W.D. VEHIC ES AT WAR
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with Welsh Test Hills
ALT-Y-BADY, Bwlch-y-Groes and the Old Horse Shoe Pass in North Wales, are notorious test hills, and their ascent is still regarded as something of an achievement by the private motorist.
As on past occasions, they were used by the War Department for its " trials of various types of mechanical tran,sport vehicles," held last Thursday and Friday, and served to show to what a high pitch of efficiency these machines have been brought. Out of 19 starters not one complete failure was recorded. It is true that fair weather gave favourable conditions, but at their best, these three hills form a most exacting trial for heavy vehicles.
These W.D. tests are comparative rather than competitive,, their objective being to ascertain,., _ether the v,ehicles have. the
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degree o -',.. ' ormance, .in their ‘:-thious ' classes, that would warrant their adoption as W.D. types. The machines are generally built to W.D. specification, but the use of standard parts and components is encouraged where possible, for obvious reasons. Of course, certain modifications are incorporated, and in last week's trials a number of experimental types was tried out. This point must not be overlooked in considering performances.
A representative• Of The Commercial Motor observed each ascent of every vehicle, and was thus able to form his own opinion of the performances.' The views ex pressed, however, and the statements made, in this connection, are not official, and we have been asked to refrain from publishing the actual War Office result
figures.
The impressions we record are largely based on stopwatch timings taken over short dis
tances, but • they should be f a:i r-l-y :accurately .representative -01 'the performances.
On all three hills timed ascents were made. On the Horse Shoe Pass and Bwich-y-Groes, every vehicle, except those drawing trailers, was stopped and restarted at about the-steepest place. On the subsequent descent this operation was repeated, a start being made in reverse. Water temperatures were taken at the summits.
The first test was the ascent of the Old Horse Shoe Pass, which is 1.01 mile long, has an average gradient of 1 in 7.65 and a maximum slope of 1 in 9.87. Proceedings were started by two experimental four-wheel-drive cars. In class B (lorries carrying 1-ton loads) were a Fordson V-8 (81,2 b.h.p:) and a Bedford (64 b.h.p.). The former made a spectacular " get-away" from the restart, rearing up as the cluteh was engaged to such an extent that the near side front wheel lifted clear of the ground. The driver made a quick change into second gear and breasted the remainder of the hill at a speed little lower than that of the cars. The Bedford, quite unrecognizable as such, was much steadier at the restart and the driver refrained from changing up until the slope eased. It was, however, only a little slower.
In the 30-cwt.-load class were a standard-looking Dennis (four cylinders) and a Bedford of orthodox appearance (six cylinders), both having 64 b.h.p. engines. Considerably _slower than the machines in the lighter class, the Dennis climbed steadily, no attempt being made to change gear. Slightly faster, the Bedford reared up at the start and its driver also stuck to the initial ratio.
The 3-ton Petrol Four-wheelers.
Five vehicles comprised the 3-ton-load class—a Fordson (88.5 b.h.p.) with a 'bottom gear of 85 to 1; a MorrisCommercial (61.2 b.h.p.) having a smart, light-brown body with a dark brown tilt, looking very military; a Comnner I,Nri (80 b.h.p.), apparently a standard model ; a Bedford (64 b.h.p.) described as " special " but looking quite normal; and a Morris-Commercial (100 b.h.p.) of experimental design.
According to our timing, the high-powered Morris-Commercial was the fastest in this class, beefing the Commer by a few seconds. The others made satisfactory climbs, outstanding points being the roar of the high-revving Fordson engine (this machine was third fastest), a slight delay, due apparently to a sticking throttle on the other MorrisCommercial, and the steady ascent of the Bedford.
Next came an Albion 3-ton six-wheeler (62 b.h.p.), of new and considerably lighter design than earlier army models of this type and make. It climbed well with power in hand, about 20 per cent, slower than the slowest fourwheeler Four interesting searchlight lorries came up next. Each towed a trailer for sound-locator equipment. The lorries each carried 3k tons, whilst the trailer weighed (gross) 2 tons 4 cwt. The makes were Guy (56.4 b.h.p.), Dennis (96.8 b.h.p.), Thornycroft (59.8 b.h.p.) and T.S.M. (70.6 Two of the trailers were by Brockhouse and Dyson respectively. These outfits being for home defence, a lower standard of performance is accepted here.
