Design Planes and Framing Timbers
Figure 20e depicts flat design planes raised at every third frame location abaft amidships. The outline of a frame depicted in a body plan of a drawing represents its shape in a single design plane that has no thickness. When this plane is viewed from the side, it appears as a thin straight line—like looking at the edge of a piece of paper. In Figures 20d and 20e two equal frame spacing intervals overlap at the midship frame location, and thus two outlines of the midship frame are depicted. Such a doubling of the midship outline is not depicted in any of the historic French drafts presented in this essay for comparison. In my opinion, when these drafts were made, they did not take into consideration on which faces of the framing timbers the shipwright would draw the frame shapes. This was a practical matter that would have been addressed during the actual construction of the vessel. Since this study focuses on the design of La Belle as built, the critical relationship between design planes and framing timber faces will be discussed, and these concepts were incorporated into all the reconstruction drawings.
Both the forward and after faces of La Belle's floor timbers and second futtocks create design planes on which the complete frame shapes could be drawn. Although it is almost certain that the curves of the frames were first drawn on these timbers, it is difficult to determine whether this was done on the adjoining or the open faces of these timbers. The notching of the floor timbers suggests that the shapes were drawn on the faces oriented toward the midship frame. La Belle's shipwrights seem to have gone to considerable effort to create a smooth continuous surface along the open faces of the floor timbers and second futtocks. La Belle's floor timbers have a greater sided dimension than the futtocks. Where they overlap the first futtocks, they are notched just enough to bring the open faces of the second futtocks in alignment with the open faces of the floor timbers while still maintaining greater timber dimensions along the centerline—the dark lines in Figure 9.
All of La Belle's surmarks appear on these open faces of the floor timbers and second futtocks that are oriented toward the midship frame (Figures 1, 3, 9). On all these frames except the midship frame, the lower surmarks are located on the floor timbers and the upper surmarks on the second futtocks. Thus in the forward part of the vessel the surmarks are on the after faces of the frame timbers, and in the after part of the vessel they are on the forward faces. Since it is the floor timbers and second futtocks that bare surmarks regardless of whether the frame is before or abaft amidships, this change in label orientation is accompanied by a switch in the relative arrangement of the component timbers of each frame. Before amidships the first and third futtocks are set before the floor timbers and second futtocks, and abaft amidships they are set abaft them (Figure 9). NEXT
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