgin replaced its HST fleet with Bombardier Voyagers (though Arriva, upon later taking over the franchise, acquired 10 power cars, 4 of which were buffered). Grand Central bought six of these for services from Sunderland to London, the remaining two having been integrated into Network Rail's New Measurement Train. This train is being replaced by IET Class 801 and Class 802. Bi mode trains.

After the privatisation of British Rail the HST sets continued to be used. 194 of the 197 locomotives built remain in service. The three units that are not in service, 43173, 43011 and 43019, were written off by fatal rail accidents in 1997, 1999 and 2004 respectively.

All HSTs operating with Great Western Railway, London North Eastern Railway were replaced by Class 800/801/802s in 2018/2019. Twenty-seven sets each with four or five carriages moved from Great Western Railway to Abellio ScotRail and be refurbished with controlled emission tanks and plug automatic doors. They will operate on services from Edinburgh and Glasgow to Aberdeen and Inverness.[18][19][20][21] The first two were delivered to Craigentinny TMD for crew training in September 2017.[22] The first entered service in October 2018.[23]

Great Western Railway retained 24 powercars to form 11 four-carriage formations known as "Castle Class" sets for use on local services between Cardiff and Penzance.[24]

Sir Kenneth Grange on 2 October 2016, with InterCity 125 power car 43185, the bodyshell of which was designed by him in the 1970s, and which had just been repainted in the Intercity Swallow livery carried between 1987-1996.

On 2 May 2016 an open day was held at Bristol St Philip's Marsh depot with a line up of Class 43s from each operator (except Cross Country) to celebrate the HST's fortieth anniversary. Several locomotives and passenger trains also appeared, such as 150 247 and 166 214 both in their new GWR liveries, 158 798 in its Springboard Opportunity Group livery and the prototype Class 41 HST. At the event, powercar 43002 (Numbered 253 001 as a Diesel Multiple Unit) was unveiled in original Intercity 125 livery, and named Sir Kenneth Grange after the Class 43's bodyshell designer.[38] On 2 October 2016, powercar 43185 had been unveiled in InterCity Swallow livery.[39] Both were operated by Great Western Railway (First Great Western) and 43002 is now preserved.

There have also been four serious incidents involving Class 43s; these accidents resulted in three power cars being written off. A fourth sustained severe damage in 2020, but has not yet been officially written off.

• Southall rail crash: on 19 September 1997, 43173 leading a Swansea to London Paddington service which failed to stop at a red signal, which resulted in a high-speed collision with a freight train.
• Ladbroke Grove rail crash: on 5 October 1999, a British Rail Class 165 unit 165 115, passed a signal set at danger while leaving London Paddington on a Thames Trains service. This resulted in a serious collision with 43011, forming a London-bound HST service.
• Ufton Nervet rail crash: on 6 November 2004, 43019 leading a London to Plymouth service, collided with a car on the Ufton Nervet level crossing. The impact with the car resulted in a serious derailment which killed six people aboard the train, including the driver.
• Stonehaven derailment: on 12 August 2020, 43140 leading an Abellio ScotRail service struck a landslide near Stonehaven on the Dundee-Aberdeen line, derailing the train and killing three.[40][41]

There have been minor incidents involving Class 43s, among which have been:

• On 28 August 1979, power car 43110 derailed south of Northallerton. The cause was attributed to low gearbox oil lubricant which caused the pinion to fail and lock the leading wheels on the train in place. With the rear power car pushing the train, this caused the locked wheels to skid, wearing a groove which developed false flanges on their outsides, one of which struck the points south of the station, which buckled the rail.[42]
• On 16 March 1986, power car 43118 received collision damage after running through a buffer stop and derailing, while leaving Neville Hill TMD.[43]
• On 20 August 2017, 43188 partly derailed on departure at Paddington while forming the rear power car of the 11:57 Great Western Railway service to Penzance. This was due to a track fault.[44]
• On 31 December 2017, 43195 hit a tree near Hemerdon, Plymouth.[45][46]
• On 17 April 2018, 43138 suffered damage due to an engine fire whilst at Penzance station.[47]
• On 6 April 2019, 43045 caught fire at Leicester whilst working 1B53 1445 Nottingham-London St Pancras.[48][49][50]
• On 13 June 2019, 43054 collided with aggregate that had been washed-out from a cutting slope near Corby, Northamptonshire.[51][52]
• On 13 November 2019, 43300 collided with an LNER Class 800 Azuma at Neville Hill TMD, Leeds.[53]

Powercar 43160 had two minor incidents, which happened at the South West England region.

