The A.C. Side-Slip Prevention Trials : Part II.
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On Tuesday morning, nature and London's traffic had provided a considerable ampule of greasy mud on the streets of the Metropolis. This, however, was a small thing compared with the surface covering of clay and soft soap which had been laid on part at the test track at the Clement-Talbot Works, at Barlby Road, West Kensington, for the purpose of testing, in a practieal, if artificial, manner, the efficacy of the devices which remain in the
A.C.G.B.I, trials. Operations commenced, on the prepared track, shortly .ttfter so a.m., and a goodly number of interested spectators had assembled. The visitors included several ladies, whose interest, it may be presumed, was stimulated by anticipations of gyretory displays by the motorbuses engaged in the tests.
Amongst the judges officiating were Earl Russell, Dr. H. S. Hole-Shaw, F.R.S., Colonel R. E. B. Crompton, CB., Mr. Dugald Clerk, and Mr. Douglas Mackenzie. Mr. Julian W. Orde, the Secretary of the Club, acted as starter. Three" Union Jack," StrakerSquire buses had been lent by the London Road Car Company, Limited, and a Milnes-Daimler "Vanguard," from No. 6 service, represented the London Motor Omnibus Company, Limited. A single-deck Arrol-Johnston vehicle, and a Straker-Squire with a similar body, completed the number of omnibuses which were used to demonstrate the working qualities of the tires, -or attachments. The programme for the tests was as follows :— Event T.—A straight run down the track : at a given point, the driver was IT Nuked to apply the brakes hard. Event 2.—Passing another bus. Observers were stationed at the widest part of the track : each vehicle was sent down, and, at that point, which was indicated by a flag man, the driver had to turn, sharply, to the left, and, after going a few feet to the left, to turn, sharply, to the right. The observers took careful note of the angles made by the vehicle during these manceuvres, and the brakes were not applied.
Event 3.—The conditions for this test were the same as those for test 2, with the exception that the driver was required to apply the brakes the moment he made the second turn.
Each device was tested at least twice in each event, and the vehicles were driven at an average speed of about 12 miles an hour.
The following are the official numbers of the 6 devices which competed :—
No. 2. Messrs. \V. Sully and P. H. Shailer's loose metal ring.
No. 8. Mr. George B. Winter's floating metal ring.
No. 22. Mr. II. B. Molesworth's sixwheeled device.
No. 31. J. Liversidge and Son, Limited : " K.T." tire with rubber studs.
No. 32. The Hartridge Tire Syndicate, Limited rubber block tire.
No. 34. The Westminster Industrial and Finance Developments, Limited : tire of leather and rubber rings.
After much " flag-wagging," the first vehicle to make its appearance round the corner of the building, and to approach the 40-yard length of prepared track, was the " Vanguard " bus, on the rear wheels of which were fitted the floating metal rings of Mr. Geo. B. Winter (entry No. 8) : the result of the jamming down of the brakes was that the side-slip developed brought the bus very close to the adjacent walls. The next to appear was a single-deck Straker-Squire motorbus, on which had been fitted Mr. H. B. Molesworth's supplementary wheel device, in which three axles, and six wheels, are em ployed. Behind the driving wheels, two more, as auxiliaries, are steered in sympathy with the front ones, and carry a certain portion of the weight of the vehicle through stout, inverted, laminated springs, which extend to the driving axle. On its first, and two subsequent trials, across the track, sufficient speed could not be developed by the bus.
The third contestant was the bus fitted with " K.T." tires on all four wheels, those in front having a single row of rubber studs, and the rear wheels a double row. Its first attempt resulted in its slipping, to a considerable angle, across the track.
At this point, a touring car was run along the track, at 12 miles per hour, to demonstrate to the onlookers the speed at which the buses were required to travel.
On one of the " Union Jack " buses, the next to appear, Hartridge tires had been fitted Lo all four wheels, and this vehicle showed an amount of slip about 50 per cent, less than those which had previously essayed to keep straight.
The next to follow was the bus fitted with the loose metal ring of Messrs. W. Sully and P. H. Sheller, and, in this case, also, the deviation front the straight line was not very considerable. Most of the buses, it should be noted, ran light.
