Development of WOP mathematical model for efficient course alteration: LNG tanker manoeuvring analysis and Mann-Whitney U test

Abstract

Route monitoring is essential for the safety of the ship during navigation. It includes navigating in a straight line and carrying out course alteration. Wheel over point (WOP) is a marking made on the charted courses to warn the navigation officer that course alteration of the ship needs to be initiated to avoid overshooting the planned track. Advance transfer technique (ATT) is one of the methods to identify WOP. Apart from presenting a practical review on ATT, this study also identifies two research gaps with regards to the technique. To fill in the research gaps found, an improved advance transfer mathematical model (ATMM) is developed in this study by restructuring the usage of the ship's turning circle. A manoeuvring analysis is then carried out in this study using a ship simulator to collect the data produced by the ATMM and ATT. The data, specifically the cross-track distance (XTD) reduction, are observed and further verified via the Mann Whitney U test using IBM SPSS. The ATMM has resulted in a better track keeping function compared to the ATT. The ATMM can be used as an algorithm in the integrated bridge navigation system to help the navigation officer in making a better course alteration.