Calculation of safe speed and minimally admissible distance of closing of ships during radar information usage

Abstract

Exceeding the safe speed and the minimum allowable distance when ships approach each other is considered as one of the main reasons for their collision, especially when using radar information when sailing in reduced visibility or in confined areas. When assigning a safe speed, among other factors, the rules recommend to take into account the state of visibility of the maneuverable capabilities of the ship, especially the distance required to completely stop the ship, as well as the characteristics, efficiency and limitations of radar equipment. But, besides the quality recommendations in the COLREGs, there are no quantitative estimates of the safe speed and excessive convergence of the ships. Each navigator subjectively assigns a safe speed and determines the minimum allowable approach distance for ships. Therefore, the development of a universal method for calculating safe speed and the minimum allowable distance when using radar information is relevant, and the method itself is effective when used on ships, especially when sailing in difficult navigation areas and with limited visibility. The developed method allows to automate the choice of safe speed and eliminate the subjective factor when it is appointed navigator