New insights regarding the Akko 1 shipwreck: a metallurgic and petrographic investigation of the cannonballs

The Akko 1 shipwreck constitutes the remains of a small Mediterranean naval vessel, discovered in Akko harbour, Israel, and excavated over three seasons between 2006 and 2008. Among the finds at the shipwreck site were eleven cannonballs. Two of them, a 9-pdr and a 24-pdr, were retrieved and studied using metallurgical and petrographic methods. The examination of the cast-iron was performed with optical microscopy, SEM–EDS, XRF and microhardness tests. The remains of the casting sand from within the voids in both cannonballs were studied by petrography. Combined with the archaeological evidence and the historical background, the metallurgical and petrographic testing may suggest that Akko 1 was a warship or an auxiliary naval vessel of similar size to, or slightly smaller than, sixth rate, and was in Akko harbour circa 1840.