STUDY ON THE MANEUVERABILITY OF WIDE BEAM TANKERS - RESULT OF A MANEUVERING TEST WITH SERIES MODELS OF L/B RATIO

This report describes some model experiments with respect to the maneuverability of large wide beam tankers, including those of an extremely wide ship form such as L/B=4. Two kinds of tests, one with a free-running model and the other with a restrained model, were carried out to make clear the properties of the hull only, i.e., without providing a propeller and rudder to it. In discussing the course-keeping ability among ship forms, the steering quality T' obtained from Z-maneuver test and the phase lag obtained from sinusoidal steering test were utilized. Through the series model tests the following has been made clear: As far as hydrodynamic force is concerned, the influence of L/B itself on the maneuvering performance of ships, including those of an extremely wide ship form is not so considerable. The influences of variation in ship hull inertia and variation of other particulars of ship hull form due to a decrease in L/B ratio are rather great. Generally, the influence of the differences contained in rudder effects due to the rudder area ratio and propeller loading on the course-keeping performance, can be said for greater than that of the ship form itself so far as the ship form tested in this experiment is concerned.