A propulsion system for a relatively large land-based vehicle, such as a locomotive or off-highway vehicle, is provided. The system may include a brushless dynamoelectric machine made up of a main alternator having a main rotor and a main stator, and an auxiliary alternator having an auxiliary rotor and an auxiliary stator, wherein the main rotor and the auxiliary rotor are disposed on a shaft for joint rotation with the shaft. The dynamoelectric machine is operable in a power generating mode, and in an engine cranking mode. A power source may be connected to pass current to one or more windings in the auxiliary stator to induce an alternating current flow in one or more windings in the auxiliary rotor. A rectifier may be connected to receive the alternating current flow from the one or more windings in the auxiliary rotor. The rectifier is further connected to supply a rectified current to one or more windings in the main rotor to induce an alternating current flow in one or more windings in the main stator of the machine, wherein the alternating current flow in the one or more windings in the main stator of the machine constitutes the current generated by the dynamoelectric machine during the power generating mode. The power source to be connected during the engine cranking mode may be first and second inverters connected to provide an AC conversion to a DC input from an energy storage device to supply a respective alternating current having some desired characteristics. The one inverter may be connected to the one or more windings in the main stator, and the other inverter may be connected to the one or more windings in the auxiliary stator to produce a torque in the main rotor of the machine. The torque produced at the main rotor of the machine is mechanically coupled to a crankshaft of an internal combustion engine of the propulsion system to start the engine during the engine cranking mode.