An experimental study on the manoeuvring characteristics of a Ro-Ro passenger vessel in large heel condition

Abstract

For estimating a ship's manoeuvrability, 3-degrees of freedom (DOF) equations of motion, which deals a ship's surge, sway, and yaw motion, are usually used. If the roll motion during manoeuvring is of interest, 4-degree of freedom equations of motion are used by adding roll motion. In the addition of roll motion, an assumption that the magnitude of roll is small is implied, so the coupling terms are considered only in the linear range. However, in case that a ship has large heel angle, the assumption of small roll magnitude does not hold any more. In this paper, estimation of manoeuvring characteristics of a Ro-Ro passenger vessel in a large heel condition is suggested. The Horizontal Planar Motion Mechanism (HPMM) model tests were conducted to find changes in hydrodynamic forces and moments acting on the model with respect to changes in heel angle. The results of the HPMM model tests were analyzed to deduce a 4-degree of freedom equations of motion and to estimate manoeuvring coefficients in the equations of motion. Copyright ？ 2015 by the International Society of Offshore and Polar Engineers (ISOPE).