Experimental study of the asymmetrical propeller loads occurring in unmanned self-propelled free running surface model tests

Propulsion system can experience large power absorption fluctuations during tight manoeuvres. In the case of a turning circle manoeuvre for a twin-screw ship, the power required by the two shaft lines can be completely different; in case of non conventional propulsion system, like cross-connect configurations, a compromise must be met in order to design a safe control system without affecting dramatically the vessel's manoeuvring performance. In this work, a series of unmanned free running self-propelled model tests have been carried out in order to investigate the influence of different propulsion system operation settings on the vessel's manoeuvring characteristics.