Four-wheel-drive Shows its A
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rantages in War Office Trials
STORMY clouds clothed the mountains of North Wales for the commencement of the War Office Trials on Tuesday last, but the prospect of bad weather did not deter an exceptionally large number of spectators from attending. The event, naturally enough, has aroused unusual interest this year
As on previous occasions, these "trials of various types of mechanical transport vehicles "—the official designation —were scheduled to be held on the three notorious hills— Old Horseshoe Pass, Alt-y-Bady (both near Llangollen) and BwIch-y-Groes, between Dinas Mawddwy and Bala, but the last-named hill was deleted from the programme on Tuesday evening, a further cross-country event being substituted.
Some 21 machines comprised the entry, ranging from small armoured cars, for quick travel under cross-country conditions, to large six-wheelers and tractors with gun trailers on tow.
An idea of the severity of the tests may be formed from the following data applying to the two hills. The, Old Horseshoe Pass climbs with an average gradient of 1 in 7.65 for 1.01 miles, and at its steepest part has a slope of 1 in 4.87.
Considerably steeper, Alt-y-Bady has a maximum gradient of 1 in 3.38, whilst for its length of 0.80 mite the average rate of ascent is 1 in 6.139.
The first of these two was tackled on Tuesday morning. Rain was threatening as the first machine, an Alvis armoured car, appeared, but the reed afforded a fairly good grip to the tyres, and no marked difficulty was caused on account of its wet condition.
This Mvis, described as a Dingo model, made the fastest climb, and was followed by a Guy Ant medium-weight armoured car. Both these machines, and, indeed, all the vehicles in the trials, with the exception of two, had fourwheel-drive,
This may be regarded as a feature of the 1938 trials, and the advantage of the system was, of course, most marked in the cross-country tests, of which a description follows later,
Under the classification four-wheel-drive, we include, of course, the six-wheelers, all three of which drive through both second and third axles.
The third machine to make the ascent was a most interesting light armoured car—a B.S.A.-Daimler. This not only drives, but also steers through all four wheels; moreover, it has independent suspension, front and rear, the mechanism including transverse radius arms and helical springs. It made a fast climb, accelerating quickly from the stop-and-restart test to which all, except the tractors with guns in tow, were subjected.
Then followed two Steyrs, one with a Morris engine and the other with an air-cooled unit. Both engines are situated at the rear, the latter, apparently, being encased in cowling.
A Morris-Commercial Quad completed the armoured car contingent and made a notably good climb, being the only medium-weight to change up after restarting.
As sole representative of the 8-cwt. class, came a Ford m.H., with Marmon-Herrington four-wheel-drive. It was an extremely smart vehicle, with short covered lorry body. It romped up the gradient. The only oil-engined machine in the Trials arrived next— a Morris-Commercial 15-cwt. general-service truck, one of the two single-axle vehicles. It performed excellently.
A high-built Fordson M.H, 30-cwt. lorry followed. Except for the live front axle and big clearance it had an orthodox appearance, and its performance we classed as good.
The other exception. in respect of four-wheel-drive, was a Bedford W.H.G. model, of similar capacity to the vehicle which preceded it. Its ascent from the stop to the summit was marred by an unsuccessful attempt to change up.
Then came three six-wheelers, described as 3-tonnersan Albion, a Thornycroft and a Karrier CK6. All had large tilt bodies and made slow, steady climbs.
A group of four-wheel-drive, four-wheeled 3-tonners came next: First, a Crossley, looking rather unstandard with independent suspension, front and rear; second, a Karrier Spider, with rigid live axles, and perhaps a little faster: and third, an Albion which we judged to perform almost equally to the Karrier. The third of the three carried a box of ballast behind the cab as it had no proper body.
To complete this hill-climb test were three tractors towing gun trailers—a Guy Quad Ant, a Morris-Commercial Q with independent suspension, and a machine of the same make with normal suspension. All made faultless climbs.
Last year the cross-country trial was., perhaps, the least interesting of the event. This year we found it the most interesting.
Naturally, the most mobile machines over the rather sodden, extremely rough, and, in places, very steep heather and grass-covered country, were the light armoured cars--the Alvis Dingo and the B.S.A.-Dairnler. They performed in a really remarkable manner, finding practically no obstacle insuperable After these, among outstanding performances, may be named those of the Ford, the Morris-Commercial oiler, the Fordson and the three gun tractors, which raced about the moor with their guns in tow.
All three six-wheelers 'were put to an extremely difficult test, the crossing, uphill, of a track between banks, with a ditch behind the farther bank. They all failed, showing the type to be inferior for that particular operation, to the comparable four wheelers having four-wheel-drive. Of these the Karrier Spider and the Albion succeeded, but on a later section, the latter. in negotiating at speed a steep step rip, broke a front-axle casing and retired.
In the afternoon, Alt-y-I3ady was climbed. It caused only one failure, the last machine on the entry list, which was geared rather too high, needing help from the Scammell winch tractor stationed above the worst section. It accom • plished the remainder of the ascent, however, under its own power. The Alvis came up almost as though the hill did not exist, and the B.S.A.-Daimler was little slower. The Morris-Commercial and the Guy, heavier machines, climbed excellently, but not so fast. • The two Stevrs showed themselves to he good stayers.
Sum ascents were made by the Morris-Commercial oiler, the Fordson and the Bedford, and neither of the singledriven-axle machines in this group appeared to suffer from wheelspin except, in the case of the Bedford, on a slippery patch early in the climb.
Impressive ascents were made by the three six-wheelers. The Albion changed up when barely clear of the section of maximum severity. The wheels of the Thornycroft and the Karrier showed a slight tendency to slip on the now well-churned-up wet surface.
Spinning wheels did not spoil excellent ascents by the Guy and Morris-Commercial, independently sprung gun tractors., A further eye-witness report on these trials will be given in our next issue.