GB1167547A - Improvements in or relating to Tank Systems for Stabilising Vessels - Google Patents

Abstract

1,167,547. Stabilizing marine-craft. MUIRHEAD Ltd. 29 Aug., 1967 [20 Oct., 1966; 20 Dec., 1966], Nos. 46950/66 and 56935/66. Heading B7M. A stabilizer for a marine craft, or buoyant structure, to minimize rolling, or pitching, thereof comprises a tank 1, Figs. 1a and 1b, containing a liquid, e.g. water, in a free-surface condition and a buoyant body, or member, 2 of spherical configuration, the top or roof of the tank being of part-cylindrical shape such that when the craft rolls said body moves towards the highest part of the tank in a direction transversely of the axis about which rolling occurs whereby the liquid applies a load to the side of the craft that is about to ascend. In a second embodiment, Figs. 2a and 2b (not shown), the body 2 is replaced by a rectangular buoyant-body (3) furnished with a plurality of wheels or rollers (4) that engage with the roof of the tank. Said roof may be modified, Figs. 3a and 3b (not shown), so that it includes two outwardly-curved surfaces, which are engaged by the wheels or rollers and vary the motion of the buoyant body accordingly. The ends of the tank may contain openings that are controlled by verticallyslidable doors or valve members (11), Fig. 8 (not shown), whereby water of floatation can flow into, or out of, the tank and the quantity of water in the tank can be varied. In a third embodiment, Figs. 4a to 5b (not shown), the body (3) is attached to the bottom of the tank by two pairs of pivoted links (5), which may be either parallel to each other or mutually inclined. In a fourth embodiment, Fig. 6, the body 3 has wheels 4 thereon engaging with a vertically movable cam 6, the location of which cam can be varied by screws 9 driven by a motor 7 through gears 8, a stop pin 10 in the centre of the cam being provided to effect locking of the body 3 in any desired position (when required). The cam may be modified, Fig. 7 (not shown), so that its profile is variable, this being effected by forming the cam from two separate parts that are coupled to each other and a single adjusting screw (9) by a hinge pin (6a), the screw being at the centre of the tank and each part of the cam being pivotally attached to the tank at its longitudinally outermost end. In a fifth embodiment, Fig. 9 (not shown), the oscillatory motion of the body (3) in response to rolling of the craft is regulated by an arcuate rack meshing with pinions (4a) on said body, which pinions are controlled by a brake (12) and roll-sensing means (13), the rack being fixed to the uppermost part of the tank. The buoyant body may be provided with wheels or rollers that engage with the sides of the tank and may be made of metal, fibreglass, plastics, or an elastomeric material such as rubber.