The Effect of Moving Weights on Ship Roll Motions

In this research, the effect of weights that lose their lashing systems and can move freely in line with vessel breadths is investigated on ship roll motions. Therefore, the effect of friction and possible barriers that impeded on free movement of weights are neglected.To study the effects; weights with different masses are hung on pendulum which is installed on an ocean going trawler model and vessel roll motions is being experimentally tested.The results show that whoever hanging weights can increase the center of gravity of vessel and decrease the vessel stability; but caused increase the period of roll motions. The findings of research also can be used in design of damping systems of roll motions.In addition, the experimental results are compared with numerical results based on the Strip Theory. The results show that the damping coefficient has important role in the accuracy of numerical results.