CATAMARANS-TECHNOLOGICAL LIMITS TO SIZE AND APPRAISAL OF STRUCTURAL DESIGN INFORMATION AND PROCEDURES

Existing United States shipbuilding facilities can handle 1000-foot catamarans with up to 140-foot individual hull beams on the premise that the hulls would be joined afloat. Major harbors and channels of the world suggest an overall beam limit of 400 feet and 35-foot draft. Drydocking for catamarans over 140-foot in breadth will require new facilities or extensive modification to existing facilities. Scantlings of 1000-foot catamaran cargo liner can be expected to be within current shipbuilding capabilities. The uniqueness of the catamaran design lies in the cross-structure and the important facets of the cross-structure design are the prediction of the wave-induced loads and the method of structural analysis. The primary loads are the transverse vertical bending moments, axial force, shear, and torsion moments. Designers have relied heavily on model tests to obtain design loads and have used general structures principles and individual ingenuity to perform the structural analysis in the absence of established guidelines. Simple semi-empirical equations are proposed for predicting maximum primary loads. A structural analysis method such as the one proposed by Lankford may be employed for conceptual design purposes. The Lankford method assumes the hulls to be rigid and the cross- structure loads to be absorbed by a group of transverse bulkheads and associated effective deck plating. This procedure in general should provide an overall conservative design and not necessarily an economic or optimized design. Additional research and development work including systematic model test programs are necessary for accumulating additional knowledge in areas of uncertainty and for the establishment of reliable design methods for catamaran structure.

  • Corporate Authors:

    Rosenblatt (M) and Son, Incorporated

    Arlington, VA  USA 
  • Authors:
    • Maniar, N M
    • Chiang, W P
  • Publication Date: 1971-9

Media Info

  • Features: References;
  • Pagination: 69 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00028580
  • Record Type: Publication
  • Source Agency: Ship Structure Committee
  • Report/Paper Numbers: SSC-222
  • Contract Numbers: N00024-70-C-5154
  • Files: TRIS
  • Created Date: Apr 10 1973 12:00AM