Diesel engine is an internal combustion aircraft, an engine, in which the fuel is ignited by high temperature gases which are compressed in the combustion chamber, resulting in combustion in the combustion chamber. Diesel engine are often used for main propulsion on a ship, which has a large engine capacity and large power. This is because diesel engines are suitable for long distance use or are more heat resistant than other types of engines. The capacity of the diesel engine is very large, and so does the power. The construction of the diesel engine is also on average with a large capacity. Diesel engines can be used with a variety of fuels, both Marine Diesel Oil (MDO) and Marine Fuel Oil (MFO)

There are two classes of diesel engines, namely 2-stroke and 4-stroke diesel engines. Usually, the number of cylinders is in multiples of two, although any number of cylinders can be used during the cranking process that can be balanced to prevent excessive vibration. Diesel engines work with fairly high compressed air, so that larger diesel engines need to add more air. Thus, supercharge or turbocharge on the intake manifold is used to meet the needs of compressed air. For a 2-stroke diesel engine, an auxiliary blower is used since a 2-stroke diesel engine has a low speed (80 to 200 rpm), while a 4-stroke engine does not require an auxiliary blower since the engine speed is already high (400 to 1500 rpm).

Operating large diesel engine requires support systems and auxiliary machineries, for example cooling system, lubrication system, running air system, fuel system, exhaust system/exhaust gas. Meanwhile, the auxiliary machineries include seawater pumps, freshwater pumps, lubrication pumps, fuel pumps, heaters, compressors and air bottles, auxiliary blowers, turbo chargers, and others. Operations can use simulators as a real picture later, but it can also use real labs such as engine halls and training ships as learning tools.