Floor timber VA, what would be the next frame in the pattern, is not fastened to the centerline timbers in any manner. Other than the frames beyond the ends of the keelson, all the other frames have bolts that extend from the top of the keelson to the bottom of the keel. Frame XIIA is so far forward that it is bolted directly to the stem timber (Figure 8). In addition, the keelson is held in place with large square-shafted spikes driven into the tops of some the floor timbers. The floor timbers do not have any such additional fastenings to secure them in place. In fact, there are no major fastening holes in any of the centerline timbers that cannot be accounted for by La Belle's specific assembly sequence.
A correlation between the centerline fastening pattern and that of "every third" surmarked frame was not discovered. However, since none of the frames provide evidence of how they were held in place prior to boring for the centerline holes, this does not cast doubt on the proposed sequence of raising the frames. Clearly the shipwrights had some temporary means of holding the raised frames in place prior to inserting the centerline bolts. The surmarked frames must have been held in place with some combination of clamps, shores, ribbands, and possibly even removable centerline fastenings. Other than a desire to have a different centerline fastening pattern for structural reasons, the delay in permanently fastening the floor timbers in place gave the shipwrights the flexibility to adjust frame positions in order to assure a fair hull shape.
The archaeological evidence presented thus far suggests that surmarks are integrally associated with frames that were raised first in the construction sequence. Indeed, during actual construction, by raising these frames on the spine timbers, the hull shape would be defined in three-dimensional space. However, in order to build a vessel by raising the frames first, there has to be some way of determining the shapes of at least some of the frames prior to the actual start of construction. This may at first glance seem like an absurdly obvious statement and thus demands some justification.
Nautical archaeology has made great progress in uncovering the evolution of ship construction in various shipbuilding traditions since antiquity (Greenhill 1995; Hocker and Ward 2004; Steffy 1994). One of the most dramatic discoveries has been the realization that, in various shipbuilding traditions prior to the partial or complete adoption of frame-first construction, hull curvature was defined by first shaping the shell of the hull with planks that were temporarily or permanently edge-joined (Casson 1963, 1964, 1971; Hasslöf 1963; 1972). In such shell-based design and construction, the shipwright judges or "sees" the developing hull curvature with the longitudinal plank runs (Pomey 1998, 2009; Steffy 1995). NEXT
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