Engines of Destruction

The Torsion Engine

Much more complex than the Battering Ram, the torsion engine uses springs to launch arrows, rocks, or anything else.

In the pictured Mangonel, a rock is placed in the sling at the end of a long arm. The arm is connected, by a heavy twisted rope, to an axle.
When the arm is drawn back, the rope tightens and stretches, and when the arm is released the rope snaps back, pulling the arm up and launching the payload.
One should note that the power comes from the twisted rope, and not from the bending of the arm.

Another common torsion engine is the Ballista. Similar to a very large crossbow, the ballista is composed of a grooved central stock, on which the projectile was placed, and two bow like arms on either side. Like the Mangonel, the ballista’s arms did not bend. the force comes from ropes twisted around axles, which tightened when a rope connecting the arms was pulled. upon release, the ropes snap back, taking the arms with them, and the connecting rope launches the projectile.