• GERMAN LORRY TRACTOR DESIGN.
Page 10
Page 11
Page 12
If you've noticed an error in this article please click here to report it so we can fix it.
Features of Extraordinary Interest in 1 :lion of Captured Vehicles. (First Article). TEIE ACTION OF the Army Council in granting facilities for the inspection/ of the collection, which has been made at Aldershot, of a number of mechanical transport vehicles captured from the enemy during the late war, enables the veil to be lifted for the first time from the secrets of Germany's, extraordinary efforts to attain mechanical supremacy in the vehicles upon which depended the road transport of her armies.
The great efforts which were made by the scientists of the Fatherland to furnish those armies with the sinews cif war is Well known, and the story of their nefarious devices will go down in,history ; but it is not generally appreciated that her automobile engineers. put forward no less strenuous efforts towards the special design of vehicles to carry those mighty and now shattered armies towards the goal which they could never reach.
' From an inspection of the vehicles at Aldershot one cannot help forming the opinion that, as regards special design for war conditions, German designers exhibited considerably more activity than we did in this country. While much of our best automobile talent was concentrated on the successful evolution of the Tank and on the rapid production of road transport vehicles which diaered !but little from standard peace-time practice, and of one or two varieties of standardized gun tractors, German designers broke out in all sorts of directions, and, if they did not succeed in producing a Tank which could compete with our production, they turned out a number of special gun tractors and " war" lorries which, from the engineering point of view, are really admirable in many respects, and give evidence of astonishing ingenuity and directness of purpose.
It is, however, rather a surprising fact, in view of the much-lauded German anticipation of the requirements of war, that, contrary to expectation and, indeed', to general report, standardization obviously did not receive, nearly the amount of careful attention which it did in this country. There could have been little co-ordina,tion as regards design, and it looks as though each German maker went his own way and produced what he thought best without much regard for what other people might be doing. It certainly looks as though the army authorities did not know their job as well as our own, and did not influence and co-ordinate design to the extent that our M.T. people did.
It • would have been reasonable to expect that, in the effort to economize resources and to_speed up production, special attention would have been paid to ease of manufacture in the general and detail aesign of the vehicles, but there is no evidence of any great effort in that direction. This is rather surprising, as in German aero-engine design this 'point undoubtedly received careful consideration.
The explanation possibly may lie in the fact that the German General Staff, in the early stages of the war at any rate, placed more importance on rail transport than on road, and, in consequence the essential requirements of the latter may have Veen somewhat_ overlooked. It is significant to note that, in spite of Germany's "preparedness," many of these vehicles are known to have been designed during the war, which rather shows that in the councils of the military experts who were planning for " der Tag," the ultimate importance of road transport and haulage had not been appreciated. The Aldershot collection comprises vehicles by many well-known German makers, including Alder, Benz, Bussing, Daimler, Deitz, DUrkopp, Dux,. Erhardt, Hansa-Lloyd, north, and Lanz.
Some 30 vehicles in all have been collectefl together, tractors being in the majority amongst them.
Although these are esSentially militar y machines for which little use could be found in commercial undertakings, from • the engineer's, point of view they are,perhaps, of the greatest interest of all.
The largest amongst them is the Lanz, which has a six-cylinder engine of 150 mm. bore by 160 mm. stroke, the cylinders being east in pairs. Two carburetters are fitted and pump 'circulation employed, the radiator being of the built-up. type, piovided with gilled tubes naade up in cletaehable sections, of which there are nine. The interesting feature of this vehicle is the huge rear wheels, which are 7 ft. in diameter and 18 ins, wide, and are provided with rim strakes and also with holes, into-which frost pins can be isiserted. The drive is taken from the engine throirgh a countershaft and differential gear to &Tinian and internal-toothed ring on the rear wheels, The tractor is mounted on laminated springs both fore and aft, and weighs no less than 12 tons. As with all the German tractors (but with few of the lorries), an exceedingly good winding drum is
fitted ; it is carried horizontally, at the rear and is driven by a horizontal pinion which slides in or out of engagement on a splined vertical shaft at the rear of the gearbox.
