Factors Affecting the Performance of High-Speed Track Layers

The aim of the paper is to present some fundamental data from which the performance of high-speed track-laying vehicles can be estimated and on which preliminary design calculations can be based.

The percentage of the gross engine horsepower that may be available at the driving sprocket is indicated and this must be equated to the resistance to motion that is likely to be encountered. Losses in the track and suspension system are discussed and reference is made to the effect of track tension. Some indication is given of the order of the horsepower required per ton of vehicle weight to achieve a unit of speed on various broad types of terrain. The effort required to climb gradients is also considered and it is shown that operation on cross-country terrain may be treated as an equivalent gradient resistance.

Mention is made of the horsepower expended in steering a tracked vehicle and the manner in which the track forces have been found to decrease with increase in turning-circle radius.

Since cross-country mobility also involves ability to cross water obstacles, some idea is given of the water resistance of the hulls of these ‘un-shipshape’ forms when afloat, and the overall efficiency that may be expected from the various means of propulsion that can be employed.