Researchers from Cardiff University and Amgueddfa Cymru – National Museum Wales have successfully unlocked a 400-year-old brass padlock recovered from the wreck of the merchant ship Ann Francis, which sank off the coast of Wales in 1583.
Using micro-CT scanning technology, the team identified the correct four-letter combination—ANCE—without damaging the historic artifact. The lock, believed to have secured a treasure chest aboard the ship, had remained sealed since the vessel wrecked during a violent storm on December 28, 1583.
How the Lock Was Cracked
The Ann Francis, a merchant ship returning from Spain, veered off course and ran aground near Margam Beach, Port Talbot, during the storm. The wreck lay buried beneath sand for centuries until its rediscovery in 1998 by metal detectorist Peter Hughes. Subsequent archaeological efforts uncovered over 800 gold and silver coins from Germany, Spain, and Portugal, along with navigational tools and ship equipment.
The brass combination lock, preserved in working condition, was one of the wreck’s most significant artifacts. Unlike traditional locks, this mechanism required a specific four-letter sequence to open. Previous attempts to manually test combinations had failed, prompting researchers to turn to non-invasive CT scanning.
Dr. David Williams, a biomechanics engineer at Cardiff University, stated: “Micro-CT scanning allowed us to peer inside the lock without damaging it. It’s not every day you get to solve a 400-year-old mystery.” The high-resolution scans produced a 3D model of the lock’s internal notches, enabling the team to reconstruct the mechanism and determine the correct alignment of the rotating dials.
Historical Context and the Ship’s Fate
The Ann Francis was lost with all hands during the storm, with historical records indicating 14 sailors drowned after the vessel wrecked. Local accounts from the period suggest a woman later accused of witchcraft, Mother Gabley, was blamed for the storm. Under the Act Against Conjurations, Enchantments and Witchcrafts (passed in 1563), such accusations carried severe penalties, though Gabley’s fate remains unknown.
The wreck’s cargo, including coins and trade goods, reflects the transnational commerce of the 16th century. The lock’s recovery and decoding provide new insights into maritime security practices of the era, as well as the challenges of preserving underwater artifacts.
Significance of the Discovery
The successful unlocking of the padlock demonstrates the potential of advanced imaging technology in archaeological research. Unlike invasive methods, CT scanning preserves fragile artifacts while revealing hidden details of their construction.
Museum specialists and researchers continue to analyze the wreck’s remains, with the lock now on display as part of efforts to educate the public about Wales’ maritime history. The discovery underscores the importance of interdisciplinary collaboration in uncovering and interpreting historical mysteries.