Torsion spring ballista

The torsion spring ballista was invented by the Shubanese at around 590 B.B and excelled at shooting projectiles farther than non torsion ballistae. The weapon was later used by Bashur who used it to throw rock shots at Guntartar siege weapons from a distance. By the time Arquado Barbarossa came to conquer the Western Horde, the technology was widespread in the region and he bought some machines from Bashur. His engineers then set to work building more of them themselves. These proved useful on his campaigns and for naval warfare. While before one had to ram an opponent's ship with theirs and then board it, the torsion spring ballista allowed one to shoot rocks at an opponent's ship from a distance (the Bashurians, Gurbazi and the Shubanese used it to great affect against the Berini ships). The Berini developed a version that could be easily assembled, disassembled and transported.

Mechanics & Inner Workings

The arms are made of wood or spring steel (like with the Bashurians) and are attached to a pair of verticle torsion axles covered in tightly twisted elastic ropes which are connected to the arm frame that holds the axles and the ammunition groove. The groove is a long piece of wood with a deep grove in it for placing giant arrows or round rocks. In the groove there is a sled that slides in it without much resistance and it is responsible for pulling back and releasing the bowstring. The bowstring has a cup in it that can hold the stone shot or the back of the arrow. The arm frame is made of two flat pieces wood that hold the groove and the torsion axles in place. The arm frame is attached to the base on joint that gives it the ability to turn in every direction and to lock in place. The sled in the groove is attached to a rope that is attached to a winch at the end of the groove.
When the sled pulls the string back, it pulls back the arms which cause the ropes to twist. The twisting rope want to untwist and thus store potential energy. Once the string is released, the tension in the ropes shoots the arms forward which swing the arms violently. The swinging arms pull the string forward and it there is something in the cup, it is propelled and shot with tremendous force.
In the version with the spring steel arms, there is extra tension in the arms which store even more potential energy which allows the ballista to shoot things farther and with more force. This is why the Berini never assaulted Bashur from the sea. Because the ballistae guarding the harbor would damage their ships from a distance.

Manufacturing process

It's complicated.

Significance

Devastating siege weapon that is really good at suppressing enemy troops or defenders. It's capable of impaling multiple men, popping heads off, damaging buildings and damaging other siege weapons (all of it though depends on it's size, a small arrow shooting ballista is capable of impaling miltiple men, but it can't cause any damage to fortifications)

Item type

Weapon, Ranged

Used by

• Twisting thunderbolt

Related Technologies

• Rope torsion spring

Related ethnicities

• Bashurian
• Berini

Base Price

Between 1 and 7 Gold Tulli (Currency) (depends on the size)

Raw materials & Components

Wood, ropes, iron.