Research was carried out in the towing tank at Webb Institute using the XY method for determining ship model wave resistance from measurements of the forces exerted on a stationary vertical cylinder by the waves produced by the model. By analyzing pairs of runs at identical speed and loading, with and without the hull form change, it is possible to determine whether the hull form change is beneficial or detrimental. Using optimization theory developed in the study, it is also possible to determine what the optimum hull form change should be and what reduction in resistance is possible. The study was carried out on two hull forms, the Series 60, 0.60 Block and the Maritime Administration Multi-Purpose Mobilization Ship (MMS). A bow bulb was fitted on the Series 60 and MMS Models and a set of port and starboard protuberances were fitted on the latter. The results are encouraging both from a point of view of establishing the validity of the proposed method, including the instrumentation and data analysis system, and from the point of view of the type of results obtained for the bulb and hull form changes selected. For example, the design bulb for the MMS at design speed is shown to be only slighlty smaller than the optimum size with only a few percent more of the bare hull wave resistance remaining possible to be saved by such a device. While further improvements are needed in the technique and equipment, the system is now available for application to practical hull form design problems using the Webb facilities. The technique is now sufficiently established that others may wish to utilize in their work.

  • Corporate Authors:

    National Maritime Research Center, Kings Point

    United States Merchant Marine Academy
    Kings Point, NY  United States  11024

    Maritime Administration

    Office of Commercial Development, 1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Ward, L W
    • SEDAT, R D
  • Publication Date: 1980-5

Media Info

  • Features: References;
  • Pagination: 40 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00323300
  • Record Type: Publication
  • Report/Paper Numbers: NMRC202 Final Rpt.
  • Contract Numbers: DO-A01-78-00-3125
  • Files: TRIS, USDOT
  • Created Date: Feb 6 1981 12:00AM