This paper describes new technologies on power electronics for marine environment. In the first place, a novel PM (Particulate Matter) reduction method by means of high frequency induction heating (HF-IH) applied for air pollution by diesel emission is introduced. The development of a new HF-IH DPF (Diesel Particulate Filter) and the experimental results are mentioned. In the second, a new HF-IH recovery system of heavy fuel oil in the sunken ship in which the viscosity of heavy fuel oil is exclusive high is proposed. The HF-IH recovery system is experimented and estimated by using mimic oil tank under low temperature conditions.

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The helical-type superconducting electromagnetic ship thruster is composed of a solenoid-type superconducting magnet, coaxial electrodes, a flow-guide, a flow-rectifier, and a helical insulation wall. Calculations of characteristics of the large scale helical-type performance are carried out on the basis of a simple model; It is supposed that (1) seawater (27°C) is incompressible, (2) voltage drop at the surface of electrodes and electrolysis products are negligible, (3) magnetic field and electric current are constant inside the thruster, and (4) the thruster is similar figures to the test thruster examined. As a couple of results of calculations, it is found that the thruster efficiency quickly increases with the length of electrode up to about 5 m and then goes up to about 0.9. The thruster efficiency also peaks at a certain point (- 0.6 m) and then falls as length of pitch of the helical insulation wall increases.

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Maintenance and inspection supporting system for ship propulsion engine from the supporting station on the land is introduced.
By this system, operating conditions of the main engine and other essential machineries in the engine room of the ship are live-monitored from the land to diagnose operating data to prevent trouble or faulty condition from occurring.

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As the results of amendment of the SOLAS chapter V, Automatic Identification System (AIS) was introduced to ships of 500GT and upwards to domestic sea area. The AIS provides new ways to gather information of other ships around own ship and send own information to the other ships and land stations. The new information has great potential to enhance navigation safety. In this article, overview of the functions of AIS, current situation and some future ideas of the use of AIS are introduced.

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This paper investigates an induction-heating (IH) system applied for heavy fuel oil (HFO) recovery system in the tank of sunken ship. For design of the system, the characteristics of load equivalent circuit parameters in case of varying the steel board square meters and gaps between steel board and working coil unit are studied. On the basis of these characteristics, the experiment of heating up heavy fuel oil in the tank under the low temperature has been tested. Through the experiment, the availability of the proposed system was verified. Finally, the design procedure of largescale working coil unit for induction heating and operation frequency is proposed.

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In Part 1, to clarify the usability of residual oil reclaimed from waste plastics as diesel fuel, the authors evaluated the correlation between the result of FIA ignition test and the calculation result of JIS K2204 Cetane Index.
In this report, furthermore, referring to also the fuel density and the distillation characteristics of marine diesel oil, the authors considered the JIS K2204 and the JIS K2280 Cetane Index from ignition characteristics standpoint.

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After unloading chemical cargos transported by chemical tankers, the discharge of the cargo residues or tank washings containing such chemical substances is prohibited according to the pollution categorization to protect marine environment from pollution produced by ships. To reduce the cargo residue quantity, stripping or straw piping devices have been developed.
In this study the residue quantity at the tank well and in the piping, the adhering quantity on the tank surface and in the piping, and the vapor quantity in the tank and the piping are investigated by the past reports on board test. There are a few ships, the residue quantity in the well or in the piping of which is reduced less than one liter in the case of the straw piping equipment and the stripping equipment are settled.
One liter of the residue is small compared to the vapor quantity or adhering quantity in the tank. To reduce the discharge quantity of chemical cargos from ships furthermore, the recovery of the vapor and adhering quantity demands deliberation.

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For steam turbine ships, it is very important to control accurately water quality of the main boiler and its plant. The recovery rate of condensed water in recent marine turbine plants has been increasing and approaching a perfect closed cycle, and the techniques of pH monitoring and Fresh Water Generators have been improved too. However, as for the automation of boiler water treatment, its development seems to be very late compared to other ship techniques.
This paper investigates, therefore, the current situation of the water quality control of marine turbine plant in order to develop an automatic water treatment system. As the fundamental research on the boiler water quality control and its automatic water treatment, this first report analyzes theoretically the water treatment data of actual ship for making clear the impacts of (1) impurity mixing from make-up water (2) boiler compounds (3) blow-down of boiler water on boiler water quality, especially pH and PO₄. The analysis shows some characteristics of boiler water quality and its treatment system which are to be helpful to marine engineers.

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