A Method for Quantifying the Risks of Human Error from Experiments with the Ship Bridge Simulator

Why do vessels collide with each other even though the Navigation Officer on Watch (OOW) keeps a lookout? This study aims to discover what causes human error of the OOW. For this purpose we conducted a series of experiments and surveys. This paper reports on results of two experiments and the present state of marine accidents in Japan. The first experiment objective is to find out the correlation between the angle of an approaching target, and error in overlook (cognitive error), and to put forward a method for estimation of Human Error Probability (HEP) from experiments using a ship bridge simulator. The next experiment objective is to find out the correlation between behavior and error in judgment (decision error). The author found that the OOW tends to overlook a target that is approaching from the port side. The other result shows that the notice time is negatively correlated with the amount of time using binoculars. This study concludes that a method for quantifying the risks of human error from experiments is necessary for implementing highly reliable Human Reliability Analysis.