A Study on the Turning Ability of Twin-engine, Twin-propeller, and Twin-rudder ship “KAKUYO MARU”‐Ⅱ

We made a turning trial of a twin-engine, twin-propeller, and twin-rudder ship “KAKUYO MARU”,that has equipped the two sets of main engines and rudders, and a comparison was made between twoengines and one engine as well as between two rudders and one rudder about the factors of turning. Thetrial results are stated below.1) Comparing to the operation of two engines, the ratio of steady turning diameter (D/L), the speedreduction rate (RATE), and the time for turning (TIME) were large when the position of engineand the turning direction was the same. And, these decreased when rudder angle was large. Also,the drift angle (ANGLE) was small and increased when rudder angle was large.2) In comparison with using two engines, D/L and TIME when using one engine and turning to theopposite direction of engine position were small and increased when rudder angle was large. Also,the RATE and ANGLE were large and decreased when rudder angle was large.3) When using one engine, D/L and TIME of turning by one rudder were 1.1 to 1.6 times larger thanthese of turning by two rudders at both turning directions and decreased when rudder angle waslarge. Also, RATE and ANGLE were as small as 0.7 to 1.0 times and increased when rudder anglewas large