Guiding axles equipped with rail wheels (diam. 400 mm.), in single or tandem configuration, keep the rail-road vehicle on the right track. Each guiding axle is suspended in a movable frame which is kept under constant pressure by a hydro-pneumatic suspension.
High volume accumulators and suitable piping guarantee a short reaction time of the hydro-pneumatic suspension. The required pressures on the rail guidance wheels are automatically set, continuously monitored and adjusted if necessary.