A trebuchet is a type of catapult that was used as a siege engine in the Middle Ages. It is sometimes called a counterweight trebuchet or counterpoise trebuchet, to distinguish it from an earlier weapon called the traction trebuchet, which employed pulling men working the mechanism.

The counterweight trebuchet appeared in both Christian and Muslim lands around the Mediterranean in the 12th century. It could fling projectiles weighing up to 350 pounds (160 kg) at or into enemy fortifications. Its use continued into the 15th century, well after the introduction of gunpowder.

The three chief distinguishing characteristics of a trebuchet are:

  • The machine is powered exclusively by gravity; most often directly by means of a counterweight, though sometimes indirectly (such as in a traction trebuchet).
  • Such force rotates a throwing arm, usually four to six times the length of the counterweight arm, to multiply the speed of the arm and, eventually, the projectile.
  • The machine has a sling affixed to the end of the throwing arm, acting as a secondary fulcrum, to further multiply the speed of the projectile.

Trebuchet in "Topanga and the Chatsworth Lancers"Edit

In addition to the Glenview defensive wall, Topanga had several pre-positioned trebuchets ready for use. When Bruce Delgado launched another attack some thirty years after The Change, Jared Tillman helped crew a trebuchet. The crew did do some good work but had to abandon the weapon in an attempt to counterattack when the The Valley forces breached the wall with a battering ram. They failed and had to fall back to a secondary breastwork about half a mile back on the Topanga Canyon Boulevard.[1]


  1. See eg, The Change: Tales of Downfall and Rebirth, pgs. 477-483, HC.