Abstract: A ship's hull has a cargo deck which is located adjacent a waterline and which is intended to carry a number of barges. The cargo deck is open toward the stern of the vessel. An interior of the hull accommodates one or more ballast tanks and a device for emptying and filling the ballast tanks with water, either completely or partially, thereby enabling the hull to be brought to a shallow draft waterline or to a deeper draft waterline. An air-compressing device generates an air flow which can be delivered to the outer surfaces of the hull by a pipe system which discharges beneath the waterline. At least a part of the lowermost surface region of the hull is flat and extends horizontally. Arranged within this region is a downwardly open cavity of small height and large surface extension. The pipe system discharges at least into the cavity. Air bubbles that are generated will also reduce friction against side-related hull surfaces, even when the hull heels steeply in heavy swells.

Abstract: A displacement ship for the transport selectively of low and high density cargo includes a hull having a trapezoidal cross-section and extending between the stem and stern of the ship. The sides of the hull form an angle of from 35.degree. to 55.degree. with the horizontal and extend upwardly above the design water line of the ship a distance at least equal to one-fourth the height of the hull. The upper extremities of the side walls of the hull terminate at the main deck of the ship which is coextensive lengthwise with the hull. At least one additional deck adapted to store low-density cargo thereon and coextensive in length and width with the main deck is positioned thereabove.

Abstract: A ship for the simultaneous storage and transport of a high density flowable bulk cargo and a lower density general cargo. The ship includes a hull, a main deck and a hold below the main deck adapted to store the flowable bulk cargo therein. A plurality of loading decks are arranged fixedly above the main deck and extend over a substantial portion thereof in spaced superposed relation. Conveying devices such as mechanical conveyors or conduits and pumps are mounted beneath the main deck and extend lengthwise of the ship so as to convey the flowable bulk cargo from one end of the ship towards the other end for discharge into selected sections of the hold.