Pages 177-185
The pressure hull of deep submergence research vehicle is an utmost important structure that secures the safety of crew members against the hydrostatic pressure in deep sea, and should be as compact in size and light in weight as possible in order to obtain easy operation and high maneuverability of the vehicle. In design and fabrication of the pressure hull, the application of high strength material which has reliable characteristic for practical use, of design method suitable for such material and fabrication procedure which satisfies the quality requirement of the highest degree have been encouraged. In the develoment of the 6500m deep submergence research vehicle "SHINKAI 6500", which is the latest submergence research vehicle following the 2000m deep submergence research vehicle "SHINKAI 2000" in Japan, the investigation in various fields was carried out in order to adopt titanium alloy, which has superior strength/weight ratio, for the pressure hull. The production procedure of heavy thickness and large size plate and forging material, and the fabrication procedure of the pressure hull were investigated by the fabrication of the full scale model made of titanium alloy and by material tests with specimens cut from the model. The collapse behaviour was examined by collapse tests using scale models of titanium alloy and by nonlinear behaviour analysis with FEM procedure. Finally, in order to confirm both the fabrication procedure and design method in total, the cyclic loading test and collapse test using scale model fabricated according to the procedure equivalent to that for the actual pressure hull. This paper presents the design and fabrication of the pressure hull of "SHINKAI 6500".
