Predicting berthed ship - passing ship interaction for different channel geometries

An investigation has been undertaken into the interaction forces and moments experienced by berthed ships due to passing ships. The aims were: (1) to quantify the influence of waterway geometry on the magnitude of the peaks and the form of the time domain interaction forces and moments; and (2) to quantify the influence of the form of the interaction forces and moments on berthed ship motions. The second aim was considered important, as in the past the peak values of the forces and moments were used, together with the assumption of an idealised form of the interaction forces, to predict the motions. It was felt necessary to verify this assumption, particularly for a range of different waterway geometries. Results were obtained from model scale experiments conducted in the Towing Tank at the Australian Maritime College to measure the time domain interaction forces and moments on a berthed ship due to a passing ship for different waterway geometries. The measured time domain interaction forces and moments are presented for three different channel geometries. The influence of the different channel geometries on the magnitude of the peaks and the form of the interaction forces and moments has been quantified. Measured and idealised interaction forces and moments were used as input to a time domain numerical simulation model to predict berthed ship motions. The influence of the form of the interaction forces and moments on the maximum berthed ship motions has been quantified for a typical mooring arrangement. From this the applicability of using an open water idealised form for cases with different channel widths and near bank geometries has been assessed.