Study and At-sea Experiment on Actively Controlled Anti-Rolling System

Abstract

This paper describes the new type of anti-rolling system that is capable of reducing the rolling motion of a ship by active control of the moving mass. Similar system has been already realized for the reduction of the vibration of large-bridge towers and high-rise building structures. Present anti-rolling system is an application of the system.
Model experiments in a wave tank were carried out with the ship model installed with the anti-rolling system. Roll amplitudes in regular waves with the anti-rolling system are similar to the amplitudes of the ship model with an anti-rolling tank in which the weight of moving water is about two times of the moving mass of the present system. Then the moving mass system are more effective for roll reduction than anti-rolling tank. Effects of the incident wave height, forward speed, and position of the moving mass on the anti-rolling performance are investigated.
Next, at-sea experiment were performed with a small vessel (L=5.93 m) having the smaller prototype anti-rolling system. The effectiveness of the present system was confirmed from the measured data of roll amplitudes.