Many people are unaware that some British Leyland products ran on the rails as well as the roads. AROnline looks at the Advanced Passenger Train (APT-E), which was BL’s first engineering partnership with British Rail.
Story: Mike Humble
I make no apologies for the fact that I love trains, and if it hadn’t been for the fact that in 1988 when I discovered my slight colour blindness during a BR medical, my career path would have certainly been much different. Growing up in Darlington (the original railway town) many friends’ parents had either worked or had some involvement on the railway in one capacity or another. My late Grandfather served 47 years on what was the LNER and British Railways so I kind of reckon it’s in my blood, be it the smoke and smut of a Gresley Class A4 loco or the screaming cry of the HST on notch 5 – my passion for trains has never died.
By taking the words ‘Coal’, ‘Steel’, ‘Rail’, ‘Leyland’ and adding ‘British’ to the title, you end up with four very different industries with one common thread running through them – turmoil. It all makes fascinating reading for those under a certain age, but I am old enough to remember each and every one of them slowly fade away into memory – trust me, if you were around at the time, it wasn’t pleasant to witness and the closure of MG Rover in 2005. For me, felt like the final nail in our industry’s coffin. For all the wrongs and rights of BR and BL, they employed some truly talented engineers and old school-designers blessed with skill and handed down disciplines now sadly lost along with the companies who employed them.
A high-speed future
Following the Beeching Report of the 1960s (an in depth analysis of the state of BR), several ideas were put forward for re-shaping and modernising the railway. At the time, it was still struggling with shrinking passenger numbers, spiralling losses and an antiquated infrastructure, which dated back to Victorian times. Today, we see the argument for a new high speed rail line from London to the Midlands making regular news articles, but this idea had been put forward in mid-’60s. This was originally discarded owing excessive cost, so any reduction in journey times from A-to-B had to be found by means of faster trains rather than a bespoke high speed line.
Some work had been done with Electrification for part of the London-Glasgow line. Electric trains running at 25,000 volts (25KV) were superior in power and acceleration than the previous steam- or diesel-fuelled locos, but the infrastructure of overhead masts, cabling and line side transformers was massively expensive – so alternative power became scrutinised. In the early 1970s, the most powerful loco on the BR network was the Class 55 (Deltic) with an available 3300bhp. These ran exclusively on the East Coast Kings Cross-Edinburgh line at a maximum speed of 100mph. But BR wanted a higher top speed and the braking system of these trains could not cope with any more increased demand.
In order to provide a high top speed, yet still operate within the existing signalling system, it became obvious that everything needed to be overhauled – from suspension designs through to braking systems. The biggest problem regarding speed BR faced, was the curvature of the track, so the idea was put forward for a tilting train that could lean into the corner while still maintaining a high speed – a brilliant concept.
Some of the best boffins were hand-picked to head up two small teams to design and built a gas turbine prototype tilting train. It needed to be able to operate on Inter-City lines, where electrification was not present. The other team were to design and produce a diesel-powered loco capable of equally impressive great speed and these projects became known as the Project APT-E – Advanced Passenger Train Experimental; and the HST – High Speed Train.
In partnership with British Leyland
During the 1960s and ’70s, Leyland Trucks had produced a working Gas Turbine engine that was incredibly small and light in relation to a very high power output. The British Railway Board approached BL with a view to working in partnership, and developing, this world-leading project, and work started quickly. The design brief was for a non-electric, self-tilting high speed train, that was to be produced in a state of the art design and research centre in Derby. The experimental train had two power cars, each equipped with four Leyland 350-series Gas Turbine engines, rated at 300bhp per unit for propulsion. These ran the alternator sets that fed electrical current to the axle mounted traction motors.
The engines were soon uprated to 350bhp per unit, after modification to the heat exchangers. The units were, in practice, jet engines which ran at extreme temperature. Other novel features included a hydrostatic braking system, which in effect was a water turbine that forced liquid through what appeared to be a torque converter in reverse. The theory behind this was that reduced friction and heat meant less wearing parts. And the secondary braking system, via discs and pads, came into effect at much lower speeds than normal.
The end result meant the train could run at higher speeds, yet still stop within the required distances of the traditional colour signals. And also, drastically reduce maintainance costs.
The train ran in a fixed formation with the bogies (axles) being articulated and shared between the coaches, while also being air-suspended and featuring a fully automatic passive hydraulic tilting system. Upon entering a curve at speed, sensors would pick up the G-forces of inertia and jack up the suspension making the train lean into the corner – just like a motorcycle would do. This would counteract the forces and provide a 20% higher cornering speed than a traditional train carriage.
After some initial Union bickering over single driver operation, the APT-E set to work proving itself. And the previously unknown technology was showcased in the media with a blaze of publicity. Schoolboys once again would marvel at the sleek shape – which looked like no other loco before.
The tapered style of the train body not only looked futuristic. But it also served the critical function of making sure that when exiting tunnels, bridges or the passing of an oncoming train running on the opposite line when in tilt mode, did not come into contact with each other. The cost of altering the thousands of aforementioned structures was not possible, so the new train had to run within the existing British Rail track and infrastructure.
Any means or gain in speed or reduction in journey times could only be acheived by attention to detail of the locomotive or train design as a whole. A 14 mile section of closed track on the former Midland Railway near Dalby was upgraded & re-opened for private test and research purposes before the APT-E was fit for proving trails on the BR network. This line was ideal owing to the number of severe curves and bridge structures it contained. The Dalby test track later featured as the site of the famous Nuclear Flask train test crash in the 1980s.
Even though some impressive runs had seen the train operate over 150mph on the Western line close to Swindon, the APT-E proved to be temperamental and costly to run. British Leyland was in a serious cash dilemma, and quickly losing interest in Gas Turbine technology following the 1970s oil crisis. But also the rival prototype HST (125) was proving to be a superior project in the long run.
The diesel beats gas turbine
The HST today, still evokes a vision of speed and efficiency even after an incredible 36 years in service. The APT project was shelved, only to become a viable option again, in 1981 – after adopting an electric powertrain. Sadly, pushed into service before its time, the APT was finally dropped after some disgraceful coverage by the media and general BR apathy in 1986.
The Governement were also putting pressure on BR to deliver yet at the same time refusing to any fund the project any further.
Sadly, the APT never had the chance to prove itself partly thanks to Government meddling and the media making a great deal of noise. The constant sniping regarding some technical hiccups and the reported nonsense that was ’tilt syndrome’ – the so called sickness caused by the APT – made sure that once again, the great of the good was destroyed by the English tradition of mocking our own industry, rather than backing it. When will we ever learn!
For those wishing to view the amazing experimental APT-E, this is on public display at the impressive new National Railway Museum in Shildon near Darlington. The electric APT-P is on public display at the Crewe Heritage Railway Centre in Cheshire.
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