The development of Superconducting Electro-Magnetic Propulsion Ship has been going on, featuring a new propulsion concept that has never been actually applied to any ship before. The propulsion of the ship is performed by the thrust force with the use of superconducting electo magnetic thruster instead of the conventional system.
Initiated by Ship & Ocean Foundation (old name: Japan Foundation for Shipbuilding Advancement) in 1985, the research and development have been continued on superconducting magnet, electrode, liquil helium refrigerator, hull form, etc. The study is now coming to the final stage, followed by the sea trial expected in next year.
In this paper, the result of the study and design concept of the said experimental ship is focussed on the propulsion system as to the feature of the propulsion plant.

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Fretting fatigue tests were carried out using a device designed specially with respect to the fretting fatigue of crank pin bolts used in marine diesel engines. A 0.46%carbon steel was tested in fluctuating tension at a frequency of 30 Hz and a clamping load of 392 N in air. The effect of fretting on the fatigue performance was investigated. The effectiveness of the electrodeposited coatings and of the insertion of a thin metallic sheet were assessed for the mitigation of the fretting fatigue failure. Fretting had a serious damaging effect on the fatigue performance, reducing the fatigue life at stresses well below the normal fatigue limit. The ellectrodeposited coatings of copper, silver, and zinc were beneficial. They showed sufficient ductility to withstand the streses without cracking and also to remain in the contact area without being extruded. However nickel and chromium coatings and seemed to penetrate into the underlying steel. Double layered coatings such as chromiun on copper on the substrate were remarkably effective in improving the fatigue life.

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Conventional sealing system using the lip type oil seal is based on the concept that the forward pressure is always kept higher than the backward pressure. However, the new type of sealing system “AIRGUARD 3AS” is applied the idea that the air or lub oil always flows from the backward side to the forward side through the lip part of seal ring.
We have carried out various investigation by use of test stands with #155 and #600 seal rings which is used under the backward leakage condition.
As a result, the cracking pressure of seal ring and oil flow ratio of forward side to backward side are always constant in all cases. Furthermore, the lift of the lip part of seal ring on sleeve liner increases almost exponentially to the air or oil flow rate.

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The space for acommodation and engine room of a fishing boat are much narrower than those of a merchant ship. Thus it is impossible to install all lighting apparatus on the required position. Judging from ”the recommended levels of illumination” of the Japanese lndustrial Standard, some parts where illuminance are lower than the standard level are found.
The heigh frequency operation of the fluorescent lamp. as the countermeasures of increase in the illumination and decrease in the electric power were noted. Likewise, experiments on the fundamental characteristic amd the continuous action performance were conducted to compare the electronic invertor ballast and the conventional coil ballast.
The following could be concluded;
1) Performance of the fluorescent lamp using invertor ballast was independent of f luctuatuons in the voltage and frequency of power source.
2) Luminous flux amd luminous efficiency of the fluorescent lamp using the invertor ballast increased to 18% and 23% respectively, compared with those using coil ballast.
3) Each secular change of luminous flux showed approximately a similar decreasing tendency. The extended lifetime of the fluorescent lamp was assumed to be 107 days approximately in consideration of the increased luminous flux within the invertor ballast.
4) Saving of running cost using high frequency operation was estimated to be 142, 000 yen per year on a research and training fishing boat.

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