My ballista-reconstruction attempt (videos)

[chipguy123]

A few years ago, I decided to take a class called 'Technology and Engineering in Antiquity' as one of my electives. It was great fun and for one of our assignments, we had the choice of either writing a test or reconstructing some piece of ancient/medieval technology. I smartly chose the latter and decided to build a ballista.
While my version clearly wouldn't have been an effective weapon, I believe it was a respectable first attempt. Enjoy!

Videos of the Ballista:

http://www.youtube.com/watch?v=UOrcoVFN2YI
http://www.youtube.com/watch?v=TxzDu4lsRTQ
http://www.youtube.com/watch?v=Y2DFx5z046Y
http://www.youtube.com/watch?v=Y2DFx5z046Y
http://www.youtube.com/watch?v=IEYC1vbc-SA

And my page which details some of its construction:
http://medieval-war-weapons.blogspot.com/

[Jona Lendering]

I liked those videos!

[M. Demetrius]

Fun stuff. A little down the trail, I plan to build an onager. Many of the same components, but in some ways, a simpler mechanism.

One thing I haven't seen explained is how to tighten the skein of rope. What secures the free end while the wraps are being added? How is the tension applied to the rope? Is there a book/site that gives more info on that?

[P. Clodius Secundus]

Fun stuff. A little down the trail, I plan to build an onager. Many of the same components, but in some ways, a simpler mechanism.

One thing I haven't seen explained is how to tighten the skein of rope. What secures the free end while the wraps are being added? How is the tension applied to the rope? Is there a book/site that gives more info on that?

Well, they do share a common power source, but its kind of like comparing a mechanised bow and a mechanised staff sling.

As far as ancient sources, there some coverage in Philon's Belopoeica as part of his justification for the wedge-engine. The most extensive description is in Vitruvius 12. 1. Loeb's translation is on line at LacusCurtius
http://penelope.uchicago.edu/Thayer/E/R ... s/10*.html It's also in Marsden's volume on the technical treatises.
For modern how-to help, check out George Metz's (Gallio's) Legio XXIV website.

[M. Demetrius]

Thanks, Clodius!

[P. Clodius Secundus]

Thanks, Clodius!

Happy to help! I'm looking at some rope related questions so I'll post any other references I find.
If you're building an onager please consider basing it on De Reffye rather than Payne-Gallwey or Schramm.

Chipguy,
It is indeed a noble first attempt. I hope you continue to apply your talents to the subject. I'm glad to see that you got your trigger issues sorted out. That first video had me concerned for your fingers. :lol: For future builds, I'd suggest you avoid Payne-Gallwey's designs as well. They are the most commercially reproduced, but they are the historical equivalent of junk food.
Have a happy New Year!

[D B Campbell]

One thing I haven't seen explained is how to tighten the skein of rope. What secures the free end while the wraps are being added? How is the tension applied to the rope? Is there a book/site that gives more info on that?

I have never built a catapult, so hats off to those of you who have!

I'm sure there are improvised techniques for stretching a nylon rope around the torsion-frame, but you might be interested to read what Philon writes about stretching a sinew rope:
"First, the tensioning of the tangled-up spring-cord happens to be time-consuming on account of the stretching-out of each length individually, and for each tensioning-operation the whole thing [i.e. the entire length of spring-cord] must be threaded-through the hubs (i.e. the washers), and it is distressed by the clamps and by the windlasses of the stretching-apparatus, being thoroughly pinched and torn" (Philon, Belopoiika W57.29-33 = KR17).

The "clamps" presumably held one end of the spring-cord in place while the entire tangled bundle was threaded down through the top washer and out through the bottom washer, where the "stretching-apparatus" presumably pulled it tight, and another clamp held the tension while the whole bundle was again threaded up through the bottom washer and out through the top washer, where the "stretching-apparatus" again pulled it tight, and ... etc. Heron (Belopoiika W108.1 = KR28) mentions clamping the end of the spring-cord to the lever. Marsden suggested that the clamp would resemble "an ordinary clothes-peg"