Ever since I was a young boy I was interested in catapults. Maybe it's the whole throwing things and watching things break that appealed to me as it does many a young man. Whatever the case I always wanted one of my own. Now that I teach robotics I use trebuchets in my lesson plans as a working example of a simple machine; a lever. The trebuchets that my students and I build in class are done using the GEARS Invention and Design System kits that we use to also build the robots. (see image on the right). These small desktop trebuchets stand about twelve inches tall and can throw a small 1 oz fishing weight across the room. Pretty cool stuff! Unfortunately, I have this problem of wanting things to be bigger, more powerful, more obnoxious, and more dangerous than I probably need.

Well, I finally got the excuse that I needed to build one that I wanted to build; a medium scale trebuchet. Of course medium may sound diminutive until you see the result which reaches over twenty feet into the sky. Add the sling to it and the projectile doesn't even get released until it is almost 35 feet off the ground. It has thrown five pound melons over the length of a football field! (and that was with only 200 pounds in the counterweight bucket!) I built it for a college class project for Late Roman and Medieval Humanities class to go along with a term paper discussing the evolution of the trebuchet, how it works, and why it was so effective. My professor, Dr. George Brooks, just finished his doctoral thesis recently and I even had a copy of it to reference in my paper. His thesis is about the Mechanization of the Middle Ages and is great reading for engineers who want a great understanding of the evolution of industrial and mechanical engineering. Unfortunately, my term paper, which was only supposed to be 1500 words, weighed in at close to 4000. So, I had to leave all that out to trim it to a modest 2300 words.

This web page is to document the design the building and the launching of this medieval siege engine. Click on next to begin...