Quantitative Risk Assessment Of The Tankers Subjected To Collision And Grounding Accidents

Marine accident is inevitable to aviod, such as collision and grounding accident, during oil tanker voyage. As oil tankers'side less protection, affected by the impact, oil tankers have been violently shaken, which may cause serious damage, easily lead to oil spills, and the event of fire. It is highly likely to escalate into a fire and explosion accidents, endangering the safety of equipment and personnel, and significant environmental pollution. Quantitative risk assessment techniques could scientifically predict the probability of accident and the extent of damage, thus reducing the risk of accidents. In recent years, it has aroused widespread concern in marine and ocean engineering field. It is significant important to establish the risk assessment of tanker transportation system, to improve the security of tanker transportation.This paper summarizes the theory of risk assessment methods and risk acceptance criteria. Risk of vessel collision and grounding accidents are identified. Probability of accidents is calculated, in virtue of computer program. On account of fault tree analysis defect, Bayesian network technology is introduced to study human and organization factors. Based on industry standards and with NEPTUNE software, the consequences of oil spills from oil tanker are simulated, realized the scope of the accident and made a scientific prediction of risk reduction measures. Combined a collision accident occurred actually, study on multi-level fuzzy comprehensive evaluation based on risk analysis.In this paper, the work and conclusions were as follows:(1) Seting out the theory of risk assessment, and tanker collision, grounding accidents risk identification; compares the advantages and disadvantages of various methods of analysis, and from both the probability and consequences of the measures of risks research; studies on the criteria of personal risk, social risk, environmental risk, after the vessel failure, for the acceptability of the ship and the development of methodologies.?(2) According to statistics on oil tanker accidents, the oil tanker collision, grounding of the accident characteristics is analyzed; based on the binomial distribution theory, the waters of a typical annual probability of occurrence of major accidents is predicted.(3) In accordance with P.T.Pedersen and Fujii collision model, refer to DNV passing ships and marine platforms collision risk analysis methods, the mathematical calculation model of vessel collision, grounding accidents is established, and computing programs are written to calculate the vessel at different angles collisions and different channel widths of the probability of an accident occurring grounding, which be found that the probability of ship collision accident increases exponentially as the perspective of growth, the probability of ship grounding incidents as the channel width increases exponentially decreasing, results and statistical data consistent.(4) As human and organization errors analysis is a dominant position of vessel collision factors. Bayesian network is introduced to make a quantitative analysis about vessel grounding on account of fault tree analysis defect, list the most likely sequence of events, put forward risk reduction measures, and from reducing the probability of events to consider proposed mitigation measures.(5) Analysis of the oil spill on the environment hazards and human impact of production activities, environmental protection industry standards and NEPTUNE software are used to calculate parameters such as oil spills speed, simulate the expanded scope. Then the probability and range of fire occurrence is predicted, proposing a new type of marine fire protection structures from reducing the accident consequences which achieved good fire protection.(6) On the basis of the theory of fuzzy comprehensive evaluation, six parameters, the quantity and character of oil, type of the sea, tanker condition, weather and human factors, have been introduced as 1st index, further divided into the 2nd index. The Analytic Hierarchy Process is used to calculate the weight coefficients of each parameter to achieve a tanker oil spill Fuzzy Comprehensive Evaluation of risk harm.