In recent years rationalization of sea transport has brought about a change in the marine transportation pattern with increasing amounts of cargo being handled by specialized carriers. Meanwhile, requirements on the performance of marine propulsion plants-the range of output, the propeller revolution-have become diversified as the usage, size and speed of ships change in line with this trend.
Under such circumstances, the medium-speed geared diesel propulsion plant is attracting increasing attention to its big merit of being able to meet any requirements in output and propeller revolution performance using the least number of engine types.
However, in spite of many advantages, it is a fact that the medium-speed geared diesel engine is still in no position to replace other engine types. This is because of the complicated maintenance problems arising from the large number of cylinders in the plant. Without any solution to this problem, the above mentioned merits cannot be used to the best advantage.
Also, as the geared diesel engine is joined organically to other equipment such as the flexible coupling, reduction gear, as well as devices for the automatic supervision and remote control of the engine into one system, development of the plant without consideration for these is unthinkable.
Based on the above considerations, development of the geared diesel propulsion plant was carried out with close research and development of:
The main diesel engine.
Labor-saving maintenance devices.
A large capacity clutch with the flexible coupling.
Light, compact reduction gear.
Detecting devices for abnormality of the engine.