It would be assembled with local wood, if necessary. The Greek ballista was a siege weapon. With the Ballista you can deal heavy damage and easily kill creatures. They were, in fact, used on ships in the late BCE era by the Romans [1,2]. For the Ballista you need Bolts as Ammunition. Ingeborg Simon / Braunschweigisches Landesmuseum This kind of ballista dates back to 399 BCE, when King Dionysius of Syracuse besieged a walled town called Motya located on the island of Sicily. Whether its pummeling enemies on the frontlines or watching over a strategic post, the Ballista won’t just level the playing field, it’ll level the competition. ANY wooden ship capable of withstanding sea voyages would not fall apart under ballista bolt attacks. Navies of the Medieval period had both ballistas and Springalds to hurl stones, bolts, arrows, and sometimes Greek Fire. A ballista is a completely different beast, essentially a giant crossbow used to hurl bolts (not stones) & more a direct fire weapon, your answer clearly showed you thought ballista are essentially the same as the first two (comments about time loading & firing stones etc), if …
Some were positioned inside large, armoured, mobile siege towers or even on the edge of a battlefield. Ballista – Standalone Ship.

While not officially designed to carry the Ballista, … Ballista were often used historically against enemy ships but generally to start fires, kill enemy personnel on deck, or to fire a grappling hook (the harpax) at the enemy ship to seize it. Yes, ballistas and other "artillery" were used on Medieval ships. A medium ranged weapon used primarily for boat warfare, as well as breaking into thatch or wood structures, it is not suggested for stone. Chew through shields, incapacitate or obliterate airborne threats of almost any class foolhardy enough to come within 2000 meters. You can build a Schooner with 4 Ballista at the back, and go on a whale hunt or go to a powerstone island and kill Cyclops or Hydras . As it stands, there are only two ship series specifically designed to transport the Ballista – the Idris and the Hercules (by transport, we mean getting it entirely inside the vehicle, properly secured, and doors closed). All components that were not made of wood were transported in the baggage train. As it stands, there are only two ship series specifically designed to transport the Ballista – the Idris and the Hercules (by transport, we mean getting it entirely inside the vehicle, properly secured, and doors closed). While not officially designed to carry the Ballista, …