The War Department's Competition.
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Thornycroft Wins the £750 Prize.
Conclusion of the Tests at Aldershot; Particulars of the Tests in the Long Valley; Complete Tables of Consumptions and Road Performances ; the Successlut Machine Bought.
Monday last, at Aldershot, witillustrations on page 27, proved itself nessed the concluding scene of the capable of unlooked-for effectiveness
War Departn.ent's :cog trials for tractors, and it was then decided, at a meeting of the Mechanical Transport Committee, which took place in the depot of the Army Service Corps, to award one prize only, and that to John I. Thornycroft and Company, Limited, of Chiswick and Basingstoke. The cash prize of L;75o therefore goes to this well-known company, and we congratulate its directors upon the result. The M.T.C. has bought the tractor at L975.
This successful tractor (No. 4) cannot, of coarse, be regarded as an experimental machine, because the cornpany has already turned out a number of paraffin-cnginvd tractors, both for the War Department and for export. " No. 4 " in the trials, which was fully described and illustrated in our issue of the 25th ultimo, embodied in its design a number of proved features of the T horn ycro f t practice, the principal departures being in respect of the arrangement of the differential locking gear, the rear spring suspension, and the disposition of the winding drum. The lastnamed equipment worked smoothly and with the maximum of convenience in operation.
The Broom and Wade tractor (No. to), as %ill be gathered from the top when it came to winding the eight ton load through the hog at Clayeart Bottom, although a snatch-block had to be used_ The work done by its single 8;-inch cylinder certainly at
tracted the favourable notice of not a few important officers who attended the trials, including MajorGeneral Heath, Chairman of the Mechanical Transport Committee and Director of Transport and Remounts in the War Department. His initial favourable impression was certainly confirmed by the performance of the tractor, although everybody agreed, having regard to the conditions of running, that it was overloaded with as much as eight tons behind it, and this fact is borne out by the low speeds which it made. We should regard this tractor as much better suited to loads not exceeding five tons gross, with which it should be able to move at a much better average speed and to use its higher gears. The Stewart tractor (No. 3), which was the one steamer in the tests, was at a great disadvantage in comparison with either of the two internal-combustion motors. The designers had been hard pushed to get the unladen weight down to six tons, and they were even more awkwardly placed— seeing that they failed— when it came to the carryingof sufficient fuel and water to run too miles without exceeding the condition of the competition which required the running weight to be a maximum of seven tons. As we duly pointed out in that portion of our report which was published on the 4th instant, it was only possible to put So gallons of water into the tanks, which had a capacity of 280 gallons, and 4cwt. of coal into the bunkers, which had a capacity of i3cwt., before the limit in question was reached. Another handicap to this machine was the close stroping of its driving wheels, which consequently failed to get a grip on many occasions, and added thereby to the fuel and water consumptions, in consequence of the long delays which were involved, -during which occurrences steam was repeatedly Iost., at the safety valve. For use in counr tries where legal restrictions do not exist, this type of machine, one of which is illustrated on page 38, should have many successful applications; the allowance of, say, an extra ton to the manufacturers would make all the difference between artificial difficulties and that freedom in design which ensures success.
Before giving a brief account of the proceedings on Wednesday of last week, we have to complete our report for the preceding day. The hill-climb from the Red Lion public-house, round the Devil's Punchbowl, to Hindhead, has a total rise of 530 feet in 5,280 yards, and was, as these mea
surements show, a comparatively easy gradient, • though a long one. The times for the ascent were : Stewart, 37 min. 34 sec. ; Thornyeroft, 69 min. 46sec. ; Broom and Wade, 118 min. 17sec.
The Final Road Trip.
Wednesday, the loth instant, was Set apart for the last of the road trips, and on this occasion, owing to the inclusion of the special hill-climb up, to the Hog's Back at Puttenham Corner, the total mileage for the day was only 17:. The selected length of this hill, the profile for which was published by us three weeks ago, has a total rise of 16a feet in 2,000 feet, with a maximum gradient of x in 7.5. The surface had recently been remetalled with a considerable proportion of binding, and the whole was in what may well be termed a " floating" condition, the passage of any mechanical transport causing a " wave " to assert itself in front of the driving wheels, and thereby
greatly to add to the power required for self-propulsion and hauling.
The Thornycroft unquestionably made the best performance, and left practically no marks on the road, its total time being 26 min. 24"; sec.
The Brcxml and Wade tractor got nearly half-way up the hill, in short spurts of about five to ten yards, the driver declutching, racing his engine, and then engaging the clutch again to make use of the energy stored in the flywheel. This method of progression naturally caused some damage to the road surface in places, and on the second half of the hill the windingdram had to be used ; during this latter operation, the tractor jumped its scotches, but no damage was done, although the incident at one time looked as though it would lead to the machine's overturning. The Stewart tractor had to wait for a very considerable period at the foot of the hill, and, when it got abont half-way up, the water in the tanks was found to be too hot for the injector to lift it. The War Department's attendant traction engine (one .of John Fowler's " Lion " type), backed down the hill, under ideal control, and furnished a supply of cold water. After this, the winding-drum +'as used for the rest of the ascent.
After each of the machines reached the top of the hill, it was submitted to brake teAs down the gradient of in 7.5, when estimated, to be travelling at a Speed of about five miles an hour, and all demonstrated their ability to pull up in six or seven feet. Speed trials were also made, over two consecutive miles, in the course of the run back to camp, on the Hog's Back. The results were as under : Stewart.--First mile, 8 min. 45} sec., second mile, 7 min. 49 sec. Thornycroft.—First mile, 6 min. 25 sec., second mile 5 min. 35 sec.
