GB1395549A - Ships rudder device - Google Patents

Abstract

1395549 Ships' rudders STOCZNIA SZCZECINSKA IM ADOLFA WARSKIEGO 31 July 1972 [5 Aug 1971] 35671/72 Heading B7V A ships' propulsion and steering arrangement comprising a propeller, a vertically extending fixed rudder-post disposed aft of the propeller, and a rudder disposed aft of said rudder-post and pivotally connected thereto so as to be pivotable about a vertically extending axis is characterized in that there is provided a blade which is mounted on said rudder-post so as to extend on both lateral sides thereof at the level of the axis of rotation of said propeller. In one embodiment (Fig. 1) the fin 1 is rigidly attached to the rudder post 2 in the plane of the axis of propeller 4. The fin may be pivotable by a hydraulic ram about a horizontal axis, at right angles to the propeller axis, 20 as to have variable angle of attack. The fin may comprise a leading part and a trailing part which are relatively movable, one part or the other being rigidly attached to the rudder post. In another embodiment (Figs. 7, 8 and 9, not shown) the fin comprises two parts one of which is attached to the rudder itself and is movable in a slot in the other part which is rigidly attached to the rudder post. Both parts extend both sides of the rudder assembly. The invention may be applied to multipropeller ships, one arrangement comprising a central fin portion rigidly attached to the rudder post having adjustable tips pivotable about fore-and-aft axes (Fig. 11, not shown). The effective area of the fin may be variable by providing fin tips which are pivoted, near one corner, to a fixed central portion about vertical axes and are movable by hydraulic rams (Fig. 12, not shown). In a modification (Fig. 13, not shown), each fin tips is displaceable sideways relative to the fixed central portion by means of a pair of hydraulic rams.