Abstract: Machine to clean and rehabilitate railway ballast and railway road beds, which can: (1) remove the ballast, clean the ballast and then replace the ballast, or (2) remove the old ballast and replace it with new ballast. The machine, while riding on the railroad tracks, can remove the metalling of the ballast from the railroad track, then run the material through a riddle to clean the metalling, and finally replace the material. Alternatively, the machine may remove the metalling, then by reversing the direction of a distrubution conveyor, the machine can replace the old metalling with entirely new metalling brought to the distribution conveyor by various feed conveyors. In this alternative mode of operation, the machine can lay a two layered ballast consisting of two different materials.