The catapult consisted of a solid base with a pivoting arm that would be pulled down and locked into place . Once the arm was in place, the projectile would be loaded into a cup at the end of the arm. The force that the catapult needed to launch the projectile came from the manipulation of twisted ropes . The catapult operator would twist ropes that surrounded the pivoting arm, causing immense tension. When the catapult was released, the ropes would twist back into shape and swing the pivoting arm upward until it reached a vertical position and hit a cushioned pad. The pivoting arm would then stop and the projectile would be flung forward. In order to change the trajectory of the projectile, the operators had the option of either “angling the whole machine or changing the angle of the crossbar” . A powerful catapult had the capability to launch a 27-kilogram stone, but had little effect on walls or fortified buildings located over 160 meters away .
The trebuchet made improvements upon both of these weapons, able to launch stones that weighed hundreds of kilograms farther and more accurately than either the ballista or the catapult. With this power, a trebuchet could destroy even fortified walls quite easily and quickly replaced catapults as the weapon of choice on the medieval battlefield.
The Evolution of the Trebuchet
One of the final improvements to reach the trebuchet was the “propped counterweight” . The propped counterweight was very similar to the hinged counterweight, except the weight was forced to make an angle with the arm instead of hanging straight down. This created an increase in falling distance and centrifugal force, both of which contributed to greater power. These improvements helped the trebuchet maintain dominance on the battlefield.
The Trebuchet in Action
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