When the counterweight drops the sling and the missile it contains are dragged down the guiding trough, whipped up into the air, and swung in an arc above the trebuchet frame. At a critical point one end of the sling slips off of a peg at the end of the throwing arm; if the sling length has been adjusted so that the missile is travelling at a 45 degree angle at that instant, the maximum distance can be achieved. The swinging counterweight trubuchet is the classic design where the frame is fixed to the earth and the counterweight consists of a basket of rocks and earth hanging from one end of the throwing arm. The basket allows the weight to fall more vertically than if it were fixed since the basket is free to swing and will adjust its fall, to a degree.
The trebuchet is one of the most famous siege engines of all time, and designing and optimizing the powerful machine involves some tedious work. Learn how to design the perfect trebuchet by watching the animated video below or continuing to read the article. To understand how to optimize the design of a trebuchet, first we need to understand exactly what designs and principles make up one. A trebuchet in its most pure form involves a counterweight that falls completely along the vertical axis and a swing arm. Potential energy is stored in the lever mechanism as the large counterweight is lifted.
Video discussing the science behind this trebuchet. The trebuchet is a medieval machine designed to hurl objects into the interior of castles under siege or even knock down castle walls. Our model trebuchet uses a swinging counterweight, instead of the simpler fixed counterweight. The swinging counterweight, though more complex to build, transfers more energy to the projectile.
Table of Contents Introduction. Related Links. Return To Research Page. There are two different kinds of counterweights; fixed and swinging. Geiselman points out that these include the length of the arm, the length of the sling, and the angle which we start at as other variables.