Broom and Wade.—First mile, 22min. 7 sec., second mile, 14 min.
43 sec. In the official nofes for the day, it is stated : " Great delay is always caused when the Stewart tractor de sires to use the winding-drum. The clutch of this drum is inaccessible and difficult to move. Generally, on the road, clouds of steam are emitted from the water tanks of this tractor. The water in the tanks becomes heated very quickly, to such an extent that the injector cannot deal with it.
Long Valley Trials.
We cannot do better than quote the official report on these, as the text should form an ample report in conjunction with our illustrations :— " The crews of the Broom and
Wade and the Stewart tractors, owing to these vehicles' being so long on the road, were worn out, and in consequence it was very difficult to enforce punctuality on their part. Neither of these vehicles was ready for the Long Valley until nearly two
hours after the official starting time. The Thornycroft tractor negotiated the three valleys without any trouble. In the 2nd and 3rd valleys, the wagon was hauled by the tractor to the bottom of the valley, the winding drum being used to haul it up the farther slopes. Very excellent tune was recorded. The other two tractors left their wagons at the commencement of the second valley, and used the winding drum for the whole of the crossing. The Stewart tractor had some difficulty, as the wagon ran away on the down slope. As regards the turn
ing circle, the Thornycroft tractor could not get round in as short a space as the other two tractors, owing to its long wheel base.
" As regards the bog, the performance of the Thornycroft in this was most remarkable. The vehicle Ira
versed the bog easily without its load. The winding drum was then used to haul the wagon across. When the wagon had been hauled about threequarters, of the way across, there appeared to be some difficulty in continuing to wind. A purchase was put on, and the wagon hauled a further distance. It was then found that the pressure of the rppe on the winding drum had been so great that the casting had split in the boss, the winding-drum shields running out of truth and fouling the frame. The Broom and Wade tractor negotiated the bog, without load, successfully, and at once arranged a purchase on the winding drum to haul the wagon across, but the winding-drum cable was not long enough to haul the wagon across the bog when used in this manner through a snatch block. The Broom and Wade, therefore, borrowed from the repair train a long length of wire rope, with the aid of which a purchase was rigged up, and the wagon successfully hauled through the bog. The Thornycroft wagon was hauled back to the road by the
Lion ' engine.
"The Thornycroft performance was much the finer of the two, the wagon being practically hauled across the bog with the vehicle's own winding drum, whereas the Broom and Wade tractor made use of material and tools which it did not carry.
'The Stewart tractor became bogged before it got half-way across the bog without its wagon. An attempt was made to extricate it by means of its own winding drum, the rope being attached to some trees. In order to get the rope from the winding drum in a forward position, it was necessary to take it at right angles round a very small roller, and at right angles again round a small fairlead pulley. The friction in both cases must have been very great, and the rope broke. Another attempt was Made with the aid of an additional rope and a snatch block, but the tractor rope again broke. The vehicle was hauled out by the Lion ' engine.
"Generally, the behaviour both of the Broom and Wade and the Thorny-croft tractors on the Long Valley and in the bog was exceptionally good. The Thornycroft appears to possess a large reserve of power. The second valley was accomplished without any apparent effort in remarkably short time, and the bog was negotiated rapidly and satisfactorily."
Repairs, Replacements and Adjustments.
Further to the details published last week, which took us to the close of the sixth trip (the 8th instant), we now quote from the official records in the depett as regards later happenings :— " gth March.—Stewart (No. 3), adjusted differential locking gear—repaired fan spring—pump covcrjoint remade—cleaned engine camshaft ; Thorny-croft (No. 4), inlet valve tappet-rocker broken, and valve converted to automatic with borrowed spring—difficulty in starting engine after long run down hill, probably due to flooding. the engine having been stopped for restive horse; Broom and Wade (No. to), clutch-lever spring re
placed—petroleum feed-pipe ;deaned, " moth March.—Stewart (No. 3), adjusted flexible fan-drive—tank gauge_ glassbroken—donkey-pump joint made twice—water in tank became too hot for injector, and cold water was taken from attendant engine ; Thornycroft (No. 4), jet of vaporiser cleaned before start; Broom and Wade (No. to), new link in driving chain.
Notes on Examination.
The official notes are " Stewart (No. 3), many bearings scored—lubricant gritty through want of proper protection—balls, of driving-worm thrust race badly scored and chipped —pump worm-drive worn—sun wheel of epicyclic change-speed gear badly worn—main driving-worm wheel worn—winding-drum rope was found tight on drum, and broken in several places—spring drive on road wheels fouling top cap of axle spring clipswinding-rope fair-leads (after pair) had scored—winding-rope fair-leads (forward pair) had spindle bent—oil separator gauge glass broken ; Thornycroft (No. 4), exhaust valves slightly gritted on seat—piston heads slightly carbonised — igniter tappet ends slightly burnt—helical-gear driving wheel worn in places (wheel and pinion not properly fitted)—first-speed pinion teeth very slightly worn--wind. ing-drunt boss cracked—bottom roller of winding-rope fair-leads (after pair) badly scored ; Broom and Wade (No. to), magneto timing-wheel worn— valve cams worn—half-compression cam badly wcrn—slight carbon deposit on piston—winding-rope fairleads (after pair) bent—nuts, bolts, etc., generally shaken loose—driving pinion and road spur-wheel worn."
The committee is agreed that the machine presented by John I. Thornycroft and Company, Limited, is a great advance on anything previously offered for long-distance road haulage work for military purposes.