Abstract: A rudder system is provided on a vessel with an open propeller or no propeller, comprising at least three rudders coupled to turn in unison and operating as a cascade. The rudders are mounted on stocks journalled in bearings carried by a box above the rudder which box is fitted into a recess in the hull. A master tiller is provided on the center stock, and the three stocks are coupled to one another within the box.

Abstract: A roll-damping tank for ships to extend athwartships and to contain liquid that moves in the direction from end to end of the tank as the ship rolls, in which the ends of the tank at the sides of the ship are configured by curving or chamfering to destroy the velocity of the wave in the tank.

Abstract: In a ship's roll damping tank, means are provided that are operative to extract substantial wave velocity energy from the liquid in the tank. Perforated pipes are laid in spaced parallel relationship across the bottom of the tank, i.e. in the fore and aft direction of the ship, to create, by injection from the pipes into the tank liquid, upflows of fluid that interfere with the normal orbital movement of the tank liquid wave particles.Wave velocity energy can likewise be extracted by means of an apertured false bottom, upward protuberances on the tank floor, and perforated or unperforated horizontal end baffles.