An Analysis of Port State Control Performance for RORO Ships Using the Bayesian Network

An Analysis of Port State Control Performance for RORO Ships Using the Bayesian Network

The number of maritime accidents involving roll-on/roll-off ships (RORO ships) resulting in casualties remains high. Currently, research on the maritime safety of RORO ships is relatively limited compared to that of other types of vessels. This study employs the Bayesian Network (BN) to analyze RORO ships recorded for deficiencies in the Memorandum of Understanding on Port State Control in the Asia-Pacific Region (Tokyo MOU) from 2015 to 2024, examining the most frequently logged deficiencies for RORO ships and their detention risks while exploring the key factors leading to the deficiencies or detentions. The analysis indicates that RORO passenger ships have a higher proportion of deficiencies related to personnel safety, while RORO cargo ships exhibit deficiencies not only in personnel safety but also in navigation safety and labour conditions. Additionally, RORO cargo ships have a higher detention rate than RORO passenger ones. The detention rate significantly increases when RORO cargo ships are recorded for structural conditions or other categories, and when RORO passenger ships are logged for other categories, International Safety Management (ISM), or safety of navigation. Furthermore, the detention rates increase significantly for RORO ships older than 30 years.