Brief Description:  The medieval ballista was a massive, dart-throwing siege weapon functioning like a giant crossbow. It utilized tension from twisted skeins of rope, animal sinew, or human hair rather than a traditional bow limb. Operated by a crew, it fired heavy iron-tipped bolts or stones along a flat trajectory for defensive and offensive combat.

Core Design & Mechanics:

The Frame: Constructed primarily of wood, it featured a solid base frame with two vertical pillars housing the firing mechanism.

Torsion Springs: Its power came from two bundles of twisted rope or sinew passed through metal rings. Wooden or metal arms were inserted into these bundles.

Loading and Firing: A built-in winch and windlass system cranked the bowstring backward. This twisted the skeins even further to store immense energy. Upon releasing the trigger, the tension snapped the arms forward, propelling the projectile with lethal force.

Projectiles and Capabilities:

Ammunition: Primarily used to launch large, iron-clad wooden bolts (javelins) or heavy spherical stones.

Trajectory: Unlike the high, arcing shots of a trebuchet, the ballista was a direct-fire weapon. It was renowned for its sniper-like precision.

Range and Impact: Larger variants were capable of throwing heavy missiles hundreds of meters. The bolts could punch through armor and were highly effective at skewering enemy infantry or destroying watchtowers and wooden gates.