Abstract: A hydraulic drive system for a wing sail on a vessel, comprising a rotatable frame at the base of the mast and hydraulic cylinders connected between the frame and the ship's structure to cause rotation of the frame in either direction through a limited angle, and a brake is provided on the frame for transmitting rotation of the frame to the mast when the frame is rotating in a direction that it is desired for the mast to rotate, and a brake is provided for preventing rotation of the mast when the frame rotates in the opposite direction, whereby the mast may be rotated through a desired angle by oscillatory movement of the rotatable frame.

Abstract: A sail support and control system designed for use as sail assist propulsion on a cargo vessel.The system provides complete powered control of the amount of exposed sail, the angle of the sail in relation to the vessel, and clew outhaul and downhaul tension so that no manual handling of rigging is required.