Science Fair Project Encyclopedia
High Speed Train
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 is capable of 125 mph (200 km/h) and is considered one of the best trains Britain has produced, although as of 2004, they are showing signs of ageing.
The HST was the first high speed train in Britain: that is, the first train to travel at over 125 mph (200 km/h). Its trade name was "Inter-City 125", spelling later changed to Intercity 125 or the more colloquial name of "Screamer", referring to the loud screaming noise made by the turbocharger of the train's 2,250 bhp (1,678 kW) Paxman engines. They are also known as 'Spin driers' owing to their high engine speed.
It was introduced in the late 1970s by British Rail, at a time when the generally accepted maximum speed of British trains was around 100 mph (160 km/h). This, plus its rapid acceleration and deceleration, made it ideal for passenger use and it slashed journey times around the country. The prototype HST still holds the world record for diesel traction at 148 mph (230 km/h).
The train is widely used on long haul passenger services even today and has been hailed by many as Britain's best train ever.
In the early 1970s, a prototype unit was produced. 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.
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 resturant 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.
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 push-pull.
Pre-2001, Cross-Country trains used 7 coaches, with one fewer First Class car in the formation. In the early 2000s, Virgin Cross-Country trains also used five-car formations giving better acceleration, 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 9 car sets.
The original Inter-City 125 livery was blue and grey coaches, with yellow front (for visibility), with the yellow 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 along the centre, 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, and carried a new InterCity logo, with the name in serif type and an image of a swallow, (incidentally known as "Roderick").
After privatisation, the individual train operating companies attached their own looks to the HST, with First Great Western changing its livery many times, finally to a pink, white and blue theme to match FirstGroup's corporate colours.
As of 2004, the HST is used by First Great Western (84 units), Midland Mainline (63 units) and GNER (23 units). Virgin Trains have also used them, but they have been phasing them out (they currently have 5 units). Network Rail also have 4 power cars for their high-speed track recording trains, which, due to their all-over yellow livery, have brought the moniker "flying banana" back into use.
The design was also used as the basis for the Australian XPT - it uses specially-built coaching stock, and has a lower top speed of 100mph (160km/h).
The HST is still in widespread use. First Great Western have supplemented their HSTs (but not replaced any) with fourteen multiple unit Class 180 Adelante trains, which can travel at the same speed as the HSTs, but because every carriage has an underfloor engine they can accelerate approximately twice as quickly, which reduces journey times. This has allowed 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.
In 2004 First Great Western announced a major overhaul upgrade for their HST power cars, including a new MTU engine.
Midland Mainline have recently updated their HST livery, and are supplementing their HST fleet with Class 222 Meridian units (similar to Virgin Cross-County's Class 220 and 221 Voyager trainsets) which will replace the slower Class 170 Turbostar units.
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