操縦性能の縮率影響に関する一資料

抄録

This paper treats many manoeuvring test results of three 360,000 DWT sister tankers and their model for studying scale effects of ship manoeuvrability. A new, sea trial measuring device, "TRIPOSIK", played an important part of the study. The device, which consists of a main station transmitting UHF radio waves on board and two slave-stations on shore, is ideal for measuring a ship's speed and its position. Even though the full scale ship showed slightly larger ∣r'∣ values than the model in large helm turnings, course keeping qualities were almost the same for both of them. Drift angle, speed drop ratio, advance and transfer in each steady turning were measured with good accuracy. The authors succeeded in obtaining a good method for simulating propeller-reversing stopping ability. A pair of differential equations for the purpose is; [numerical formula] [numerical formula] By solving these equations the path and speed after the propeller is reversed can be accurately simulated. Other factors such as head reach, lateral reach, stopping time and heading angle at zero advancing speed also coincided well with observed ones. Through these facts, it might be said that this method is not only useful for these ships but also can be applied for any other ships which have a conventional propelling system.