All About Catapults

Updated on February 7, 2018

All About Catapults

Catapults have a certain mystique and a very long history. They have been used in warfare and in fun competions. Here are resources to learning more about catapults and how to make them. The great thing about making a catapult is that when the project is complete you are not done! You still have to fire it off! Have competitions or create games with it.

The History of the Catapult

The catapult wasn't something that just was invented one day. It was something that developed slowly over time and it was a logical development of the crossbow. It is generally accepted that crossbows were invented first and over time they got larger and larger until they were considered catapults. But a big crossbow isn't considered a catapult. There were some changes that define this switch from big crossbow to catapult and it was when the makers made two significant changes. First they started putting things other than crossbow bolts into it. And second they made the switch to a swinging arm. So we can consider that the first "real" catapult was the first crossbow that had a swing arm and had the bolt taken out and some kind of other object like a rock put in.

Nobody really knows when the catapult was exactly first invented but 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.

Catapults, the Middle Ages and the Medieval Arms Race

We often think of catapults as weapons of war that sieged medieval castles, and while this is true, they actually saw very limited use during the middle ages. Catapults were engineering feats that took a lot of engineering knowledge and quite a bit of resources. They also took a long time to make which meant they had to be made ahead of time and then brought along to an enemy's castle for a siege. Which meant they were a logistical problem.

Catapults were also a victim of a medieval arms race. As catapults started being used builders of castles started making their castles catapult resisitant with thicker walls and further distances between walls which put the catapults out of range. The final demise of the catapult pretty much came as gunpowder started being used and the cannon was created.

A Mangonel Style Catapult

A Simple Catapult

The Development of the Catapult over the Centuries

We may never exactly know when the first legitimate catapult was developed but it is generally credited with being around the 3rd to 4th Century BC. An interesting thing about catapults and siege engines in general is that they developed over time from smaller weapons. The Catapult is pretty much a derivative and direct result of the Bow and. The catapult is the end result of the desire to make weapons that are bigger, more powerful, and can hurl bigger objects longer distances.

Flexion Based Power

The Beginnings of the Catapult is with the Greek Gastrophetes (Belly Bow) This was a bow that was laid out horizontal and braced up against the belly. This way the user could use both hands to draw back the string. It was more powerful than the regular bow.

These Belly Bows got larger and more powerful and eventually they were taken off the belly and placed on a stand (This allowed them to get even larger. This new arrangement was called the Oxybeles. If you consider a catapult to be a siege weapon that stands along and is not hand-held then the Oxybeles is the first of this type.

Torsion Based Power

The Ballista - A fundamental change came about in the development of Cataputls with the Ballista. Up until this point all of the typical catapult like weapons used the bending of wood as their source of power. The ballista used Torsion in the form of twisted ropes. This twisted rope torsion power was much stronger than the bending of wood and the ballista got much bigger and much more powerful.

Even though the ballista used torsion for its power it still looked much like a crossbow in that it had two arms. This configuration changed significantly and other types of siege engine configurations came into use.

The Mangonel - When we think of a catapult this is often what we think of. Twisted ropes were attached to an arm with a bucket at the end. When the twisted ropes were released the arm shot forward and came to a stop against a crossbar. This would shoot whatever was in the bucket.

The Onager - This is an interesting variation on the Mangonal in that instead of a bucket it had a rope and sling.

The Trebuchet - Often considered to be the height of Siege Engine making because its simplicity allowed tremendously large ones to be made. It used gravity as its form of energy. This is what made it so simple.

Build A Catapult

Free Online Resources

Make a Small Catapult

A Site with a variety of projects on how to make a catapult of the table top size including a small wooden one and a popsicle stick one.

A Site with a variety of projects on how to make a catapult of the table top size including a small wooden one and a popsicle stick one. Make a Catapult

Make a larger Catapult

Excellent video from the Weekend Builder on how to make a larger backyard style catapult out of pvc plastic pipes

Excellent video from the Weekend Builder on how to make a larger backyard style catapult out of pvc plastic pipes Make a pvc catapult


Catapult Making Kit at - Nice little table top sized wooden catapult.

Learn More About Catapults

Resources for learning about catapults, their history, how they were made and how you can make them.

  • Wikipedia article about Catapults
  • Airplane Launching Catapult Did you know that catapults were used to launch airplanes off of naval ships? Here is a great pic of just this type of catapult with the plane mounted and ready for launching.
  • A compound catapult - Neither a catapult or a trebuchet yet a little bit of both. Nice article including the necessary mathematical formulas. A nice project by a high school student.
  • The Sinews of War: Ancient Catapults - Interesting article about the history of catapults - The construction of catapults is called "belopoietics" ( poietike = making of; belos = projectile, projectile-throwing device)


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      aidan 4 years ago

      im only in middle school and if you need to make a catapult got to

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      momo8 6 years ago

      thnx for the info i have to do a booklet on catapults for dt so im going to use some of this for it


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      chloe_101 6 years ago

      any good pictures of a simple diagram?? or primary source???

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      yalmanza 7 years ago

      how am i soppose to build a catapult i don't understand im in middle school

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      Tyler 7 years ago

      this helped with my homework

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      georgia 8 years ago

      How tall roughly was the average medieval catapult pleeeeeeeeeeeeeeeeeeeeeeease??????????

    • profile image 8 years ago

      Why the catapult was known like "stomach kat" or something like that? I heard on History channal, but can`t find it on handwrighting. Please help?

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      clayton 8 years ago

      thanks for the ancers and for the paragraphs

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      alladin dykey 9 years ago

      good workies mcklerkiez!!! :)

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      Wyatt Holmes 9 years ago

      I personally think that what you have done is a great idea im using your info to build my catapult for my science fair my science teacher says I might win!!!! thank you for all of your help. =]