INSTITUTE OF NAUTICAL ARCHAEOLOGY - Bodrum, Turkey |
| ULUBURUN |
Laboratory Research and Analysis
by Dr. Michael Fitzgerald
The Uluburun shipwreck materials received a great deal of individual study during 1995. The following is a report on a selection of this ongoing research.
The Uluburun and Cape Gelidonya Pan-Balance Weights
Final drawings of the 151 domed, sphendonoid, discoid, and zoomorphic Uluburun weights were completed in the fall of 1995, while cataloging for final publication began during the summer. Weights from the l3th century B.C. Cape Gelidonya wreck (excavated by Dr. George F. Bass in the 1960s and reexamined by INA in 1987-89) are also being examined for comparison purposes. Excavation data for the weights from both sites were compiled, and then each weight was measured twice (to 1/100 of a millimeter) and weighed three to five times (to 1/100 of a gram). All data were entered into computer files and are being analyzed by statistical programs designed to ascertain the units common to the mass standards that were in use during the Bronze Age. For this analysis, only weights preserving their originally intended masses are being considered. Preliminary descriptions of the Uluburun weights were recorded and then supplemented by detailed examination under the microscope. The weights are now being examined a second time, again under the microscope, as the initial descriptions are edited and loaded into computer files. The 65 weights from the Cape Gelidonya wreck are also being examined in this way. This will constitute a comparative data base that will permit a more comprehensive evaluation of the pan-balance weights from both Bronze Age shipwrecks, indeed of all known pan-balance weights from the period.
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Beginning in mid-June of 1995, we reorganized the Uluburun hull remains, inventoried and mapped them, and then began cleaning, recording, and drawing the wood at full scale (fig. 2). Because this is the only appreciable quantity of wood from a Bronze Age seagoing hull raised from the seabed, the work was conducted with extreme care. Consequently, it took from mid June to early September to meticulously draw and record 15% of the remains. Since the first hull remains were exposed in the summer of 1984, we had known that the ship's planking was assembled with mortise-and-tenon joinery like that found on Greek and Roman ships of more than a millennium later. That meant that the use of this construction technique in the Uluburun hull is the earliest known occurrence in the history of seagoing ship construction. Thus, we had been afforded the unprecedented opportunity to compare details of this shipbuilding method with those evident in Greek and Roman ships of similar size, i.e. some 15-18 meters in length. The work in 1995 revealed several unexpected explanations for what we had previously observed. It had been clear from the beginning that the Uluburun ship's joinery was more robust and more widely spaced than that found in similar Greek and Roman hulls, which seemed consistent with our knowledge of mortise-and-tenon shipbuilding concepts. Unlike most Greco-Roman mortise-and-tenon joints, those in the Uluburun hull remains were found to be extraordinarily deep, extending from one plank edge to within 1.5 or 2 centimeters of the opposite plank edge. Secondly, each joint cut from one plank edge is positioned immediately next to the nearest joint cut from the opposite edge, so mortises often intrude on one another. Occasionally, the edge surface of a tenon nearest the adjacent mortise displays chisel marks made when the mortise from the opposite plank edge was cut. This practice, which required removal of a volume of wood some 13-15 centimeters long and 1.5-2 centimeters thick over nearly the entire width of the plank, would seem to have compromised severely the structural integrity of the planks and thus the hull. Yet it was observed so consistently that pairs of internal "frames" of tenons extended up the sides of the hull planking every 24-26 centimeters, center to center. We do not yet know if this was simply a convenient way of maintaining consistent joint spacing, or if it represents a specific, conscientiously executed structural practice. Several other construction features underscored the importance of understanding these issues fully. During the summer of 1995, we received the results of new wood species analyses. They revealed that the hull was built of cedar (Cedrus sp.), instead of fir (Abies sp.) as previously identified and published. This new identification is not at all surprising when we consider that Bronze Age references often mention cedar as the timber most preferred for building ships. Cedar is a shipbuilding material far different from fir in its mechanical and physical characteristics, including suitability to extended submersion in saltwater.
The summer's work did not yield evidence for the employment of either frames or metal fastenings in the Uluburun hull. Work will resume in the spring of 1996.
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Final drawings of 39 of the 95 intact or
reconstructible jars recovered from the site are now complete, 30 having been finished in
1995. Cataloging for final publication will commence in spring 1996. Capacity studies of
the jars continued on a limited scale. When several jars were ready to exit desalination
together during the summer, we developed a means of measuring with precise repeatability
(within less than plus or minus 0.06%) the wet volume capacities of the jars, corroborated
by net water weight. Two to four separate measurements of a jar's volume were taken at
each of several capacity levels (lip or brim, interior and/or exterior neck features that
could be associated with stopper location or fill level, and the neck/shoulder junction).
All jars presently in water will be measured in this way before drying and dry volumes
will continue to be taken after drying, with the hope of deriving correlations between wet
and dry volumes. In this way we may be able to apply a correction factor to dry volumes
obtained in previous years and to those yet to be taken of jars already cleaned,
conserved, and in storage.
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- Conservation by Claire Peachey
- The Copper Oxhide and Bun Ingots by Patricia Sibella
- Dendrochronological Dating of the Uluburun Ship by Cemal Pulak
