low-speed engine

The low-speed diesel engine is a type of internal combustion engine primarily used in marine vessels. It operates on a two-stroke cycle and is characterized by slow rotational speeds, typically between 80 and 120 revolutions per minute. This slow speed allows the engine to directly drive a propeller without the need for a speed-reducing gear, which is often required for medium-speed engines.1

Low-speed diesel engines are known for their ability to burn lower-quality, less expensive fuels. While they are heavier and larger than medium-speed engines for the same power output, their efficiency and fuel flexibility make them a preferred choice for many ship designs, especially where engine height is not a limiting factor. The fundamental principle of a diesel engine involves compressing air to a high temperature, then injecting fuel that ignites spontaneously, converting chemical energy into mechanical energy.12