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A 3-dimensional, full-vehicle computer model was created of a conventional 218 tonne payload capacity mine haul truck. Simulations were performed of a number of situations typifying in-service operation to gain insight into various aspects of the dynamic response of the hauler. A 0.25 g lane change maneuver was simulated that can represent a wide range of haul truck movements in a mine, such as collision avoidance or following a change in haul road alignment. Peak wheel loads of approximately 100 tonne were recorded, and these are about 1.7 times greater than the rated capacity of the tire. Travel on an uneven haul road was also simulated and dynamic wheel loads were predicted that are 1.3 times tire static loads. The characteristics of the road surface used in the simulations were measured with an ARRB Transport Research Ltd. road profiler. Unevenness features of sealed and unsealed roads are presented and discussed.

The suspensions of large capacity rear-dump mining trucks are required to operate under extremes of vertical load. This imposes conflicting requirements for the fundamental suspension functions in the achievement of adequate isolation of the sprung mass from road unevenness, and acceptable roll stability and directional control during cornering (particularly when fully-laden). The following factors introduce further complications-high centre-of-gravity of the sprung mass of the laden vehicle, highly non-linear characteristics of the suspension spring elements, and relatively close spacing of the rear springs. The steady-turn roll response of a conventional 218 tonne (240 short ton) payload vehicle has been analysed to determine the loads imposed on suspension spring-elements and tyres, and to establish the roll behaviour as a function of lateral acceleration.

A detailed investigation of the emergency straight-path braking behaviour of a sample of 59 volunteer motorcycle riders with a wide range of riding experience and skill has been performed on the test track with the aid of a motorcycle instrumented to measure and record a number of variables related to the braking task. Analysis of the data revealed that the skilled riders applied larger front and rear brake-lever force inputs, had shorter reaction times, and were able to proportion their front and rear brake force inputs in the manner required for optimum utilization of the available tyre/road friction. By contrast, the braking behaviour of the less-skilled riders could lead to early “lock-up” of the rear wheel. This finding suggests that less proficient riders could brake a motorcycle more effectively if it was equipped with an integrated and/or anti-lock braking system.