Trebuchet

Categories: Siege engines | Fortification

For the font, see Trebuchet MS.
Image:Trebuchet.jpg
Trebuchet at Château des Baux, France

A trebuchet (IPA: /'tɺɛbjʊʃeɪ/</span>, /tɺɛbjə'ʃɛt/ or /tɺɛbjə'tʃɛt/, also sometimes called a trebucket IPA: /tɺɛbjə'kɛt/</span>, < Old French trebuchet < trebucher "to throw over" < tres "over, beyond" and buc "torso" < Latin trans and a Germanic word) is a medieval siege engine, a weapon employed either to batter masonry or to throw projectiles over walls. The name engine was derived from the Latin word ingenium meaning ingenious device.

The trebuchet was a development of the Chinese traction trebuchet. In the traction trebuchet a large crew of men pulled down on ropes to propel the missile. In the European trebuchet these men were replaced with a large fixed or pivoting counterbalance weight.

Trebuchets are often referred to as a variety of catapult, though it would be more correct to describe them as a scaled-up sling.

Contents

[edit]

Action of the trebuchet

Image:Trebuchet1.png
Three-quarter view of a trebuchet

A trebuchet is moved by a counterweight. The axle of the arm is near the top of a high strutted vertical frame. The shorter arm of the balance carries the counterweight and the longer arm carries the sling that carries the shot. The sling is usually braided from rope, and has a captive end attached to the arm, and a free end whose loop slips from a hook. A trigger, usually a toggle in a chain, holds the arm down after the trebuchet is cocked. Cocking is often performed with windlasses. The cocking sometimes was assisted by removing some or all of the stones or sand that acted as the counterweight. Because of the long winding time, a trebuchet's rate of fire was extremely slow, often not more than a couple of shots an hour. Yet some of the smaller types of trebuchets could fire a couple times a minute.

In operation the long, nonweighted end is pulled toward the ground, and held by a trigger. When the trigger is released, the arm pulls the sling out of a channel in the base of the frame. When the ball moves close to the top of its arc, the free end of the sling slips from the hook, and the missile flies free. The trebuchet's arm and frame then oscillate for several cycles.

Image:Trebuchet2.png
Side view of a trebuchet

The efficiency of a trebuchet can be improved by helping the weight to fall more nearly straight down. One method is to place the weight in a swinging or jointed bucket. The sand or stones in the bucket can also be less expensive than fixed metal weights, as well as being easier to gain access to on site. Another trick is to place the supporting frame of the trebuchet on wheels. These improvements may improve overall throwing distance.

Aiming a trebuchet is best practiced with a scale model. Usually small adjustments in elevation can be made by changing the angle of the hook holding the free end of the sling, a process which requires a heated forge on a full-scale engine. For larger, quicker adjustments, the length of the sling can be altered. The release angle will normally be chosen to optimise range, and depends on the elevation of the target. After the desired range is achieved, the trebuchet can be moved toward or away from the target. Small adjustments from side-to-side can be made by moving the channel in which the missile and sling slide in the base of the frame.

Trebuchets were formidably powerful weapons, but relatively short-ranged compared to later gunpowder artillery, with a range of up to about 300 yards. Castle designers often built their fortifications with trebuchets in mind; for instance, Caerphilly Castle in Wales was surrounded by artificial lakes to keep besiegers and their siege weapons at a distance. The range of most trebuchets was in fact shorter than that of an English longbow in skilled hands, making it somewhat dangerous to be a trebuchet operator during a siege. This meant that sieges could be long drawn-out affairs, sometimes lasting for years at a time.

The payload of a trebuchet was usually a large rounded stone, although other projectiles were occasionally used: dead animals, the severed heads of captured enemies, barrels of burning tar or oil, or even unsuccessful negotiators catapulted alive.

The largest trebuchets could weigh dozens of tons. Not surprisingly, they were not readily transportable and instead had to be built on the spot where they were to be used.

[edit]

Usage of the trebuchet

The trebuchet is thought to have been invented in China between the 5th and 3rd centuries BC, and reached Europe around 500 AD .

