A new type rudder "VecTwin" has been arisen and 25 sets of it supplied for various kinds of ships in Japan. All of the ones show good manoeuvring movements such as free berthing and unberthing in short time, station keeping, short stopping distance, shiphandling with very low speed, spin- like turning by aiding a bowthruster, shiphandling in astern running and so on. The movements can be done with keeping propeller rotating ahead. In a voyage of rough sea condition, she keeps straight course with small helm corrections. Actual results of the VecTwin ships are dealt here for evaluating the manoeuvring performances.
