ABOUT CATAPULT
What is a catapult?
A Catapult is a ballistic device which used to shoot or launch a projectile to hit a target. The catapult uses a mechanism that stores potential energy which when released launches the projectile.
History
Catapult have been one of mans earliest engineering achievements. As early as the 8th Century BC, catapult have been recorded as being used for offensive and defensive siege-tactics in wars. Based on historic texts China is the first to develop catapult and describes a catapult called the 'Hui' which was used during the battle between King Zhou and Duke of Zheng in 707BC.
Soon the technology was developed throughout the Ancient Middle East and Europe. The Romans were one of the worlds greatest empires who used catapults as siege weapons against cities. One of the catapult that was developed by the Romans was the 'Onager' (meaning 'wild ass').
Types of catapult
There are 3 main types of catapult:
1. Trebuchet
The trebuchet is one of the earliest catapult design invented. Unlike other catapult, the trebuchet uses a counterweight system to store energy to launch the projectile. A pivot along the beam allowed each side of the beam to move counter clockwise to each other thus when the side with the weight was released from a certain height, the potential energy is used to launch the projectile. The energy of the potential energy of the weight is proportional to the initial velocity of the projectile which determines the range of the projectile. The projectile path for the trebuchet is parabolic however it had limited range compare to other catapult designs. The trebuchet was a siege weapon, thus it was not portable in battle.l
2. Springald (Ballista)
The springald or ballista was a Greek inventions used during wars. It generally was a mounted crossbow that could shoot bigger arrows and rocks, and was immobile. The main principle used in the ballista is that it potential energy is stored in torsion ropes which when released launches the projectile. The projectile launched had a straight path and thus had a shorter range than compared to other catapult designs. A Variation of the Ballista is the Springald which it's only difference was that it had a vertical springboard at it's lower end allowing it to be used in compact spaces and terrains.
3. Mangonel
The mangonel is a Roman invention which name was derived from the Greek word "manganon", meaning "engine of war".
The design of the of that mangonel initially had a sling but a arm was later replaced seeing the it had better accuracy
and complications when launching the projectile. One of the ways that the mangonel differs from the ballista is the
projectile path. The projectile path of the mangonel is an arc or parabolic than the straight path of the ballista.
However, it uses the same principle of storing potential energy in torsion ropes as the Ballista. There are other variations
of the mangonel, one of which is the onager which was more portable given it's small size to the mangonel.
The design of the catapult in this project is based on the onager design.
