STEAM ROAD HAULAGE IN FRANCE.
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Comments on the Behaviour of Various Types of Steam Wagons Under Severe Conditions on the Western Front.
STEAM VEHICLES have been considerably used for road haulage throughout the war in France, and it is proposed to give a short account of their performances and how they stood the rough road conditions. Steam haulage in France may be roughly divided into two classes :—
(a) Heavy and light traction engines, used for gun hauling, ordnance workshops and forestry work. (b) Steam wagons, chiefly used for carting stores, for road repairs, ete. . With reference to Class A. These machines were comparatively few in number and, except for those employed on forestry work, were only used on road work occasionally when gunshifts were required, and consequently the crews had ample time for adjust, meats, etc., with the result that the boilers and mechanism were almost always in first-rate order.
Certain mechanical troubles were experienced with one Make of heavy, tractor, the cast-iron steering brackets bolted to the front water tank being liable to, fracture, and the atrakes on the road weeels were made of material soft enough to hammer out and spread on the rough pave roads of Northern France, causing fracture of speites. In facta.fo acute did this trouble become, that the supply of new road wheel., after 12 months in the field, was necessary in a few eases in order that the damaged wheels could be sent to a heavy base repair shop for rebuilding, this jobbeing too big to undertake in a field workshop.
The traction engines (chiefly light machines, five-ton compound type) employed on timber haulage were very hard worked and in some eases gave considerable trouble. In one make, the second motion shaft bracket was prone to failure, being of ca,st-iron, and too light for the rough bush roads. Spare parts were also very difficult to get. In another make, no provision was made for keeping dirt and grit out of the compensating centre bush on the road axle, this bush consequently wearing very rapidly, and causing excessive strains to be thrown on all gearing. Boiler troubles, in Class A engines, were, non-existent, an occasional leaking stud stay being the most serious item. .
Turning to Class B. These vehicles were far more numerous and were mainly of four makes and of fiveton capacity. Three makes had loco-type boilers with overtype engines, and one make was fitted with vertical water tube boilers and engines under the frame. Of those vehicles with overtype engines, many were taken from civilian employment at the outbreak of war and are still doing excellent work. However, by far the larger number were built for the War Department after the end of 1914; most of these were fitted with some form of unloading device, generally endtipping bodies worked either mechanically or by hand. A small number were fitted with a fixed body and a form of sliding bottom worked by hand. This proved not thoroughly satisfactory, as the hinges connecting the steel slats in the bottom readily broke and the gearing operating the roller for -drawing out the bottom was prone to failure. In fact, it is safe to say that in every case this type of unloading gear, was out of action within' a month of starting work in Points at which rrame frac Wagon due to exces France. Re-design of details would, no doubt, get over the troubles.
As regards the chassis of the' overtype vehicles, these proved themselves wonderfully reliable, but certain defects, probably due to road conditions, showed themselves. The chief trouble, mostlywith one particular make, was the fracture of either the right, left, or both side members of the frame, generally at the front bolt holding the radius rod bracket to the lower flange of the channel section, or sometimes at the bolt through the top flange, holding the driver's cab in position. In the writer's opinion, these fractures were caused by a certain "hogging anct sagging" such as occurs in a ship's hull, an unbalanced moment being set up causing the frame to fracture at the weakest point. This liability to fracture was accentuated by the loads not being evenly distributed. The accompanying sketch illustrates points of fracture.
The method adopted, with .great success, for re pairing the broken frames, was to fit into the web of the channel and bearinghard on the top and bottom flauges, a flat patch of 6 in. by in. or in. mild steel, 5 ft. 6 ins, king, chamfered on the top and bottom inside edges to suit the fillet, and held in place by bolts through such existing rivet holes in the web as came in and by I in. limits, the holes being. drilled along the centre
tare occurred on a steam line of the web where steely bad roads. existing rivet holes did not
One maker strongly reinforces his frames for a-ft. each side of the radius rod brackets by means of a heavy special section of angle steel, and no frame troubles have been experienced with this make.
Front springs on the overtype vehicle gave consider able trouble, as did the attachment of the swivel jaw retaining plate to the bridge under the smokebox, and also the attachment of the bridge to the smokebox. The rivets constantly, worked loose, and the .only remedy.was to cut out the rivets, reamer out the holes and put in fitted bolts.
The loco type boilers developed few troubles. Cer tain slight leakages where the horn plates, carrying the crankshaft, spring from the boiler,' and leakages at steering brackets, and from the vertical seams in the firebox, generally between fourth and fifth rivets up from the foanda,tion ring, were the most frequent, and were easily cured by judicious use of the caulking tool.
The undertype vehicles, which were -fitted with
mechanically-operated end-tipping bc&es, 'did not prove a great success for work near the line, and could have been better employed at the base ports where roads are hard and suitable fuel is obtainable. Constant traffic through the, stone sidings cut up the roads badly, and this type of vehicle, when not loaded, has considerable weight on the front wheels, the water tank being fitted behind the driver's cab. The front wheels would sink a few inches in the soft ground, and the adhesion of the rear driving wheels was often not sufficient to move the vehicle out of the mire, with the resuIt that towing had to he .resorted to. The boilers are designed for coke fuel or, at any rate; the best quality of Coal. These were usually unobtainable up near the line, the fuel generally. supplied being a mixture of small coal, coal dust and dirt. The result was inefficient steaming in two cases, collapse of the top TOWS of tubes and tube plates occurred, due to shortage of water and the failure of the fusible plug to drop owing to an accumulation of soot and dust between the top row of tubes and the superheater element.
The feed water used in France varied very considerably in quality ; buait can be said that, north of a line drawn east and west through Hazebrouck, the water is good,containing little mineral matter and forming practically no scale on internal surfaces. South of this line the water is mostly bad, containing lime in considerable quantities and forming heavy hard scale, no matter how carefully the boilers are washed out. The general practice was to wash out . at hoist every ten days, if in any way possible.
The loads carried averaged about 4 tons and the usual daily journey performed about 25 miles. The ork. none by the steam vehicles in France has proved them to be an unqualified success for this type of work. The drivers were for the most part experienced and. careful men, taking a great interest in their vehicles and carrying on their work often. under shell fire and generally over bad roads. With their vehicles they contributed in no small degree towards the successful termination, as, without good road; the rapid movement of troops and guns could not otherwise have br en accomplished.