A hydro stressor consists essentially of a hydraulic pump which transmits its force through connecting vans to clamps which grips the rail. In case of mechanical tensor the force is exerted mechanically by longitudinal jacks by means of this force the rail can be pushed or pulled to a desired length. In case of pushing the force should not exceed 30 tons otherwise the track is likely to buckle on that account. The rail are however normally pulled only during the distressing operations. The rail tensor is capable of distressing a rail at any time when the rail temperature is less than distressing temperature.