Investigation on ship mooring forces including passing ship effects validated by experiments

Abstract

Additional loads on the moored system are generated due to the interaction effects of a passing ship in the proximity of a moored ship and, in the worst case, can even cause the breaking of mooring lines. Existing studies on mooring lines considering passing ship forces and the effects of passing ship parameters on mooring line tension are limited. A mooring analysis is performed using OPTIMOOR to evaluate the impact of passing ship forces and environmental loads on mooring line tension. Results indicate a maximum mooring line tension increment of around 40% due to passing ship forces. The passing ship forces are obtained from the experiments conducted on scaled tanker models. A wide range of significant parameters, such as the passing ship size, passing ship speed, the separation distance between the ships, water depth and moored ship's length, are considered for the study. It is observed that the Froude number based on length (FrL) has the most significant impact on the passing ship effects compared to displacement ratio (DR) and Froude number based on water depth (FrD). Also, FrD influences the interaction effects more when compared to DR. The experimental results are compared with numerical simulations.