Experts have cracked the four-letter code on an ancient brass padlock recovered from a shipwreck off the Welsh coast, using CT scanning to solve a 400-year-old mystery.
The lock was found in 1999 by metal detectorist Peter Hughes in sand near Margam in Port Talbot. It is part of a wider treasure hoard from the Ann Francis, a ship caught in a storm on 28 December 1583 on the way back from Spain, whose cargo remained buried beneath the sand for centuries.
Hughes, from Maesteg, found the lock among hundreds of artefacts he uncovered over decades of searching on Morfa beach. Found near a collection of Spanish silver coins and close to two coin weights, it is thought the lock may have protected these objects or secured a chest containing valuable items that did not survive, such as documents or textiles. The 69-year-old said he was on a day off and walking along the beach with his metal detector when he came across a coin, “the start of a journey that lasted 21 years”. He said he was “delighted” that the expert team at Amgueddfa Cymru and Cardiff University had cracked the code after he spent years trying to solve the mystery himself. “I tried to unlock it for about 20 years, I tried moving the dials, finding the right combinations, and I failed,” he said. “But with the aid of modern technology we've been able to crack what's like the Da Vinci code, really.”
Dr David Williams, a research associate at Cardiff University's School of Engineering, said he was “sceptical” when asked to use a scanning device to try to solve the mystery. He described the process as micro CT scanning, “something you'd get at the hospital, but for smaller items”. The team saw letters on the first scan, the second scan “went terribly”, and on the third scan a different approach revealed the code. “I was blown away that we actually cracked it,” he said.
The code spells out ANCE. Senior curator Alastair Willis said the discovery was “incredible”, noting the complexity of the mechanism: four rings with six letters each give 1,296 different combinations, all of which must be aligned with a loop at the top.
His colleague at Amgueddfa Cymru, senior curator Siân Iles, said the lock was in “excellent condition” and still functions as it would have done hundreds of years ago. She said it was a small object, probably a lock for a chest or small box, and the contents are unknown. “There are some things we'll never know, but it's something that would have meant something to the person who knew that code,” she said.
Hughes passed the hoard of artefacts to Amgueddfa Cymru in 2017, and the collection, with the lock at its centre, was put on display at Swansea Waterfront Museum in July 2026.
Analysis
Why This Matters
- The successful scan shows how modern technology can solve archaeological puzzles without damaging fragile objects.
- The lock adds context to the Ann Francis hoard, helping curators date and interpret the wider collection of coins and artefacts.
- The contents the lock may have protected are unknown, leaving an open question for future research.
Background
The Ann Francis was caught in a storm off the Welsh coast on 28 December 1583 while returning from Spain, and its cargo lay buried in sand for centuries. The padlock was found in 1999 by metal detectorist Peter Hughes, who spent decades searching Morfa beach and passed his collection to Amgueddfa Cymru in 2017. The collection, with the lock at its centre, has been on display at Swansea Waterfront Museum since July 2026.
Key Perspectives
Peter Hughes: the detectorist who found the lock, said he was “delighted” and “truly thrilled” after trying and failing to unlock it for about 20 years.
Dr David Williams: the Cardiff University researcher who scanned the lock, said he was “sceptical” at first and “blown away” that the code was cracked.
Alastair Willis: senior curator at Amgueddfa Cymru, called the discovery of the code “incredible” and noted the complexity of 1,296 possible combinations.
Siân Iles: senior curator at Amgueddfa Cymru, said the lock was in “excellent condition” and still works as it would have done hundreds of years ago.
What to Watch
- Whether further research on the Ann Francis hoard reveals what the lock originally secured; curators say some things “we'll never know”.
- How the collection performs on display at Swansea Waterfront Museum and whether it generates renewed interest in the wreck.
- Whether the CT scanning technique is applied to other artefacts from the collection, such as the Spanish silver coins and weights.
Checked
12 claims in this story checked against 1 source: 12 supported.
Show each claim
- SupportedThe code has been cracked on a 400-year-old padlock from a Welsh shipwreck.BBC News: “Experts have cracked a four-letter code to open an ancient padlock from a shipwreck off the Welsh coast using modern scanning technology. The 400-year-old brass lock”
- SupportedCT scanning revealed that the lock’s combination spells ANCE.BBC News: “Museum experts have used CT scanning to examine the lock's internal mechanism, identify the correct letter combination and solve the mystery.”
- SupportedThe brass lock is from the Ann Francis, which was caught in a storm on 28 December 1583 while returning from Spain.BBC News: “It forms part of a wider treasure hoard from the Ann Francis ship that was caught in a storm on 28 December 1583 on the way back from Spain.”
- SupportedPeter Hughes found the lock in 1999 in sand near Margam in Port Talbot.BBC News: “The 400-year-old brass lock was discovered by metal detectorist Peter Hughes in the sand near Margam in Port Talbot, in 1999.”
- SupportedThe Ann Francis’s cargo was hidden beneath the sand for centuries.BBC News: “Its cargo was hidden beneath the sand for centuries.”
- SupportedHughes said finding a coin began a journey that lasted 21 years.BBC News: “"That was the start of a journey that lasted 21 years."”
- SupportedHughes said he tried for about 20 years to unlock the padlock and failed.BBC News: “"I tried to unlock it for about 20 years, I tried moving the dials, finding the right combinations, and I failed," he said.”
- SupportedDr David Williams said he was sceptical about being asked to use a scanning device to solve the mystery.BBC News: “Dr David Williams, a research associate based at Cardiff University's School of Engineering, said he was "sceptical" when he was asked to use a scanning device to try and solve the mystery.”
- SupportedWilliams said the first scan revealed letters, the second went badly, and a different approach on the third scan produced the code.BBC News: “"We did a first scan to see if we could see anything and we were quite surprised that we could see letters," he said. "The second scan went terribly, but with the third scan, we tried a different approach, and figured out the code."”
- SupportedThe lock spells ANCE and has four rings with six letters each, giving 1,296 combinations that must align with the loop at the top.BBC News: “"There are four different rings, and because there are six different letters on each of the rings, there are 1,296 different combinations, and you have to make sure they're aligned with the loop at the top."”
- SupportedHughes passed the hoard to Amgueddfa Cymru in 2017, and the collection went on display at Swansea Waterfront Museum in July 2026.BBC News: “Hughes passed on the hoard of artefacts to Amgueddfa Cymru in 2017, and the collection, with the lock in the centre, was put on display at Swansea Waterfront Museum in July 2026 .”
- SupportedSenior curator Siân Iles said the lock was in excellent condition and still functions as it would have hundreds of years ago.BBC News: “His colleague at Amgueddfa Cymru, senior curator Siân Iles, said the lock was in "excellent condition" and paints a picture of the period. "This is a wonderful example of one that still functions as it would have done hundreds of years ago," she said.”
