Risk assessment to improve reliability in towing system of tugboats using fuzzy based FMEA

The towing system is one of the most crucial parts of a tug boat. The towing process in tugboats, where a lot of machines and ship equipment are involved in the process, carries many risks and potential failures. Therefore, this operation can cause serious injuries, fatal accidents, equipment damage, disruption of towing operations and loss of time and money. In this study, a comprehensive risk analysis was conducted to increase the reliability of the tugboat towing system. Firstly, the failure modes, causes and results of the towing system were determined. Then, the failure modes and effect analysis method were integrated with the rule-based fuzzy approach and risk prioritization was performed. According to the findings, the three critical failure modes among 23 failure modes were towing system rope failure, insufficient air supply to the towing system from the compressor and cracking or breaking of system components, respectively. Additionally, corrective and preventive actions were suggested for a total of eleven failure modes with high RPN values. This study aims not only to provide a theoretical contribution to the prevention of towing system-related accidents, but also to provide a practical framework that can be used in practice for all maritime stakeholders, especially tugboat owners and crews.