At first glance two steering wheels appear to be fitted, one under the other, but closer examination reveals the fact that, by arather novel arrangement, the rotation of the lower wheel actuates the brake.
The Horch machine is chiefly notable for the very ingenious rear-wheel design and the adjustable "spud" arrangement. The rear wheels are chain
driven, and on a ring bolted to the brike drum tangential pin-pointed arms are carried, the outer ends being similarly connected to a series of "spuds" hinged on the inside of the wheel rim. Normally, the spuds do not project through the rim, but, by the removal of a pin, the ring, to which the arms are attached can be rotated; so that they assume a radial,
position and push the spuds through slots in the rim. This seems to be a particularly practical and useful
arrangement. But, obviously, on reversing, the spuds would be drawn in—which is rather a defect This tractor is very well sprung, the front springs being carried on bell-crank levers at each end; which connect up to powerful coil springs. • -Auxiliary springs of this type are a notable feature of nearly all the vehicles. In the ease of the • Horch great care has been taken to carry them, tubular horizontal housings being formed in. the dumb • irons and spring brackets, This feature is a typical example 'ofthe somewhat drastic methods of the Ger.
mat designer. There are no half measures. Having decided on an innovation, it is boldly conceived ana -.tarried out with an utter disregard for convention and little attention to appearance for appearance's sake. The result is sometimes a little crude to our English notions, but geeerally sound. Utility is the • keynote throughout. In connection with auxiliary springs it is interesting to note that, from reliable sources, infOrmation has been obtained that., during the' war, the percentage of spring breakages amongst the German transport vehicles was very small, so that their adoption seems to have been fully justified.
An extraordinary arrangement of r ear wheels is to be seen on the Erhardt tractor, the exact object of which it
is rather difficult to appreciate. There rare four rear wheels of fairly large diameter, placed equidistantly in line across the chassis. Presumably, the idea is to obtain increased ground contact area, an object which might, one would have thought, have been met by increased wheel width. These four wheels are mounted in pairs on separate carriages, independently sprung, there being four heavy semielliptic springs.; each pair of wheels is chain driven from a countershaft, and radius rods are fitted. A cane clutch transmits the drive from the engine 1.6 a gearbox, giving eight forward speeds and two reverse. All the wheels of this novel vehicle are fitted with smooth, steel tyres of a peculiar pattern, which give them a certain amount of resilience.
The Diirkopp tractor has a. four cylinder engine of
64 in. by 7 in. bore and stroke, an internal-cone-type clutch, and a compound gearbox giving eight forward
speeds and two reverse. This is one ofthe few machines with a transverse front spring, and the steel-spoked wheels are peculiar in that they are partially enclosed by a plate in order to prevent mud from squeezing into them. A very large horizontal winding druin is mounted low underneath the chassis, so that there is a. fair lead fore and. aft. This machine has a very large radiator of quite artistic shape, as will be seen from the illustration. It is rather extraordinary that, for this rough work, such a huge radiator should have been made of sheet metal and solder.
One of the most interesting of the tractors is the Bussing, and it differs considerably from the others. It has .a six-cylinder engine with overhead valves operated through long push rods and rocker arms ; the cylinders are cast in pairs, which, apparently, was the practice on most of the vehi cles. The engine is mounted so high that to facilitate starting a chain sprocket is carried, in the usual start
ing handle position, a short chain connecting it, to another sprocket Tower down on the right-hind side, with which the starting .handle can engage at a convenient height.
This tractor is very well sprung and coil auxiliaries assist the front springs.
The horizontal winding drum is carried in front of the chassis, below the radiator, and is driven by gearing at the end of a long shaft carried justinside the, frame and itself driven by a short roller, chain from the gearbox.
This drum is long and of comparatively small diameter and the,calale passes between two vertical roller guides in front which are carried on a frame engaging with a leading screw which rotates at the same time as the drum. The guide, therefore, travels automatically along the drum as the cable is wound up or paid out. Next week we shall deal with the lorries.