Analysis of offshore waiting at world container terminals and estimation of CO2 emissions from waiting ships

Delays of container services seriously affect the lean, extensive global supply chains such as the just-in-time system. A major cause of ship delay is port/terminal congestion, causing offshore waiting, and these delays create a domino effect on other ships through terminals and ships. During the supply chain crisis, started from the second half of 2020, many ships were forced to wait offshore for more than days at major ports, especially in North America, Europe, and China. This study developed the method for identifying offshore waiting ships of terminals, calculating the waiting time of these ships, and estimating the increment of CO₂ emissions by utilizing log data sent from ships’ automatic identification systems. The calculated results of major world ports were analyzed to understand the relation between the degree of congestion and offshore waiting time capacity and the relation between the waiting time capacity and CO₂ emissions.