Steering quality of a ship is affected by a time constant T_E of her steering gear. The time constantT_E depends upon the wheel advance angle of the steering gear. By reducing the wheel advance angle, the time constantT_E is decreased and steering quality of a ship may be improved.
This paper deals with the improvement of steering quality by reducing the time constant T_E The results obtained are as follows ;
(1) For small boats which have small time constant in steering, the effect of reducing the wheel advance angle may be remarkable.
(2) If the wheel advance angle is zero, starting angular acceleration of a rudder is abnormally large.
(3) For the conventional wheel advance angle 510°, calculated values of starting torques acting upon steering gears are very small compared with designed maximum torques of steering gears. From the viewpoint of the starting torque, the conventional wheel advance angle may be considered too small.
(4) Adequate reduction of the wheel advance angle compared with the conventional one does not result abnormal overload of a driving motor of a steering gear.