Under The Condition Of Uncertain Bulk Liquid Chemicals Ship Safety Evaluation Method And Application Research

Bulk chemical tankers transportation is the subsidiary market in the traffic and transportation market. It serves the logistics of the production and consuming in the petroleum industry, coal industry and inorganic chemistry industry etc. These industries play very important roles not only for people’s living but also for national security. However, bulk chemical tankers transportation is the market with high danger and complication. The operation process of the bulk chemical tankers need more deliberation especially in loading, discharging and the hold washing. Besides, the safety training and safety equipment preparing are more indispensable for bulk chemical tankers. Once accident happen to the bulk chemical tankers, the destroy effect would be much more serious than other kind of maritime accident. Briefly, the research the safety of bulk chemical tankers has great significance both in theory and in practice.Uncertainty has high influence on the safety of bulk chemical tanker. How to make safety assessment for bulk chemical tanker is difficult point in the industry. The current research focus on the expert’s experience on board, which is lack of the theory support. Safety assessment of bulk chemical tanker under uncertainty is the main topic which will be research in this dissertation.The main results achieved in this dissertation are as follows:(1) The approach of safety assessment to bulk chemical tankerThis dissertation design a new safety approach, named bulk Chemical Tanker Safety Assessment (CTSA), basing on the formal safety assessment (FSA), which concerns the features of bulk chemical tankers. By using of the ETA method, regulatory influence diagrams, maritime hazard matrix and entropy value method, the CTSA approach is proved be more effect than FSA approach.A result of application of CTSA approach is hazard elements of bulk chemical tankers. There are 14 hazard elements for single vessel including chemical tanker’s certification, manning management and personnel on chemical tanker, bridge management, mooring, chemical cargo operations, engine department management, danger operational safety, health safety and personnel protection, firefighting, lifesaving, environmental protection, security, hull, accommodation.Another result of application of CTSA approach is trial safety checklist design of bulk chemical tankers.(2) Data fusion under uncertaintyHow to fuse data form safety assessment under uncertainty is difficult point in the safety area of bulk chemical tanker. Comparing with several theories of data fusing, this dissertation takes advantage of Dempster-Shafer theory to solve the problem. Besides, the range of suitable for using and paradox problem is also analyzed. Finally, a safety index of bulk chemical tanker is calculated.There are four kinds of uncertainty relating with maritime affairs, which are uncertainty of fuzzy, uncertainty of uncompleted, uncertainty of unascertainment and uncertainty of random. Dempster-Shafer theory could help to solve the data fusing problem caused by uncertainty of uncompleted but hard to solve the data fusing problem caused by uncertainty of unascertainment. Thus it is necessary to extend the close frame discernment to open frame discernment in Dempster-Shafer theory.(3)Test of safety index of bulk chemical tankerIt is difficult point to evaluate the result of safety assessment. Thus, this dissertation designs an approach to test the safety index of bulk chemical tanker. In the first place, large vessel model and small vessel model are defined. Then by using of sampling step, two bulk chemical tankers are confirmed. Experts are sent to these two vessels and get the subjective comments. Comparing the result of safety index with the subjective comments, the approach of data fusion is tested.Compared with the previous studies by other researchers in the world, the main innovations and contributions of this dissertation can be summarized as following three points:1. Basing on the formal safety assessment (FSA) model, which has been widely used in many areas. A new approaches i.e. bulk Chemical Tanker Safety Assessment (CTSA) which is more suitable in the bulk chemical tanker transportation is designed. Besides, the concept of open safety document is defined.2. Take advantage of Dempster-Shafer theory, an algorithm of safety index for the bulk chemical tanker is designed, which hasn’t be solved by current researches.3. For solving the data fusing problem caused by uncertainty of unascertainment, extending from close frame discernment to open frame discernment in Dempster-Shafer theory is achieved.