Experimental study on the hydrodynamic forces induced by a twin-propeller ferry during berthing

The paper presents the experimental study on the influence of wall effect on the hydrodynamic forces induced by the propellers and thrusters of a ferry during the berthing. The program of the model tests was developed for the twin-propeller, twin-rudder, man-manned model of a car–passenger ferry in 1:16 scale, equipped with two bow thrusters. The different combinations of the operational settings of bow thrusters and propellers operating in the push–pull mode allowed to observe and quantify the variation of the hydrodynamic forces due to the changes of the water depth to draft ratios and distances to the quay. The results of model tests are introduced and discussed in the paper. The difference between the measured total hydrodynamic force and superposition of the component forces induced by the propellers and thrusters has been investigated. According to the structure of the generally accepted modular manoeuvring model, the proposition of the weight factors for the component forces comprising the interaction effects has been introduced and discussed.