Historical Background and References

Onager? What's an Onager?

Many people ask me where I got the name "Onager" - well here is the answer : it means "Wild Ass". This was a nickname given to these catapults by the Ancient Romans  who built and operated these siege engines. The action and force of the arm produced a powerful  kick, like  that of the the wild ass, hence the name.

         My first Catapult - "Baby Onager" - This little model was throwing golf balls over 125 feet!

The idea for this catapult came from my research on medieval weapons.  The book that really got me going is by Sir Ralph Payne-Gallwey entitled "The Book of the Crossbow". This book contains some drawings with details and dimensions of this torsion type of catapult. The author built a reconstruction of an Onager around the turn of the century, and achieved some impressive results. Once I read about this, I was convinced that the Onager was for me! In addition Payne-Galwey gives a good basic history lesson on catapults including some fascinating historical accounts.

Here is a drawing of Sir Ralph's reconstruction of a catapult which inspired me to build my Onager. You will notice many similarities to my Onager (i.e. the frame, the sling, the cable attached to the arm to winch it back for firing.)

This is an artist's drawing of a Roman Onager. The scale at the upper left of the picture is 6 feet high, which makes this catapult almost 10 feet high, and the arm about 12 feet long. That's one mean Siege engine!

             Another excellent source on catapult design and history is by Eric Marsden called "Greek and Roman Artillery". He also did his own reconstruction of an Onager, as well as some Balistas - another type of catapult. A more contemporary book on Catapult building is called "Catapult : Harry and I Build a Siege Engine" by Jim Paul. This book is a must for anyone considering doing something of this sort. He not only has  very funny stories to tell about his own adventures in Catapulting, but he also includes very interesting historical catapult anecdotes.       

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