PEG, a hot box, and the Vasa

Keeping the hull

On 11 October 1982 the hull was lifted on a supporting steel cradle. After it was raised, the ship was covered in water-saturated foam and sprayed with seawater to keep the timbers from drying out. Mary Rose Trust Without spraying, the Trust says, the wood could have shrunk by anything up to 50%. Mary Rose Trust The part recovered, the starboard side, had been protected by a blanket of organic rich silts on the seabed. Mary Rose Trust

Polyethylene glycol treatments (PEG) were chosen to stabilise the ship. PEG was selected because of the success of this resin in the historic treatment of waterlogged wood, including the treatment of the Vasa, the 17th-century Swedish warship. Mary Rose Trust The ship could not be submerged in PEG, so it was sprayed instead. Phase one began on 30 September 1994 and continued until 2003, with a low molecular weight PEG. Phase two, from 2004 to 2013, used a higher molecular weight PEG. Mary Rose Trust

Treatment with polyethylene glycol (PEG) began in 1994, according to that timeline. Mary Rose Trust

In 2013 the ship carefully began to be dried in a giant ‘hot box’. It is estimated that over 100 tonnes of water were removed between 2013 and 2016. By May 2016, the ship had dried enough to allow the drying ducts to be removed. Mary Rose Trust From 2016 to the present day, the ship has been kept in an environment of 55% relative humidity and 19º Celcius, the Trust says. Mary Rose Trust

The current Mary Rose Museum opened in 2013, the timeline says. Mary Rose Trust

The comparison with the Vasa is in the sources, not an invention of this site: PEG was chosen in part because of its success on that earlier hull. The sister site vasa.nautical.im takes up the Swedish ship in its own right.