Abstract: Rollback-preventing apparatus for a rail vehicle for engaging a toothed rack securely joined to the rail track includes a detent pawl attached to the wheel of the rail vehicle. The detent pawl has a ratchet which is shaped for engagement in the toothed rack. The detent pawl is frictionally engaged with a friction disk that is rotated by the wheel of the rail vehicle. The extent of rotational movement of the detent pawl is limited by a stop. The frictional engagement between the detent pawl and the friction disk raises the ratchet above the toothed rack during travel of the rail vehicle in the normal direction, preventing engagement and noise. If the rail vehicle begins to move backwards, the ratchet of the detent pawl is moved by the frictional engagement of the disk and detent pawl into engagement with the toothed rack and thus prevents the vehicle from rolling backward.