Trebuchet

A trebuchet is a very large weapon meant to throw projectiles over long distances. Trebuchets are generally wooden machines that use long throwing arms powered by heavy counterweights. The largest trebuchets are capable of hurling stones and other objects weighing hundreds of pounds. Engineers designed the first trebuchets based on earlier military technologies. During medieval times, armies used trebuchets to great effect when attacking castles and other fortifications. Although gunpowder-powered cannons replaced trebuchets, the old throwing machines are still used in modern times for study and recreation.

Background

Artillery refers to large weapons that fire powerful projectiles over long distances. These weapons are larger, stronger, and more destructive than other range weapons, such as rifles, bows and arrows, or slings. Since ancient times, artillery has been an important and constantly developing aspect of warfare.

Armies have used artillery not only for its long range and massive destructive power but also for the fear it spreads among enemy forces. Using artillery, an army can attack enemies that may be far away, well protected, or unprepared, shattering their sense of security and throwing them into disarray. Artillery became especially important as military defenses developed in size and strength; the additional firepower was necessary to break through defensive walls or lob projectiles over them.

In ancient times, armies developed several kinds of artillery weapons. One of the first was the ballista, which was a greatly enlarged version of the crossbow, a handheld weapon. The ballista used tension in tightly twisted ropes to fire spears or similar projectiles. This weapon had great velocity and was effective in attacking soldiers and horses but could not pierce stone walls. To attack walled fortifications, military engineers created an even more powerful weapon—the catapult.

Catapults consisted of a base, a large wooden arm on a pivot, and ropes. One end of the arm had a scooped-out cup that held the projectile, usually a large round stone. Operators twisted the ropes tightly until they created very strong stored tension. When the ropes were released, their energy caused the arm to swing along the pivot at high speed. Like a giant arm throwing a ball, this motion cast the projectile far into the distance.

Catapults represented a major improvement over other forms of artillery in attacking walls. Heavy stone projectiles hitting with great force could eventually damage and destroy even the thickest fortifications. However, catapults were limited in their size and strength. They also were difficult to aim with much accuracy. As civilizations created stronger and larger defenses, including the mighty castles of the medieval era, military engineers set about inventing an even more powerful weapon.

Overview

Over hundreds of years, engineers used the principles of the ballista and catapult to develop a new category of artillery weapon, the trebuchet. Trebuchets became most famous during medieval times when invading armies used them to attack, and often disable or destroy, castles and other major fortifications. The destructive power of trebuchets made them an early weapon of mass destruction, unequaled until the creation of gunpowder.

Structurally, the main features of trebuchets closely resembled those of earlier catapults. Trebuchets were built atop large, heavy wooden bases. Some bases lay flat on the ground for greater stability, while others had wheels for easier transportation. In the center of the base was a tall wooden pivot. A long throwing arm, usually formed from a single old-growth tree, was attached in an off-center way to the pivot.

Engineers placed a very heavy counterweight on the shorter end of the throwing arm. Counterweights could take many forms. Some were solid blocks of very heavy materials, such as stone or lead. More advanced trebuchets had empty wooden boxes that could be filled with smaller stones or dirt on location, making the weapon's basic structure much lighter and easier to transport. To the opposite end of the throwing arm, engineers attached a net-like sling. This sling held the projectile, usually a carved spherical stone.

Operators hoisted the short end of the throwing arm, including the prepared counterweight, into the air. Then they chained or bolted the longer end with the sling to the base. Operators performed the needed calculations for aiming and loaded the projectile into the sling. To fire, they detached the throwing arm from the base. The much heavier counterweight fell straight down, causing the throwing arm to swing quickly upward along the pivot and hurl the projectile from the sling.

Engineers modified the basic trebuchet design many times over its centuries of use. Eventually, it became a highly efficient machine. Its relatively simple design and operation meant it could be built on a very large scale. Large trebuchets were capable of hurling enormous stone projectiles weighing hundreds of pounds. Additionally, the use of a sling instead of a cup allowed operators to adjust aim and range by simply lengthening, shortening, or angling the sling rather than moving the entire trebuchet.

Trebuchet technology developed in many lands during the same general period. Historians believe the earliest models may have been developed in China. These machines were relatively crude, however, and used the strength of humans pulling on ropes instead of a counterweight. This meant that huge groups of people were required to operate the weapon. Other trebuchets developed in the Middle East and Europe. The development of the counterweight cemented the technology into common military use.

Trebuchets became one of the most feared weapons of medieval times. They reduced the strength and security of castles and other fortifications, which had previously been almost impervious to direct attack. They could be modified for different tactics. Records indicate that trebuchets sometimes fired flaming projectiles meant to set fire to wooden structures. They often fired very strange projectiles as well, including dead bodies and diseased animals meant to spread sickness and pollute the enemy's food and water supplies.

The era of gunpowder technology brought an end to the trebuchet as a weapon of war. Gunpowder allowed cannons to have a destructive effect similar to that of trebuchets but with much more reliability and much less effort. In modern times, many people are still fascinated by this medieval weapon. Some people and organizations have built their own trebuchets based on original plans for recreation and study. These machines often fire unorthodox projectiles, including cars and pianos, to the delight of spectators. In addition, trebuchets have been used in pumpkin-chucking (sometimes called "punkin' chunkin'") contests to hurl pumpkins over great distances.

Bibliography

Carrillo, Christopher. "The Trebuchet." Illumin/University of Southern California, 2018, illumin.usc.edu/140/the-trebuchet/. Accessed 19 Jan. 2018.

Denny, Mark. Ingenium: Five Machines That Changed the World. Johns Hopkins UP, 2007.

Gurstelle, William. The Art of the Catapult: Build Greek Ballistae, Roman Onagers, English Trebuchets and More Ancient Artillery. Chicago Review Press, 2004

Kagay, Donald J., et al., editors. On the Social Origins of Medieval Institutions: The Medieval Mediterranean. Koninklijke Brill NV Leiden, 1998.

Nolan, Cathal J., editor. The Age of Wars of Religion, 1000–1650: An Encyclopedia of Global Warfare and Civilization, Vol. 2. Greenwood Press, 2006.

Norris, John. Artillery: A History. History Press, 2013.

"Secrets of Lost Empires." PBS, Nov. 2000, www.pbs.org/wgbh/nova/lostempires/trebuchet/builds.html. Accessed 19 Jan. 2018.

Toms, Ron L., et al. Catapult Design, Construction and Competition with the Projectile Hurling Engines of the Ancients. RLT Industries, Inc., 2006.