Before gunpowder was invented and used, the Middle Ages had various ways to battle opponents or conquer areas. Most commonly used were war machines constructed for sieges and taking territory. Unlike a ballista, the mechanism was not complicated to create or use.
The Trabuco, a machine that functioned very similar to a catapult, was a tool in 400 B.C. that could easily turn the tide of battle according to infoescola.com. At its core design, it is noticeable that it is derived from similar mechanics to a sling. Originating in China, they did not use the first Trabuco for just firing stones. It is said that they even launched the dead to spread disease into the territories that they were at war with, dating back to being some of the start of biological warfare.
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In the Middle East, around the thirteenth century, Arab merchants acquired the unique design of the Trabuco and redesigned it. The original design would use gravitational energy and convert it over into kinetic energy. By adding a counterweight, the velocity of the item being projected increased dramatically, showing that the larger the counterweight, the more force will be applied to the projectile when launched.
Trabuco was not so simple that everyone could get accurate shots. It required physical calculations for the amount of gravity that might be applied to the counterweight and projectile as well as estimating the potential kinetic energy being generated at the time of use. Shortly after its remodel, the Europeans adapted the medieval weapon of mass destruction after encountering it during the crusades.
It is earliest documented that the Vikings and Nordic people used it around 863 A.D. during their battles across the continent. It was not until the invention of gunpowder that the use for the Trabuco died away. Now, it exists to help teach mechanics and basic principles with physics. Occasionally, events like pumpkin throwing championships will bring one out for entertainment.