HYDROSTATIC STABILITY OF LARGE HYDROFOIL CRAFT

Predictions of the weight fraction of the strut and foil system for large hydrofoil craft based on extrapolation from existing smaller vessels indicate that the strut and foil system will require an increasing percentage of the weight as vessel size increases. These projections have led to the belief that there is an upper bound on the size of hydrofoil craft. In order to maintain reasonable drafts in the hullborne mode, hydrofoil ships must have retractable foil systems. For larger craft, where the relative weight of the foil system is large, retracting the foils will have a considerable effect on the position of the vertical center of gravity. Consequently, a large hydrofoil craft operating with foils retracted may encounter a critical hydrostatic stability problem. This paper examines the potential stability problems which large hydrofoils will have to overcome. In particular, a 1,378 ton hydrofoil, for which the conceptual design has been completed, is studied in the various hullborne operating configurations. Results of a stability analysis are presented and compared with the Navy's stability criteria. Preliminary weight estimates for this large hydrofoil indicate that earlier extrapolations of the weight fraction of the strut and foil system may be excessive. The calculations also show that the stability must be improved when the vessel is operating with foils retracted. Two methods of improving stability in this condition are suggested and their effect examined.

  • Availability:
  • Corporate Authors:

    American Society of Naval Engineers

    Suite 507, 1012 14th Street, NW
    Washington, DC  USA  20005
  • Authors:
    • Adee, B H
    • Mathewson, E L
  • Publication Date: 1978-12

Media Info

  • Features: References;
  • Pagination: p. 37-47
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00187976
  • Record Type: Publication
  • Source Agency: American Society of Naval Engineers
  • Files: TRIS
  • Created Date: Feb 3 1979 12:00AM