Marine Propulsion System, Composed of prime mover, transmission and propulsor, is the mechanism or system used to generate thrust to move a ship or boat across water. The main components of a typical marine propulsion system are shown in Fig.
The function of prime mover is to deliver mechanical energy to the propulsor. and sometimes to generate simultaneously the needed electric for various applications onboard the ship (Lighting, control system, pumps, navigation equipments, HVAC, etc.
The prime mover can be classified according to the power Sources.