A Study on the Standard of Ship Safety Distance on Bridge Crossing Navigable Waterways based on Traffic Distribution

Abstract

Currently, there are bridges in the navigational waters where ships pass through from all parts of the world. However, this is a risk factor for ships that pass through the lower part of the bridge. It cause accidents between bridge and ships. In this study, AIS(Automatic Identification System) data were collected for one month at Incheon bridge which is bridge crossing navigable waterways for the purpose of analyzing the safety distance between bridge pier and ships. The marine traffic survey was conducted by ship’s length and type and based on the results, the survey was conducted on the traffic distribution by divided two-way and one-way passing ship. As a result of traffic distribution, The average deviation for the passage centerline was about 0.05 to 0.08 times the main span width and the traffic distribution was analyzed to be the most similar to the lognormal distribution. In this study, the separation distance between bridge piers and ships was analyzed according he confidence intervals, referring to the UK MCA. As a result, the most suitable safety distance according to confidence interval was that the two-way was chosen as 3.4 times of ship’s breadth and the one-way was chosen as 2.8 times of ship’s breadth by maximum ship’s breadth. According to the above results, the distance according to the confidence interval was chosen as the safety distance and the ship safety distance between ship impact protection and ship’s route was 0.18 times route width for two-way traffic and 0.23 times for one-way traffic.