7000 m class ROV KAIKO7000

On May 29th, 2003, 10000 m class ROV KAIKO cruised for research mission in Nankai Trough at the southeast of 130km off Cape Muroto in Kochi prefecture. After completing the research mission at a depth of 4675 m, the vehicle of KAIKO has been missing because the secondary cable connecting the launcher and vehicle was snapped. Immediately, the vehicle has been searched from surface and air but it could not find. JAMSTEC has planned to remodel the 7000m class thin cable system ROV UROV7K as a replacement of the KAIKO vehicle, though operation depth and kinematical performance of it are lower than KAIKO vehicle. And JAMSTEC would use it temporarily for deep sea research, until new KAIKO system would be built. The system with KAIKO launcher and remodeled UROV7K is called KAIKO7000. UROV7K had the battery for power source and it was linked with the support vessel using a fiber optic cable of 1mm in diameter. It was developed for the missions of monitoring deep sea mooring systems and to survey deep seafloor. Some parts of UROV7K have been remodeled for replacement of the KAIKO vehicle. Main remodeling points were power supply system, increasing thrust and communication line. Furthermore, the safety measures pointed out by the Committee for the Investigation of Accident, have been included, too. KAIKO7000 has been finished remodeling in March, 2004, and the sea trials have been started in April, 2004. This paper describes about remodeling of KAIKO7000.