Buzlu sularda risk değerlendirmesi ve deniz kaza analizi

The crux of this thesis is to understand sea ship navigation in ice-covered waters. Arctic sea ice melts fast and soon the North Pole is foreseen to be open water. Besides several disadvantages of the global warming to the environment and ecology, it brings some opportunities to the transportation industry. For instance, the Northern Sea Route shortens the maritime distance approximately 7000 nautical miles comparing to the conventional Suez Canal route. This research examines three main topics that are tightly connected each other and may significantly affect polar navigation. Before preparing the voyage plan, statistics and root causes of marine accidents are emerging issues for the polar regions. Secondly, all probable risks and their levels require attention. Finally, if it is decided to navigate through ice-covered waters, the route selection problem should be dealt with through a proper procedure. The mentioned issues are investigated as three chapters in the thesis and each chapters are summarized as follows. In the third chapter, navigational risk factors of the ice navigation are defined and numerical weights of each risk are obtained by using Improved Fuzzy Analytical Hierarchy Process (IF-AHP) method after conducting expert consultations. Navigational routes of North Pole take a significant role of having economic and time advantage for global logistics. Its geographical position, presence of ice, heavy weather conditions, strong currents and winds are some risks for Polar transportation. There always have the possibility of unpredictable catastrophes (marine accidents) such as a collision, grounding, hull damage, etc. in ice-covered waters. Reflections of such unwanted incidents might be very costly for economic, political, environmental and safety concerns. However, there are limited researches regarding to analytic and systematical risk identification and determination of risk levels. The novelty of this chapter is that we consider the expert consultations in order to transform the linguistic expressions into numerical values. IF-AHP method including the expert aggregation and consistency check is used to analyze the data. The results and discussion are expected to guide the representatives understanding to minimize the probable risks before they occur. The aim of the fourth chapter is to understand minimizing the vessel damages and marine accidents occurring in the Arctic region by using Fuzzy Fault Tree Analysis (FFTA) algorithm. Ice navigation has been conducted intensively in summer seasons of the year in the last five years. Therefore, navigation-oriented risk assessment is an emerging issue in the polar regions which are gained from the previous marine accidents in terms of safety. In this chapter, root causes of collision and grounding for the ice navigation are constructed. Risk levels of each factor are determined by expert consultations. Mitigation effectiveness of the precautions is also discussed to prevent the future incidents and provide an enhancement of the safe navigation.