Abstract
In the present report, an attempt is done for estimating effects of stern forms on hydrodynamic property and on manoeuvrability of full ships. Three model ships with different stern forms, such as Normal stern with rectangular rudder, Mariner stern with hanging rudder and Mariner stern with bulb and hanging rudder are firstly introduced and results of captive model tests for the models are secondly examined in detail. It is pointed out from comparisons on hydrodynamic derivatives of hull forces that the manoeuvrability of "Mariner type with stern bulb" is worst in directional stability. Results of digital simulations are lastly reported and effects of stern forms, rudder types and rudder areas on manoevurability are pointed out. It is finally concluded that an enough attention should be paid for the inferior stability of the Mariner-type ship with stern bulb at the initial design stage.
