Siege Engines
     The Onager - Colt                                                                                03/09/'03

I am still working on the larger onager and have yet tried to overcome the flexibility problems. I found a vague drawing of a "catapult" on the web today. I spent an hour in my room and built a working model of it, I have named it the Monager, or Manual Onager.

. Please forgive the poor quality of the pictures as they were taken with a digital camera which is not of the highest quality. In some pictures the larger onager may seem to be tilted or skewed but it is just the camera.

The onager is a form of catapult that has been in use for thousands of years; it was used by both the Roman and Greek armies. The onager is affectively a type of torsion catapult which uses a single arm and thick coil of a twisted  rope material for power. The onager consists of two upright posts with a crossbeam, usually at the top, with the rope coil suspended between the two uprights (imagine something like an American football goal). Through the twisted portion of rope is the throwing arm, normally this arm rests upon the crossbeam when the weapon is not being used. The arm is  cocked (drawn back and readied to fire) by a crank and ratchet type system. Once the firing arm is fully cocked the missile is loaded onto the end of this arm. There are  several variations of the onager and my test model represents the type that uses a basket (in this case, the head of a teaspoon) while the one being currently constructed will attempt to use a sling system. The onager is almost stupidly simple to use in operation and was a powerful ballistic weapon for thousands of years. You can conduct a search of Google's image database for "onager" to find some images of it if you wish.  My two onagers are constructed from materials  which I have found lying around the house. Thick bamboo kabob skewers, hemp twine (wonderful stuff, I used it for the string on my slings), a hotglue gun and various simple handtools.

Why do I build this type of thing you might ask. Boredom, sheer boredom. The only good thing on television anymore is the History Channel and currently they are playing a marathon of shows on the Wild West which I have seen each episode of a few  times. While I am not browsing the Bad Astronomy Bulletin Board (BABB) or playing The Sims I go off to my room and sit in the floor, with makeshift materials, and build things.
Test Onager 2
Test Onager 3
Test Onager 1
This was the test model I built just to see if I could  succeed. It is constructed from single lenths of the skewers I mentioned above and held together mostly by hotglue. The arm is constructed from two lengths of skewers bound together by glue and wrapped in twine with a teaspoon head affixed to the end. It is very weak because the two upright supports begin to bend inward if I twist the twine anymore.
Onager 3
Onager 2
Onager 1
This is the onager which I am currently constructing. Its basic structure is complete, the uprights, base, and supports. When I twisted the twine last night though the uprights bent inward. I am currently adding more supports to counteract this. The base of this onager is constructed of paired skewers glued and bound together. The two uprights are three skewers glued together and thickly clad in twine (they seem to be strong but very flexible) the crossbeam is also made in a similar manner. All of the joints are bound with twine to give them added  strength.  I will add more pictures of this once it is completed.
Monager 2
Monager 1 Monager 3
As I mentioned above I built this from a vague drawing I found on the internet and  I have named it the Monager (Manual Onager) as it was simply named "catapult" before. I have also given it that name because of its powersource, the manual drawing back of the cord by a person. I have not yet bound the joints on this model with twine and I do not believe that I will need to, the glue seems to be sufficiently holding. It consists of two upright beams which are crossed over and then two smaller ones which intersect these low and form the cradle for the axle. There are other various crossbraces which are required to hold the structure rigid. The arm is  made up of two skewer lengths with two short pieces going across (to form the head of the throwing arm) and a single crosspiece at the opposite end to form an anchor-point for the pullcord. The basket it is made of a sqaure section of canvas suspended between the two crossbeams at the head of the arm. The pullcord   goes down from the anchor-point and under two of the crossbraces to lead out the back of the monager.

The description of this is long because I have never seen one of these before and I doubt many others have. I tried to make the basic structure clear but if you wish clarification or more pictures you can email me at Please include "monager" in the subject line.
Glider 1
Glider 2 Glider 4
Glider 3 Glider 5
Glider 6
Glider 7
Glider 9
Glider 8