Code cracked for Margam shipwreck padlock solving 400-year-old mystery

A 400-year-old brass padlock, recovered from a shipwreck site off the Welsh coast, has finally been unlocked after experts deciphered its four-letter code with the help of advanced scanning technologies. This intriguing item, found in 1999 by metal detectorist Peter Hughes near Margam in Port Talbot, was part of a larger treasure collection originating from the Ann Francis ship. The vessel had been caught in a storm on 28 December 1583 during its return voyage from Spain, and its valuable cargo remained buried beneath the sand for centuries.

Peter Hughes, who hails from Maesteg, described the padlock as one among hundreds of artefacts discovered during years of searching along Morfa beach. The lock was located close to a variety of Spanish silver coins and two coin weights, leading to the belief that it once secured precious valuables such as documents or textiles, which have not survived over time. Reflecting on the discovery, Hughes recalled, “It was by chance – a day off. I was walking along the beach with my metal detector on a day off, and I came across a coin. That was the start of a journey that lasted 21 years.”

The mystery of the lock’s code puzzled Hughes for decades until specialists at Amgueddfa Cymru and Cardiff University employed CT scanning technology to digitally examine the lock’s mechanism. This allowed them to identify the correct combination, revealing the letters “ANCE.” Senior curator Alastair Willis highlighted the complexity of the lock, noting that it contains four rings, each with six letters, producing 1,296 possible combinations. He further explained the presence of additional fixed letters that likely served to mislead potential thieves, making the unlocking process even more challenging.

Senior curator Siân Iles praised the lock’s exceptional preservation, emphasizing how it offers a vivid glimpse into its historical period. She pointed out, “This is a wonderful example of one that still functions as it would have done hundreds of years ago…it probably would have been a lock for a chest or a small box, we don’t know the content, and that’s part of the story, there are some things we’ll never know, but it’s something that would have meant something to the person who knew that code.” After gifting the artefacts to Amgueddfa Cymru in 2017, the collection, including the padlock, was put on display at Swansea Waterfront Museum in July 2026