The patent relates to a marine propulsive apparatus and a device and method for increasing the apparatus' efficiency by controlling the amount of wetting of the apparatus over a range of speeds. A housing, mounted in a cavity formed in the stern of a ship, encloses a drive shaft connected to a propeller. A control surface is pivotally connected to the hull of the ship ahead of the propeller and in a raised position contacts the stern portion of the hull to form the upper wall of the cavity. A hydraulic device is used to raise and lower the control surface, the latter directing the flow of water across the propulsive apparatus. As the speed of the ship increases wetting of the propulsive apparatus is decreased.

  • Supplemental Notes:
    • Government-owned invention available for licensing. Patent application filed 24 May 73.
  • Corporate Authors:

    Department of the Navy

    Washington, DC  United States 
  • Authors:
    • Mantle, P J
  • Publication Date: 1974-8-20

Media Info

  • Pagination: 4 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00130681
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: AD-D001384/7 Patent, PAT-APPL-363 447
  • Files: TRIS
  • Created Date: Mar 29 1976 12:00AM