DEVELOPMENT OF THE ORDNANCE FOUR-WHEEL-DRIVE TRUCK 190068
The necessity for a powerful heavy-duty truck with power transmitted through all four wheels was apparent shortly after the United States became involved in the war. An intensive study of the four-wheel-drive situation finally resulted in the design of the Ordnance four-wheel-drive truck and the modified form known as the artillery wheeled tractor. Seven factors influencing the preparation of the specifications are stated and discussed. The determination of proper gear ratios is analyzed. The considerations leading to the adoption of the universal-joint type of driving-shaft are mentioned and its application commented upon. Ten specific points of internal interchangeability of the mechanism are enumerated.
In connection with the opinion that the province of the four-wheel-drive truck begins where two-wheel drive leaves off and ends where the track-layer begins, it is stated that four-wheel drive can and will compete successfully in certain applications not only with the track-layer but with the heavier sizes, at least, of rear-drive trucks.