Best of British : BR Class 43 – High Speed Train
Twenty twelve is of course our Jubilee and Olympic year, and here at AROnline we celebrate our own transport legends in the first of this new short series that pay homage to some true gold-winning icons.
Words: Mike Humble
It’s quite staggering when you take stock and think that it has been 16 years since the railway industry was (hastily) privatized. Doesn’t time simply fly. The railway in Britain has always been a topic of much debate with passengers, enthusiasts and politicians ever since ‘Locomotion No: 1’ lurched and clanked its way along the Stockton to Darlington line way back in 1825.
Some say that progress hasn’t changed that much since those early pioneering days – especially on some regional branch lines, but on a personal note, the railway was and still is a shining example of ingenuity, perseverance and Victorian pride. Living and growing up in Darlington with countless friends and relatives in gainful employment with B.R, it seems natural that my passion for rail is almost equal to that of the motor car.
Great Britain has changed the face of travel in so many different areas, in aviation there is the Harrier Jet or Concorde while on the open sea there is the QE2 liner – each one of them gaining the respect and admiration from man and boy alike all around the world. Prior to the huge road & motorway investment programme of the 1950s and ’60s, the only way to travel around Britain was by rail.
Even though the big four groups had been nationalised into British Rail, they still operated to a certain degree as separate entities that regarded other regions as inferior – sounds similar to a certain car maker too. The Beeching years had slimmed down the infrastructure and raw cost base with British Rail adopting a hard nosed attitude towards business – the early signs of the age of the train.
The British Rail board (BRB) had transformed regional lines by means of Diesel or Electric multiple units but long distance travel was still in the command of steam right up to the late 1960s. Various prototype diesel locomotives had been assessed with only a handful being regarded as a success – the class 37, 40, 45, 47 and 55 (Deltic) being notable backbones of the then newly branded Inter City network.
To this day, many still bemoan the loss of steam traction, but to be fair, this had to cease in order for the railways to survive in any form. Steam was labour intensive, expensive and hopelessly inefficient, even the most efficient and fastest locomotives such as the Gresley A4 class for example offered somewhere in the region of only 30% efficiency when in supreme mechanical order.
The fastest and most powerful diesel locomotive on the BR network prior to the HST was the 3300bhp Class 55 Deltic with a top speed of 100mph, they would go faster with only minor alterations but rolling stock braking and track limitations would not permit this. The class 55 was also an expensive machine to both operate and maintain with its 16-cylinder two-stroke Napier engine prone to terminal failure unless exacting tolerances were adhered to in the traction depots.
During the late 1960s, the BRB (British Rail Board) sanctioned a new technical research division based in Derby to look into the idea of a new breed of high speed train, not just the locomotive, but also carriages. Initially, gas turbine was the desired traction, but a splinter group claimed to be able to design and build a prototype diesel electric train conforming to normal engineering practices.
The go ahead was given for both gas turbine (APT) and diesel (HST) prototypes and within an incredibly short space of time, the finishing touches were being added at both Derby and Crewe to the prototype High Speed Train. Whereby the APT boasted novel features like tilting suspension and a fluid based Hydrokinetic braking system, the HST used bogie mounted air suspension and disc brakes.
The chosen power unit was produced by Paxman of Colchester designated the Valenta 12RP200L rated at 2500bhp per unit, though production versions were de-rated to 2250 driving a crank mounted AC alternator set supplying the traction motors with motive power to a loco at each end.
The prototype entered trail service in the Summer of 1973 with a rake of brand new air conditioned coaches which became known as the Mk3 design. First deployed on the Kings Cross – Edinburgh East Coast route, the set was then placed in the hands of the Western region operating on the Paddington to Bristol route for crew evaluation.
BR operating staff and managers were so impressed with this new train that the desire to develop both the HST and APT would have most of the effort made towards the diesel electric option. A low axle weight in relation to size allied to full air suspension made sure track damage was minimal during high speed running – electric class 86 and diesel class 55 locos were heavy steel sprung locos notorious for harming the rails.
Experiences gained found the HST to be a reliable train with only a handful of minor teething problems which were mainly resolved before production sets entered service in 1976.
The line speed was 125mph which could be achieved under normal signalling and the ultra efficient braking system exceeded all set out criteria, but high speed running proved to have a high wear aspect on the pads and modifications in service partly addressed the strong smell of hot brake linings coming through the air conditioning which some passengers found alarming. A full passenger HST service commenced in 1976 on the Western region, with full squadron service taking place on the Eastern region the following year.
The age old problem of union action initially caused major concern to BR, drivers demanded higher pay for operating faster trains. BR got around the problem by re positioning the crew seat from behind to alongside the driver and once word got around at just how good these locomotives were, the waiting list to join the Inter City driving pool reached an unheard of length.
The supreme acceleration and braking efficiency meant that the HST could operate at speeds 25% higher than the Deltics pulling Mk2 stock and yet still brake safely within the existing four aspect signalling system. Automatic doors between the carriage vestibules, double glazing and full air conditioning made for a soothing ride for passengers – it was not unheard of for passengers to willingly stand even in first class just to experience rail travel at over two miles a minute once passenger services commenced in 1976.
