1. C A T A P U L T S Physics, Background and History

2. Definition
A machine that converts POTENTIAL ENERGY into mechanical motion or KINETIC ENERGY”
Comes from the Greek word “Katapultos,” meaning “shield crusher”
AKA: Siege Engine or Siege Machine

3. The Invention
The catapult, as we would recognize it today, was invented by the Greeks about 399 BC but various forms were found in central Asia much earlier than that
During the war with Carthage, Dionysius of Syracuse produced the Gastraphetes or “belly bow” catapult

4. The Invention continued…
By 330 BC two distinct types of catapults emerged
One fired javelins (spears) called a Euthytonon
The other was the stone throwing Palintonon

5. How was it used in Medieval times?
First we need to understand the society of the Middle Ages
Fear was rampant (AKA: Dark Ages)
There was huge disparity between the rich and poor (Feudalism)
Castles were constructed to protect nobles (& peasants but only during crisis)

6. Castle construction Moat Draw bridge Portcullis Guard tower/ Barbican
Murder holes

7. Portcullis

9. Catapult AKA Siege Machine or Siege Engine
What is a siege?
One army surrounds an enemy, keeping help, goods and water from leaving or entering the castle

10. Medieval warfare Infantry (usually the poor)
Archers (trained/ paid military)
Battering Ram
Psychological warfare
Flaming shrubbery and brush
Dead, diseased bodies
Heads of tortured victims

11. Battering Ram

12. Catapult Structure & Design
A typical catapult has each of the following:
Arm
Base
Elastic Force
Fulcrum

13. Most catapults were made of wood
The elastic force provided by twisted rope, springs, saplings
The fulcrum is the point of support for a lever- which in the case of a catapult is the arm

14. Factors Affecting Distance
Mass of object being hurled
Strength & flexibility of arm
Mass of arm
Length of the arm
How far the arm is pulled back
Angle of base or release (best angle?)
Small transfer of energy into distortion

15. Types of Catapults
Roman design and others found during the Medieval period

16. Ballista
Roman
Double armed – like a bow
Shot large spears or javelins

17. Mangonel or Onager
French
“Engine of War”
Typical catapult

18. Trebuchet French meaning “to stumble” Used a sling with the arm
Extremely accurate
Most advanced of all catapults

19. Fixed Counterweight
Trebuchet

20. Swinging or Hinged Counterweight Trebuchet