Abstract
With a view to clarifying the empirical relations which stands between the turning motion of a given ship and the steerage, the authors have attemted the qualitative and quantitative analysis mainly in respects to the above title. In the first part, we have worked up a practical approximate formula according to which we can calculate an altering angle from original Co. to the desired Co. by the data easily determined on board ; in the second part, treated the qualitative problems in steering aspects which are mostly concerned with the handling of the ship, namely, the effect of the rudder in the initial stages of circular motion, the turning power of remaining after the helm is put amidship, the angle altered Course ; at last, made the relations clearer which lie among these handlings in which we have depended upon only intuitional and empirical capability. However, our treatment in each part has been considered merely from the manoeuverer's point of view. Therefore, although the results obtained may not be exactly mathematical, they are believed to be sufficient guides for practical use, as showed by the experiments of a training ship, Wakashio-Maru.
