Gas Powered Public Transport - how it began

Once again, the octagonal oak dining table had been pressed into service as a base of operations for the secret project which, if successful, would revolutionise public transport, reduce the dependence of bus fleets on diesel or, worse, petrol fuels (which were expensive and polluting).

Once again, dinner would be served on trays in armchairs as the plans, notebooks and slide-rules were deemed too valuable to move for such a minor interruption.

It was the latter part of 1972 and outside the house, only a tiny team at Rolls-Royce Engineering in Crewe, Cheshire knew about the discussions. Could liquid petroleum gas (LPG) be used to power a bus? Rolls Royce had an engine running on natural gas in their works driving a power plant on test, but the technology was not available to them to make it mobile. With very few adjustments it could be made to run on LPG.

LPG is a by-product of crude petroleum refining and at that time was made up of about 70% butane and 30% propane, with the precise proportions depending in ultimate purpose. The specification could be tightly controlled. North Sea natural gas had only 1% butane / propane proportions. Some US oilfields could reach 20% but this differed from well to well and even over the life of a well. Today, there are many different types of gas going through trials and even in use.

The world was in the middle of a fuel crisis: prices were rising inexorably and public transport, already subsidised, was not only costing national and local governments more, but fares on the buses were also going up thereby affecting millions of people every day. There was also the first signs of environmental pressure to reduce the harmful exhaust emissions on vehicles, particularly in towns .

Rolls-Royce had been considering an LPG powered engine for some time - but it took a discussion between Teesside Municipal Transport (TMT) Chief Engineer Roy Cotterill and his brother-in-law Lionel Gibbs, a Marketing Executive at Rolls-Royce, to create the realisation that RR had something that had the potential to revolutionise public transport.

Several months earlier, Roy had told Lionel that the price of diesel oil was causing significant problems for the industry. Lionel simply asked "what if you didn't have to use diesel?" Having a favourable answer, he returned to Crewe and immediately proposed to the product development team that he and Roy undertake a feasibility study - could the RR development engine fit in the engine bay of the most common buses - the Leyland Atlantean and the Daimler Fleetline.

The scope for market development was huge for these two buses formed the backbone of the global double decker bus market. If the project was successful, the potential for converting existing vehicles was enormous whilst licensing the engines to both Leyland and Daimler for insertion into new vehicles would also create a large new market.

Rolls-Royce were not as convinced of the value of the project as Lionel who, after all, had not been able to openly discuss it with Roy and so had only the broadest concept to present. "You can go ahead and produce a feasibility study," Lionel was told. "But you have to do it in your own time."

That would not have been much of a burden if it hadn't been for the geography involved: Crewe is in the North-West of England and Teesside is in the North-East. And the roads connecting the two were - indeed remain - winding roads through the Pennine Hills so that a typical journey was half a day each way, especially in winter. There was a motorway across the Hills but it was a long way around.

Lionel turned up with a bundle of plans. "It's a secret," he said. "Take a look at this."

Roy was amazed: the engine was smaller and lighter than the existing unit: physical modifications to the engine bay would not be extensive and there would be a weight dividend.

"It's almost silent when it's running," said Lionel. "The only noise your bus will make is from rattling panels!" Roy humphed - rattling panels are an inevitable side effect of the vibration of the engine. "And as the engine hardly vibrates, there will be a lot less of that, too."

Roy's interest was aroused: depending on the fuel consumption (which was difficult to calculate as bus use is different to any other form of use - a largely urban cycle with a very frequent stop-start and periods of running at tickover) and the price of the fuel the advantages of less vibration (therefore less maintenance of parts that work loose) and less noise (both in the workshop and in streets where, for example, a route or, worse, a terminus is in a residential area) were extremely valuable concerns.

"I’ll have a word at work," said Roy.

The response of the senior management at Teesside Municipal Transport was muted but supportive. The authority was already cash-strapped because its funding came from local government which had a political agenda that required extensive routing to be provided at minimal cost. Public transport was a social service not a commercial enterprise but funding was always difficult to prise out of the Council. An R&D project would be impossible to fund.

