Development of the Algorithm to Estimate the Accident Risk for Coastal Ferry by Analysis of Lashed Trailer Accelerations

Coastal ferry has the main purpose to transport cargo such as vehicles and trailers, as well as to transport passengers. For safe cargo transportation, the cargo securing safety of coastal ferry must be ensured to prevent the maritime accident. However, the standards for the cargo securing safety are not properly presented as the rules for coastal ferry in accordance with actual operations. Therefore, coastal ferry is exposed to the risk of accidents due to not sufficient standards for the cargo securing safety. In this study, the accident of coastal ferry that occurred in Korea and Japan are analyzed from the perspective of cargo securing safety. First, the wave conditions at the time of the accident were reproduced using a wave simulation model. The reproduced wave spectrum was applied to the ship motion models to estimate rolling and pitching of the coastal ferry. Finally, the acceleration of the trailer loaded on the ferry was calculated based on the ship motions. The simulated results were compared and evaluated with the standard value of IMO's Cargo Securing Manual. As a result, the exact accident time was predicted, and the wave height and ship motions were additionally presented as evaluation criteria for cargo securing safety. The results of this study are expected to improve the safety standards of coastal ferry and could reduce the maritime accident cause by the insufficient cargo securing.