Ship's hull vibration damper

Abstract

There is described an apparatus for inclusion in a ship comprising a mass (10), means (16) for vibrationally coupling the mass (10) to the ship's hull (12) and means (28) for damping the movement of the mass (10), the mass (10) being so sized and located as to, when in use, reduce the fundamental and/or harmonics of a transverse two node mode of wave-induced vibration in the ship's hull (12). There is also described an apparatus for inclusion in a ship comprising a mass (10) made up in part of the tackle or fitments of the ship, means (16) for vibrationally coupling the mass (10) to the ship's hull (12) and means (28) for damping the movement of the mass (10) so as to thereby, when in use, reduce vibrations in the ship's hull (12). In a preferred embodiment the mass (10) is in part comprised of a chain locker and that portion of the chain stored therein. By reducing vibrations in the ship's hull (12) significant stresses may be relieved and the performance of the ship enhanced. A ship incorporating the apparatus and a method of reducing vibrations in a ship's hull are also described.