Various proving trails and speed records were broken too, with a HST set recording a speed of 148mph – the drivers simply loved these race horses as they became nicknamed. Once in service they settled down to be generally reliable, but the hot summer of ’83 caused many overheating issues which after much investigation was caused more by poor maintenance practices and unsatisfactory cleaning of the radiator cores than a defect in manufacturing. Some problems similar to our very own Rover K-Series engines with earlier power units became commonplace in the early years which blotted and almost perfect copy book.
A high number of turbocharger failures soon became apparent under the punishing diagrams these trains operated to were found to be caused by the cylinder liners not sealing correctly and allowing coolant and lubricant to mix. This would cause the viscosity of the oil to break down at extreme temperatures (the turbo would operate at temperatures well in excess of over 600 degrees) and cause a premature failure of the thrust bearing inside the delicate turbo. Large quantities of oil would blow through the exhaust systems and in rare circumstances cause a fire on the loco roof. Paxman altered the casting procedure during engine production which virtually cured future problems and occasional head fracture issues were also less commonplace.
Other problems in service revolved around hairline cracks in the axle boxes on the train bogies, but again, once this was identified BR were quick to develop a modified component which put another teething problem to rest. Even to this day, the BR Mk3 coach is still regarded as being the best rolling stock on the network. These passenger coaches were the high watermark in design for BR which have more than shown themselves to be robust, hard wearing and extremely strong – a factor that has been demonstrated after some serious rail disasters such as Ladbrooke Grove and the Ufton Nervert crossing accident. Subsequent later rolling stock have yet to equal the Mk3 for longevity and build quality.
As privatisation loomed, certain engineering updates were undertaken on the HST power cars and many power cars on the Eastern Region operated in conjunction with the new class 91 electric locos owing to a delay of driving van trailers (DVT) and Mk4 carriages. Initially, the HST power car did the job of providing power for the trains air con and lighting systems, but extended periods of just idling without providing traction power caused accelerated wear and carbon build up in the engine. Engineers had no choice but to rewire the loco to multiplex systems so they would not only provide power for the train, but work traction wise in conjunction with the 6600bhp electric class 91.
During this period, some truly astounding acceleration times were noted thanks to the complete set having almost 9000bhp on tap. Having personally experienced the hybrid HST/91 combo many times, the build up of speed would actually push you back into your seat – bloody marvellous. As the 1990s progressed, some experimentation with re-engineering the power cars saw BR trail the use of both Mirlees and the modern Paxman VP185 engines to replace the obsolete Valenta RP design, the VP185 became to engine of choice but before they could be rolled out into the whole fleet, Government plans for privatisation ended the opportunity for total fleet upgrades.
Following the tragic events of 1996, the once respected InterCity brand was dead, replaced with a myriad of new private companies, all with one thing in mind – profit. With the exception of Virgin Trains, no real money would be available for new rolling stock to replace the HST, so asset utilisation became the buzz words.
The HST came into its own more so during this post sell off era, the diagrams and routes under the BR era were punishing enough, but the modern private world of smaller engineering budgets and tighter timetables found the HST being nothing short of thrashed within an inch of its life. Engine failures, broken air con, missing buffet cars & carriages with non working lights were symptomatic of this privatised rail industry.
Keeping the trains running was an epic task undertaken by depots scattered around the network, while we slept in our beds the trains would be fed, watered and repaired all ready for the morning commuter journey. Costing was to the penny too, BR reckoned that to stop a HST from 125 mph cost £120 in wear on the brakes so correct driver training was key to getting the best levels of efficiency.
Drivers would report that each HST set would have its own character and traits just like steam locomotives, no two power cars would feel exactly the same, and in the days before speed limiters and black boxes, some ‘unofficial’ speed records would be noted – the driving crew simply adored them while engineering staff certainly earned their corn!
Project Rio, which was the temporary diversion from London to Manchester via Derbyshire (once the route of Midland Pullman) during 2003/2004, saw worn out and life expired HST sets formally operated by Virgin Trains. This was possibly the low point of the career of the HST. I personally used this service many times, and on each occasion there was either a cancellation or breakdown.
Some operators saw an ideal opportunity to improve the HST to a point where they almost seemed like a new train. GNER who treated their class 91 fleet to a ‘Mallard’ upgrade programme of new seats and décor, with WiFi on board, new lighting, tannoy systems, applied the same technique to the HST they operated on non electrified routes.
First Great Western have also provided a similar range of upgrades for their fleet, but reliability still remains a big problem on the Western lines. Sadly no Paxman Valenta powered HSTs remain in passenger service, most of todays operators have chosen a German MTU engine which is quieter, more fuel efficient and much cleaner in operation. The much missed scream of the turbo and howl from the Marston cooling fans have been replaced with a truck like sounding gurgle in this modern sterile world – but one thing is for certain, the HST offered the age of the train back in 1976 and continues to do so – almost 40 years later!
Quite staggering to think that it’s all down to British teamwork and British ingenuity courtesy of our much missed friend: British Rail.