AN INVESTIGATION ON SHIP MODEL TESTS OF TWIN SKEG HULL LINES FOR YANGTZE RIVER - NEW PASSENGER SHIP TYPES

With a view to improve the energy utilisation of passenger ships for lower Yangtze River liner service, two new types of afterbody design were tank-tested. Both types have the same parameters: B/T = 5.667 and Block Coefficient = 0.552 and the same forebody lines based on the existing twin-screw ship 'Dong-11'. The afterbody lines are different: one has twin-stern, the other twin skeg. Comparative self-propelled model tests, streamline observations and wake measurements are presented and discussed. It was found that for this particular shallow draft vessel the twin-skeg configuration with outward turning propellers gave better results both in Delivered Horsepower and Quasi-Propulsive Coefficient. An analysis of the effects of skeg on resistance and propulsion is made. It is proposed that the twin-skeg lines-plan is worthwhile to be considered as energy-saving shape for broad but shallow draft river vessel.