RAIL GRINDER

A rail grinder vehicle includes a series of connections between grinders and a chassis frame such that pairs of the grinders may be operated in an independent mode allowing separate movement and in wave control mode wherein the pair of grinders are coupled together for movement in unison. The grinders are supported from a K frame which is pivotably mounted at the center of the vehicle for stability. Each grinder is mounted upon a grinder support element and associated structure such that the grind stone of the grinder may be positioned relative to the rail and will automatically and simultaneously orient the grinding face of the grind stone at a proper angle relative to the rail corresponding to the desired position. A control system including a hydraulic system which is controlled by an electrical system is used to operate the grinders and maintain the individual grind motors at a constant power during grinding in an independent mode. The control system includes a feedback loop and is operable in a wave control mode to automatically select a torque signal representative of the motor operating at the highest power as the input signal to the feedback loop.