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How to get free fuel for 4400 miles
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a mockery of the whole braking regulations because if a chassis has an efficiency of only 50 per cent when empty it is going to have far from adequate braking when full and the problem about excessive braking can easily be overcome by the fitting of light-laden valves which proportion the braking effort according to the load applied to the axle.
Braking continues to be one of the more interesting aspects of vehicle design and the situation is far from satisfactory from an operator's point of view. A look at the exhibits at Earls Court that are suitable for the higher gross weights will show that nearly every manufacturer has a different layout. In my report of the Scottish Show in 1965 I went into some detail about the different types of system fitted and while things have changed slightly the same circumstances prevail. How the maintenance staff of a mixed fleet of heavies cope with brake troubles I do not know. Many chassis now have completely duplicated main systems for the secondary brakes on rigids including the new Bedford KM rigids, Seddon models and Commer chassis, others apply the secondary to the driving axle of rigids only whilst outer-axle braking is common for artics. And on the new twin-steer tractive units some have the first front axle and the semi-trailer auxiliary connection for the secondary whilst others include both front axles.
Spring brakes are to be seen on many of the stands to meet requirements of the secondary brakes and the parking brakes. Th are not to get legal but this is anticipated when experience has b gained with these units. Companies using spring brakes which at present available only through Westinghouse include Leyla Atkinson, ERF (on all chassis featured by this company), Fod Guy and DAF. The Westinghouse/MGM spring brakes have additional chamber mounted on a normal-type diaphragm actua and air pressure in front of the diaphragm in this second cham holds off the spring. When the air pressure is destroyed (intentiom or through a fault) the spring pressure applies the brakes. Spr brakes are not new to this country but ERF has done a lot of NVI to get the Ministry of Transport to authorize their use. Now alternative to them is available from Westinghouse. This is the k actuator which appears only on an Atkinson chassis and consi essentially of a dual-diaphragm chamber with an extension inc porating a locking device. When one diaphragm is actuated brakes are applied normally but when pressure is applied to other the operating shaft is held in the "on" position to act a parking brake. In this way the units perform in more or less the sa way as spring brakes.
At the moment only Westinghouse offers these two new type; brake actuating units but Clayton Dewandre is working on simi lines and will probably be introducing similar actuators within next year.
Still confusion
While braking systems have not changed much in being still a fairly high state of confusion there are examples on many chas of the latest developments in equipment. Most are small units I will nevertheless make worthwhile improvements in vehicle ope tion. Two good examples are the "g"matic load-sensing valve a a combined condenser and automatic drain-valve unit for a pressure systems produced by Clayton Dewandre. The "g "ma equipment is intended to be fitted at driving axles and semi-trai axles and proportions the braking effort at the wheels according the load applied.
Although not preventing wheel locking like the Dunlop Maxa] in the components section, the most dangerous thing that c happen with an artic, the device reduces the chance considerab It deserves to be standard on all tractive units as it is on thc versions of the Bedford KM, as well as on all semi-trailers. T Clayton Dewandre condensing unit is getting fairly popular. It a small finned chamber containing an automatic drain valve and al gives benefits from the safety angle. Moisture is prevented frc getting into the air system to freeze up the valves and make fix inoperative in very cold weather.
As I said at the beginning there is a lot more of interest in coi ponents at the Show, primarily engines and transmissions. important exhibit is the turbocharged Leyland 0.680 which giv 240 b.h.p. , and we now have the long-awaited higher-power lardner—the 6LXB—which gives 180 b.h.p. This can be seen on uite a few Show models. Higher-powered engines were a feature f the last Show together with vee diesels. There is not the accent on es at this Show although Guy, Dodge and Dennis have Cummins ees and Dennis and Seddon have the Perkins V8. The future Ford eavy-weights announced on the opening day of the Show will !so have vee engines and a new vee unit from one of the heavy chicle manufacturers is likely to be available before long. So the ict that there are not as many vee engines at this Show as at the ist should not be taken to mean that manufacturers are losing iterest.
;ay has V8 Guy, in fact, is featuring a new version of the Big J on the emonstration park with a Cummins V8 but it is significant that minis use the Perkins 6.354 in the Pax 22 which is based very irgely on the Maxim which uses the Cummins V8 or Perkins V8. 'he latest Dodge model is not at the Show, it having been announced nly just before opening day, and this model—the K1000—is a 6-ton gross four-wheeler fitted with the Perkins 6.354 also. This /as rather a surprising move by Dodge as the 500 Series publicity lade great play on the fact that the Cummins vee diesels were tandard throughout the range and the Perkins 6.354 was optional .nly for gross weights of 15 tons and below. The first company to announce before the Show that it was to offer semi-automatic transmission in standard goods models was Leyland Motors Ltd. and the company has two chassis on the stand —the Steer and a Beaver 30-ton tractive unit—with this feature. Other companies showing a similar semi-automatic layout are Atkinson (on demonstration), Foden and Scammell. Guy has the SRM fully-automatic transmission in a Show chassis and on the demonstration park ERF, which was one of the first companies to show interest in this unit is featuring a chassis with Allison fullyautomatic transmission.
It is rather surprising that automatic or semi-automatic transmission for goods should have jumped from light vans—BMC and Conuner have offered the Borg-Warner Type 35 for some time— right up to the maximum capacity machines; BMC do in fact reduce the gap slightly by showing an LD 30 van on the Morris stand with fully-automatic transmission.
Advantages These transmissions give advantages in life and reduced maintenance but most operators will be wanting to know how much they are going to cost. Atkinson say that specification of the SelfChanging Gears unit will add between £350 and £550 to the price according to the amount of work required to fit it to the engine; these prices refer to the Gardner 6LX and Cummins engines respectively but I have heard that with Leyland the price increase will be in the region of £700. This seems very high but, looking at the prices listed in the Show catalogue, may not be wide of the mark. The Leyland Beaver on the Show stand with semi-automatic is quoted as costing £4,500 and the Steer £4,795.
Leyland plans to offer the Beaver with semi-automatic as a standard chassis produced on a special line to give quick delivery. The likely reason for this is to combat the threat to sales from the Continental makers who have as their main selling point almost immediate delivery. But I wonder if Leyland has chosen the right model to do this with, for one of the biggest things against buying an overseas vehicle is the price. And the Leyland price with semiautomatic is not much different to that listed in the catalogue for Magirus-Deutz and Mercedes-Benz chassis with a comparable specification except for the transmission.