Analysis of accidents involving davit launched lifeboats during lowering operations

In the event of an emergency situation on a vessel, such as a collision, fire, grounding, flooding, or other incident that may result in the ship being abandoned, the vessel is equipped with lifeboats, which are designed to ensure the survival of the crew and passengers. In the process of safely abandoning the vessel, the operation of launching the lifeboats acquires a vital importance. This thesis aims to identify the underlying causes of lifeboat accidents during the lowering of lifeboats on ships with side-launched davits. To achieve this, a model is presented through the use of a Fuzzy Logic Based Bayesian Network method, which incorporates expert opinions on the relationship between marginal and conditional probabilities. The results of the model indicate that the most significant factor contributing to the accidents during lifeboat operations with side-launched davits is the presence of adverse sea conditions, with an impact degree of 20%. The underlying factors contributing to the development of "Insufficient brake lining" and "Fatigue of the lifeboat hull" have been identified as having an influence of approximately 13% on the incidence of lifeboat accidents. The effect of the root cause "Insufficient installation error in the steel wire rope of the lifeboat davit" on the occurrence of lifeboat accidents is revealed to be 12%. Similarly, the effect of the root cause "Inadequate release hooks" on the lifeboat hook release mechanism is found to be 11%. Furthermore, among the root nodes identified as contributing to the occurrence of lifeboat accidents, "Inadequacy of lifeboat plug" and "Inadequacy of lifeboat gripe gear" have the lowest degree of effect, with a rate of 2%. In this context, it is hoped that this thesis study will make a significant contribution to the literature in terms of determining how lifeboat accidents occur and what are the root causes of these accidents and gaining ideas and experience to prevent accidents. It is expected that this thesis will serve as a reference source for the prevention of accidents that may occur during lifeboat operations, and it is considered that it will provide a comprehensive account of the subject matter, thereby filling a gap in the training curriculum. Keywords: Lifeboat, Davit, Lifeboat Accident, Fuzzy Logic, Bayesian Network.