Scientists have deciphered the four-digit code of an ancient lock discovered at a shipwreck site off the coast of Wales. Experts managed to examine the lock’s internal mechanism using computed tomography, allowing them to see its structure without damaging it.
Treasure hunter Peter Hughes found the brass lock in 1999 on Morfa Beach, near the town of Port Talbot. It was later established that the lock was part of the treasure aboard the Spanish ship Ann Francis. The vessel was caught in a storm on December 28, 1583, while returning from Spain, and its cargo remained buried beneath the sand for several centuries.
Hughes discovered hundreds of archaeological objects, including Spanish silver coins and special weights used to weigh them. The lock may have been used to secure these items or to lock a chest containing documents, textiles, and other objects that have not survived over time.
The treasure hunter spent around 20 years trying to find the correct combination on his own but was unsuccessful. Specialists from Amgueddfa Cymru – Museum Wales and Cardiff University scanned the lock using micro-computed tomography and uncovered the code: ANCE.
The lock has four rotating rings, each bearing six letters. Together, they provide 1,296 possible combinations. In addition, there are fixed letters at the ends of the lock that could have confused anyone trying to open it.
Cardiff University researcher David Williams admitted that he initially doubted whether the experiment would succeed. However, after several attempts, the specialists were able to see the lock’s internal structure and find the correct code.
According to museum collection officials, the lock has been remarkably well preserved and still works as it did several centuries ago. The archaeological collection was transferred to Amgueddfa Cymru – Museum Wales in 2017, and since July 2026, it has been on display at a museum on Swansea’s waterfront promenade.
The discovery demonstrates how modern technologies can reveal new information about archaeological objects without damaging their historical value. In the case of the lock, the challenge was not simply to find the code, but to understand the mechanism hidden inside it—a task that had remained impossible even after years of manual attempts.
It is also remarkable that the lock has remained functional despite spending centuries buried beneath the sand. It is not only part of the shipwreck’s history but also a material record of everyday life, reminding us that archaeological finds can tell us about more than major events: they can also reveal the ordinary objects people used and how they used them. Its exhibition at the museum makes this story accessible to the public.
