High Speed Train
Resource Type: Image | Posted on 2nd December 2011 by Liam Physick
Here we see a High Speed Train, another iconic locomotive class. Also known by its brand name InterCity 125, a High Speed Train consists of two Class 43 diesel-electric powercars (a vehicle similar to a locomotive but incapable of being detached from the train and sometimes capable of holding passengers or luggage, as is the case here) at either end of a fixed formation of Mark 3 coaches, usually seven or eight (generally four or five standard class, one buffet and two first class - these designs are known, respectively, as 8+2 and 7+2). Originally called the High Speed Diesel Train (HSDT) It was designed by Kenneth Grange: originally hired simply to design the livery, he instead decided to redesign the body, in conjunction with aeronautics engineers, and he presented his ideas to British Rail, which accepted them. Grange devised a high power-to-weight ratio for the powercars (1678 kW per ~70 tonnes), improved crashworthiness and top-and-tail working, removing the need for the locomotive to run around at termini. The lighter axle loading allowed the HST to travel faster than other trains on lines not suited to full-speed running, like the Edinburgh to Aberdeen line, thus substantially reducing journey times. Not only was the HST faster, it also had better acceleration and deceleration. Its origins lie in the late 1960s, when BR decided to pursue a parallel approach to its future express trains: the Research Division in Derby was already developing the Advanced Passenger Train-Experimental (APT-E), so in parallel to this BR decided in 1970 to build two lightweight diesel locomotives, Nos. 43000 (now in the National Railway Museum) and 43001 (now scrapped), designed by the Chief Mechanical and Electrical Engineer’s Department, also in Derby, capable of travelling at 125 miles per hour to top-and-tail a rake of the newly-built 23-metre-long Mark 3 coaches, to act as a stop-gap until the APT proved itself. In August 1972, the prototype HST, designated Class 252, of two locomotives and seven coaches was completed: by the autumn it ran trials on the main line, and on 12th June 1973 reached 143.2 miles per hour, a world record for diesel traction. By 1976, the Class had proved itself, so BR decided to order 27 production HSTs to cover passenger services from London Paddington to Bristol and south Wales. The first production power car in Class 253, No. 43002, was launched late in 1975: unlike the prototype, there were no conventional buffers on the streamlined front end, the drawgear was hidden under a cowling, the cab window was larger and there was no driving position at the inner end. In October 1976, HSTs began to run in the Western Region: around this time also, the InterCity 125 branding appeared on the powercars. By May 1977, all 27 HSTs were in service in the Western Region: they completely replaced locomotive-hauled services (and superseded the sleeper trains to Cardiff), and by early 1977 the last diesel-hydraulic Class 52 locomotives on the Western Region had gone, as the success of the HST meant that Class 50, a diesel-electric, was relegated to the slower services previously covered by Class 52. The speed and frequency of the HST led to a dramatic increase in passenger numbers, an effect only previously seen with the introduction of electric traction. As a result of Class 253’s success on the Western Region, Class 254 HSTs began to be produced in 1977 for the East Coast Main Line: eventually, 32 sets were used on this route, but unlike Class 253, they used the 8+2 formation, rather than 7+2. In May 1978, the HST first saw service on the ECML, initially on the services from King’s Cross to West Yorkshire, Newcastle, Edinburgh and Aberdeen, and later to other destinations such as Hull, Cleathorpes and Middlesborough, with an additional eight services ordered to cater for this, but due to difficulties in obtaining investment, only five were actually delivered and one more was diverted to the Western Region. Within a year of the HST’s introduction, the Deltic had been demoted to slower services and the HST had reduced the London-Edinburgh journey by an hour, to four and a half hours. Capitalising on their popularity, more were built up to 1982, as they took over the services from London to the West Country (14 sets) and expresses on the Cross Country Route from the North East to the South West (18 sets, replacing Class 47) - despite the fact that these routes were not conductive to 125 mile per hour running. Later, five Western Region sets and and three sets on the Cross Country Route were reallocated to the services from St. Pancras to the East Midlands and Yorkshire, and 10 sets on the East Coast Main Line were transferred to the Midland Main Line. Later still, the London to Edinburgh service was expanded to Aberdeen and Inverness. BR actively set out to market them to maintain and increase their success. In total 95 sets were built, including 197 powercars, numbered 43002-43198. In the 1980s, more coaches (a total of 848 Mark 3 coaches were eventually built for the HST) were built for the Class 253s in the Western Region, thus making them 8+2 rakes in common with their Class 254 counterparts: by the 1990s, only the Cross Country services remained 7+2, with only one first-class carriage. On 27th September 1985, a special press run to mark the lauch of the new Tyne-Tees Pullman service between Newcastle station and King’s Cross, in a 5+2 formation, briefly hit 144 miles per hour north of York station: the fastest-ever diesel-powered train carrying passengers. The fastest-ever run by a diesel train was set on 1st November 1987, when an HST hit 148 miles per hour as it descended Stoke Bank on a test run for a new type of bogie later to be used by Mark 4 coaches on the same route. They proved immensely popular with the public, largely thanks to a television advertising campaign fronted by Jimmy Savile (not such a good idea in retrospect), and their success guaranteed the future of many threatened rural lines. They also led to increased house prices by making cities distant from London suddenly far more accessible. Most of the HST fleet is still in service today (though three powercars have been scrapped as a result of accidents) and remains the backbone of many express services on the British main line, owned by many of the privatised train companies that have sprung up since the 1990s. But they are getting old, and have been partially repaced in some areas: for instance on the East Coast Main Line following the electrification of the London-Edinburgh line, which led to the introduction of the InterCity 225 (hauled by a Class 91 electric locomotive). Elsewhere, the HST has either been replaced or augmented by high-speed diesel-electric multiple units like the Bombardier Voyagers (owned by CrossCountry, East Midlands Trains and Virgin Trains): these have greater acceleration than the HST due to their higher power/weight ratio, and are more efficient and give better braking performance. Nevertheless, they often annoy passengers with the noise they generate from the underfloor engines, in contrast to the Mark 3 coaches. In 2007, the government launched the Intercity Express programme to try to find an electric-powered replacement both for the HST and for the InterCity 225 on the East Coast Main Line and Great Western Main Line: in 2011, the contract was given to Hitachi to build the Agility Trains. However, some HSTs still be used on services from London to Devon and Cornwall, as there are no plans to electrify those routes, and with rewiring, the coaches are estimated to last until at least 2035.
Categorised under: Landmarks, Landscapes & Locomotives
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