trebuchet Blog and Journals

2007 Science Fair Project
 
By
 
DragonDude
 

The Medieval Era, also know as the Middle Ages, ran from about 500 AD to 1500 AD. European countries were often at war, under attack by the Vikings, Mongol and Islamic invasions and other rival European nations. The kings could not fend off such forces with their armies alone, so they and their nobles built castles and walled cities all over the country to protect their kingdoms in an eventual attack. These fortifications offered protection to the nobles, their armies and to the peasants for weeks and even months in the event of a siege. Siege warfare was more common in the middles ages than straight out battles. Major invasions were concentrated on castles rather than land. In most of the battles, siege engines were used to conquer walled cities and castles.
 

A siege engine is a machine that is designed to demolish or get around castles, city walls and other fortifications in warfare.
 

Siege engines were first used by the ancient Greeks, Spartans and Carthaginians around 425 BC. These early siege engines were assault ladders, battering rams and later catapults. A battering ram is just a hefty, heavy log carried by several soldiers and usually used to break down doors, gates and sometimes walls.
 
The Spartans used battering rams, but it seems that the Greeks limited their use of siege engines mostly to assault ladders. Some archaeologists have recently proposed that the legendary Trojan Horse was not a secret container for stealthy attackers, but rather a large battering ram resembling a horse.
 
The first Mediterranean people to use advanced siege machinery were the Carthaginians, who used battering rams and siege towers against the Greeks. These engines influenced the ruler of Syracuse, Dionysius I, who loved to destroy things.
 
Philip II of Macedonia and Alexander the Great used siege engines quite often. Their large engines spurred an evolution that led to impressive machines, like a siege tower in 304 BC: nine stories high and plated with iron, it stood 125 feet tall and 60 feet wide and weighed 360,000 pounds.
 
The most common engines were simple battering rams or tortoises. Tortoises were covers propelled in several clever ways that allowed the soldiers to attack walls with a certain degree of safety.
 

The Romans preferred to assault enemy walls building earthen ramps (agger) or simply scaling the walls with ladders. Soldiers working at the ramps were protected by shelters (gallery), which were arranged to form a long corridor.
 

 
Wicker shields (plutei) were used to protect the front of the corridor during its construction. Sometimes the Romans used another engine resembling the Greek ditch-filling tortoise, called a testudo. Battering rams were also widespread. Siege towers were first used by the Roman legions around 200 BC.
 
The first documented occurrence of ancient siege artillery pieces in Europe was the gastraphetes ("belly-bow"), a kind of non-torsion bolt-thrower. These were mounted on wooden frames. Greater machines forced the introduction of pulley system for loading the projectiles, which had extended to include stones also. Later torsion systems appeared (ballista), based on sinew springs.
 

 
The onager was the main Roman invention in the field.
 

The most common siege engines used were battering rams, siege towers, different types of catapults and the trebuchet.
 

These were large mechanical objects, often on wheels that were used to ram the walls and doors of a castle in an attempt to break them down. Sometimes battering rams were part of a siege tower. The image below shows a simple covered battering ram. They often had wooden structures around them to protect the soldiers using the ram.
 

 

Attackers sometimes built a siege tower to scale castle walls. Soldiers lay in wait inside the structure as others wheeled it to the castle. Once there, the soldiers lowered a drawbridge at the top of the tower onto the castle wall. Some towers were almost 100 feet high, and many archers and catapults could be crowded into a single tower.
 
Siege towers were difficult and time-consuming to build, however, and castle defenders could burn them down with fire arrows or firepots (launched pots filled with flaming liquids such as tar). Sometimes castle knights launched surprise raids on a tower to destroy it during construction. To protect their siege engine, attackers draped it with rawhides of mules or oxen.

A catapult was a large machine used to throw objects, often rocks, arrows, pots of fire, or even spears, at a castle. This would destroy the castle walls and buildings. When we think of a catapult the one shown here is what we envision. But more often than not the catapults used for sieges didn't have the cup that you put the thrown object into.
 

 
The catapult makes use of tension from twisting ropes or leather straps to propel the arm forward. The arm is propelled against a stop where the projectile is released.
 
The main types of catapults were onagers, as seen above, and named after the wild donkey for the way they kicked, and mangonels (see below).
 

 
Catapults could be very troublesome. After each firing the machine needed repositioning. Catapults sometimes buckled and shattered when propelling objects much smaller than that which the trebuchet was capable of hurling. They sometimes had a sling, which could generate more force and throw the object further with more accuracy. This sling effect was later developed into the trebuchet.
 

Only one engine was the invention of the Middle Ages, the trebuchet. It was the deadly weapon in medieval times. It relied on a counterweight and was simpler in design and construction than most others. Prince Louis of France is credited with bringing it to England in 1216. Similar to the catapult in that it was designed to throw large objects but it was more efficient than a catapult because it could be built faster and at less cost, yet it could throw heavier objects even further.
 
The trebuchet was more efficient and more stable than other types of catapults. Using counterweights, a complete transfer of energy to the projectile was possible. They flung further and hurled harder.
 

 
The basic theory of the Trebuchet was like that of a see saw. One end had a heavy weight. The other end extended much longer and had a sling where the thrown object was put. When the trebuchet was activated the heavy weight would fall, and the swinging of the seesaw would propel the object.
 

Siege weapons are now considered obsolete owing to the effectiveness of aircraft and missiles, which have made fortifications and walled cities obsolete. The only defensive structures are now deep bunkers and tunnels used for military command and control.
 
Even these may be of questionable value as it appears that the most survivable command and control of mobile defensive forces (such as modern tactical and strategic aircraft, mechanized cavalry and mechanized infantry) is through the use of mobile command centers.
 
 

Castle
By Christopher Gavett.
Dorling Kindersley Ltd., 1994.
 
This colorful large-format book is a good introduction to everyday life inside a castle, covering entertainment, food, work, and more.

Medieval Siege Warfare
By Christopher Gravett and Richard and Christa Hook.
Reed International Books Ltd., 1990.
 
This book has good information about the weapons used during a siege and their evolution during medieval times.

Cross Sections: Castle
By Richard Platt.
Dorling Kindersley Ltd., 1994.
 
This is a colorful book for young adults. It is an introduction to everyday castle life. It has intricate drawings of castles, and includes a castle siege.

Siege Warfare,
Microsoft Encarta 95, Microsoft Corporation. 1995
 

These were used as additional items in my Science Fair presentation.
 
Arming and loading a catapult.
 

Cartoon showing the uses of a catapult.
 

How to make an origami catapult that really works.
 

You can see a photo of my presentation at our school's Science Fair from April 2007 by clicking here.