The diesel engine was invented by Dr. Rudolf Diesel in 1893. He was born in Paris. Initially, he was appreciated for designing many heat engines. He applied for many patents in the United Kingdom, Germany, the United States and Switzerland, and succeeded in getting the patents. The diesel engine uses a combination of oil and air inside a cylinder. The cylinder is compressed by a piston continuously. The mechanism used in the diesel engine works on the basis of the ignition of oil inside the engine. There are two kinds of diesel engines–two-stroke and four-stroke. Initially, the mechanism was used in ships and submarines. Since 1910, in ships and submarines, we have been using diesel engines. Later, we started using the technology in electric generators, trucks, loco-motives, etc. The most recent use of a diesel engine is in automobiles. Today, the world’s largest diesel engine is a Common Rail marine diesel known as Wartsila-Sulzer RTA96-C.