• On 3 April 2016, the powercar was involved in what was described as a 'low impact' collision at Plymouth railway station. A local commuter service collided with a Plymouth to London Paddington train at low speed and the powercar received damage to its nose and valancing.[54]
• On 14 September 2017, around 1 year and 5 months after the 'low impact' collision incident, the powercar was severely damaged by a fire in Exeter.[55]

Hitachi Class 800 Super Express undergoing testing at Old Dalby test track. These trains replaced most of the HSTs on the Great Western Main Line and all the HSTs on the East Coast Main Line.

Built between 1975 and 1982, the fleet is now in its fifth decade, and replacements for the High Speed Train are currently being built. This project, the Intercity Express Programme is being spearheaded by the Department for Transport. A consortium headed by Hitachi has designed and is building the replacement Hitachi Super Express Train. Various formations are being built; both electric and bi-mode (electro-diesel) versions in 5 or 9 carriage lengths. The initial batches will replace HSTs on the Great Western Main Line and East Coast Main Lines.

On the Greater Western franchise, the last of the full length HSTs was withdrawn in June 2019. Between twelve and twenty HST sets were originally to be retained and refurbished to carry on providing services between London, Devon and Cornwall, where no electrification was planned, and where the Class 800's engines would not be capable of negotiating the steep gradients along the South Devon Banks, through to the mid-2020s.[56] A report published in 2011 concluded that the Mark 3 coaches could remain in service as late as 2035 with some minor rewiring and enhancements required under disability legislation,[57] however, it was announced in March 2015 that the HSTs would be replaced with the Class 802s, a more powerful derivative of the bi-mode Class 800s.[58]

Initially, high-speed Bombardier Voyager and Alstom Class 180 (Adelante) replaced numerous HSTs, but all locomotives and sets have been brought back into service as a result of increasing demand. Some Great Western sets were cascaded to Abellio ScotRail to replace the Class 170 units while others were retained by GWR to operate local services.[59]

Grand Central railway leased five more Class 180 units cascaded from Great Western Railway to replace their HST trains and increase their overall fleet size.[60] This in turn allowed the HSTs to be cascaded to East Midlands Trains.[61] The East Midlands Trains sets were passed to the new East Midlands Railway franchise which announced it would replace them with Class 810 bi-mode units in the early 2020s.[62]

Upon being retired, 43002 was preserved by the National Railway Museum in York.[63] It is to be joined by 43302 (43102)[35]

The National Railway Museum in York has preserved 43002, the first production power car.[64] The shell of 43018 is preserved at the Crewe Heritage Centre having been donated by ScotRail. The Railway Heritage Designation Advisory Board has nominated 43302 (43102) for preservation as holder of the record for being the fastest diesel locomotive on the planet.[65]

Angel Trains has donated 43018 to Crewe Heritage Centre.[28] Porterbrook donated 43048 and 43089 to the 125 Group. Both moved to the group when their lease ended with East Midlands Railway.[66] Locomotive Services Limited have saved five powercars, 43046, 43055, 43058, 43059 and 43083 along with a full set of Mark 3 coaches for use on excursion trains.

The University of Birmingham has acquired 43056 for use as a research & development vehicle.[67]

In 1977 Hornby Railways launched its first version of the BR Class 43 (HST) in OO gauge.[68][69]

• InterCity 125 - Two Class 43 power cars sandwiching a rake of Mark 3 coaching stock.
• Mark 3 coaching stock - Coaching stock developed for the HST.
• High-speed rail in the United Kingdom - General history of UK high-speed rail transport.
• XPT (Express Passenger Train) - Australian high-speed train whose design was derived from the HST.
• Intercity Express Programme - New high-speed train intended to replace the InterCity 125.
• Passenger locomotives in use in the UK

• 125 Group (2019). Inter-City 125 Owners' Workshop Manual. Haynes. ISBN 978-1-78521-266-6.
• 125 Group (2018). 125 The Enduring Icon. Amberley. ISBN 978-1-4456-7859-7.
• "HST nameplate review". Rail. No. 317. EMAP Apex Publications. 5–18 November 1997. p. 52. ISSN 0953-4563. OCLC 49953699.

Wikimedia Commons has media related to British Rail Class 43.

• 125 Group
• Testing the prototype HST
• HST profile on Trainspo