Harpax was a Roman siege machine invented by Marcus Vipsanius Agrippa, which he used during the struggle at sea with Sextus Pompey. It allowed the “harpoon” to launch towards the enemy unit, which could then be pulled to the side and boarding carried out.
According to sources, the machine was first used in 36 BCE at the battle of Naulochus Bay near Sicily.
Interestingly, harpax was not the first machine used by the Romans for boarding. Since the Punic Wars it has been known corvus – a ramp equipped with a powerful spike that stuck in the deck of the enemy unit. The advantage of harpax was that the catapult was much lighter than the so-called “crow”, which was to weigh a ton. What’s more, harpax had a longer range and it was not easy to unload the rope because the metal gripper was long.
The best effect of the new tactics is the fact that Sextus lost 180 of 300 ships during the battle.