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256 on the outside more frequently than 'on the inside of the points, in order that the volume of the. ship may not be less than that given by the design. In copying and drawing the body plan, it is advisable to draw the midship section first, and then the others in rotation, as the draftsman is thus better enabled to see what he is doing, and exercise his judgment. Fairing the After Body Should the preceding operations have been carefully carried out, the fore body will be fair, and work, which will be treated of subsequently can be proceeded with at once. Be- fore entering upon this, we will, how- ever, first consider the after body. All that has been said of the fore however, the best way to ensure the ship being fair when the fore and after bodies are joined amidships, 1s to set off in the half-breadth plan lines parallel to the middle line of that plan, and distant from it the greatest breadths at the several level lines; and take care, when penning the battens to the respective lines, to prevent them from, extending beyond the parallel lines. The body being fair, we might now proceed to lay off the cants, etc., by it: but, before doing so, we will first show how to fair the body by what is known as the contracted method. The extremities of a ship are the parts which require the most care in fairing, this being due, not only to the greater curvature at those parts, THE MARINE REVIEW June, 1918 already given. It must be observed that in the figure more than the usual portion of the body is shown as being faired by this method. Work Must be Done Carefully © Draw upon the floor, perpendicular to. any chosen base line, as Many equidistant straight lines as there are sections to be faired, and number these perpendiculars to represent the square stations. These lines need not be spaced more than a sixth or q seventh of the spacing of the stations apart. Next, produce each level and diagonal line (diagonal. line usually) in the body plan to any point chosen at a few feet beyond the midship section, the reason for this will be seen presently. Then measure along Booby PLAN ba a OCA L Bow LINE See fs LEVEL LIN Te a7 es \ LEVEL LIM ----_ = = + SHEER PLAN 9) 1 Top SIDE LINE e D LEvEL| LEVEL LINE) i Fe tS ener 8 e a KS \ HALF BREADTH PLAN ale INOOLE LINE ow £ 3 FIG. 12--DIAGRAM SHOWI body is true of this; a- slight varia- tion is, however, made with reference to the bearding lines. Owing to the 'swell allowed to house the = screw shaft, and the general fineness of the after body, which would cause the -heels of the timbers to run off to a thin wedge, a somewhat irregular stepping line is cut in the stern post and deadwood for the endings of the timbers than bow lines, as owing to the great curvature at the counter, which is in a direction perpendicular to the buttock planes, the intersections are more trustworthy than by any other plans, and, hence, they are almost the only criterion of the fairness at that part. It is well, in fairing the body, to scarf or overlap the lines in the half-breadth plan, that is, to fair a few feet of the midship. portion of the ship in both bodies, Perhaps, (See Fig. 4.) Greater . care is required in getting in buttock | but also to the fact that most of the problems in laying off occur at the bow and stern. As we shall see further on, the mid- ship portion of the ship, although by far the largest, is yet that most easily disposed of by the draftsman, and owing to its. being so straight, very little fairing is required for it. Fairing by Contracted Method To save time and labor, as well as for the advantage derived from being able to do in a small space that which would otherwise occupy a large part of the floor, the body is often faired by ithe ~shown in Fig. 10. First determine by an examination of the body plan how much of it shall be faired by this method, observing that it is well to leave such portions of the two bodies as may have great curvature to be faired by the method contracted method. .termination outside NG METHOD OF DRAWING DIAGONALS IN SHEER PLAN each level and diagonal line from the the body plan just fixed upon, to where it inter- sects with each of the square sta- tions to be faired; set these distances upon the corresponding perpendicular lines just drawn, measuring, of course, from the base line; and draw lines, by a batten, through these points. Treat all the level and diagonal lines in' a similar manner; and at the. top sides use level lines drawn in the same places as when fairing that part of the ship by the ordinary method. Fair these lines in the same manner as if the spacing of the perpendiculars were the correct room and Space, Alternate the processes by recopying the body from these curved lines, and vice versa, until the curves pass fairly through all the points obtained for them, after which this fictitious half-breadth plan may be rubbed out, ithe midship portion of the body being