After this, Mr. Molesworth's sixwheeler was tried in the opposite direction on the track, in order that a greater speed might be acquired by the vehicle on the gradient at the other side of the building. As the corner to be negotiated, when the bus approached in this direction, was considerably easier than in the other, it was decided to change the direction for all the vehicles, and, after a short interval, to hose the sand away from the untreated portion of the track, and to put down a further sepply of prepared loud, another start was made. Num
her 2 device, in its next trial, showed signs of wishing to lie at right-angles to its proper path. The " K.T." tires, run over the track, again, exhibiteu, or.ce more, a considerable amount of slip, and another trial of No. 2, which followed, resulted in the bus getting its rear-end well round to the position desired for the steering wheels. In two successive trials of entry No. 8, the bus kept a straight line very well; No. 32 (the Hartridge tire), on its next run, stopped, in about to yards, without a great degree of slip, and this bus was run again, more quickly, with excellent results. The reappearance :A the six-wheeled bus was marked by want of speed, but no apparent slip, and this was followed by the Hartridge tires, once more, the bus being, on this occasion, driven by Mr. D. H. Duff, at a good speed, and the amount of slip being about the same as in previous trials. The bus with Mr. Winter's apparatus, on making another run, had, as a passenger, a fair lady, who bravely took an inside seat. Unfortunately for her nerves, the vehicle bumped up against the solid brick wall, which proved itself, as usual, to be one of the most efficient non-slipping devices extant. Entry No. 22, on its next run over the course, showed a slight amount of slip, but, promptly, righted itself. Previous to their next attempt, the Hartridge tires got into a hole, when trying to start at the top of the hill, and, coming down at a slower speed, bumped into the kerb, making the worst slip shown, so far, by them. This completed Event i of the trial, for those devices which had, already, been fitted to vehicles, and the second part was immediately commenced. In this, the course was arranged as shown in the accompanying diagram, and the flags (A) were meant to represent an omnibus, those at B, a street refuge, and those at C, a hansom cab, or other vehicle. It will be noted that the "` sharp turns," to the left and to the right, provided for in the programme, were somewhat overstated, but, nevertheless, considerable difficulty was experienced by the vehicles in performing the double movement. Entry No. 2, the first to try, wiped the flags out, and got, nearly, at right-angles to the track ; the Milnes-Daimler, which followed, scored a bump on the refuge ;
and Mr. Molesworth's bus made a good attempt, knocking down, only, the last flag on the left. The bus with " tires, which followed, would probably have annihilated the refuge, and, most certainly, have crushed the hensom cab. The Hartridge tires slipped somewhat, and the bus struck the pseudo refuge. A little later, the Arrol. Johnston bus, with the Westminster Finance and Development Company's tires, made its appearance, driven by Mr. II. P. G. Brakenridge : it went
Diagram of Events 2 and 3.
through, though somewhat slowly, knocking down one flag only. The tires of this company are composed of six rings of leather, and five of rubber, set, alternately, round the circumference of the wheels ; the leather rings
stand out, about a inch above the rubber ones, and are I inch wide, com pared with the inch width of the latter. They were secured to the Stevenson wheels, to wnich they were
fitted, by means of flanged rings, 4 inches wide, and about ;Iinch thick. In Event No. 3, the same evolutions had to be performed, with the additional condition that the brakes should be put on hard, immediately after making the second turn. No. 8 device got nearly straight across the track, utterly demolishing the hansom cab. Mr. Molesworth's device, which followed, was the first to get through without touching any of the obstacles, and, when the brakes were, subsequently, locked on the wheels, but a very slight degree of side-slip was noticeable. On a second attempt, it went through, again, splendidly, but the IIartridge-tired bus, which followed, slipped after the first turn. At 1.15 p.m., an adjournment was made, for an hour, for luncheon, after which the proceedings were resumed, when No. 34 entry, on the ArrolJohnston bus, went through the first event with very little deviation from the straight line. In the second event, six flags were knocked down, and, in the third, it showed a greater amount of side-slip, but stopped, well, when the brakes were put on.
The 6-wheeled vehicle, then, went through this event, with very satisfactory results, and an extra test was, afterwards, imposed upon it by the judges, in order to ascertain how the vehicle would behave on a cambered mad. The track, after the luncheon interval, owing, possibly, to a slight fall of rain, seemed to be somewhat worse than earlier in the day.
The behaviour of the various sideslip prevention devices goes to show that, perhaps, the most successful of all was Mr. Molesworth's, the theory of which is, that a sufficient number of wheels to support the vehicle should be maintained in true rolling contact with the road surface, without having transmitted to them either the driving efforts of the engine, or the retarding effect of the brakes. The 6-wheeled vehicle demonstrated, very clearly, its capability of running, in a practically straight line, over the appalling surface mud laid down for these trials.