The inventions of Archimedes

The ''iron hand''

An impressive defensive war machine invented by Archimedes to face Roman ships in the siege of Syracuse. It consisted of a jointed beam based on a rotating vertical beam or platform. At one end of the beam was a grappling hook ("iron hand") which hovered by chain and at the other end a sliding counterweight. When not used, the machine was laid alongside the wall in a horizontal position (so as not to be visible from the sea), wound and secured by rope and a manual winch (for balancing the counterweight). When a ship approached the wall, operators threw the hook against it and rotated the vertical beam (via horizontal levers). When the hook caught the ship, the operator, by pulling a special lever, ("kataklis") released the rope balancing the counterweight and the end of the beam, which had the counterweight, descended to the ground while the other end, which had the hook, ascended overthrowing or elevating the hooked ship. With the slope of the horizontal beam, the counterweight slid rearwards, executing even more torque and tilt to the beam. When the sliding counterweight reached the end and after the beam stabilised, the operators cut the rope holding the chain of the hook so that the hovering ship would be crushed against the water or adjacent rocks.

SOURCES: "Polybius, Histories, 8.6.1-6", "Livy Titus, History from the acquisition of Rome VI, 24.34.10-12", "Plutarch, Lives parallel (Markellos) 5, 15.2-3"