The trebuchet, or Trabuco, was an ancient war machine originally designed and used by the ancient Chinese during siege warfare. In ancient times it was common for the defenders of a country and fortify themselves behind huge stone walls or inside of well-protected castles. These buildings were quite impenetrable, especially when you consider the absence of modern-day weaponry such as gunpowder or the ability to attack from the sky. A well-supplied fortification could normally stay self-contained for months, leaving the attackers to fight a war of attrition and receiving many casualties as a result. In order to remedy this, siege weapons, such as the Trabuco, were created to remove these fortifications.
The concept of the Trabuco is quite easy; you use built up momentum to hurl a large object into the fortified location and hope that it is powerful enough to topple it down. The first Trabuco used by the Chinese were traction Trabuco according to redetrabuco.com.br. These simple siege machines were operated by a small team of soldiers who used manpower to hurl the stone forward.
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The projectile was held in a leather strap attached to a long pole. This pole was connected to a heavy stand in order to plant it firmly to the ground. These archaic Trabuco were eventually replaced by more powerful counterbalance versions that required more operators were larger and could do a significant amount of damage to fortifications and their defenders.
Counterbalance Trabuco used an attached end weight to launch a large number of projectiles at once towards a target. These weapons were slow to load as a team of operators needed to place stones into a large net by hand. Once loaded the chief operator would pull a lever after surveying where the shot would land. Once pulled the barrage of stones would travel a considerable distance, striking the target and causing massive damage. The Trabuco was used until the invention of gunpowder, which officially labeled the siege weapon as being obsolete. Gunpowder devices were far more capable and damage inducing, required less time to load and less training.
Find more about Trabuco: http://www.infoescola.com/curiosidades/trabuco/