High Speed Train
From Free net encyclopedia
- This page covers British Rail's Intercity 125 High Speed Train. For the general concept of high-speed trains around the world, see High-speed rail.
A British High Speed Train (HST), also known as an Intercity 125, consists of two diesel power cars either end of a rake of between five and nine (but usually seven or eight) 'Mark 3' carriages. The train operates scheduled services at a maximum speed of 125 mph (200 km/h). It is considered to be one of the best trains Britain has produced, having been in regular service on premier routes for around three decades, although they are now showing signs of ageing.
The HST was the first high speed train in Britain: that is, the first train to travel at 125 mph (200 km/h). Its trade name was 'Inter-City 125', later changed to Intercity 125, and it was colloquially known as a 'Screamer', referring to the loud screaming noise made by the Napier turbocharger of the train's 2,250 bhp (1,678 kW) Paxman 'Valenta' engines, originally developed (in normally aspirated form) for marine applications. They are also known as 'spin driers', owing to their high engine speed. Paxman Diesels went on to become part of the MAN B&W Diesel Group.
The HST was introduced in the late 1970s by British Rail, at a time when the maximum speed of British trains was 100 mph (160 km/h). The increased speed and its rapid acceleration and deceleration made it ideal for passenger use and it slashed journey times around the country. The prototype HST held the world record for diesel traction at 230 km/h in 1973 and at 238 km/h in 1987.
During the late 1990s a batch of 25 HST power cars were re-engined utilising 12VP185L traction engines. These new Paxman engines attempted to bring improved fuel consumption and reduced emissions to the HST. However they have proved to be less reliable in service then hoped. The 12VP185L has also been introduced fleet wide within the Australian XPT series.
The train is widely used on long-haul passenger services even today and has been hailed by many as Britain's best train ever.
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History
The first prototype unit was produced in the early 1970s. At this stage, it was considered that each power car was a locomotive in its own right, and the carriages in between were ordinary hauled stock. As a result, the two prototype power cars were allocated Class 41 (numbers 41001/002) and the carriages were numbered in a new series for 'Mark 3' stock (numbers 1xxxx).
Shortly after the introduction of the prototype unit, it was decided to classify the whole set as a permanently-formed diesel-electric multiple unit. It became Class 252, and both the power cars and the carriages were renumbered into a new series (numbers 4xxxx), with the locomotives becoming 43000/001.
The HST was mostly designed by British Rail's in-house engineering teams at the Railway Technical Centre and incorporated British Rail's newly developed cutting-edge vehicle technology. Final design work, including shaping the distinctive "shark's nose" front of the power cars, was carried out by leading industrial designer Kenneth Grange of commercial design group Pentagram. Grange is also credited with the decision to remove the buffers from the power cars, which resulted in a much more streamlined appearance.
Production units started to appear from 1976, and these were allocated Class 253 for the Western Region units (which had only one restaurant and kitchen car) and Class 254 for the Eastern Region units (which had two restaurant and kitchen cars). The power car and intermediate carriages took numbers in the 4xxxx series, following the prototype unit stock.
In the 1980s considerable trouble was experienced with the power cars, and this contributed to the abandonment of the permanent formation of power cars with carriages. Arrangements reverted to that originally adopted for the prototype unit; two locomotives either end of a rake of carriages. This time, though, no stock was renumbered and henceforth the production power cars have been referred to as Class 43.
Formation
An HST is usually made up of 8 British Rail Mk3 coaches (two first-class carriages, a buffet car with first-class restaurant, and five standard-class carriages), with a power car on each end. This 'top-and-tail' arrangement removes the need for the locomotive to run round its train, instead employing bi-directional push-pull operation.
Before 2001, Cross-Country trains used seven coaches, with one fewer first-class carriage in the formation. In the early 2000s Virgin Cross-Country trains used five-car formations, giving better acceleration and shortening journey times. In recent years Great North Eastern Railway (GNER) has added a standard-class carriage to its sets to provide extra seating, resulting in nine-car sets.
