Marine diesel engines have high thermal efficiency, good economy, easy starting, and great adaptability to various types of ships. After their introduction, they were quickly adopted as the main propulsion power for ships. By the 1950s, diesel engines had almost completely replaced steam engines in newly built ships and are currently the primary power source for civilian ships, small and medium-sized warships, and conventional submarines. According to their role in ships, they can be classified as main engines and auxiliary engines. Main engines are used for ship propulsion, while auxiliary engines drive generators, air compressors, or water pumps, etc. Generally, they are divided into high-speed, medium-speed, and low-speed diesel engines.
The world's top ten Marine diesel engine brands include DEUTZ from Germany ), German MAN, American Cummins, British Perkins, VOLVO, Japanese Mitsubishi, German MTU, American Caterpiller, South Korean Doosan Daewoo, Japanese YANMAR