Many kinds of sea livings accrete to the propeller surface of ships at anchor. As a result, main engine gets into the torque-rich condition and the rotational frequency of propeller decreases. These cause the drop of propulsion efficiency.
To prevent the accretion of sea livings, propeller-coating has recently been examined by using anti-fouling and self-polishing type paint which contains copper compounds and organic tin compounds. This type of paint is much used now for the bottom plates of ships or fishing nets for ocean cultivation etc.
It becomes, however, one of the severe social problems since our sea environments is polluted by the toxic components or heavy metal of the paint dissolving out into the sea.
Then, the experiments wrer made applying propeller-coating to our training ship “YUGE-MARU” by using a nontoxic paint which is made of special silicon resin and which is fit for special uses at land.
The results of one year's experiment show that the surface of propeller is kept clean and the film of painting is attached firmly to the surface.
By these effects of this coating, the corrosion protection of ship has been improved and the amount of fuel consumption of main engine has been reduced 6%.