The HMA Materials Handling Rail Rapper Unit is used to stress and destress sections of tracks which have been used for long periods of time. When the track has been fastened and the track is exposed to cold and hot temperatures, the rail will stress over time.

The HMA Materials Handling Rail Rapper consists of a tractor to provide traction for a controlled work speed, as well as the Rail Rapper Unit. When the machine is heating the rail during the work mode, the operator walks beside the machine. The Rail Rapper Unit strikes the railhead with an oscillating hammer so as to free the movement of the track as it lengthens due to increased temperature.