Roman Siege Engine Onager COBI 20068 - Imperium Romanum

You know that:

• The first written records of the use of the onager come from the year 353 by the legionary Ammianus Marcellinus.
• Many types of these catapults were produced in the Roman Empire, and the design therefore depended on the particular workshop.
• The common basis of the siege engine was a frame made of oak beams, which lay on the ground, and a vertical structure of the projectile stop.
• Projectiles were hurled by a wooden arm with a firing plate or a leather sling.
• The energy of the shot was supplied by a torsion spring made of tendon-like ropes.
• To extend the launch arm, the Romans used a tiller, which could be a fixed part of the machine, but also a separate one, usable for multiple catapults.
• Roughly hewn stone or clay balls mixed with flammable substances were usually used as ammunition.
• With the catapult ready, the gunner hammered out the wooden fuse, which released the energy of the tensioned torsion cables.
• When fired, the throwing arm hit the stop. The Romans called the impact "donkey kick". Hence the name of the machine Onager (donkey).

Technical parameters:

• dimensions: length 4 m, width 2 m, height 2-3 m
• weight 300 - 600 kg
• maximum range 370 m (optimally up to 170 m to maintain sufficient projectile energy)
• projectile weight +/- 45 kg
• torsion hemp rope drive
• service 2

Roman law Lex Militaris disciplinae:

"The war machines of the great Rome on land or at sea are the property of the emperor. The carriage army is exempt from this regulation."