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A mixed bag of tests in the year

3rd May 1968, Page 72
3rd May 1968
Page 72
Page 73
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Page 72, 3rd May 1968 — A mixed bag of tests in the year
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A REVIEW BY THE TECHNICAL EDITOR OF 'CM' ROAD TESTS CARRIED OUT IN THE PAST TWELVE MONTHS

THE MAJORITY of vehicles tested since last June when the last review of this type was published have been maximum-gross artics or p.s.v. These categories contain no fewer than 12 of the 21 vehicles put through their paces by CM staff.

Nevertheless, vehicles have been tested in all except two of the categories used in these reviews and as one is that which would normally include maximum-weight fourwheelers it illustrates the heavy-vehicle manufacturer's concentration on attics which is a continuing trend in this country.

The lightest-vehicle section with five tests contains a varied selection of vehicles, the first to be tested being the Bedford CA which was supplied as a Martin Walter 12-seater. The model was, however, tested as if it were a van with a payload of 12.5cwt and generally good results were obtained. Braking was good and fuel consumption at an acceptable level. The CA was found to be an easy vehicle to drive with light controls and very good visibility.

For the next test we came to an unusual commercial vehicle, the Reliant three-wheel pick-up for lficwt loads. This model was developed primarily for use in overseas markets and gave surprisingly good roadholding although the seats were not terribly comfortable. A good feature of the Reliant was fuel consumption when figures comparable to those normally obtained with much lighter vans were obtained, but with only a 27 bhp petrol engine acceleration performance was below the normal standard.

This criticism could not be made of the Ford Transit 17ewt van which was tested with automatic transmission. But against this, fuel consumption was a little down particularly when running at high speed. No brake tests were carried out on the Transit as this was a supplementary test to the original on this model; for the record the 17cwt version stopped from 30 mph in 41.5ft which made it well up to the standard expected of this class of vehicle.

The first foreign-made vehicle of the five that have been tested in the year appears in this section. It was the Volkswagen 1-ton van, a model which has been sold in fair numbers in this country. The test was of the latest version with re-designed front end, changed suspension and an engine with 47 bhp output as against 43 bhp. Results were generally good but there was some tendency to wander when running at high speeds in the very windy conditions during the test and so a high-speed consumption run could not be carried out. The brakes were very effective and acceleration performance acceptable while the Changes to the cab had made the vehicle more pleasant to drive.

Completing this section there is the Ford Escort 6cwt van which was introduced only one month ago; the test report appeared in our issue of April 19. The Escort was outstanding from a handling point of view and returned excellent fuel consumption results and acceleration times. Braking was marred by wheel locking and while the distances were only slightly extended through lack of adhesion on the road, hand

brake performance was disappointing due to slackness in the cable linkage.

As the Commer 13-ton-gross fourwheeler is the only model in section three, it is necessary to go to previous years to get comparison figures. Fuel consumption was better than usual while acceleration and braking performance were up to the standards expected of this class of machine. The test confirmed that the Commer CC has brakes which comfortably exceed the minimum requirements for the latest regulations and it was also a pleasant vehicle to drive with really comfortable cab.

Maxi mu m-weight vehicles There are three foreign vehicles in the next section in which tests were carried out, that dealing with maximum-weight goods vehicles. The first of these was the DAF T1800 which was tested in Holland at 28-tons gross. The T1800 is one that is imported into Britain and the test was carried out on a tractive unit actually built for this country. With a 150 bhp diesel pulling 28 tons it was expected that the DAF would be a little short of power and this was illustrated by the acceleration times. But against this fuel consumption was good,

as was braking.

Next in the list is the Ford D1000 artic which was also tested at 28 tons and while getting top marks for fuel consumption and acceleration performance this model had brakes which were below the standard set by most vehicles in this category. There was some trouble with the brakes due to pulling to one side but when this was corrected further testing was carried out which proved that the modifications made had been completely satisfactory.

Now that 15-metre overall length is permissible, 32 tons on four axles can be obtained but operators may prefer to operate shorter outfits in which case five axles are required on an artic for this weight. Twin-steer tractive units offer a simple way to do so with the minimum weight penalty and the first to be introduced was the Scammell Trunker II. The test of this model gave good stopping distances but the general performance was not very exciting and fuel consumption was on the low side. Mastering the gear change on the Trunker took a little time but after some use the action was satisfactory.

Interest shown by Fiat of Italy in Britain as a market at the 1966 Commercial Motor Show has not resulted in anything concrete but one of the models featured by the firm at Earls Court was provided for road test and appears in this section. The vehicle came straight from demonstration work for the tests and may not have been fully serviced before I took over but it nevertheless gave satisfactory results. The roads were wet for the brake tests but satisfactory figures resulted and in the dry extremely short distances could have been expected. Fuel consumption was about the average that is put up by maximum gross artics and acceleration was good.

The test of the Atkinson/Dyson 32-tongross tractive unit gave the chance for the first test on a vehicle equipped with the Rolls-Royce Eagle diesel engine. The test chassis did not do well on acceleration and braking but fuel consumption was at an acceptable level. There was a claim that better figures had been obtained with the vehicle but re-checking confirmed those obtained on the test and the difference was put down to the fact that speedometer readings were used to assess the previous performance while test figures are taken over accurate distances; the speedometer was about 4 per cent fast.

