HEAVY TRUCK DEVELOPMENT

Evening Post, Volume XCVII, Issue 56, 8 March 1919, Page 14

HEAVY TRUCK DEVELOPMENT

CRAWLING TRACTION FAVOURED

(By "Chassis.")

One of the outstanding features of recent motor truck development on the Western front is the abandonment of the wheel in favour of the crawling type of traction and steering. Close observers of the war have long pointed to this as the inevitable upshot of war developments, the doubtful clement being only that of manufacture. The evolution leading to the acceptance of the crawler has been plainly marked. Heavy ordnance was at first transported by the Germans on tractors, to the large wheels of which huge traction blocks were secured. These were- far from efficient, and gave way to tractors of crawling drive, which got over softer as well as rougher ground, besides travelling faster on fair roads. The principle was more drastically demonstrated in the British tanks. These are designed to resist shocks by brute strength of construction, the foundation back of tho endless driving band being_ unyielding, as against the familiar crawling drive which yields and accommodates itself to the inequalities of the ground. In a rougher but very effective way the tank, when it runs against and tips itself over a large obstruction, brings about this same result of accommodation by means of its rhombic shape. While this development was going on', in fact, even before it had started, the heavy five-ton motor trucks with ordinary wheels wore getting stalled on the Western front with exasperating frequency in ploughed fields, and even in the roads, often blocking or congesting urgent traffic in both directions. The fault was in most pases with the driving system. The. American quads, with, all four wheels driven from the engine, did much better, and were bought up by the French in as large number, as available. Their own four-wheel-drive trucks were much heavier and less flexible, and did not do so well; so by degrees lighter and lighter units came into vogue for the front service. All the while the crawl-drive tractors were making their appearance in increasing numbers, their efficiency being undoubted. To-day this form of locomotion is an easy first for transport over heavy roads and tracks, and the trend of affairs in this direction affords reasonable grounds for assuming that when peace is signed the crawl drive tractor -sill largely replace wheel-driven' motor trucks for heavy commercial work, and where road conditions are bad.