The corvus gave Roman infantry a secure route onto an enemy ship when their naval experience was still limited. Polybius describes a bridge 1.2 metres wide and 10.9 metres long, with low parapets, a pole-and-pulley mechanism, and a beak-like spike that gripped the opposing deck. A naval-architecture calculation at TU Delft judged that a device weighing roughly a ton would probably have little effect on a much larger quinquereme's stability. Its tactical constraint was more direct: once the bridge held the ships together, the Roman vessel could not withdraw its ram. Improved maneuvering and boarding skills helped make the device less useful as the war continued.
Chapter · 48:40-52:15
The corvus turns a sea fight into a Roman infantry fight
A spiked boarding bridge let Rome exploit its infantry strength against a more experienced maritime opponent.