Manoeuvrability and off-road capability are the key criteria for evaluating military transport vehicles. The suspension, the axle system used and the type of steering are the most important vehicle features in this respect. The specifications laid down for these components depend on an armed force’s requirements for its equipment and the geographic and climatic conditions in the intended area of operation.
RIGID AND PASSIVE STEERING
In rigid vehicles, the towed unit is not actively steered; the tractor unit pulls it in the direction it is travelling instead. Passive steering is the simplest type of steering, where frictional forces occurring as the vehicle travels around a bend are transferred to the wheels. Both of these systems are used if no stricter requirements are imposed on vehicle manoeuvrability for their use.
In this steering system, hydraulic cylinders are used to transfer the steering angle of the tractor unit to the axles on the towed unit. This steering has a direct, precise effect, ensuring optimum manoeuvrability. This type is required especially if the overall length of the semi-trailer is around 20 metres and is recommended if the trailer has more than five axles.