The Catapult Trireme is a large naval unit with a catapult mounted on top of the deck in Age of Empires. It fires every 3 seconds and throws large rocks and boulders toward enemy targets at a long distance. Once the Trireme has been upgraded, the technology which enables Catapult Trireme becomes available at the Dock. Like all stone throwing heavy siege weapons, Catapult Triremes deal 28 bonus damage against buildings after accounting for building armor.
It has fewer hit points and fires slower than its original counterpart, but more than makes up for it with damage per projectile, more range and doing damage to a certain location rather than a single unit. Because of its relative low amount of hit points compared to other units, a successful naval victory through a full-scale assault can be obtained by escorting them with a large group of Triremes.
Being a Trireme, it is not an upgrade to Trireme itself, but a separate unit. It can be upgraded into a Juggernaught once Engineering is researched. It benefits from such researches as Alchemy for its attack strength, Ballistics for its accuracy and Engineering for its range.
The ultimate warships of antiquity were advances on the trireme that occurred after the death of Alexander the Great. These ships were first broadened so that multiple rowers could apply power to each oar. Based on limited descriptions and detailed figures from crew and rowers, it is believed that the largest ships of this period may have had catamaran hulls. The broadening of ships and decks added weight and further reduced speed and maneuverability, but increased stability. Decks supported catapult artillery and large marine contigents. Ships engaged each other primarily with missile fire and boarding.
—Age of Empires manual
A group of Catapult Triremes, facing all possible directions.