Supporting a sagging ship: HMS Victory and load cells

It’s probably the most famous ship in the Royal Navy that doesn’t actually float any more, but HMS Victory has been saved from ‘sagging’ in its dry dock with the help of load cells.

Launched in May 1765 from the docks at Chatham, and at the time the largest ship build for the navy, HMS Victory was Nelson’s flagship at the Battle of Trafalgar. Now it sits in dry dock at the National Museum of the Royal Navy (NMRN) in Portsmouth.

Float your boat

Since arriving in Portsmouth in 1922, the ship has rested on a cradle of 22 steel brackets. However, the original oak timbers of the ship had begun distorting under the Victory’s weight of 3,600 tonnes. It’s the lack of water that’s caused the problem: normally, the hull would be kept in shape by the pressure of sea water on the outside of the ship. So, a plan was made to mimic the floating action and keep the Victory in shape.

Propping up history

Now HMS Victory sits on a series of 134 steel props, monitored in real time by a series of load cells. As Andrew Barnes, project director for NMRN said:

“Each prop has a load cell so we can know, on a minute-by-minute basis, how much of HMS Victory’s weight is being carried, providing the museum with invaluable insight into her stability and helping us to prevent damage to her structure.”

Installation of the system continued throughout lockdown and now conservators can review and repair any existing damage. Now that individual museums in the the Portsmouth Historic Dockyard have reopened, and the rest reopening from 24th August 2020 including HMS Victory, visitors will soon be able to walk down the Under Hull Path to stand under the ship’s hull and keel for the first time in 100 years, and admire the original timbers close up.

A touch of seasoning

One of the reasons that HMS Victory’s timbers have lasted so long might be down to seasoning. Originally commissioned to serve in the Seven Years’ War, by the time the wooden frame of the ship was completed, it was surplus to immediate requirements. So, the massive frame sat under cover for three years, rather than just a season, allowing the timbers to harden fully.

If you’ve never visited the Historic Dockyard in Portsmouth, including HMS Victory and the fascinating Mary Rose museum, it’s well worth a visit before the kids go back to school. More info at Historic Dockyard