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RHA ANNUAL CONFERENCE,

25th October 1974
Page 74
Page 75
Page 74, 25th October 1974 — RHA ANNUAL CONFERENCE,
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PLYMOUTHReport by lair, sherriff

'Limitless future for the diesel'

Conference delegates press for Stirling engine development; and hear of backloading problems in Germany

A STRONG future for the diesel engine, and a poor record for the German haulage industry's elaborate back-loading network — these were two themes which emerged from last week's Road Haulage Association annual conference; the early proceedings were reported in CM last Friday.

The final business session on the first day was entitled "Women in transport" and appeared to be taken seriously by only one or two of those who spoke. Others used it for facetious comments on the question of whether women could be employed as drivers or fitters.

The next day the conference returned to a more serious note. when Mr N. M. F. Vulliamy, assistant director of engineering, Perkins Engine Co Ltd, presented a slide-illustrated paper entitled "Developments in goods vehicles' engines," Mr Vulliamy, opened his paper by suggesting to the delegates that while in general he would be looking at the development of engines in relation to fuel economy, it should be understood that not only engine development should concern itself with reducing power wastage.

Those concerned with the development of transmissions, brakes. tyres. cabs and bodies should be thinking in terms of fuel economy too, he said. Mismatched transmissions, the wrong gearing, and oil drag were transmission factors which had to be considered in this regard. Sticking brakes or the incorrect inflation and misalignment of tyres affected fuel consumption as did the wind resistance of the cab and body.

Legislation for the reduction of noise. smoke and the improvement of safety standards all had an effect on engine efficiency. Noise reduction when engines were encapsulated, reduced the power efficiency and increased weight. as did smoke reduction. Safety regulations also affected the vehicle weight and in so doing affected the fuel consumption.

Mr Vulliamy said the Perkins V8 540 was quieter than the shorter-stroked 510 but even this engine could not manage better than to convert 35 per cent-of fuel into useful power.

Fuel cells could provide 100 per cent conversion but had attendant problems.

External power losses in the diesel included 10.2 bhp to drive the fan, 5.6 for the compressor. 4.3 for the water pump, 2.3 for the steering pump. 3.7 for the injection system and 0.3 for the alternator.

The greatest power loss was from the pistons at 15.5 per cent and the rings accounted for 8.5 per cent with the remaining engine friction adding 5.1 per cent. Having fewer rings would, of course. help immensely, and the Americans had developed a two-ring piston which would eventually come onto the British vehicle market.

Oil drag was one factor which the operators could overcome, said Mt Vulliamy, if they were to use an SAES or 10 in light-lead conditions: This would produce less oil drag and reduce fue consumption, resulting in more powet for less fuel. He thought, however, thai fuel suppliers would shortly be looking for greater economy in the refining stages and this would mean eventually a lower gravity fuel,

Too expensive

Looking at the alternatives to the diesel engine, he suggested that a stratified-charge machine would be 'too expensive for commercial purposes; that in addition to being too thirsty the gas turbine was not living up to its earlier promise; and until new materials were forthcoming development of the turbine would remain in a semisuspended state. External combustion engines had perhaps a slightly more hopeful future but he believed that steam could be used only for cars and buses. However, one had to commend its simplicity and silence.

Of the Stirling engine, Mr Vulliamy said that despite being 158 years' old this concept had an operating cycle equal to the best, but it would take, in his opinion, another 10 years before it could go into production. He told the delegates that the Stirling required both high pressure and high temperature, and hequoted figures of 300 psi and 1,6000 F.

Mr Vulliamy believed that the Stirling had a very interesting future, and said that the Swedish development was incredibly quiet. The great deterrent at the moment was that the Stirling needed vast sums spent on research.

Having reviewed the alternatives, it was his opinion that there was a limitless future for diesel engines, but he agreed that a lot more work had to be done. He said that his own company's Squish Lip system had been developed to meet North American emission legislation. It was designed to retard injection timing heavily and reduce pressure, temperature and smoke to bring quieter and lighter vehicles and effect fuel savings. "But," he warned, "this will not be tomorrow; we cannot promise substantial fuel consumption improvements in the immediate future."

Mr J. Kirby (East Midlands) said that of Perkins last three engines the P6 had been good but dirty; the 6,354, in the early days, a complete failure; and the V8 was very thirsty. He thought Gardner produced the best engine in this country — but, regrettably, not in quantity. He asked; "Why can we not have more of the Gardner type engine from other engine manufacturers like yourselves."

Mr Vulliamy said that he was not surprised that that question had come up -in fact, he rather expected it. "We all admire Gardner, but for various reasons we cannot set out to reproduce a Gardner engine. It would take years to get to their standard of workmanship and their attention to detail. They take tremendous care and it would be difficult to compete," he said.

Stirling engine

Referring to the Stirling engine, Mr A. R. Butt, (West Midlands) said that if it had in its favour reduced fuel consumption with less noise and smoke, then surely in the present atmosphere governments should make the cash available for the research to be stepped up.

Mr Vulliamy replied that the Stirling engine was certainly both clean and economical and he felt that governments might be prepared to take a look at the research costs. Mr F. C. KingSmith (West Midlands) asked if the fuel cell with its 100 per cent conversion efficiency could be used as a method of propulsion. The speaker said that fuel cells converted energy from liquid fuel into forms of power. Mainly this was electricity. "If they had to be used with vehicles there would require to be an electric motor to drive the wheels," he said.

Mr C. E. J. Peak (Western) said that if the fan was so inefficient as to account for 10 per cent of the exterminal power losses, might not an electrically driven fan be the answer. The speaker said that this could be done and that clutched fans might also provide the answer, but that there would be other problems connected with this type of operation.

Mr G. G. Archer (Eastern) asked if the exhaust gases could be used to drive the fan and would this not reduce the external losses. Mr Vulliamy agreed that this was a possibility. "It is an interesting and novel suggestion which I will take away and investigate," he added.

Mr C. W. Bridge (Eastern), while agreeing that engine development was important, said: "I am less concerned about your engines of the future and more interested in what we have today. When will you provide operators wil an efficient after-sales service?"

Mr Vulliamy concluded: "Although am not part of the sales organizatio. like everyone at Perkins, we are coi cerned that you should get a good afte sales service. We thought we had it righ so perhaps some of the responsibilii lies with you, the customer. If you wi tell us where we are falling down then will know what must be done about it.


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