A Pro-Forma approach to Car-Carrier Design

Abstract

In this work a pro-forma approach is developed for assessing truck and centre-axle tag-trailer or 50/50 car-carrier designs in terms of their compliance with the South African Performance-Based Standards (PBS) pilot project requirements. First, the low-speed performance standards were considered using a low-speed pro-forma design developed by deriving equations for frontal swing, tail swing and low speed swept path. Thereafter, the remaining performance standards were considered, incorporating additional checks to be performed when evaluating a potential vehicle. It was found necessary to specify a minimum drive axle load in order to meet the startability, gradeability and acceleration capability standards. The required drive axle load was determined as 19.3% of the GCM. It was confirmed that the static rollover threshold performance can accurately be predicted by means of the applicable New Zealand Land Transport Rule method. This simplified approach can significantly benefit the PBS pilot project by offering a cost effective method to investigate the PBS conformance of proposed car-carriers.