Good Performance by the
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BEDFORD-CARRIMORE 7-8-TONNER
FOLLOWING our recent road test of the new Bedford 3-tonner, the results of which were published in our issue dated August 3, we have now had an opportunity of testing the short-wheelbase edition of this model, used in conjunction with the new Carrimore 7-8-ton semitrailer attachment specially designed for use with this chassis. In this report it is unnecessary to dwell at any length upon the details of the tractor unit, these having been fully described in our previous road test. Particulars of the chassis will, however, be found in the specification panel accompanying this article.
The new Carrimore semi-trailer is of lightweight cdnstruction, and is designed to carry a pay-load of 7-8 tons. The model tested carried a drop-sided body 19 ft. in length and 6 ft. 6 ins. wide. The sides are 18 ins. deep and are in halves, giving easy access to any portion of the load.
The main frame members are of 5-in. by 21-in, channel section, well trussed and strengthened by no fewer than seven cross-members. The bottom half of the turntable is free to rock to a restricted extent, and the pull is taken on a hardened steel cone, into which fits the cone-type bolster block, which is locked into position by a fork controlled by a lever situated on the mounting.
A neat and effective method of anchoring the springs to the axle is employed, in that the spring pad— which is hydraulically pressed on to the axle case—has upon it a transverse groove, into which fits a spring strap. This, in turn, is bolted to the top anchor-plate.
Braking Features.
Brakes of 16 ins, diameter are fitted to both of the rear wheels and are applied through the medium of a Dewandre servo by the pedal on the tractor unit. A separate ratchet-type hand lever also applies the trailer brakes through the medium of cables.
A further feature of interest relating to the trailer brakes is that the brake cross-shaft is carried on extensions of the spring brackets, so that the brake rods pivot on the centre line of the spring pins and unequal operation due to spring flexing is thus eliminated.
As a matter of interest, and in order to gain a fair comparison as to the performance of the Bedford when dealing with a load of eight tons as contrasted with a load of three tons, we subjected the outfit" to our usual tests over a similar route and over the same observed hills as in our previous trial. It was amply proved that this Bedford chassis has sufficient power and an adequate performance to deal successfully with the
greatly increased load. It is, perhaps, interesting to note, in passing, that, as from October 1, the speed limit for this class of vehicle has been increased from 10 m.p.h. to 20 m.p.h.
Starting from the Carrimore concern's works in North Finchley, we proceeded to the Barnet By-pass by way of Barnet Village, and we were agreeably surprised to find that the ascent into Barnet Village was taken —despite traffic checks—in second gear with a minimum speed of 10 m.p.h.
Good Acceleration.
Acceleration tests proved that a lively performance was to be expected and the acceleration on top gear from 10 m.p.h. gave promise of excellent results on further tests. That this promise was amply fulfilled is illustrated by an accompanying graph, in which is shown the acceleration from 5 m.p.h. in third gear, from rest through all the gears, and from 10 m.p.h. on 'top gear.
The brakes proved to be adequate for all needs, and the only criticism we offer would be to reiterate that made in our previous test, when it was suggested that the degree of lightness of operation had, perhaps. been exceeded, from the point. of view of controllability.
Proceeding to our usual North London test hills, the approach to 13rockley Hill was taken in second gear with plenty of power in hand, andthe speed .at the commencement of the 1-in-8i section was 10 m.p.h. A -change to first gear was necessitated shortly after this point, and the remainder of the hill was negotiated in this gear, the minimum speed being 4 m.p.h., rising to 7 m.p.h. before the summit was reached. Without over-" revving" the engine on the low. bottom gear, the time taken over the section from
the commencement of the steep section to the water trough marking the summit of the hill was 2 mins. 40 secs. With an air temperature of 62 degrees F., the temperature of the cooling water at the end of the climb was 186 degrees F.
The climb into Elstree Village was accomplished in first gear and the sharp right-hand turn in the centre of the village was easily negotiated. On Cocks Hill stop-and-restart tests were made on agradient of 1 in 7.
Clutch Characteristics.
Careful manipulation of the clutch was necessary to obtain a smooth restart on this gradient, and whilst the vehicle would get away safely each time, a certain amount of buck-jumping was noticeable if the clutch was not engaged with great care. The outfit could be easily held on the steepest part of the gradient on the foot brake or on the tractor hand and trailer brakes. The tractor hand brake alone was, however, insufficient to prevent the vehicle creeping backwards.
Consumption tests were taken on an out-ancl-return route of 25 miles from the Carrimore works through Barnet and Hatfield, returning to the starting point, via the Barnet Bypass. The journey took 73 minutes, giving an average speed of 20.5 m.p.h. and a consumption figure equivalent to 9.1 m.p.g. The standard carburetter settings were used.
From the point of view of the driver, the controls come well to hand. The driving position is comfortable-and a word of praise is due to the excellent steering, which is light and positive. The ratchet-type trailer hand brake is well positioned and is particularly useful for checking the vehicle down hills.
At the price of £472 10s., this Bedford-Carrimore outfit represents excellent value, and with its good performance, which should make for economy of operation, it should appeal strongly to hauliers requiring a vehicle that will carry a heavy load at a minimum of cost.