Nautical Research Journal
Station 5 is a good place to start. T e outside bottom (Out Bot) entry here reads 0-0-0 or 0 feet, 0 inches and 0 one-eighth inches. By tradition, measurements in boatbuilding are rounded off to the nearest 1/8-inch. Any discrepancy is adjusted during construction. T ere is no elevation here because the bottom of the hull is resting on the base line. Next on the table of off sets is 0-4-7 or 4 inches and 7/8-inch, the height of the inside top edge of the fi rst plank or strake (1st STR). Mark it on the vertical. In a similar manner, mark the second strake (2nd STR) at 1 foot, 0 inches and no 1/8-inches or (1-0-0). T e top inside edge of the third strake, the sheer strake is marked at 1 foot, 6 inches and no 1/8-inches (1-6-0). Note that the thickness of the bottom, 1½ inches from the scantlings, is ignored. T us, if we measured the depth of the boat from the inside, its depth would be 1 foot 4½ inches rather than the stated 1foot 6 inches. Continue marking all the heights, inside the planking, above the base line on all of the vertical station lines.
Now bend battens through the appropriate points to obtain the desired fair curves. To hold them in position modelers may use common sewing pins inserted on either side of the batten into an underlay of thick corrugated cardboard or a cork board. Pushing pins through the batten will negatively alter the fair curve, as would a knot or weak spot in the wood. T is writer happened to have some small lead weights to serve as “ducks”, special weights draſt smen use to hold battens in place. (Figure 7) T ose interested in the diff erence between English and American styles of ducks should consult Chapelle’s Yacht Designing and Planning, page 17.
As the battens are applied, errors in the table of off sets become evident. Most seem to be simple transposition or transcription errors. At the bow (B), the top of the fi rst strake is probably 2-5-0 rather than 2-0-5, clearly just transposed numerals. Other errors are not as easily understood. At the stern there is confusion in the fi rst and second strakes. T e top the fi rst strake should probably read 1-9-0 rather than 1-5-4 and the top of the second strake should
read 2-4-5 rather than 1-5-4. Trust your batten and eye.
A fi nal caution is worth noting. T e constructed drawing does help us correct our table of off sets but it does show the hull as viewed from the side on a vertical plane. T us the extreme fl air of this hull will show approximately correct plank width only at bow and stern with great foreshortening at Section 5. A body plan (upper leſt in Figure 4) can show approximate plank widths, not counting for laps, but is not necessary once properly constructed and marked frames are mounted.
Half breadth
T e half breadth drawing in the Gardner plan is more of a construction drawing showing details such as fl oor boards, thwarts and other details that do not directly aff ect the shape of the hull. One line is important and that is the outline of the bottom as seen from inside the bateau. Points plotting this line are shown as “HALF-BREADTHS INS. PLANK”, “OUT BOT”. T is is a little confusing because, as the bottom is cut out with vertical edges, both the inside and outside edges are the same. More wood will be removed from the outside edges of the bottom aſt er the frames have been mounted and correct bevels established. Use the half breadth section to plot points down from the centerline of our half breadth plan at each section line. Use your batten to plot a fair curve through the points and you have one half of the full-size pattern for the actual bottom of your 1:12-scale bateau. T e other side will be exactly the same.
Frame loſt ing
Loſt ing all nine frames of the bateau is basically the same. All have the same base line as on the sheer plan and the same centerline as on the half breadth plan. Each frame is composed of two side timbers
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