Title: Modelling Marine Accident Frequency Major Subject (name and Code): Systems and Operations Research Mat-2 Minor Subject (name and Code): Strategy and International Business Tu-91 Chair (name and Code): Applied Mathematics Mat-2

In this thesis, the author concentrates on marine accident frequency models and on the analytical estimation of accident frequency in the Gulf of Finland. The Gulf of Finland is a sensitive sea area and a part of Baltic Sea. Automatic Identification System (AIS) data of 2008 is used in the calculations of ship-ship collision and grounding frequency. In addition, an estimate of collision frequency in the Gulf of Finland in 2015 is made based on a future traffic scenario. The focus is on the number of accident candidates. Causation factors, which quantify the probability of not making successful evasive manoeuvres while being on an accident course, are taken from earlier work. IWRAP Mk2 program is utilized to make the calculations. Ice conditions are not considered in the analysis. The results imply that the main shipping route through the Gulf of Finland is the most prone to ship-ship collisions. Especially its eastern part seems risky. The obtained ship-ship collision frequency, 0.26 per year, was in line with collision statistics but the result was found to be rather sensitive to the values of input parameters. An estimate made for 2015 showed a raise of 164 % of the number of ship-ship collision candidates compared to 2008. The yearly grounding frequency of 0.31 was obtained for the analysed area at west side of Kotka. The analysis did not reveal particularly risky locations. The result was reasonable in the light of grounding statistics but the model was found to be sensitive to parameter values that could not be defined in sufficient detail. Date: February 2, 2010 Language: English Number of pages: 91