Containerships have remarkably larger hatches as compared with conventional cargo vessels, resulting in the reduc- tion of deck rigidity and overall torsional rigidity. Several studies on the torsional rigidity of ships hull structure having larger hatch openings have been carried out taking the effects of cross decks into consideration. The width of cross deck which resists the hull torsion has to be limited to the minimum from the economical point of views of container loading and therefore it is not always easy to fulfil these contra- dictive conditions successfully, in the design of the hull structure. Accordingly, the effectiveness of bulkhead structure against torsion and the effect of the rigidity and numbers of bulkheads on the torsional rigidity of ships hull are examined both theoretically and experimentally in the study herein presented. At first, it is confirmed from elementary theory and expermients that bulkheads are considerably effective for the torsion of the thin walled beam of U-shaped section whose torsional behavior can be described with bending- torsion theory. Secondly, a method of analysis to calculate the torsional regidity of the beam which has uniform open section and arbitrary numbers of elastic bulkheads is derived on the basis of the obtained resistive behavior of the bulkheads from a series of experiments on ships model. Thirdly, the application of this analysis to a container ship, introducing the equivalent length of the box beam form is discussed. Further researches are made to obtain a more accurate analysis for practice applications introducing the effect of the bow and stern in ships form directly into the the theoretical process of the bending-torsion analysis. Lastly, it is concluded that the effective bulkhead structure will prevent a larger reduction in torsional rigidity of container-ship hull structure.

  • Corporate Authors:

    Ship Research Institute, Tokyo

    38-1, 6-chome, Shinkawa, Mitaka-shi
    Tokyo,   Japan 
  • Publication Date: 0

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 21 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00007442
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 22 1973 12:00AM