A combined cycle power plant for a railway locomotive is disclosed. In one embodiment, the power plant comprises two prime movers operating independently of one another. The waste energy of one prime mover is used as the energy source of the other prime mover. The shaft work of each prime mover is connected to a common load. The shaft work of the first prime mover is directly connected to the load, whereas the shaft work of the second prime mover is selectively coupled or decoupled to the load using a clutch.