Railway transport is generally acknowledged for its low cost, environmental friendliness, energy efficiency, safety and fast speed, both for short and medium distances, compared to other means of transportation. The adhesion between train wheels and the rail has a key role on all these factors. As railway systems are open systems, the adhesion between the wheel and rail is inevitably affected by contaminants reducing the capability of the train to transfer force to the rail, thus reducing the efficiency of traction and braking processes. Rolling Stock electronic control systems generally include slip control subsystems, available to control possible sliding in case of degraded adhesion when the vehicle is in the traction phase and when it is in the braking phase. These subsystems are known as Antiskid or Antislide, or even Wheel Slide Protection, hereinafter referred to as WSP.

Matteo Frea, Faiveley Transport Italy (Wabtec); Roberto Tione