ON THE STRENGTH OF CONTAINER SHIPS

The major problem in the design of a ship with large hatch opening such as a container ship is to make clear her torsional behaviour. Theoretical investigation was carried out on this problem and besides this, a model test was carried out to confirm the reliability of the theoretical investigation, finding the coincidence with each other. The torsional behaviour of the Hakone Maru was investigated by this method. Torsional moment acting on the hull was obtained statically and the value of the moment was compared with that of Wildes and Vedelers. Distortion of hatch opening of a container ship is six times as large as that of an ordinary cargo ship. In the case of container ship, the breadth of outboard deck is small and its horizontal rigidity is considerably low. Therefore, the transverse strength of main hull is of great importance. Three-dimensional structure analysis was carried out by the use of digital computer to obtain stress distributions in double bottom and side structure. In addition to the above-mentioned investigation, a model test was carried out in order to investigate local strength stress--concentration in hatch corner and fatigue strength of the cross point of longitudinal bulkhead and inner bottom platings. The results obtained from these investigations were adopted in the design of the structural details. ( Author )