STRUCTURAL STRENGTH OF LARGE BULK CARRIERS

The recent tendency to construct larger ships, which originated in oil tankers, is now prevailing into bulk carriers. The calculation of the structural strength of bulk carriers which have top side tanks and hopper tanks cannot be done with such perfectness as that of oil tankers because of their complicated structures. The authors tried to calculate it more accurately by using a space frame structure model. This calculation method can be divided into 2 parts. In the first part, the structural strength of the 3 holds is calculated by using the computer program for the space structure and load distribution among the longitudinal members and the transverse members is obtained. Using this load distribution, the second part of the calculation is carried out to obtain the bending moment and the shearing force of the transverse members. The main points of the results of the method of calculation employed and the results of its application to the analysis of a 133,000 DWt bulk carrier are as follows: ( 1 ) If the rigidity of the side frame is increased, stress arising in itself becomes smaller, but stresses in the adjacent members in the hopper tanks and the top side tanks become larger on the contrary. ( 2 ) Stresses and deflections increase with hold length. ( 3 ) When a ship is to be enlarged, the hold aspect ratio ( length/breadth ) should be reduced in order to prevent birth of large stresses. Needless to say, this should be done in relation to the structure of the hold i.e. the height of the double bottom, the structure of the side frame, etc.

• Corporate Authors:

  Mitsubishi Heavy Industries Limited

  5-1 Marunouchi, 2-chome, Chiyoda-Ku
  Tokyo 100,   Japan 
• Authors:
  • Hagiwara, Koichi
  • Nawata, Takuo
  • Watanabe, Shomitsu
  • Matsumae, Hiroshi
• Publication Date: 1970-1

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 43-51
• Serial:
  • Technical Review
  • Volume: 7
  • Issue Number: 1
  • Publisher: Mitsubishi Heavy Industries Limited

Subject/Index Terms

• TRT Terms: Hulls; Strength of materials; Structural analysis
• Old TRIS Terms: Hull strength
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00003090
• Record Type: Publication
• Files: TRIS
• Created Date: Oct 30 1971 12:00AM