Iron artefacts from the Akko Tower Wreck, Israel, and their contribution to the ship’s characterization

Abstract

The Akko Tower Wreck was found inside Akko harbour, Israel, in 1966, next to the Tower of Flies, after which it was named. The shipwreck was excavated in 2012 and 2013. During the underwater excavations, two metal concretions were retrieved, X-rayed, and on opening were found to contain three almost identical iron-bound deadeyes. An iron bolt was also retrieved, covered with concretion. Metallurgical characterization was used to elucidate the manufacturing technology and to date the items. The artefacts were found to be made of annealed wrought iron. The use of wrought iron, forge-welding, and the presence of 0.1-0.2 wt.% Mn may indicate manufacturing in the mid-nineteenth century. Combined with the transition from hemp to chain cable for rigging in 1808, and by the 1840s to wire rope, all the indications are that the deadeyes were made in the second quarter of the nineteenth century. The size of the deadeyes, and the dimensions of their chain links, may indicate their use at the topmast of a brig of about 160 T. This agrees with other evidence in suggesting that the Akko Tower Wreck is the remains of a European vessel which sank in Akko harbour about the second quarter of the nineteenth century.

Another Link in the Chain: Archaeometallurgical Investigation of an Anchor Chain from the Nineteenth Century Akko Tower Shipwreck

“…This difference in material selection was the result of the different requirements for the two components [9, p. 100]. The characteristics of the link material examined are consistent with other contemporary rolled wrought iron items [17,18,20,36]. These characteristics include the typical wrought iron structure of a low carbon iron matrix and a network of elongated inclusions with a high silicon oxide content [36].…”

“…6a, spot scan) 43.4 36.9 7.2 3.9 3.3 2.6 1.1 0.8 … 0.6 0.2 … Slag in the weld area (Fig. 8, area Since Si does not reduce in either of the direct and indirect smelting methods, its presence represents the slag inclusion distribution in the link's wrought iron matrix [15,17,18]. The link and rod material was made from relatively pure ferritic iron, rich in slag inclusions, such as single-phase fayalite (Fe 2 SiO 4 ), two-phase glass-wüstite inclusions, and three-phase glass-wüstite-fayalite, typical of wrought iron objects [17, p. 110].…”

“…However, further analyses of the inclusions, such XRD, EBSD, TEM, are needed in order to study their phases. Based on the homogeneous microstructure of the link and rod, they were wrought iron products, produced by the 'puddling' technique of refining pig iron into malleable wrought iron [15,[17][18][19][20]. The equiaxed iron ferrite grains in the rod (Fig.…”

“…The high quality of the link material (based on its chemical homogeneity and the texture of the slag inclusions), the stud material (considering the general lack of cracks and pores), and the high quality of the weld (based on the limited amount of discontinuities) are as expected for anchor chains, considering that both the Royal Navy and Lloyd's required a testing certificate for each anchor chain they procured. Previously investigated ferrous finds from the Akko Tower shipwreck included iron-bound deadeyes with non-studded chains and a bolt [18]. These artifacts were determined to be uniformly manufactured of wrought iron with homogeneous preferentially oriented slag inclusions.…”

“…128-129, 146, 166]. The typical microstructure of wrought iron objects produced by the 'puddling' technique consisted of a ferritic matrix combined with embedded elongated slag inclusions, indicating the direction of plastic deformation during the forging process [17][18][19][20]. The 'puddling' process of refining cast iron into wrought iron continued to be common until the middle of the nineteenth century [13].…”