Building a Trebuchet

Trebuchet Project

Counterweight Calculator

Link to the NOVA companion web site for the video on Trebuchets.

On the same site, you can read about other Medieval weapons in Medieval Arms Race or read about life in a Medieval Castle.

You can also Destroy the Castle using a Trebuchet.
Experiment with all the variables to see the effect of changing them:

  • stone ball weight
  • sling length
  • counterweight design
  • distance from the castle
  • whether to add wheels
    Hint: you must choose an option from each category before you can fire the trebuchet.

Global Spec Trebuchet Challenge: A game which allows you to change the trebuchet design, including the mass of the projectile and the counterweight and the launch angle, to maximize distance, accuracy and power. has plans and kits for sale, but it also has pictures of model Trebuchets and other types of catapults, and a Trebuchet simulator.

Full size reproduction Trebuchets at Caerphilly Castle, Wales.