Around Sheffield with
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SIXWHEELER
A Day's Trial of the Shefflex DL6 4-5-tonner. A Solidly. Built Six-wheeler with a Trailing Axle. Fuel Economy at Consistent and Fair Speed
LAST year two trailing-axle, rigid six-wheelers were added to the range of vehicles made by Shelllex Motors, Ltd., Tinsley, Sheffield. Each was a development of a well-tried four:wheeler of con.ventional design. We recently took the opportunity for subjecting to our standard one-day road test an example of the DL6, which is rated as of 4-5-ton pay-load capacity and sells in chassis form for £590.
This vehicle has a Dorman fourcylindered engine and drives through a cone clutch to a separately mounted four-speed gearbox. Power is taken to the centre axle, the third one being of the trailing type, but, of course, provided with internal-expanding brakes. Each axle, of the bogie has its' own qemielliptic springs, and each longi tudinal pair is coupled by a short balance beam.
The chassis handed over, to us carried a lorry body by .1, W. Flear, Ltd., of Burton Road, Sheffield. The cab was the full width of the vehicle and the seat squab could be removed and placed in a horizontal position on brackets,thus making it into a sleeping bunk ; the squab and cushion provided two .6-ft, berths, to enable the driver and mate to take their rest in the periods now prescribed by the Road Traffic Act.
In the body were five steel billets making a dead load of 4 tons 14 cwt. The addition of sundry tools, personnel, etc., brought the dead and live-load total to 4 tons 18 cwt. 1 qr., So that the vehicle, as tested, was fully laden, but the figure did not exceed the maker's recommendations.
Since the introduction of this Model, the wheelbase of the bogie has been reduced, and on the machine we tried it was 3 ft.
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4f ins. when: laden,the distance between the peripheries. of the tyre . treads being 3 ins. • Aspeedometer . was provided on thevehicle for our test." This was the only item of non
standard equipment. • . •
Aninteresting point in connection with the Sheffiex designis • that when it is propoSed to use the vehicle On rough surfaces the pun
chaser can specify sprockets on the hubs of the bogie )wheels, and roller chains can be employed to coutfle the wheels, thus giving a four-point drive.
In connection with the figures in the succeeding paragraphs, it should be borne in mind that the vehicle was brand new and had covered only about 15 miles prior to
our test. The speedometer was found to have a mean error of 5 per cent., and this has been eorrected in the readings which we quote. It should. be noted that with a somewhat lighter body than was specified by the purchaser of the vehicle we tested, the unladen weight would be below 3 tons, thus bringing it into a
class which is annually taxed at £.32. At the start of the trial the fuel tank was filled, with a measured quantity of commercial spirit, and the first portipn of the run was employed to give consumption rates. The carburetter setting maintained throughout the day was . 110 main jet, 100 compensating jet and 23 choke in the Zenith ii A Z-type instrument.
Leaving Tinsley and' travelling towards Worksop, the route was hilly for most of the way, and it was necessary to make considetable use of the lower gears. The fuelconsumption return averaged one gallon for 7.91 miles. Amplified. details will be found in the accompanying panel.
At the conclusion of this specific test, level roads were reached, and the braking and acceleration were tried. It WAS found that the hand brake, operating on the two driving wheels, was the more powerful of the two sets. From 21 m.p.h., the foot brake gave a stopping distance of 103 ft;, whereas,:.under the same conditions and using the hand brake as well, the' distance was reduced tó64 ft.' It is probable that the stopping distances wOuld be improved after greater service, when the facings had bedded down. In subsequent models larger brakes are to be employed and the drums till be 143 ins. diameter instead of 14 ins., and all 'shoes of 2.; width. In place of the straight balance beam, a Y-shaped member will be+mployed on each side. This should tend to-.give less interference
m.p.h. on third gear, whila the speed range on top gear was 7.4 m.p.h. to 35 m.p.h. The acceleration figures are given in the form of a graph.
It was found that second gear sufficed for gradients of about 1 in
8, and first gear gave ample power on steeper hills. Despite the stiffness of the new. engine the water temperature was 190 degrees F. after a quarter-of-a-mile climb on second and third gears. The air temperature was 49 degrees F. When running on the level the average water temperature was 150 degrees, which is sufficiently low to ensure an adequate cooling margin, but, at the same time, high enough to assist in the maintenance of a good average fuel-consumption rate.
All the controls were easily operated and the ignition lever demanded only infrequent attention. The gear change was easy, whilst the steering wheel called for slight movement as the box was a high
geared one; owing to the C ompa ratively small weight on the front wheels this did not prove to be unpleasant on the road.
S u m marizing our impressions of the Shetnex DLO, in the light of the circumstances under which it was tested, we found that the fuel-consumption rate was up to expectations for a vehicle of the gross weight in question, and the general handling was good. Acceleration was satisfactory and would improve with further running-in: Suspension was of a high order of efficiency and the results obtained from the new braking system should be fully in accordance with modern requirements.
As regards the questionof accessibility the _ maker has given considerable thought to this vital matter. The engine, for example, is carried upon two angle-section members and held to them bz four bolts. 'When the last-named have been removed and the detachable front member has been taken away the engine can be slid out forwards.
The gearbox is suspended from two cross-members of the frame; removal of the holding bolts and disconnecting of the transmission-shaft Line at bothends enables the complete box • to be lowered to the ground. Another point which illustrates this topic is the conveniently placed brake-adjusting turnbuckle.