Trebuchets were first used in Italy at the end of the 12th century, and were introduced to England in 1216 during the Siege of Dover.

Due to the increasing popularity of gunpowder, the trebuchet lost its place as the siege engine of choice to the cannon. The last historically recorded military use was by Hernán Cortés, whose gunpowder was in short supply, at the 1521 siege of the Aztec capital Tenochtitlán. This trebuchet was shot once, but suffered a severe miscalculation. According to popular myth, the trebuchet's first projectile landed right on the device, destroying it. It is also somewhat unclear from the sources as to what kind of contraption was actually built. Whether it was an actual trebuchet or merely a catapult is unclear.

[edit]

Trebuchets in contemporary culture

A simulation of trebuchets in action can be seen on TV and in movies. Northern Exposure aired an episode in their 3rd season entitled "Burning Down the House" (Original Air Date: February 3, 1992) - and again in their 4th season, called "Heroes" (Original Air Date: October 19, 1992) - in which they fling a piano and a coffin, respectively.

In the 1999 French film The Messenger: The Story of Joan of Arc (Jeanne d'Arc) by Luc Besson, a trebuchet was built and put into action for several war scenes, related to the siege of the city of Orléans by English invaders during the Hundred Years' War.

In the 2003 film The Lord of the Rings: The Return of the King, the defenders of Minas Tirith fired their trebuchets from the top of the city's walls. Trebuchets were in fact used in this way as their recoil is less than that of a comparably sized torsion weapon.

In the 2003 film Timeline, during the battle of Castlegard, the French army used a trebuchet to launch fire at the British fort.

In the 2005 film Kingdom of Heaven, during the siege of Jerusalem, the army of Saladin uses trebuchets to launch fireballs at the city.

In the computer game "Age of Empires II: Age of Kings" (Developed by Ensemble Studios), a trebuchet is the ultimate siege unit and is produced only from castles.

Today, people still build and use trebuchets as a hobby. For example, the Punkin Chunkin competition, an annual competition to throw pumpkins for distance, has a trebuchet category. Modern hobbyist trebuchets sometimes replace the counterweight with banks of springs.

The United States organization, Science Olympiad, hosts a "Storm the Castle" event for middle and high school students involving the trebuchet. The competitors build a small trebuchet (maximum one meter long, 75cm wide, 75cm high) and fire projectiles at targets of varying distances. In the 2005 Science Olympiad season, the middle school team from Solon Middle School in Solon, Ohio won first place.

On the ABC hit television drama, Lost, the first-season episode "Deus Ex Machina" features a lesson about the construction and use of the trebuchet, as the plane crash survivors build one in an attempt to gain entry into a mysterious hatch in the soil of the island where they are stranded.

[edit]

Variants

If instead of using a counterweight, the shorter arm is pulled by 2 or more people, the trebuchet is called a traction trebuchet or perrier. Descriptive terms, such as a "witch with ropes for hair" were used by some sources to describe how a traction trebuchet looks.

Other names for counterweight (or counterpoise) trebuchets include bricole or brigola, which translates as two-testicle and refers to trebuchets with a a split counterweight, and couillard, which translates as testicle and refers to a trebuchet with a single counterweight.

A very recent development is the floating arm trebuchet, where the counterweight drops down vertically.
Another is the so-called F2K trebuchet, in which the counterweight drops vertically and the arm has an extra set of rollers for smoother transition of energy from the counterweight to the arm. Both of these types of trebuchet are more efficient than the standard Fixed-Axle trebuchet. A third type of trebuchet, called the MRT, or Multi-Rotational (Arm) Trebuchet, has an arm that rotates 2 or more times before it releases the projectile.

[edit]

External links

Image:Commons-logo.svg
Wikimedia Commons has media related to:

de:Trebuchet fr:Trébuchet he:טרבושה it:Trabucco nl:Slingerarm fi:Trebuchet ja:トレバシェット pl:Trebusz ru:Требушет sv:Blida zh:投石機