Apparatus to reduce vessel motions

Abstract

The invention relates to apparatus for reducing the relative motion of a vessel and for reducing the intensity of waves reflected from the vessel. According to the invention, the vessel is provided with at least two specially designed tanks or cavities, one on the starboard side of the vessel and one on the port side of the vessel. The tanks extend above and below the mean water line of the vessel. In one embodiment of the invention, each tank has (a) a bottom plate which extends substantially laterally outward from at least a portion of the bottom of the vessel and which is freely accessible to the surrounding water; (b) vertically aligned, transversely extending, outwardly directed, perforate plates which are spaced apart along a longitudinal length of the tank, and (c) a vertically aligned, longitudinally extending perforate plate or bulkhead which is spaced apart from the vessel along a longitudinal length of the tank. In other embodiments, more than one perforate longitudinally extending bulkhead or baffle is provided between the bottom plate and a laterally extending upper member to further reduce the intensity of waves reflected from the vessel. In another aspect of the invention, buoyancy chambers may be provided to counterbalance the weight added by the perforate plates, bulkheads, and the bottom plate. In yet another aspect of the invention, only longitudinal bulkheads are used in combination with the buoyancy chambers to reduce the relative motion of the vessel.