So if Roy wanted to play inventor, he could do so on his own time. But he could have a bus to play with if he could come up with the money to pay for the time spent in converting the bus - and putting it back into its original state.

Roy and Lionel decided that their employers had given enough of a green light for them to do some more work and at RR the Chief Engineer became involved – meaning that at least some of the meetings were now in Cheshire, not far from the factory where the chassis were made and the bodybuilder who turned them into buses.

The technical challenges were, in summary quite simple: remove the existing engine, modify the engine bay, change the fuel tank, insert the new engine and mate it to the transmission.

Anyone who has ever taken any mechanical device apart knows one thing: the first time you put it back together, it never goes back together in the same way or without some part being discovered on the floor during sweeping up.

Over a period of months, calculations of gearing, design of what would today be called "interfaces" and manufacture of parts were all, discussed at RR and then brought back to Teesside with both men squeezing time out of busy work days and family life.

In Teesside the family was lucky: the project was happening all around them and it was exciting. In Cheshire, there were just absences as "dad" shot off to Teesside whenever possible.

Out of hours visits to the workshop became commonplace for both men as they lined up the various components - but they still didn't have an engine because RR had not released the "secret" tag. And they still didn't have a development budget.

At some point, one of the men mumbled something about getting government money and a light went on. Several weeks later, after a series of presentations and meetings, mostly held in secret because of the potential military application of the RR Engine, the then government gave a grant to the project. With that commitment, RR agreed to cover any difference in operating costs.

The money was to convert one bus, to run it for a year including lending it to other local government-owned public transport systems for evaluation, where feasible, because lack of suitable refuelling points would limit where the test could take place, and to reconvert it at the end of the year if TMT and RR decided that was what they would do.

By this time, the secret was now out as the TMT Committee were required to give their full approval to such a radical project. And so a Daimler Fleetline went into the corner site of a workshop at RR, reversed into place so that the minimum was visible to any passer-by and its engine and transmission removed.

The gearbox was retained in its original state, but a multi link chain reduction box was used to drop the drive line by some 8 inches and change all differential input rpm`s (revolutions per minute – the engine speed) to the standard.

The diesel tank was replaced with four tanks for LPG. Then the new engine was fitted. A range of new instrumentation had been designed and now added to, or replaced, most of the dials normally found in the cab.

The fuel tank was charged and the engine primed and started.

It was indeed almost silent and with the bus at rest, the time when the panels vibrate most violently, hardly moved at all. A handkerchief held over the exhaust pipe (a completely new system had been designed and fabricated) showed absolutely no black spots.

The bus was taken out onto the road: the test driver brought it back after a short trip. He was shaking. "It's terrifying," he said. "It's so quiet I don't know if the engine is running and because there is no vibration, I can't tell when to change gear." The project had challenged one of the most basic principles of "seat of the pants" driving - in effect it had removed from the driver two of the senses that he relied upon for the feedback from the vehicle - feel and sound.

The two things that had been seen as positive side effects had unintended consequences that, potentially, may be seen as negative. But after two or three more sessions, the driver reported that, once he had got used to it, the bus was a dream to drive. More, he said, "after a day in this, I would not be so tired from being shaken about. And because I won't be deafened by the constant noise and won't be in the habit of shouting all day, I won't talk so loudly when I get home."

Suddenly, the possible downsides from the driver's point of view had become positive benefits.

Now the time came to announce the Gas Bus to the world, and it went off to the paint-shop, which had an annual tradition of dressing up a bus as "the Christmas bus" and had an ad hoc special projects team.

A new paint job married the fleet colours with the RR logos and “The Clean Air Bus” slogan in big letters down the side.

The press launch saw the handkerchief demonstration and the formal driving of the bus out into the streets and onto its first service route - and into controversy.

TMT was a very innovative organisation: it adopted many ideas that later became entrenched as the norm across the transport industry world-wide including such things as security screens for drivers, standards of signage and other things that were either invented or developed, generally by the engineering team. Many of their improvements of component design were adopted by manufacturers. In addition, the County Council team had special bus operation projects and one of these was to free up buses from traffic jams, and equally important to keep buses out of circuitous one way systems by bus-only lanes which a) saved time in jams, b)saved distance and c) meant that bus routes could remain in places convenient for foot-passengers therefore reducing the reliance of many on their cars.

