Researchers decode a 400 year old combination lock from a shipwreck

Researchers at Cardiff University and Museum Wales decoded the secret combination of an Elizabethan padlock found in a shipwreck.

The lock belonged to the Ann Francis, a merchant ship that wrecked on Margam beach in Wales in 1583. The vessel was returning to Norfolk, England, from Spain with a cargo of gold and silver bullion. Metal detectorist Peter Hughes discovered the lock between 1996 and 2017 near Sker Point.

The lock remained in excellent condition despite spending over 400 years under the sand. To determine how the lock functioned without damaging the artifact, Dr. David Williams used a micro-CT scan. Usually used for studying biological structures like bones, the technology created a 3D image of the internal mechanism. This allowed the team to see how internal notches lined up with the exterior letters. The team identified the combination as ANCE.

While the researchers solved the mechanical mystery, they noted that the specific meaning of the code to the original owner remains unknown. The lock was found near Spanish silver coins and coin weights, suggesting it once secured a chest of valuables.