关键词: 交通运输工程, 两船距离, 转向避让难度, 最小转向角

Abstract: Altering course is the most common and effective method of collision avoidance, but the extent and effectiveness of altering course is significantly influenced by the time choice of avoidance. Starting from the ships’ maneuvering mathematics model, the difficulty to avoid collision by altering course and minimum alter angle were proposed and the corresponding mathematics model was established. Furthermore, the relationship between the distance between ships and the difficulty to avoid collision by altering course was deduced. The quantitative explanation why the difficulty of altering course and the minimum alter angle increased sharply with the decrease of the distance between ships was given. And the proposed point view is verified with the case study of famous scholar S.Lenart.

Key words: traffic and transportation engineering, distance between ships, difficulty to avoid collision by altering course, minimum alter angle