横切り状態における船舶間の相対位置の解析

抄録

A large number of studies have been made on the evasive area which a navigator would like to keep free with respect to other ships as defined by Ms. Goodwin. Only few studies, however, have so far been made on the evasive area for crossing situation. In this paper authors examined the evasive area for crossing on passage routes. According to studies until now, the distribution of ship's tracks was a normal distribution and its σ could be expressed by a regression equation of width of these paths and marine traffic capacity. Furthermore, the boundary of the evasive area was an ellipse around a certain ship. As to the distribution character of the relative positions between vessels that proceed in the crossing traffic lanes, we assume the following : (a) When two vessels are independent each other, the density distribution of the relative positions between these vessels is the uniform distribution. (b) When two vessels have the relations of the give-way vessel and the stand-on vessel, the density distribution of the relative positions between these vessels is the distribution with two peaks on the boundary of the evasive area. From both of the above theoretical considerations for the distribution character and the radar observations in the KURUSHIMA Strait, it was confirmed that the density distribution of the relative positions of the give-way vessels changed from the distribution with two peaks to the uniform distribution. Furthermore, it became clear that the give-way vessels passed through the neighborhood of the stern of the stand-on vessels.