# Accident Risk Analysis of Gas Tankers in Maritime Transport Using an Integrated Fuzzy Approach
## 4 Findings
### Interaction Analysis Between Fuzzy DEMATEL and Risks  
In the second part of the study, the risks obtained in the first part using the Fuzzy Delphi method were analysed using the Fuzzy DEMATEL method. The Cause Score, Result Score, and Total Interaction Scores were determined using the Fuzzy DEMATEL method. The risks were ranked from the highest to the lowest scores obtained. In the next stage of this study, the sum of the rows (R) and the sum of the columns (C) were calculated using Equations (A17) and (A18) to produce an effective FTA diagram. The R \(-\) C and R \(+\) C values were calculated using Equations (A19) and (A20) with the R and C values. Table 6 presents the risks according to their score rankings. \begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Risk Factor (R)** & **Cause Score (R)** & **Outcome Score (C)** & **R + C** & **R \(-\) C** \\ \hline R1 & 0.79 & 0.74 & 1.53 & 0.05 \\ \hline R2 & 0.92 & 0.85 & 1.79 & 0.07 \\ \hline R3 & 0.81 & 0.74 & 1.55 & 0.07 \\ \hline R4 & 0.96 & 0.85 & 1.81 & 0.11 \\ \hline R5 & 0.83 & 0.78 & 1.62 & 0.05 \\ \hline R6 & 0.76 & 0.70 & 1.46 & 0.06 \\ \hline R7 & 0.84 & 0.76 & 1.60 & 0.08 \\ \hline R8 & 0.78 & 0.74 & 1.49 & 0.04 \\ \hline R9 & 0.94 & 0.83 & 1.77 & 0.09 \\ \hline R10 & 0.72 & 0.69 & 1.41 & 0.03 \\ \hline R11 & 0.95 & 0.85 & 1.80 & 0.10 \\ \hline R12 & 0.74 & 0.70 & 1.44 & 0.04 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Distribution of risks according to Cause Score, Consequence Score, and Total Interaction Score. \begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Risk Code** & **Risk Factor** & **Explanation** & **Risk Group** & **Priority Score (0-1)** \\ \hline R16 & Failure of cargo tank & Failure of the gas tank cargo pressure control system & & \\  & pressure control systems & due to failure to perform routine checks, technical & \\  & & failure during operation, or failure and & \\  & & disengagement in the event of an accident [1, 68, 71]. & & \\ \hline R17 & Incorrect valve or pump & The failure of personnel to carry out routine & \\  & & operations during gas handling operations may be & \\  & & operation due to human & attributed to a number of factors, including a lack of \\  & & error & awareness, negligence, fatigue, or similar reasons & \\  & & & [1, 22, 25]. & \\ \hline R18 & Failure to fully comply & There was a failure to ensure that sufficient & \\  & & operational requirements were in place, in & \\  & with international gas & accordance with the established rules and & \\  & transport regulations & precautions that should be observed during gas & \\  & & operations and in accordance with international gas & \\  & & transport regulations [1, 68, 71]. & & \\ \hline R19 & Inadequate post-accident & This refers to a situation where the emergency crisis & \\  & & management plans prepared by the company for & \\  & & crisis management plans & personnel to follow in the event of an accident during & \\  & & gas operations are inadequate for the accident in & \\  & & question [25, 26, 72, 73, 74]. & & \\ \hline R20 & Impact on cargo and & Disabling ship electronic systems due to & \\  & vessel operations due to & cyber-attacks [75, 76]. & security & 0.77 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: _Cont._According to the data obtained in the study, R4 (Risk of fire or explosion) ranked first. This was expected as it is considered to be the highest risk factor for gas tankers. R11 (Large gas leakage due to accident) was ranked second. Gas leakage poses a serious risk due to its rapid spread throughout the ship and into the environment. In third place was R2 (Gas leakage following collision or grounding). For this risk factor, the risk is very low because the incident occurs under the ship, although cargo spillage poses a serious hazard. Risks between R1 and R13 and those between R15 and R17 were identified as accident-causing risks because they have positive (+) values. Risks R14, R18, R19, and R20 were identified as accident-influencing risks because they have negative (\(-\)) values.