VIBRATION REDUCING DEVICE

PROBLEM TO BE SOLVED: To reduce vibration against vibration in the multiple directions of a structure by hanging a weight at the tip of a wire type body connected to the structure and regulating the length of the wire type body in compliance with a vibration period of the structure. SOLUTION: In navigation of a ship body S, a computer 7 finds a rocking period T0 of a weight 3 on the basis of a data significant wave period T1 electrically transmitted from a measurement device 4 so as to compute a length (r), which is necessary for reducing a vibration, of a wire 2. Then, a winch 5 is driven by means of a controller 8 so that a length of the wire 2 is adjusted to the found length (r). When the periods T0 , T1 are close or substantially equal to each other, the weight 3 will stay there because of inertia, however, the weight 3 starts pendulum motion to the ship body S because of a dynamical theoretical balance as the weight 3 is hung by means of the wire 2. As a result, inertia reaction force due to the pendulum motion of the weight 3 and gravity due to gravity shift of the weight 3 are applied to the ship body S, and consequently, the vibration of the ship body S is reduced.