The orientations of these standard radius arcs were determined by increments on the upper bilge diagonal and the breadth diagonal. As a result, they progressively tip outward, moving forward from one frame to the next. These standard radius arcs are "cut off" or trimmed by curves with varying radii above and joined to curves with varying radii below.
The trimming breadth curves are tangent to the 7 ft 6 inch radius arcs and intersect the recurve diagonal at the offset points. As a result, the maximum breadth points of the frames before amidships do not fall on the straight "maximum beam" diagonal. Instead they define a curve such as the one depicted in Figure 44b and that can be seen in the Profond draft (Figure 6). The offset points on the maximum beam diagonal fall outside the frame curves due to this filleting procedure. Thus I view this maximum beam diagonal as a supplementary design diagonal. It is on this supplementary beam diagonal that I plotted the same maximum width as on the transom to begin the process of defining the shape of frame XIIA. This was necessary in order to establish the lengths of the diagonals forward that were then subdivided by offsets.
The way the guide points on La Belle's diagonals are joined has repercussions on the procedures that can be used for transferring the resulting frame shapes to the actual timbers during construction. The use of arcs of different radii to draw each of the design frame sections would have made it necessary to draw the resulting body plan at full size for construction. This enlargement of a ship drawing to full size is known as lofting. It is also possible that an accurate design drawing, specifically the body plan, was only developed at full size—at 1:1. Such graphic design at full size may have been an intermediate step before the adoption of scale drawings in French ship construction (Boudriot 1998a:130–131; Rieth 2001:260; 2003b:79–80). However, on the basis of the complexity of the reconstructed design procedures, I believe that at the very least La Belle's preliminary design was first worked out in a scale drawing.
From the lofted body plan, La Belle's shipwrights would have then fashioned templates for the laying out and cutting of the frames; these templates would be used to transfer the curves onto the actual timbers. This process necessitates that the frame sections drawn in the body plan represent the shapes of the frames in single flat design planes, thus they could be transferred to such planes created on the timbers themselves.
The frame shapes would first be drawn on timbers selected for the floor timbers and second futtocks on what would become their open faces oriented toward the midship frame. Surmarks would then be transferred onto these faces and the location labels carved. NEXT
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