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

In the 2016 excavation season of the Akko Tower shipwreck, a ferrous stud-link anchor chain and a rod, both covered with thick encrustation and concretion, were retrieved from the site. The chain links, studs, and rod were analyzed by metallurgical methods, including: radiographic testing, x-ray fluorescence, light microscopy, scanning electron microscopy with energy-dispersive spectroscopy, optical emission spectroscopy, and microhardness measurements, in order to determine their composition and microstructure. The links and the rod were made of wrought iron, while the studs were made of gray cast iron with a significant silicon content of 2 wt.%. The welding zone of the links was identified. The chain was end-welded by forge welding, and the stud was fixed mechanically. The design and manufacturing characteristics of the chain are typical of nineteenth century stud-link anchor chain, which supports the dating of the ship. It is suggested that the chain served the secondary anchor of the ship.