Six-Wheeled “Guy” Truck

Sun (Auckland), Volume I, Issue 284, 21 February 1928, Page 6

Six-Wheeled “Guy” Truck

Remarkable Design and Performances Shown MODEL NOW IN AUCKLAND “Headlight” had the pleasure last week of witnessing the performance of a “Guy” six-wheeler truck, one of the first six-wheelers to come to the Dominion. The distributing agency is held by John Burns and Co., Ltd. The truck is designed so that the drive is delivered to all four rear wheels equally, through two complete sets of rear axles. To allow' full freedom of movement to the rear wheels over rough country the main carden shaft, after passing through the first rear axle, is provided with two universal joints before entering the second rear axle. This means that, no matter how broken or steep the going, full power is always available. An additional provision for heavy work is the auxiliary gearbox—there

are normally four speeds forward, but each one of these has a lower and more powerful equivalent in the auxiliary gears, making a total of eight forward gears. Ratios range from 7.5 to 1 (top gear in main box), to 94 to 1 (low gear in the auxiliary box). Reverse gear is 39 to 1. With this equipment there can be no surprise at the power and climbing ability of this truck—it literally can’t be blocked anywhere. (With the chain track supplied, the makers reckon it will climb a gradient of 1 in 2 with soft surface!)

A truck such as this is. of course, used primarily for very heavy work, so that the chassis design is pretty solid. It must not be thought, however, that carriage is heavy and lumberous. As a matter of fact, by using two axles instead of one the load per axle is halved, and the tyres sink into the road to approximately half the amount. In addition, halving the axle weight of itself reduces the shock to the vehicle and load, while with the double cantilever springs used the movement of the vehicle and load is only half the movement of the rear axles. This means that the shocks to the load are reduced 75 per cent, compared with a four-wheeled, singlespring vehicle of similar weight. The braking on this truck is interesting. It is one of the first vehicles to come to New Zealand fitted with what is known as the Vacuum Servo motor —that is, the slightest touch to the pedal brings into operation an auxiliary mechanism which in turn exerts pressure on the brake drums on the four rear wheels.

This model of “Guy” (known as the 3-5-tonner, as it is designed to carry five tons on hard roads and three tons across country) has been adopted by the British War Office under its subsidy scheme. -