STUDIES ON MANEUVERABILITY OF SHIPS IN RESTRICTED WATERS

Abstract

The effects of finiteness of water depth and channel width on the coefficients used in the equations of motion were studied by measuring the hydrodynamic force and moment acting on models of a supertanker and Mariner type ship in a towing tank. The virtual mass, the virtual mass moment of inertia, the hydrodynamic damping force coefficients and hydrodynamic damping moment coefficients, etc are measured for different water depths and differnt channel widths, and then they are compared with those measured in the infinitely deep water. By using the coefficients thus measured, the maneuverability of ships, in particular the course keeping quality, is discussed in detail. It is concluded that it is possible to remove the instability by simple automatic steering, that is directional control.