The Trabuco, also known as the trebuchet, was an ancient siege engine that was capable of throwing large stones a far distance. The weapon was generally built on site, making it immobile. It was operated by a team of trained weapons engineers and was one of the most feared weapons of its time for its ability to quickly knock over and destroy enemy fortifications.
The first trabuco was invented and used by the ancient Chinese. It was a fairly small weapon and was nothing more than a large wooden pole attached to a heavy base. This particular version of the weapon could be operated by two Chinese soldiers, who held onto sidebars and used their own bodies as a lever to swing the pole, which contained a leather sling that held a stone. According to youtube.com, the soldiers would then use a combination of their body weight and physical strength to build up momentum on the pole, spinning the device until the desired speed was placed on it. When the soldiers stopped moving the leather sling would successfully release the stone and it would quickly launch itself across the battlefield and strike anything in its path. This first trebuchet was useful as an anti-personal weapon and could be quickly built in large quantities.
Read more on infoescola.com
The second type of trabuco was built during the Middle Ages and was a much larger and powerful weapon. This version of the weapon took a considerable time to build on the battlefield and was solely used as a means to destroy enemy defensive positions. The device was far more complicated than its Chinese predecessor and was capable of launching a multitude of massive stones a very far distance. Trabuco weapons were very useful but due to the lengthy amount of time needed to reload in order to fire again were only practical during a siege where there was little fear of a physical retaliation from the defenders.
Both trebuchets were rendered obsolete when gunpowder was invented and replaced them during siege warfare. The trebuchet is an impressive piece of military history that is emulated by enthusiasts and historians today.
Find more about Trabuco: http://pt.bab.la/dicionario/espanhol-portugues/trabuco