Abstract: A railroad track rail grinding car having both vertical and horizontal grinding stones, with the horizontal stones being individually positionable to contact selected areas of a rail head profile and with the vertical stones being mounted on a flexible beam that can be bent to adjust the grinding path of the vertical stones. Both vertical and horizontal stones are surrounded with shrouds from which a vacuum pulls dust and sparks.

Abstract: In accordance with the present invention, there is provided a chassis adapted for travel along a railroad rail with the chassis having a plurality of bearing points located between the chassis and the rail for supporting the chassis on the rail and for allowing movement of the chassis over the rail. The bearing points are aligned along a reference line and are at least variably spaced on opposite sides of a sensing point mounted on the chassis. At least one bearing point on each side of the sensing point contacts the rail surface as the chassis moves over the rail. A sensing device is provided at the sensing point for continuously sensing the distance between the reference line and the surface of the rail as the chassis travels along the rail. The sensing device has an output which is a function of the sensed distance between the reference line and the rail surface.