The book Structures describes how trebuchets are quite inefficient compared to the Roman Ballista, which the author alleges the medieval folks forget how to mak

The book Structures describes how trebuchets are quite inefficient compared to the Roman Ballista, which the author alleges the medieval folks forget how to make. Much of the energy is wasted in the counterweight swinging. By contrast, he alleges bows, including hand-drawn, crossbows, and ballistas (or scorpions, or springalds for you AoE fans)are close to 100% efficient. This is relevant, since as the original com mentor pointed out what the video-maker built is arguably closer to one of those torsion weapons than a counterweight trebuchet.