Investigating the Capsizing Incident of the RoPax OCD Vessel Utilizing the RAO Approach in Wave Conditions

RoPax is the most famous ship in the world that simultaneously carries multipurpose such as passengers, cargo, and vehicles in bulk. Cargo ships experience the most accidents, but RoPax ships contribute the most casualties worldwide. RoPax OCD is practical and economical for the short-medium route but vulnerable in intact dynamic stability that causes capsize. The paper analyses the data of RoPax Opened Car Deck (OCD) accidents in range time (2003-2021) in Indonesia water that is reviewed by the Response Amplitude Operator (RAO). Internal ship data is obtained from Indonesia's National Transportation Safety Committee (NTSC), and external data on wave characteristics are obtained from Global Ocean Waves Reanalysis Waves of Copernicus Marine Service. From RAO analysis of eight capsizing cases of RoPax OCD show that 62.5% occur in sub-critical (effect of low stability moment), 25% occur in supercritical (a result of small weight inertia moment), and 12.5% occur in critical (a consequence of small damping moment). The conclusion is that stability problems are the leading cause of the capsizing of RoPax, so existing ships must improve their stability or be diverted to operation areas with suitable wave characteristics.