What Is The Difference between Marine Diesel Engine And Regular Diesel Engine?

The photo is showing a Cummins marine engine.

We can distinguish the diesel engines by application. We mean that a diesel engine that is placed in a ship has a different specification than a diesel engine that is used as a generator set, pump set, power pack or another industrial application.

Technical differences based on application

Although basically the same engines are built, the specific application is the cause of technical differences. An industrial diesel engine can be used in many ways and for many applications. For example as a generator set, pump set, hydro pack or another application. A marine diesel engine is an engine that is placed on board a ship and often functions as a propulsion engine. The most notable differences are the speed, the exhaust, the flywheel housing connection, the cooling system and the control.

The biggest difference is the cooling system

The biggest technical difference between a marine and an industrial diesel engine is the cooling system of the engines. A marine diesel engine is cooled indirectly by sea water. By using a heat exchanger, the seawater can cool down the high temp engine water. In a diesel engine with an industrial application, the cooling is achieved by a radiator through which cold wind passes and thus cools the warm engine water.

Difference in exhaust: dry or wet exhaust

The difference in the exhaust is that an industrial engine has a "dry exhaust" and a marine engine often has a water-cooled, also called a "wet exhaust". The water-cooled exhaust ensures that the radiant heat in the engine room is limited. This prevents an unsafe situation from occurring or that the temperature in the engine room becomes too high.

In marine diesel engines, the flywheel housing is to SAE standards

A ship works with a gearbox. A special flywheel housing has been mounted to enable the connection between the diesel engine and gearbox. This flywheel housing is sized according to the SAE standard. With an industrial engine, these dimensions are often different and more tailored to connect a gearbox or other drive to the diesel engine.

Marine diesel engines run less

Another remarkable difference is that a marine engine often makes 1800 rpm. This, in combination with a delay in the gearbox, gives the ship's propeller the correct speed to propel the ship. An industrial engine often has a speed above 2000 RPM. These relatively high speeds are necessary in this industrial application.