Research Cooperation With Maritime Research Institute Netherlands(ＭＡＲＩＮ)

      The NMRI enters into cooperative research agreements with various foreign research institutes.These agreements are expected to expand the more effective utilization of research resources, the sharing of research achievement, to develop further new research themes, and to expand and popularize the research achievement. As one of such arrangements, on November 4, 2002, the NMRI concluded a comprehensive cooperative research agreement with the Maritime Research Institute Netherlands (MARIN), located in Wageningen, the Netherlands.

　　　Based on the above-mentioned agreement with MARIN, Dr. Yoshitaka Ogawa, senior researcher of the NMRI’s Maritime Safety Department, stayed at MARIN. He engaged in joint research on an intact stability of a large passenger ship. This joint research aims at the development of a methodology to evaluate and improve the weather criterion, which is the one of rules of the International Maritime Organization (IMO), from a safety and rational rule-making point of view. The research entails both numerical simulations and model tests in wind and waves at different operating conditions.

The numerical simulations of the probability of capsizing were conducted by the cooperation work between the NMRI and MARIN. The computer program for the estimation of the probability of capsizing was developed by the NMRI. With regard to the roll motion as an input for this program, a time domain simulation program, which is developed by MARIN, was used.

In addition to the numerical simulations, model tests in a severe sea state had been carried out at MARIN’s Seakeeping and Manoeuvring Basin (SMB) by means of the large passenger ship.

  Based on the examination by means of both numerical simulations and model tests, it was confirmed that

(1) the probability of capsize in winds and waves is higher than the one in waves only, and

(2) the loading condition, which is specified by the weather criterion, has an impact on the safety level of a large passenger ship.

 As a result, it was clarified that winds and waves should be considered in weather criterion not separately but simultaneously for the provision of the adequate safety.

 These findings are reflected in a joint paper of The Netherlands and Japan for the 46th Sub-Committee on Stability, Load Lines and Fishing Vessels Safety of the IMO (IMO/SLF46/6/12).