SIEGE WEAPONS

We typically think of a catapult as something that was used in the Middle Ages to destroy the walls of a castle. But catapults have a very long history dating long before the time of castles and they were developed and designed in many different ways by many different cultures over the centuries.

What is a catapult?

The general definition is that a catapult is a machine that stores energy then quickly releases this energy to fire a projectile. To be a "real" catapult the machine generally has to be too large for a person to carry. If we just used the storage and release of energy to define a catapult then a longbow would also fit this definition. So the size of the machine is important.

How did catapults develop?

Catapults are an offshoot of the Crossbow. Over time crossbows got larger and larger. They went from being a hand-held weapon to something called the Belly-Bows which were so large they had to be braced against a knight's belly. From there they got even larger and became something called stand crossbows where they were mounted on stands. Eventually they got large enough to be defined as something in their own right and no longer crossbows. This size change also brought about changes in how they operated.

When did the first catapults appear and where? The earliest writings of catapults were that they originated in China around the 3rd and 4th Century BC and this type of early catapult was much like a big crossbow. They stood around 8 feet tall. True that these are catapults but the thing that makes a catapult into the machine we generally consider to be authentic is the development of the swinging arm. This is the arm that holds the bucket and projectile.

Variations of Catapults

The term "catapult" is used to define a very wide variety of large machines for hurling projectiles and some of the more common variations include the trebuchet, which is a catapult that uses gravity and a seesaw effect to hurl its projectile. Another variation is the ballista, which is similar to a crossbow and uses twisted skeins of material to create torsion as its way of storing energy for release.

Catapults can be classified according to the physical concept used to store and release the energy required to propel the projectile.

The first catapults were tensional catapults, developed from the Roman ballista. A member under tension propels the throwing arm, very much like a giant crossbow. A small simple version is used as a toy.

Subsequently, torsional catapults were developed, such as the mangonel and the onager. Mangonels have an arm with a bucket, cup, or most often a sling to hold the projectile at one end. The bottom end of the throwing arm is inserted in rope or fibers that are twisted, providing the force to propel the arm.

Finally, the last type of catapult is a trebuchet, which uses gravity rather than tension or torsion to propel the throwing arm. A falling counterweight pulls down the bottom end of the arm and the projectile is thrown from a bucket attached to a rope hanging from the top end of the arm, essentially like a sling attached to a giant see-saw. The counterweight is much heavier than the projectile.

History

In Europe, the first catapults appeared in later Greek times (400 BC-300 BC(, early adopters being Dionysius of Syracuse and Onomarchus of Phocis. Alexander the Great introduced the idea of using them to provide cover on the battlefield in addition to using them during sieges.

The End of Catapults

With the invention and use of gunpowder and the subsequent creation of artillery the catapult became obsolete as the weapon of choice for warfare around the fourteenth century.

Catapults have a long history and changed dramatically over many centuries. The true catapult that we think of today as a siege engine only saw limited use in the middle ages. Just as it was coming into its power as a machine of destruction gunpowder and artillery quickly replaced it as the weapon of choice.

The second development was the trebuchet in the 12th century. The trebuchet was a giant stone throwing engine powered by gravity in the place of tension or torsion. A trebuchet built and currently maintained in England with a 12,000 lbs counterpoise attached to it's arm is capable of throwing a 1400 lbs car 87 yards and 100 lbs iron weight 235 yards 44 Such engines wrecked havoc around Europe and were employed by the Crusaders during their sieges in the near east.A trebuchet also sometimes called a trebucket.(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.

A trebuchet is a medieval siege warfare weapon used to break down the walls of castles. It was the successor of the Catapult; it could take heavier rocks and projectiles, and fling them farther, with more accuracy. It worked by dropping a great weight that was attached to the short end of a long lever-arm. The long end of the lever was thereby raised with considerable velocity, pulling a sling that contained the projectile. The sling would increase the effective length of the lever arm, adding even more speed to the final projectile before the sling released it.

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.

Action of the 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 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.

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 perfect release angle is when the missile will fly at roughly 45 degrees, because this optimizes range. 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 200 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 a 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.

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 last historically recorded military use was by Hernando Cortezs, whose gunpowder was in short supply, at the siege of the Aztec capital, Tenochtitlan (now Mexico City), in 1521. This trebuchet was shot once. Due to a miscalculation the trebuchet fired up into the air, and came right down. According to popular myth, its projectile landed right on the device, destroying it. It is also somewhat unclear from the sources as to what kind of contraption that was actually built. Whether it was an actual trebuchet or merely a catapult is unclear.

Siege armies used a battering ram to break down a gatehouse door or even smash a castle wall. To shield themselves from attack, they built a covered shed, in which they hung a thick tree trunk on chains suspended from a beam above. Carpenters tapered the trunk into a blunt point and capped it with iron. The slow forward movement as the battering ram was wheeled toward the castle wall earned it the nickname "tortoise." Soldiers swung the hanging trunk back and forth, and the forward end of the trunk moved in and out of the shed like a tortoise's head, battering its target.

Castle defenders tried to burn the shed down with flaming arrows, though attackers responded by covering the shed with animal pelts or earth to make it fireproof. Defenders sometimes dropped mattresses down to cushion the blows or lowered grappling irons to grasp the trunk, preventing it from swinging.

Two major developments occurred in the area of siege artillery during the late middle ages. The first, the introduction of the crossbow to England by the Norman invaders, occurred in 1066.43 The Norman crossbow functioned and was used exactly like the Arcuballista of the late Roman Empire, indicating the maintenance of this concept in western continental Europe where the Normans lived prior to their invasion of England. Cocked by hand or with a winch mechanism and fired from the shoulder, a crossbow loaded with a metal tipped arrow was capable of piercing even the thickest armor.

The crossbow's role in warfare ended in large part at the beginning of the 16th century, due to the advent of gun powder weapons, but still remains in recreational use around the world today.