Dynamic stability of planing ships

At present, most of the dynamic research on planing ships has been directed towards analysing the ship's motions in either the 3-DOF (Degrees Of Freedom) mode in the longitudinal vertical plane or in the 3-DOF or 4·DOF mode in the lateral vertical plane.
For this reason Delft University of Technology and MARIN have started the set-up of describing the dynamic behaviour of planing ships in a 6·DOF mathematical model. This research program consisted first of all in developing a 6-00F computer simulation program in the' time domain. Such a simulation program is to be used to predict the response of these type of vessels to disturbances during high speed sailing.
For describing the behaviour of planing ships in still water static tests have been executed with two planing hull forms in the towing tank of Delft University of Technology. The test program consisted of measuring three force- and three moment components as a function of the pitch, rise (draught), roll, drift and speed of the model.
At a next stage a model test program is anticipated to determine the added mass and damping components of these two hull forms and also the rudder forces. In the meantime the program is in operation while using empirically estimated values for these quantities.
In this paper the set-up of the mathematical model will be presented. Also a discussion will be given about the use of these static contributions in a time domain simulation to model the behaviour of the ship.