" EOPLE get the legislation they merit" says Alex
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Williamson and he qualifies this statement with the com
ment: "Vauxhall welcomes the current legislation relating to vehicle design; it was long overdue". Mr. Williamson is particularly interested in the history of transport law and points out that, even in 1662 there were regulations—one was introduced to limit the weight of road vehicles to 1 ton and the number of horses that could be employed to six as a means of safeguarding road surfaces against rapid deterioration. Mr. Williamson regards the current axle-load limit of 10 tons as a reasonable figure bearing in mind the rate at which roads disintegrate under heavy pounding.
He believes that in the not-too-distant future production will increasingly be concentrated on vehicles in two general categories, namely those with payload ratings up to 7 tons and trucks with ratings of 16 tons or more. Vehicles in the 10/12-ton gross category will tend to diminish.
Although a 40ft container (or two 2011 containers) cannot readily be accommodated on existing maximum-length vehicles, the regulations must be changed to facilitate their transport by road. In the main, loads will be carried in 2011 containers, singly or in pairs, and vehicles will be designed with this in mind. It is probable that clearing houses will be established strategically to which two-container artics will deliver their loads, and from which single-container rigids will be used to distribute the containers locally.
On design trends, Mr. Williamson emphasizes that use requirements will influence design to a greater extent than regulations. In general, steady progress will be made but the chassis of 1977 will have the same form as existing chassis and be powered by a conventional diesel engine giving a minimum power-to-weight ratio well in excess of 6 bhp /ton—probably around 8/10 bhp /ton. The gas turbine may come into its own for vehicles running "vast distances" with high gvw. Although, in America, where the fuel consumption of long-distance trunking vehicles is a relatively minor consideration, the gas turbine has not yet "taken over" to a worthwhile extent.
American long-distance drivers normally, observes Mr. Williamson, have the use of multi ratios and with the help of a tachometer they maintain a near-constant engine speed approximately corresponding to the maximum torque of the engine and so achieve a near-optimum overall economy. In this country drivers can hang-on to top gear because of the favourable torque curve of the modern diesel engine, and the multi-ratio gearbox is rarely exploited to the full. Driving techniques are often dictated by traffic conditions in the UK, whereas road conditions and gradients are more often determining factors in America.
With the developing UK motorway system, there is now greater scope in this country for maximum-torque driving and this will be made easier by the provision of suitable gear ratios and appropriate instruments. Graphs prepared by Vauxhall technicians show the gradability in each ratio of the heavier vehicles in the company's range, some of which are equipped with two-speed axles. From these graphs the vehicle's climbing speeds on the gradients of typical routes can be assessed. No graphical method has yet been devised, however, for assessing the "inertia gradability" of a vehicle giving the speed of ascent of a gradient, following a descent at high speed.
Mr. Williamson emphasizes that an improvement in engine power is best obtained by increasing the cubic capacity of the unit because torque is proportional to capacity and bigger engines give better performance. Turbocharging has its place, however, as a useful means of increasing the power of a basic engine and current Bedford engines are designed to accept turbocharging.
Advances in engine design will be made by controlling heat dissipation and improving reliability; the Bedford KM range of engines in which the pistons operate in un-linered cylinders and the valves have no guides was given as an example. A high rate of coolant circulation in the engine block by suitable venting of the water pump, combined with the use of a wax thermostat equipped with a jiggle pin, can give efficient control of coolant temperature without the use of radiator shutters, which, however, are a help in accurate control. Reducing cold running to a minimum combats the formation of acid products of combustion. • According to Mr. Williamson Bedford "short motors" started a trend in engine maintenance. These are available at an attractive price and comprise the major part of the unit incorporating improvements that have been introduced since the original engine was built.
In a general comment on en route maintenance problems, Mr. Williamson points to the advice typically given to the driver of a trunking vehicle in America. "Buddy, the only tool you need is a dime—to phone your base if you run into trouble. We'll do the rest." The driver who struggles back to base with an ailing vehicle is, apparently, unpopular with his boss, also with Mr. Williamson who regards such a practice as a potentially dangerous and expensive exercise.
On the question of braking, Mr. Williamson states that the braking of Bedford vehicles is up to current safety standards and that the continuous braking performance of a vehicle is as important as peak efficiency because kw people "know what it's like" to brake at a rate of more than 50 per cent. Designing weight out of a vehicle is a major objective of Bedford engineers and a reduction in kerb weight giving an increase in payload of 10 to 15 cwt has often been achieved by attention to detailed weight-saving.
Mr. Williamson considers that the front wheels of a vehicle should be the first "to approach locking" particularly in the case of an articulated outfit, and that the semi-trailer brakes should approach the locked condition before those of the driving axle. While the use of light laden valves on the tractor and trailer can provide a "75 per cent solution" to the artic braking problem, the "probable best" is an anti-locking system applied to all wheels.
Bedford chassis are designed to give uniform flexing and thus combine light weight with a durability that provides for the arduous operating conditions encountered in newly developing countries. Chassis modifications to cater for such conditions can, therefore, be provided in the form of special springs, axles, gearboxes and so on. But the chief problem in catering for exports arises froni variations in the regulations relating to ancillaries such as lights and flashers and in Mr. Williamson's opinion, there is an urgent need for international agreement covering the design of equipment in this category.
While Mr. Williamson agrees with the proposed noise regulations, he considers that coping with future legislation may be the most difficult technical exercise of any presented so far. It is reasonable to cater for a noise level of 89dB but reducing the level of larger engines to anything like 80dB would create major difficulties.
Over the years, increasing attention will be given to driver comfort and to easing the control of steering, braking and clutch operation. Conventional types of gearbox will be retained in lighter vehicles but automatic transmission may well become a necessary feature of vehicles in the 32-ton category and for the larger vehicles that it is anticipated will be provided for in future legislation.