Find Spot MPM2077 - Whitworth solid shot, Portsmouth Harbour

Whitworth solid shot retrieved by grab from a crane barge in Portsmouth Harbour in 2016 during the Queen Elizabeth Class Capital Dredge Project.

Single Whitworth solid shot of 145mm calibre, 500mm long. The shot had six flat sides in a spiral arrangement and hexagonal cross section with rounded corners. Due to corrosion it was uncertain whether it had been fired or was unspent when it reached the seabed. The calibre is close to a 70-pounder gun.

The spiral hexagonal bore design was patented in the late 1850s by Sir Joseph Whitworth. A series of 70-pounder Whitworth shots were fired during artillery experiments at Portsmouth in the 1860s. Due to the proximity to the shore it was thought this shot was probably not fired during these experiments and was more likely dumped at sea. It has been dated to between 1850 and 1870.

UID: BWL1_0028 in Queen Elizabeth Class Capital Dredge Project report.

Wessex Archaeology, 2018, Queen Elizabeth Class Capital Dredge Project Her Majesty's Naval Base, Portsmouth: Archaeological Assessment Report (Unpublished document). SPM646.