In July 1545, the flagship vessel of Henry VIII’s fleet met an ignominious end. Locked in a stalemate at the Battle of Solent, England and its perennial enemy, France, were exchanging cannonfire when the Tudor king’s prize ship, the Mary Rose, began to keel over. As Henry watched in horror, the vessel careened toward the bottom of the English Channel, drowning all but 34 of its nearly 500-men crew.
Some 400 years later, divers discovered the wreck of the Mary Rose submerged in layers of silt. According to History Extra, the ship was remarkably well preserved, yielding everything from wooden dishes to lice combs still covered in nits. Researchers raised the Mary Rose from its watery grave in 1982, paving the way for its conservation and exhibition to the public, but in recent years, steady deterioration sparked by centuries spent underwater has threatened to destroy the historical goldmine.
Still, the Mary Rose isn’t doomed just yet. As Matthew Taub writes for Atlas Obscura, scientists from the University of Glasgow in Scotland, the University of Warwick in England and the Mary Rose Trust have developed a new technique that halts the decay of salvaged shipwrecks’ wooden structures. The process, detailed in a presentation at this week’s 256th National Meeting & Exposition of the American Chemical Society, uses nanoparticles—miniscule magnetic particles measuring just a thousandth of the width of a strand of human hair—to remove the iron ions responsible for a vessel’s decay.
According to a press release, marine bacteria settled into the Mary Rose’s wooden timber as it lay at the bottom of the seabed. These bacteria produced hydrogen sulfide, a gas that reacts with iron ions (imagine the rusted state of the ship’s cannons) to form iron sulfides. The chemical reaction is fairly harmless in low-oxygen environments like the seafloor, but as soon as the sulfides are exposed to oxygen, they produce destructive acids.
To combat this deterioration, the researchers rely on nanoparticles of iron oxide coated in a substance that morphs from a gel to a liquid based on changes in temperature. The Times’ Rhys Blakely explains that the particles “permeate the wood as a liquid, capture iron ions and then [are] drawn to the surface, where the polymer can be transformed into a gel and gently peeled off like a plaster.”
Nanoparticles can’t completely reverse the ill effects of the Mary Rose’s time underwater, Atlas Obscura’s Taub notes, but they will be able to remove the wood’s rusted reddish hue, returning the ship to a semblance of its former glory.
Prior to the development of the new technique, researchers prevented the ship from fully drying out by spraying it with water and wax. In 2013, however, the Mary Rose was finally dried and enclosed in a climate-controlled box. Although conservators used a supplement known as polyethylene glycol, or PEG, to preserve the ship’s hull, the polymer was unable to keep the Mary Rose's wooden beams from warping during the drying process, Sarah Knapton reported for The Telegraph in October 2017.
Now, the flagship vessel’s fate is finally secure.
“Conservators will have, for the first time, a state-of-the-art quantitative and restorative method for the safe and rapid treatment of wooden artifacts,” lead researcher Serena Corr, a chemist at the University of Glasgow, said in a statement. “We plan to then transfer this technology to other materials recovered from the Mary Rose, such as textiles and leather.”
The Mary Rose served Henry VIII for a total of 34 years. Its tenure as the Tudor king’s favorite ship saw the rise and fall of six queens and, perhaps unsurprisingly, lasted 10 more years than the king’s longest relationship, a 24-year marriage to his first queen, Catherine of Aragon.
Still, like most of Henry’s female companions, the Mary Rose experienced a sudden and unprecedented fall from favor. Upturned under mysterious circumstances, the flagship sank to its undersea grave with roughly 500 innocents—and one ship dog, a mutt dubbed Hatch—trapped within.