Abstract: A multiple function railway maintenance machine includes a plurality of cars connected together to form a self-propelled consist having cabs at opposite ends so that it can be driven along railway tracks to an area requiring maintenance work. The cars are provided in their beds with rails which extend between the cars continuously. A crawler type service vehicle is mounted on the rails and has a cab from which the service vehicle can be driven along the rails for precise positioning. The service vehicle has a rotatable and articulating boom that interchangeably receives different working heads.