This is a Self Propelled SlotMachine. It is owned by Georgetown Rail Equipment Company, owners of Loram, the operators of rail grinders. Herzog also has a similar machine that looks even more like a brick of cheese than this one. Behind the power is an articulated gondola car that can be used for moving track panels, collecting ties, or any number of uses. I have no idea the provenance of the locomotive, but it looks like a cross between some havarti, a blueberry, and an MP15.