Solving the Dynamo Problem.
There is an interesting point in connection with these machines. The engines drive dynamos and silence is of great importance. Direct coupling is, therefore, specified. The T.S.M. is petrol-electric, so the problem is already solved; of the others, alternative practices are to form the armature as part of the transmission shaft, and to mount it as a sleeve on the shaft. Experiments are still progressing. This is a good example of the intensii.-e work the War Office is doing in connection with mechanization.
By our observations, the Thornycroft was the fastest and the. T.S.M. the quietest.
After these a fast and impressive ascent was Made by a Fordson-Unipower, completely disguised, towing a gun trailer. The gross weight of the 18-pounder gun and limber was nearly 3 tons; the tractive unit carried nearly 1 ton.
Much interest was aroused by the two H.S.G. producergas lorries. "All lit up,': exclaimed a spectator, when the first hove into sight, the incandescent fire centre shining brightly through the tuyere. The first (61 b.h.p.) carried 2 tons and the second (80 b.h.p.) 3 tons. The latter was considerably the faster, and only about 15 per cent. slower B14 than the slowest petrol 3-tonner. It is of note that the smaller gas vehicle was tested the previous day on petrol and climbed successfully, but not so fast. We understand that the War Office is making further investigations of these machines. • There was only one case of cooling water boiling and all brakes and clutches were satisfactory.
After this hill some diversion was caused by a short crosscountry run, in which only a few of the vehicles participated. These careered over the heather with various degrees of difficulty and at various speeds. Little importance attaches to this, as the Welsh venue is chosen for its hills rather than its ground surface.
In the afternoon Alt-y-Bady was tackled. This is 0.89 mile long, has an average gradient of 1 in 6.69 and a steepest of 1 in 3.38.In this test the vehicles with trailers did not participate, and the bigger H.S.G. was excluded on the score of width.
Taxed Almost to the Limit..
Severe as is the gradient, only one machine stopped, and it restarted, but several made heavy going of it and appeared to be just about at their limit. In our opinion, the hest climb was that of the Commer. Other outstanding ascents were made by Bedfords, Dennis, Fordson and Morris-Commercial makes. The Albion was slow, but gave the impression.. that it would climb the wall of a house. Its bottom gear is 107.4 to 1: The H.S.G. failed on the steepest' part. It momentarily misfired and stopped. Two possible explanations were put forward—that there was a shortage of gas and that the ignition was at fault. However, with negligible man-power assistance, it eventually restarted after several attempts, and completed the climb.
At the summit was anchored a Scammell six-wheel-drive machine with power winch and cable, but its services were not required.
On the Friday, all the machines repeated Thursday morning's test on the famous Bwkh-y-Groes. Length is the element of difficulty here. It rises at an average of 1 in 7.1 for 1.55 miles, with a maximum gradient of 1 in 4. From the overheating aspect, matters were not improved by a following wind. Nevertheless, there were only three cases of boiling.
'Iwo Fast Ascents.
Two machines were baulked and had second runs. One of these was the Commer, which made fastest time of the five 3-4onners. The other was the Bedford 30-cwt. machine; it was the faster of the two in this class. The small Dennis had a tappet Slack back on the first climb, but got up slowly and later made a second much faster ascent.
Outstanding performances were those of the Fordson 1 and 3-tormers, the Morris-Commercial 3-tonner, the Albion, slow but apparently effortless, the Thornycroft searchlight outfit and the bigger H.S.G., which was, we believe, the only machine to arrive at a point within sight of the stop-and-restart line in second gear. As before, the vehicles with trailers were not required to stop• and restart, but the big Dennis outfit experienced trouble from hot plug points arkd paused for a brief spell, thus being the only one in its class to make a restart on the hill.
The gradient proved too much for the Fordson-Unipower, and it was compelled to leave its gun halfway up. It completed the climb with the forward portion of the trailing unit.
On the descent, hot brake drums were common, only the Dennis 30-cwt.
vehicle coming through without criticism in this respect.
After the conclusion of the actual trials, Army and manufacturer conferred to discuss matters with a view to still further improvements in the design of W.D. vehicles, which, it was stated, represented a marked adance on that of the machines taking part in the trials of 12 months ago. By the courtesy of Major-General Davidson, our representative was admitted to the conference.