Microstructural analysis of brass and zinc nails from the wreckage of a sailing ship

A microstructural examination has been conducted on nails removed from wreckage of an unknown wooden sailing ship found on Onslow Beach, North Carolina. Large nails (about 12cm long) were used to connect the planks to the timbers, and these were of cast brass of about 34% Zn. Some Pb and Sn were also present. Casting was probably done using a banded Fe mold. Small (about 1cm long) pure Zn nails were removed from the planks, and were probably used to attach Zn sheets. From information in the literature about the use of brass nails and Zn sheathing, and of wooden ship construction, it is estimated that the ship was constructed around 1820 if made in the United States and around 1850 if made in Britain.