The siege engine my group is using is a torsion catapult which was invented in the year 400BC, and was used by the Romans. The romans used a torsion catapult in times of war.
Back then creating a catapult would not have been easy as they did not have tech labs, with multiple electric drills and appliances, all they had was hand held items such as hammers, nails, pickaxes, string etc. In order to retrieve materials, they would have to hunt for materials that involve animal skin or meat. To retrieve timber, they would cut down trees with an axe. Also in these medieval ages there were many missiles that were used for the torsion catapult e.g. Stones, Fire, sharp wood poles, body parts, Dung and dead animals.
A Mangonel is a torsion catapult and can launch a long distance of 1,300 feet.
The string that was used was made out of human hair or animal sinew. The reason why this engine was build was because the other catapults at the time were mainly heavy such as the ballista so the Romans decided to create a lighter more efficient catapult, which was the torsion catapult. This catapult still wasn't very light and easy to maneuver, but compared to other catapults it’s much more efficient.