After hundreds of years submerged in sea water, marine archaeological objects are complex materials due to degradation and inclusion of foreign compounds from the surrounding environment. When excavated and exposed to air these can transform to damaging products which can destroy material, resulting in historical loss. The Mary Rose, King Henry VIII’s favourite warship, was made entirely of wood. However, a new paper called “Complementary analysis to de-convolute co-located contaminants in marine archaeological bricks” published today in the Journal of Cultural Heritage reveals how Prof. Eleanor Schofield, Deputy CEO for the Mary Rose Trust and Dr Donna Arnold from the University of Kent, and their teams used Diamond Light Source, the UK’s national synchrotron to examine bricks used in the galley of the Mary Rose warship in two brick ovens to cook warm food for more than 400 sailors and soldiers.
In October 2022 the Trust will celebrate the 40th anniversary of recovering the starboard side of the Mary Rose. The hull is displayed within a purpose-built museum in Portsmouth Historic Dockyard, surrounded by some of the 19,000 objects found during the excavation. Over 3,000 of these were bricks from the ovens. After initial washing treatments to remove the salty seawater the bricks were dried and then either put on display as part of an impressive reconstruction of one of the ovens, or put into storage. Prof. Schofield explains; “These bricks were thought to be stable and inert, however, salt crystals started to become visible on the surface of the bricks. These crystals were a worrying sign and indicative of potentially serious and continuous damage that was being caused deep within these precious historical artefacts.”
“The key to preserving these important artefacts comes from understanding the chemical and physical processes that are occurring inside the bricks. It was essential to use non-destructive techniques that do not damage the bricks but reveal subtle internal processes that can help us preserve them for centuries to come”, adds Dr Donna Arnold.