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Big noises meet at Med E Conference
IN HIS keynote address to an Institution of Mechanical Engineers conference in London last week, Ron Mellor, Ford of Europe's vice president, car engineering and now responsible for the development of all Ford diesel engines, called for more technical research on the subjects of vehicle noise and vibration. He warned of the risk that attention to these subjects "will suffer in the headlong rush for economy and performance".
Mr Mellor described vehicle noise as "the single most important subject in legislative plans". His view, as a vehicle manufacturer, was that two of the key issues were that "legislators should concentrate on the impact of external noise and not be involved in internal noise; and that sufficient time should be allowed to meet lower noise limits, with harmonisation at least across Europe."
One of the men most closely involved with those legislative plans joined Ron Mellor in a panel of experts for a discussion session at the conference. John Furness is director/chief mechanical ongineer of the DTp's vehicle safety directorate. He was recently awarded the IIVIech E's top annual prize (CM last week).
In reply to a question from Michael Russell of Lucas CAV about the possibility of tax incentives being introduced for low-noise vehicles, Mr Furness said that this "had not been entirely ruled out", but he thought it "not the best method" of achieving quieter commercial vehicles. I-le pointed out that there were "legal difficulties" in giving tax incentives for quieter vehicles. One of these he said is that "you have to define what you mean by 'quiet' ". Another disadvantage of the tax incentive scheme, as currently being operated in the Netherlands, is that it is contrary to the idea of harmonisation. "UK government policy is to deal with noise at source", said Mr Furness. Ron Mellor was more forthright in his condemnation of tax incentives for noise reduction proposal. "The idea horrifies me," he said.
John Furness was pressed on the question of future legislation for interior noise levels in cornmercial vehicle cabs by Bob Pendlebury, manager, truck development, at Ford, Basildon. The DTp's chief mechanical en gineer said that the reason for wanting to control interior noise levels was that a commercial vehicle cab in a workplace. "We have been guided by the Health and Safety Executive, and so have the manufacturers," he said. "One of the problems is finding a suitable test method. I do not see this as a matter for early legislation."
The discussion was brought back to more immediate problems, specifically those being faced by fleet engineers, by Roger Denniss, Bass UK's director of fleet engineering. He wanted to hear the panel's views on those commercial vehicle noise sources which are of less concern to design engineers, but which are often more annoying to the public, than the engine. He mentioned air brakes exhausting, unladen leaf spring suspension clattering and doors being slammed. "Public spirited operators are prepared to pay more for quieter vehicles," he said.
Cedric Ashley, director of the Motor Industry Research Association, accepted that this was "a very interesting point". "These are important factors. Socially responsible operators do want good standards. While these noise sources are unlikely ever to be legislated for, commercial pressures will prevail."
John Furness expressed a similar view, reminding the delegates that the legislation laid down minimum standards. "When large fleet operators write-in items in their specifications, they are often ahead of legislation," he said.
Colin Shurmer, assistant staff engineer, noise and vibration, from Bedford, highlighted the problem of reconciling in-service legislative standards (or lack of them as far as noise is concerned) with those which new vehicles have to satisfy. "We spend a lot of money build ing vehicles to comply," he said, "and then they are changed the first time they go into a workshop for a service."
Mr Shurmer also echoed the concern, which had already been expressed by a number of manufacturers' representatives, that the current drive-by noise levels needed to be more clearly defined and less open to different interpretation in other countries. Specifically he called for standard test surfaces.
Bedford has found that the result can vary by as much as 2-3 dB(A) according to the type of track surface. "Ambient temperature and fuel quality are also critical," said Mr Shurmer. "We need to know the rules if we are going to play the game."
In his response, John Furness made it clear that the DTp was already giving due consideration to all the points raised by Colin Shurmer. He implied that external noise testing of heavy goods vehicles may in future be included in their annual tests, if the DTp can devise an effective static noise test which correlates well with the drive-by test.
Cedric Ashley confirmed that objective measurement of noise from in-service vehicles, was difficult. "At the time we devised the lug down test for smoke emission, we looked at measurement of noise as well," he said. "Correlation with driveby noise was a problem."
Though John Furness had insisted that his department did not like regulations and would rather achieve its objectives in other ways, Ron Mellor evidently was unconvinced. "A department which produces regulations improves its year on year efficiency by producing more regulations," he said.
While he endorsed the views of other manufacturers, that engine encapsulation was going to be the only way of satisfying future noise limits, he expressed serious doubts about its real effectiveness in reducing traffic noise nuisance. "I am fearful that much encapsulation will be left in operators' workshops," he said. "The manufacturing industry spends a lot of money and effort in developing ways of satisfying regulations governing new vehicles. After that it is an anarchic free for all."
The other panel members at the conference were Peter Fietz from Daimler-Benz, Stuttgart; Michael Lewis, chief engineer of BL Technology; Teodors Priede, professor of automobile engi-, neering at the Institute of Sound and Vibration Research, Southampton University. The chairman was John Hollings, consultant to Rolls-Royce Motors, car division.