Apart from the engine the Atkinson was identical to a chassis tested previously with another make of power unit and this had given better consumptions but the rear axle ratio was lower on this test. Braking had also been much better on the first vehicle so that it is likely that some adjustment was necessary.

Good performance

Good fuel consumption figures, brake stopping distances that have rarely been bettered by maximum gross artics in recent years and really excellent acceleration performance were the main features of the test of the Scania-Vabis LB76 which was carried out in Sweden at 32 tons gross. The test was made following modifications to the model which included the use of a more powerful engine.

The Scania-Vabis was a comfortable vehicle to drive with light controls making it more like a light commercial. Noise level was low but it was found that starting off on inclines was rather a delicate operation due to "bucking" of the front end as the clutch started to take up the drive. After some pretty harsh treatment in trying to get off on a 1 in 6 gradient a propeller shaft broke bu this was found to be of an obsolete type; th( material had been changed for the curreni production.

Two go-anywhere vehicles and a dumf truck make up the vehicles tested in tit( Special Types category. First of these waf. the Land-Rover with six-cylinder 2.625 litre petrol engine. With a 16cwt payload acceleration performance was extremely good and braking was to a good standard also Fuel consumption was naturally worse thar with the four-cylinder petrol versions of the Land-Rover previously tested but where performance is desirable this factor is ol little relevance. As usual the 4 X 4 was put over the very severe test circuits at the FVRDE, Bagshot Heath and Chobham and performed extremely well except that on one of the water hazards water found its way into the engine to cause an involuntary stop.

'Like a horse'

A much lighter machine, the Steyr-Puch Haflinger carried a payload of nearly lOcwt and gave fine consumption, braking and acceleration. This model was tested off the road and performed more like a horse than a pick-up in proving its value for crosscountry work. Brake testing of the Haflinger had proved difficult because of the tendency for the rear wheels to come clear of the ground during maximum-pressure stops. Less pressure improved the situation but in the case of the Heathfield dump truck where the same phenomenon occurred, modification was required.

On the first tests frightening things happened under maximum pressure braking with the rear tyres clear of the ground and the load transferring alternately from one front wheel to the other. After alterations to the effort at the front, satisfactory re-tests were completed and the stopping distances recorded were up to standard. In normalroad tests, fuel consumption was satisfactory although at high speeds the figure dropped considerably; the vehicle achieved reasonable acceleration times.

As well as this normal road work the Heathfield was taken to a quarry for site evaluation and here efforts to bog it down were completely defeated. Over atrocious conditions the dump truck was readily kept going despite the fact that at times the front bumper was performing as a bulldozer in clearing earth from in front of the vehicle.

Passenger vehicles

Coming to the final section we have the six passenger vehicles. The first tested was the Leyland Panther Cub with Strachans 45-seat single-deck bus body. This rearengined chassis gave fuel consumption figures which show that it should be reasonably economical to operate although more fuel was used when two stops and six stops per mile were made than is usual with a single decker. The Leyland Pneumocyclic semi-automatic gearbox on the test vehicle made driving extremely easy and acceleration times put up were at an acceptable level. Braking was also satisfactory and the general feel of the brakes

was good, as waS. the ride given by the leaf-spring suspension.

Sticking to the same make but jumping to later in the year brings one to the LeylandVerheul single-decker which was tested in Holland. This model has an integral body built by Verheul and employs running units, including a Leyland 0.680 diesel, Pneumocyclic semi-automatic gearbox and other components employed in Leyland p.s.v. chassis. Although identical testing to that which would have been done in Britain was not possible sufficient information was obtained to show that this single-decker had many things to its credit.

The Daimler tested in the past year was theesirrgle-deck version of the Fleetline, this

particular model being of interest because it allows standardization in a fleet of mixed single and double-deckers. The steering was found to be on the heavy side but apart from this it was an easy vehicle to drive, again helped by the use of semi-automatic transmission, in this case the Daimatic unit.

Tests at M I RA

There was very bad weather on the day of the test and for this reason tests were carried out at MIRA where a road surface with a similar adhesion character when wet to that of most roads when dry was used for the braking tests. While being slightly down on fuel consumption at normal speeds the Fleetline did reasonably well when driven fast and acceleration performance was adequate for this class of vehicle.

A different kind of suspension was used in the AEC Reliance—coil springs—and this was the main reason for the road test The suspension gave as good a ride character as air suspension in the tester's opinion and there were also favourable comments about the ease of driving the model with the Monocontrol semi-automatic transmission. Fuel consumption was good and the Reliance put up a reasonable performance on acceleration and braking tests.

The two Bedford p.s.v. chassis tested earlier this year were checked simultaneously. There was a full road test of the VAL but complete figures were not obtained with the YAM because the only change in the chassis since the previous test of this model was in respect of the engine, and braking performance would not have differed. Both coaches handled well and gave respectable acceleration performance.

Wheel locking on the brake tests of the VAL resulted in extended stopping distances but generally the two chassis were considered to be well designed for touringcoach duties apart from a high level of engine noise reaching the driver.

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Organisations: Earls Court
People: Maxi

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