Today, these things seem remarkably ordinary: in the early 1970s, they were revolutionary. The concept of the bus lane was beginning to attract attention in the industry - but Teesside went one stage further: when a road was converted to one-way, the bus routes would have to be diverted, and that would reduce the convenience of the buses for passengers and mean additional mileage. What if the buses continued on their original route? So the contra-flow bus lane was invented.

Just one problem, drivers reported that when the RR powered bus used the bus lane: people crossing the road watch the traffic in the one-way system but listen for the bus in the bus lane. And the Gas Bus doesn't make a noise. "We have to brake to avoid people stepping out into the street in front of us," the drivers reported. History does not record the name of the first person who stepped out directly in front of it but none were injured beyond grazes. Each one said exactly the same "I didn't hear it coming."

A year later, the bus's trial was re- evaluated. But the oil crisis that had made the project interesting to the government had ended and fuel prices were falling. And a government policy had, ironically, torpedoed the project: the government had increased the duty payable on LPG, so significantly increasing its cost. This affected a large number of other vehicle classifications such as taxis as well, and this had made the running costs unviable.

A request to the Government for further funding to bring the product to market was declined. The Department of Transport representative told the TMT General Manager that “ What was environmentally desirable yesterday is not seen in the same light today”.

However RR agreed to pick up the bill for the increased costs for two more years, after which the engine was returned to Rolls-Royce where its fate is unknown. The Fleetline reconverted to its original specification and livery, later to be photographed in a scrap-yard.

A quarter of a century on, the project is almost unknown and engineers are busy reinventing the technology - and claiming the concept as their own.

But nothing is all that new says Roy: in the 1940`s war years the Midland Red bus company (now subsumed into the National Bus Company) was operating at least one single deck gas powered vehicle in the Burton on Trent area of Staffordshire. It towed a trailer with a large gas bag mounted on it. Details of this are very sketchy but it frequently ran into Barton under Needwood where Roy travelled on it to school.

In July 1998, The University of California, Berkley, issued the following press release: " News conference to debut a University of California, Berkeley, passenger bus recently converted from a diesel fuel engine to a new technology powered by natural gas. It is the first passenger bus in the world to use this technology, which is from Westport Innovations Inc. of British Columbia." There is a difference: the Westport approach was to convert an existing engine.

In 2001, new regulations in India required all new buses to be natural gas powered. Ashok-Leyland, India's leading bus manufacturer, ordered 400 gas-powered engines from IMPCO Technologies, Inc. of California. There's an irony: the Daimler Fleetline was built by a company in the Leyland Group and was a near relative of the Leyland Atlantean.

Also in 2001, Westport and Cummins, one of the world's largest diesel engine manufacturers announced a joint venture to produce engines especially designed for natural gas. By 2003 Cummins-Westport was able to say " Transit fleets favour the powerful Cummins Westport C Gas Plus. Since it was introduced in June 2001, more than 1500 of these clean natural gas engines have been ordered for Boston, Washington, D.C., Atlanta, Phoenix, San Diego, Los Angeles, Sacramento and other cities.

In January 2004, Ken Livingstone, Mayor of London, announced the introduction of three buses powered by hydrogen gas, touting their quietness and clean-air technology as "greenest, cleanest and quietest ever."

And what of the two men who started it all?

Lionel is running a 1600 acre estate in Shropshire where Roy spends a few days every couple of months doing paperwork to help Lionel keep up to date with the never ending government regulation of cattle farming.

Roy has moved to Kent where he does proof reading for a couple of publications and provides a guiding hand for several family businesses. He keeps his garden in immaculate order with the eye for detail that made the implementation possible, and tends to his grandkids with equal care.

And every day he eats his dinner from the octagonal oak table.

Unless one of his sons has a bundle of papers spread out over it saying "take a look at this?"