Scientists crack code on 400-year-old treasure ship padlock

Key Points:

• Scientists used advanced micro-computed tomography (CT) scanning to decipher the four-letter combination (ANCE) of a 400-year-old brass padlock from the shipwreck of the Ann Francis, which sank off South Wales in 1583.
• The Ann Francis was discovered in the late 1990s by metal detectorist Peter Hughes, who found a treasure trove of gold, silver coins, and personal items, but was unable to unlock the padlock despite two decades of attempts.
• The padlock’s complex mechanism featured four rotating rings with six letters each, creating 1,296 possible combinations, along with stationary decoy letters designed to mislead looters.
• Researchers believe the padlock may have secured valuable items such as the captain’s chest containing Spanish silver, textiles, or maritime documents, though its exact contents remain unknown.
• The successfully unlocked padlock, praised for its excellent preservation and historical significance, is now exhibited at the National Waterfront Museum in Swansea, providing insight into 16th-century maritime security.