Abstract
Formerly, authors had dealt with the fact the steering qualities of an actual ship may be described in brif by System parameter T and K in the transient response. Such treatment, in making analitical study, give a convenient guide to the problem of shiphandling at sea as well as to problem of design work refering to steering and course keeping. The above title considered here is one of their most striking applications, and is adequate as a method of maneuvering board when deducing at what distance from the intersection of the original course and desired course we ought to put helm over. To begin with, for want of the basic consideration of the Thumb rule for altering course, the author has taken up the analitical idea that Distance of New Co. are built up of straight running part V(T+t_1/2) and circulr running part [numerical formula] over the original course by using the System paramer, and, in the following part, has treated a practical method of deduction by making us of the Turning test diagram in consideration of the influence of ship's condition and steering, i.e. draft, angle and time when helm over, slip over the original course due to turning lag after easing helm amidship.
