Abstract

This paper investigates the hydrodynamic behavior of a berthed engineering ship using a potential model incorporating the damping lid method, which effectively mitigates the strong hydrodynamic interactions caused by narrow-gap resonance. First, the viscous correction approach is validated against experimental data. Then, the abrupt variations in the ship’s hydrodynamic characteristics at resonant frequencies are analyzed for different gap widths. Subsequently, by comparing the ship motion responses obtained from the response amplitude operators (RAOs) and the Cummins equation, the damping factors at specific frequencies are identified. Finally, under severe sea-state conditions, a safety assessment of the mooring system is performed. The results reveal that narrower gaps lead to stronger hydrodynamic interactions. Moreover, the predicted extreme load responses confirm that the mooring system is capable of ensuring the ship’s safety. This study provides useful insights for the design of berthed structures with narrow gaps.OPEN ACCESS Received: 30/09/2025 Accepted: 21/11/2025