Marine Diesel Engine

The marine diesel engine is the adaptation of the diesel engine to ship propulsion, most often built as a slow-speed, two-stroke, crosshead design distinct from the diesel engines used in road vehicles: marine slow-speed engines run below 300 revolutions per minute, many well under 120, against 1500 or more for an automotive diesel, and their crosshead construction, which separates the piston assembly from the connecting rod, lets them withstand loads an automotive engine design could not, while their crankshaft can drive the propeller directly with no gearbox. The reciprocating marine diesel first went to sea in 1903 aboard the Vandal, a diesel-electric river tanker, and diesel propulsion steadily displaced the marine steam turbine through the twentieth century; most ships built since about 1960, in both two-stroke and four-stroke form, have used diesel engines, which remain the dominant prime mover in merchant shipping today for their operating simplicity, robustness and fuel economy.