DRAWBAR DEBATE
Page 86
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Many of the country's leading drawbar operators were in London last week for the Drawbar Revolution conference; we summarise the news and views.
• If drawbar weights were increased to 38 tonnes, they would replace many of the 32.5 tonne artics on UK roads — and every thousand 32.5-tonners replaced by drawbars represents a saving to operators of £9.6 million.
So says Melvyn Peters, who opened the Drawbar Revolution conference at the Polytechnic of Central London last week. He presented the results of a study by PCL into the effects of a weight increase in drawbars (for details of the cost implications see Page 46).
Peters predicted that the drawbar vehicle parc would continue to grow steadily in the UK, even if there was no increase in maximum weights. Despite the steady growth in the UK since 1983, there were still only around 4,300 combinations on our roads compared with 56,235 in the Netherlands and 140,000 in West Germany.
Most drawbar operators in the UK were still experimenting with the system, said Peters. The average drawbar fleet had six vehicles, but 50% of drawbar operators planned to buy at least another three units during the next three years.
If the Government raised the weight limit to 38 or even 40 tonnes, more than half of current drawbar operators would increase the payload of their units, and at least 50% would operate at the higher weight, he added.
Drawbars failed to cover their road track costs said Peters, so any increase in weights was likely to be accompanied by a rise in VED. It would be a pity if such a rise put operators off drawbars, he said, "because the effet of the tax is next to nothing in the long run compared with the big saving in overall distribution costs".
Alan Hill of HDL wanted to know when a drawbar weight rise was likely to come into effect. Peters saw little prospect of such a rise until the Government's hand was forced by harmonisation in 1992.
Peters was also asked about the HGV licence for drawbar drivers. He felt that drivers shoudl take a supplementary test before driving drawbars, and that the HGV classes 1 and 3 should both be accommodated as drawbars do not behave like artics.
Bob Paton from Leyland Daf asked ab out standards for pin connectors between drawbar units — a topic which received considerable discussion during the day. Peters said that West German experience indicated a 40rnm diameter was not strong enough, particularly for central-aided trailers, and that 50rnm should be minimum.
Tom Dee from VBG Concessionaires referred to the same problem in his speech: "The nub of the matter is in the bearing service area of the two bushes within their respective eye forgings," he said. "The 50trun eye will last virtually indefinitely, providing it is serviced, whereas the 40mm, because of its slender proportions, is prone to banging loose within the forging."
Dee's company advises on the design of drawbars, and he used the conference to emphasise the need for good overall design in drawbar units. Often a large number of parties are involved in the development of a drawbar unit, and all too often no one ensured that the whole system would work properly together.
He included a series of slide showing drawbars that had been badly designed, and the accidents had resulted. These included a tanker unit designed for high speed operation on German autobahns which became uncontrollable above 60km/h (37mph). He also showed one instance in which the designers prevented a fatality by making the coupling very strong. In this instance an American drawbar prime mover drove over the edge of a bridge 40m above a ravine — the trailer remained on the bridge and kept the vehicle from falling, and the driver was rescued after a nerve-wracking eight-hour wait!
Ray Smith Demountable sales director David Browning told the conference of the flexibility provided by drawbar units fitted with demounts: "Sometimes to be distribution-efficient is more desirable than to be transport efficient," he said. Though drawbar vehicles with demount bodies might be expensive to buy, they could replace several vehicles — and even depots — and could often be used efficiently 24 hours a day.
Because of the high initial cost, many of Ray Smith's customers are contract hire companies, but Browning warned that contract hire companies may underspecify demount drawbars in an attempt to save costs. He was also concerned that some contract hire companies allowed drivers insufficient time to get used to drawbars.
The importance of driver training in drawbar operations was echoed by John Ostle, distribution engineering manager of BOC Gases Division, and Bill Day, distribution executive of International Distillers and Vintners. Both companies operate drawbars — indeed BOC operates the largest fleet of drawbars in the country, with more than 100 prime movers and some 80 trailers.
Driver training is vital for drawbar operation said Ostle. BOC trains its drivers using a driving school with drawbar experience, and has its own instructors for training on the job.
Driver acceptance of drawbars would be better if the system was designed for easy operation, said Ostle. Particular attention should be paid to ease of coupling. Some drivers would find converting to drawbars easier than others, however, so comapnies should be prepared to select drawbar drivers carefully.
Ostle said the Government should make a clear commitment to future drawbar weight limits so that British manufacturers and operators could prepare for the future.
Bill Day from IDV said the switch to drawbars had provided his company with savings of £250,000 a year in distribution in Surrey, Sussex and Kent. By using drawbars IDV had been able to introduce a stockless depot in Sevenoaks which served all three counties.
E by Richard Scrase