To cope with the demand for energy saving on marine propulsion plant, many investigations had been carried out in concerned fields, then, as well known, new type of long-stroke, large-bore, marine diesel engines with low fuel consumption were developed and some sort of energy saving propulsion plant were published, and they are now in service.
We would like to mention, in this paper, various kind of measures applied on large-bore marine diesel engines to reduce fuel consumption through some examples on KSZ-C/CL type engines and also introduce the outline of our Kawasaki Super Economical Propulsion Plant (KSE plant) and its service experiences as an example of now used energy saving propulsion plants.