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2010
Conference Paper
Titel
Quantification of maritime operational risks to enhance alert management onboard ships
Abstract
For safe, efficient and environment-friendly navigation from port to port, enhanced computer- based systems are installed on the ships navigational bridges. By means of new rules and regulations of the International Maritime Organization (IMO) many of highly sophisticated technical systems were made mandatory over the last years. This is mainly to support the bridge team in detecting potential dangers and to manage the risks by appropriate control measures. Main types of maritime operational risks are: risk of collision, risk of grounding. As part of maritime safety management, specific dedicated decision-support systems, with implemented alarm functions, are integrated into the navigation systems of modern ships. However, with respect to collision avoidance, the alarm functions are still based on conventional algorithms. They are robust but often of little use, because the number of triggered warnings is sometimes higher than the workload capacity of a human operator. Often the system triggers an alarm for an encounter situation classified as dangerous whereas the human operator's assessment according to his mental model is e.g. 'not critical'. One reason therefore is that the algorithms are based on fixed static limit values and only few selected information are used although new systems provide a wider range of situation parameter. On the other hand, compared to collision avoidance systems used in aviation, onboard a ship a collision warning might be ignored or the alarm could even be switched off. Consequently, the accident rates are still at a high level. Within this paper, investigations into the situation regarding the use of collision warnings in maritime traffic are described. Results gained during field studies onboard will be presented and discussed. The development of a concept to automatically adapt alarm thresholds by using enhanced fast-time simulation techniques will be introduced. ©2010 Taylor & Francis Group.