Archimedes’ crane-like implement could not be considered a robot because it required the participation of a crane operator. However, it was a precursor to the industrial robot manipulator used in modern factories. The gun lifted enemy ships out of the water and overturned them.
It was developed specifically to fight Roman invaders in Syracuse in 213 BC. The historian Polybius described a scene when Roman ships approached the walls of the city facing the sea. A giant hand came to the aid of the enemy fleet and “lifted the bow of the ship out of the water and placed it upright on the stern.” The operator then “secured the machine, making it immobile, and then started a mechanism that released the hook and chain. The ships either overturned, standing badly in the water, or filled with confusion and seawater.”
Plutarch adds: “A horrible sight was often observed: the ship was lifted out of the water in mid-air and spun in place until every man was thrown in an unknown direction.”
The Claw gun was a brilliant example of the application of Archimedes’ two laws, the law of leverage and the law of buoyancy, which together could turn multi-ton ships upside down. Knowledge of forces and equilibrium was used to calculate the force required.
In fact, we have no direct evidence that Archimedes ever created this device, and ancient historians may certainly have exaggerated his achievements, even if such an implement did exist. However, recent experiments by engineers have confirmed that the Claw was technically feasible at the time.