- Catapults are any device that throws an object, although it commonly refers to the medieval siege weapon. - Trebuchets are a TYPE of catapult, using gravity (with a counterweight) or traction (men pulling down), to propel the arm and often employing a sling at the end of the arm for greater distance.Aug 4, 2008
The sling is not what makes it a trebuchet instead of a catapult. Catapults get energy from tension (usually torsion) and the arm hits a stop near the top of its arc to release the projectile. Trebuchets get their energy from gravity.Oct 29, 2013