The concept that plant safety must go hand in hand with engine excellence is increasingly entrenched. The Wheel sliding protection, the subject of the paper, is the device thanks to which the wheels are prevented from slipping and locking. Initially there is a digression about the braking system of the train and a comparison with its direct antagonist present in the automotive field: the ABS. Then there is the description of all its parts and the way in which they communicate with each other. All followed by the working principle of operation based on a detection and comparison of pulses provided by a speed sensor.