• Journal of the Institute of Convergence Signal Processing
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• v.25 no.2
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• pp.86-93
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• 2024

This study evaluates the stability of a 4.99-ton small coastal fishing boat using data interpreted according to the second-generation intact stability criteria of the International Maritime Organization (IMO). The focus is on the ship's behavior under surfriding/broaching conditions during sea navigation, ensuring compliance with international standards. The data processing procedures presented apply stricter criteria than the first-generation intact stability standards to assess the ship's intact stability in waves. However, if the vessel deviates from its standard condition, a separate intact stability assessment based on actual loading conditions is necessary. The surfriding/broaching data processing procedures utilized a program developed by the Shipbuilding and Ocean Equipment Research Center at Kunsan National University. The results were analyzed and compared in detail according to the conditions, parameters, and criteria used for the calculations. Additionally, the study presents the results of Level 1 and Level 2 assessments according to IMO regulations, providing a parametric analysis of the small coastal fishing boat's stability. This allows for the evaluation of intact stability in hydrodynamic motion scenarios.tract.

• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.518-525
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• 2019

Recently, the Sub-Committee on SDC (Ship Design and Construction) of IMO have discussed actively the technical issues associated with the second-generation intact stability criteria of ships. Generally, second generation intact stability criteria refer to vulnerability five modes ship stability which occurs when the ship navigating in rough seas. As waves passes the ship, dynamic roll motion phenomenon will affect ship stability that may lead to capsizing. Multi-tiered approach for second generation of intact stability criteria of IMO instruments covers apply for all ships. Each ship is checked for vulnerability to pure loss of stability, parametric roll, and broaching/surf-riding phenomena using L1(level 1) vulnerability criteria. If a possible vulnerability is detected, then the L2(level 2) criteria is used, followed by direct stability assessment, if necessary. In this study, we propose a new method to verify the criteria of the surf-riding/broaching mode of small ships. In case, L1 vulnerability criteria is not satisfied based on the relatively simple calculation using the Froude number, we presented the calculation code for the L2 criteria considering the hydrodynamics in waves to perform the more complicated calculation. Then the vulnerability criteria were reviewed based on the data for a given ship. The value of C, which is the probability of the vulnerability criteria for surf-riding/broaching, was calculated. The criteria value C is considered in new approach method using the Froude-Krylov force and the diffraction force. The result shows lower values when considering both the Froude-rylov force and the diffraction force than with only the Froude-Krylov force was considered. This difference means that when dynamic roll motion of ship, more exact wave force needs considered for second generation intact stability criteria This result will contribute to basic ship design process according to the IMO Second-Generation Intact Stability Criteria.