AN EXPERIMENTAL STUDY ON THE TURNING CHARACTERISTICS OF A TWIN-SCREW SHIP IN HEELED CONDITIONS

Abstract

A ship in a heeled condition has different manoeuvrability when it sails. The aim of this study was to investigate the change of turning ability of the ship in heeled conditions with different speeds. Free running model tests (FRMT) with a 1/41.37 scaled twin-screw ship was conducted in three heeled conditions and two speed conditions. The tests were analyzed with trajectories and navigation data. The test results reported that the heeled state of the ship strongly affects decrease in speed and increase in yaw rate when the ship turns, so that tactical diameters at starboard turning circle tests decreased by 30% in -19.5° portside heeled conditions.