The iron anchors from the Tantura F shipwreck: typological and metallurgical analyses

The Tantura F shipwreck was discovered in 1995 in Dor (Tantura) lagoon, about 70 m offshore. It was a coaster that plied the Levant coast during the local early Islamic period. Among the finds exposed in the wreck site were two iron anchors of the T-shaped type. This type of anchor, dated to between the second half of the fourth and the thirteenth centuries AD, is found throughout the Mediterranean. The anchors were analyzed by typological and archaeometallurgical methods, including radiography, metallographic cross-sections, microhardness tests, SEM/EDS analysis and Optical Emisson Spectroscopy (OES) analysis. Light microscopy revealed heterogeneous microstructure consisting of ferrite, Widmanstätten ferrite-pearlite or pearlite, which is typical of wrought iron made by bloomery. The metallographic and microhardness results revealed that decarburization had occurred, probably during the final hot-working process. The OES analysis, supported by SEM/EDS data, showed that the anchors are similar in composition. Soda-blast cleaning followed by chemical etching revealed the forge-welding lines, clarifying the manufacturing process, which is similar in the two anchors. Thus, it is likely that both anchors belonged to the same ship and, hence, were in situ. This information extends the limited knowledge of technologies and materials used, specifically for the development of metallurgy in the Eastern Mediterranean during the early Islamic period, and enlarges the database of the typology of anchors of that period.