Ballista

A is a common type of siege engine used by the citizens of the Land of Water, and extensively, the Land of the Night. During the exodus of ninja from the Land of Water during one of the country's civil wars, ballistae were used to sink two of the escaping vessels. Their design was later studied and improved on by the citizens of the Land of the Night, resulting in a weapon of great offensive power that can be used to lay waste to an opposing force.

Design
The ballista works on the same basic principle as a crossbow. It consists of a long beam with a nook into which the projectile is inserted. The rear end of the projectile rests against a rope held on two lengths of wood, attached to the main body by torsion springs of rope. In normal crossbows, the string would be drawn by the shooter manually. As ballista arms were far too powerful for anyone to pull, the string (or rope, in this case) was fastened via another rope to a ratcheted winch, which was used to pull the firing rope. Ballistae mostly had wheels for transportation.