Liveries
Image:Brsince78 photo 2444.jpg The original Inter-City 125 livery was blue and grey, with a yellow front (for visibility) continuing down the side of the power cars. This led to the nickname 'flying banana'.
The next livery was in less widespread use. It was brownish-grey, dark grey (almost black) around the windows with a red and white stripe below the windows, and retaining the yellow bands on the power cars. A later variant of this livery saw the yellow side-bands replaced with light grey and did not feature the British Rail name or logo: it carried a new InterCity logo, with the name in serif type and an image of a swift (known as 'Roderick').
After the privatisation of British Rail, individual train operating companies painted the HSTs in their own colours, with First Great Western in particular changing its livery many times, finally to a pink, white and blue theme to match First Group's corporate colours.
Usage
Image:43116 at waverley.jpg As of 2004, HSTs are used by First Great Western (84 units), Midland Mainline (63 units) and GNER (23 units). Virgin Trains also used them; they were phased out in 2003. Network Rail also uses an adapted HST for its New Measurement Train.
The design was also used as the basis for the Australian XPT, which uses specially-built coaching stock, and has a lower top speed of 100 mph (160 km/h).
The future
The HST is still in widespread use. First Great Western has supplemented their HSTs (but not replaced any) with fourteen diesel multiple-unit Class 180 Adelante trains, which can travel at the same speed as the HSTs. Because every carriage has an underfloor engine, they can accelerate approximately twice as quickly, which reduces journey times and allows for more frequent train services. In-car noise levels, however, are higher than in the HST because of the underfloor engines, which, combined with less-comfortable seats and harsh interior lighting, has made them unpopular with passengers. They also proved to be unreliable, leading to a significant overhaul programme in 2004 to fix the major problems. These trains have now been replaced by more HSTs, and have been cascaded into First Great Western Link services. However from 2007 the Adelantes will be leaving Great Western for another TOC (probably Virgin Cross Country or Midland Mainline).
In 2004, First Great Western announced a major overhaul upgrade for their HST power cars, including a new MTU engine. Two Power Cars are currently undergoing trials in service with the new engine. In 2005, they undertook a trial refurbishment of a pair of HST coaches to bring them up to modern standards. Another coach has been refurbished with experimental aircraft style seat back screens. As part of the Greater Western francise commitments First Great Western have announced that they will be refurbishing the entire fleet as well as re-engining all Powercars with the MTU engine [1]
In January 2006 the first batch of power cars were taken to Brush Traction to have MTU engines fitted.
26 of Great Western's HST fleet are to be refurbished into a high density layout of mostly airline seats for services in the M4 corridor to Bristol and Cardiff, to improve accelleration the Buffet cars will be removed. The remainder will be refurbished with new seating (leather in First Class), at seat power points and retain the buffet for the long distance services to Swansea and the Westcountry.
Midland Mainline has recently updated their HST livery, and is supplementing its HST fleet with Class 222 Meridian units (similar to Virgin Cross-Country's Class 220 and 221 Voyager trains), which will replace the slower Class 170 Turbostar units.
GNER still operate HST sets on non-electrified portions of its ECML franchise - upon its taking ownership of the sets in 1996 the Mark 3 coaching stock was given an extensive interior refurbishment. Today the sets are found operating ultra-long distance services between London King's Cross and the North of Scotland. GNER are committed to giving their HST sets a further refit as part of its new franchise in order to bring them up to the same Mallard standard as their recently refurbished 225 fleet.
The Great Western power cars have also had major modifications to their cooling system to prevent overheating on hot days. GNER's solution to the overheating problem is to haul sets under the wires using Class 91 Electric Locomotives
The proposed HST2 replacement is currently on hold. Siemens submitted an electro-diesel design based on their new Venturio models, but the Strategic Rail Authority has ordered a halt to any further progress, amidst much debate about the form a replacement should take.
See also
- InterCity 225, the HST's electric counterpart