A quinquereme is estimated at roughly 45 metres long, five metres wide and about 100 tons displacement, with its deck about three metres above the sea. Roman builders reportedly copied a wrecked Carthaginian ship, yet their versions were heavier. That extra weight made manoeuvring harder and demanded more effort from the rowers to approach Carthaginian speeds. Heavier structure may also have helped the hull withstand shock from a ram strike, so greater weight did not automatically mean inferior construction. Naval architect John Coates estimated that a galley could sustain about seven knots.
Notable Point · 1:14:21-1:16:38
Roman quinquereme weight and ramming tradeoffs
Approximate dimensions and construction differences show why copying a Carthaginian hull did not produce an identical fighting ship.