Pompeii's battle scars linked to an ancient 'machine gun'

Paul Arnold

contributing writer

The ancient city of Pompeii is one of those archaeological sites that keeps on giving with one discovery after another. While much of what we know about the Roman settlement comes from the eruption of Vesuvius in AD 79, another significant event from nearly a century earlier is also yielding fresh insights into its past.

Ancient 'machine gun'

In a paper published in the journal Heritage, a team of researchers from Italy claims to have uncovered evidence of highly advanced weaponry used during the Siege of Sulla. Some commentators have likened it to an ancient version of a machine gun.

Pompeii's northern walls show significant signs of battle damage. Over the years, much research has focused on large, circular craters formed by heavy stone balls launched from standard Roman catapults. Scattered between these craters are smaller, four-sided holes arranged in a fan-like shape, often attributed to wear and tear or general battle damage.

The research team had a different explanation. They believed the distinct shapes were possibly caused by a polybolus, a weapon capable of firing multiple projectiles in rapid succession.

Ballistic scars

To test their idea, the researchers produced high-resolution 3D models of the holes using laser scanning and photogrammetry. By analyzing the exact depth, width, and shape of the impacts, the team worked backwards to infer the type of weapon involved and the likely forces behind the strikes. Everything pointed to a high-velocity machine rather than a handheld weapon.

To see if they were on the right track, the research team compared the digital data to third-century BC Greek engineering blueprints that describe the mechanics of a repeating catapult. They were also able to match the fan-shaped pattern on the walls to the mechanical sweep of the weapon described in the manuals.

Another supporting line of evidence came from museum collections. Surviving projectiles from other Roman military sites, such as iron-tipped bolts associated with the Scorpion catapult, matched the dimensions of the 3D models created from the wall damage.

"The unequivocally radial configuration of the closely spaced impacts observed at Pompeii... makes it reasonable to hypothesize the use of an automatic scorpion intended to strike archers emerging in succession from the lateral posterns of the towers or, higher up, defenders who briefly exposed themselves between the merlons once the provisional wooden parapets had been severely compromised," wrote the team in their paper.

Having identified the weapon, the researchers linked it to the damage to the siege of the city by the Roman general Lucius Cornelius Sulla. They reached this conclusion because the city was buried by volcanic ash less than a century after the military action, which perfectly preserved the impacts. This ensured they were not erased by the passage of time.