In this article the offtracking characteristics of single-unit trucks and trailer combinations are described. Offtracking results were obtained by use of scale models of vehicles making turns on radio ranging from 25 to 255 feet. Individual vehicle offtrackings are influenced by three variables the degree of turn, the length of vehicle wheelbase, and the turning radius. It was determined that the offtracking measurements of a trailer combination may be calculated by adding the offtracking measurements of the individual vehicles in the combination. Also, the offtracking is greatest when the projection of the rear axle axis passes through the turning radius center, even though the projections of the other axles on the vehicle or trailer combination do not pass through the turning radius center at the same time.
Abstract