曳船及びトロール漁船等の推進器設計に關する一考察

概要

論文の詳細を見る
Tug boats and trawlers have their screw propellers operated in two different conditions, i. e. voyaging free and towing other vessels or trawling nets in fishing. Therefore, for instance, a propeller designed as the most suitable for free voyages is not always so efficient as can utilize the power from the engine fully enough in towing conditions. Requirements in those two cases are inconsistent with one another, so it is theoretically impossible to design a propeller that fulfils both requirements simultaneously, as long as a castant pitch propeller is used. Therefore a variable pitch propeller will be taken into consideration. But it is not so widely used for its complex mechanism, high price and lack of responsibility. In this paper, The authors intended to establish a method of designing propellers that are most effic-ient synthetically in both conditions voyaging free and towing, when an engine was given and constsnt pitch must be used. They applied this method to the case of a tug boat belonging to the Ministry of Transportation "Dai-ku Tetsuei-maru" and compared its results with those of towing and speed trial tests by the actual ship. They believe this method can be also applied to the design of propellers of fishing boats, such as trawlers or small trawlers, that is a question to be solved in our country now.
1949-07-25