Abstract: A railway grinding system is capable of grinding a frog, another switch, or another railway section of interest in situ over a precisely defined path that is unaffected by the geometry of the railway section to be ground. The system includes a frame providing the reference path and a grinding machine movable along the reference path. The grinding tool preferably has at least four degrees of freedom with respect to the reference frame. Versatility can be further enhanced by permitting one grinding tool, such as a cup grinder configured to grind a generally horizontal surface of the railway, to be replaced with another grinding tool, such as a flange grinder configured to grind a generally vertical surface of the railway. The frog grinder can perform either single-event reconditioning grinding or periodic maintenance grinding.