How to Preserve a 460-Year-Old Shipwreck

The Mary Rose served as English King Henry VIII's principal warship for 35 years until she went down outside of Portsmouth in 1545. Now, 460 years later, an international team of researchers is working to preserve what's left of the ship.

Using synchrotron X-ray devices from the Stanford Synchrotron Radiation Laboratory and the European Synchrotron Radiation Facility, they determined that the 280-ton hull - which was recovered from the sea in 1982 - has about two tons of sulfur distributed throughout it.

Shipwrecks preserved in seawater commonly accumulate sulfur, which creates conservation problems once the sulfur comes in contact with oxygen. Sulfur converts to sulfuric acid, which slowly eats away at the wood until the hull is destroyed.

Researchers also found plenty of iron and pyrite, which poses as a conservation risk since the moist iron speeds up the conversion of sulfur to sulfuric acid. To preserve the ship, researchers have suggested chemical treatments to remove or stabilize the iron and sulfur and reducing the humidity and oxygen levels around the ship.

This research was published this week in the Proceedings of the National Academy of Sciences Early Edition.