Scientists crack code of 400-year-old lock found on Welsh shipwreck

Nation.Cymru staff

Researchers have cracked the code of a combination lock recovered from a ship wrecked off the Welsh coast more than 400 years ago.

Experts from Amgueddfa Cymru and Cardiff University used CT scans to examine the brass lock’s internal mechanism without damaging it, revealing the four-letter combination: ANCE.

The lock was recovered from the Ann Francis, which was returning from Spain when a storm blew it off course on the evening of December 28, 1583. It was wrecked on Margam Beach, near Port Talbot.

Its cargo lay beneath the sand for centuries before metal detectorists began uncovering coins and other objects.

Dr David Williams, a research associate at Cardiff University’s School of Engineering, used micro-CT scanning to create a detailed three-dimensional image of the lock.

“By creating a detailed 3D image of the internal mechanism, I could see how the notches lined up with the letters and identify the exact combination,” he said.

“We normally use this technology to study bones and other biological structures, so investigating a 400-year-old padlock was certainly a first for us!

“I had to wait until later that evening for the museum team to test the combination, so getting the message that we’d cracked it was incredibly satisfying.”

The lock is believed to have secured a small chest containing valuable possessions. It was found near Spanish silver coins and close to two coin weights recovered from the wreck site.

Researchers say it may have protected those objects or a chest containing materials that have not survived, such as documents or textiles.

Although the mechanism has now been unlocked, the meaning of its combination remains unknown.

Alastair Willis, senior curator for numismatics and the Welsh economy at Amgueddfa Cymru, said: “Elizabethan combination locks are known in Britain, but this one is in exceptionally good condition and is associated with a dated wreck, making it a unique find and the code a tantalising mystery to solve.

“Of course, now we’ve solved it, we are left wondering if the code meant something to its owner.”

Detectorist

Metal detectorist Peter Hughes discovered most of the hoard between 1996 and 2017, after dredging and storms exposed objects beneath the sand.

He said the lock’s lettered rings still turned easily when he found it.

“When I found the lock I was immediately astonished by the incredible workmanship and its astonishing condition,” he said.

“I also remember being left excited at the prospect of finding wonderful things from the treasure chest it once locked.”

The hoard was acquired by Amgueddfa Cymru with Welsh Government support.

The lock is now displayed at the National Waterfront Museum in Swansea alongside other finds from the Ann Francis, including gold coins from the reign of Ferdinand and Isabella of Spain and a boatswain’s whistle.

The exhibition, Tides of Treasure, runs until June 2027.