This paper presents a new type of propeller design diagrams which will be useful in the early stage of ship design. It has been derived from the results of systematic open propeller tests conducted at the Ship Research Institute, the Ministry of Transportation, and of similar tests by Prof. Troost. When ship speed, EHP, engine power and number of revolutions or diameter of the propeller for a ship are given, the optimum diameter or number of revolutions, pitch ratio and propeller efficiency are easily found in the diagrams. In addition to the design diagrams mentioned above, new cavitation diagrams based on Dr. Nakajima's cavitatation criterion are given in the paper. To these cavitation diagrams are added simple cavitation criterion curves derived therefrom which very much help the designer decide the critical number of revolutions free from propeller cavitation at the early stage of design.
