# Accident Risk Analysis of Gas Tankers in Maritime Transport Using an Integrated Fuzzy Approach
## 5 Discussion
\begin{table}
\begin{tabular}{l l l l} \hline \hline
**Rank** & **Risk Code** & **Risk Description** & **Key Insight** \\ \hline
1 & R4 & Fire or explosion risk & Highest risk; influenced by multiple cascading failures via AND gates \\
2 & R11 & Large gas leakage due to accident & Central risk with multiple mechanical and environmental contributors \\
3 & R2 & Gas leakage following collision & High risk in port/narrow waters; often under-addressed in past studies \\
4 & R9 & Toxic gas release & Combined result of operational, regulatory and emergency preparedness gaps \\
5 & R14 & Inadequate emergency & Affects both fire and leakage scenarios; a critical systemic procedures & vulnerability \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Top-ranked risks and key insights from analysis. and structural variables such as containment and ventilation, highlighting the need to incorporate both physical and operational design features into risk reduction strategies. An integrated framework combining event tree analysis and Computational Fluid Dynamics (CFD) has been proposed to measure LNG leakage risk and is supported by empirical case studies of valve failures [4]. The application of predictive analytics through artificial intelligence-enabled IoT systems has also been shown to improve early warning capabilities [70], potentially reducing the escalation of such incidents. Risk R3 (Corrosion and leakage in tank or pipe systems), which is classified as medium risk (1.55-0.07), reflects safety vulnerabilities related to both external environmental exposure and internal system ageing. The sensitivity of these systems to weather conditions and operational stress requires frequent inspections and preventive maintenance. Similarly, risk R15 (Technical failure in fire extinguishing systems) (1.67-0.09), although not among the highest-rated risks, highlights the importance of system reliability in emergency conditions. Despite regular testing and drills, system malfunction or accidental damage during incidents can render these systems ineffective. Extensive literature confirms the complex risk profile of gas tankers. Ref. [71] emphasises that even small leaks in LPG-carrying systems can rapidly escalate into significant emergencies if not dealt with promptly due to the thermodynamic behaviour of the mixture. Therefore, effective gas detection, leak isolation, and sensitive safety protocols are indispensable elements for the safe operation of gas tankers. The lower priority risks R20 (Impact on cargo and ship operations due to cyberattacks) (1.50-0.06) and R10 (Damage to tanker structure by marine organisms) (1.41-0.03) should not be overlooked. The increasing integration of cyber systems into maritime operations, including navigation, cargo tracking, and remote diagnostics, particularly with the advancement of autonomous ship technologies, has become a growing concern regarding cybersecurity vulnerabilities. Similarly, biological contamination and structural degradation caused by marine organisms, although occurring over a longer timeframe, can compromise hull integrity and affect fuel efficiency, necessitating proactive structural management and contamination prevention strategies. Mechanical failures were shown to be strong causal factors in both fire and gas leakage scenarios. As identified in the Fuzzy DEMATEL analysis (Table 6), risks such as R3, R7, and R16--each representing specific mechanical weaknesses--ranked among the highest contributing risks in the model. These findings confirm existing research indicating that mechanical integrity is crucial to the safe operation of LNG/LPG tankers. Preventive maintenance regimes and system redundancy should, therefore, be prioritised in safety management strategies. Environmental factors also play an important role in the likelihood of accidents. A recent study [72] has shown that LNG tankers operating in rough seas are subject to sloshing effects and dynamic instability, which increase cargo movement, structural loading, and the likelihood of mechanical failure.