The authors manufactured experimentally rolling reduction device (hereinafter referred to 'ARS' : Antirolling System), and investigated motion reductions of a small fishing boat drifting in beam sea conditions. The summary of fact obtained from this investigation was as follows : 1) The spectra of roll angle and acceleration on Y-aXis in the boat with ARS were about 53% of that in the same boat without it. And the effect of motion reductions of experimental boat was shown in Fig. 14. 2) The double amplitude of roll angle, pitch angle and acceleration on X, Y, Z-axis could almost exactly be found by Reyleigh distribution even during ARS operation. 3) The balance-bag worked effectively on narrow frequency zone for the free rolling period of the boat. 4) The tension of the suspending wire rope was fluctuated greatly because an impulsive force was added to the boat with ARS. And the maximum tension was well applicable to Weibull distribution.
