After the oil crisis in 1973, it has become more important matter than ever to save the energy consumption in every field, and nowadays this matter is taken into account most seriously especially for the internal combustion engines.
The major trends of the technical progress and developments in the internal combustion engines have been concentrated to the realization of the following problems;
(1) Enhancing the power rate of the engines to improve their economic characteristics by reducing the production cost per output of the engines.
(2) Reducing the fuel consumption of the engines to improve their economic characteristics by cutting down the heat energy consumed.
(3) Rationalizing the selection and arrangements of the main engines and auxilially equipments to realize the higher economy as the whole system of the plant.
(4) Enhancing the reliability and durability of the engines to make the maintenance cost as economically as passible.
(5) Incorporating the modern automation system in the engine room to improve the environmental conditions and successfully to preserve such better conditions for engine operotors and also for other people.
This paper involves mainly a recent technical view on the above problems relating to the internal combustion engines for marine use and land use as well.
