Field Artillery

[Gaius Julius Caesar]

Possibly because the horses were always turning their heads at the most inconvenient moments!! hock: :lol: :roll:

[D B Campbell]

I wonder why this invention was considered to be impractical.

Well ... there's the minor matter of how it's supposed to work! Where are the bow-arms?!

[Gaius Julius Caesar]

Perhaps there is an internal spring mechanism,,,,what is that snaky/spring looking thing wrapping around the front of the box? :? P

[Spiridonov Alexander]

I wonder why this invention was considered to be impractical.

Well ... there's the minor matter of how it's supposed to work! Where are the bow-arms?!

Bow-arms stand inside/ Attantion: field frame stand at the MIDDLE of beam/ It is one of confirmation of inswinger-theory/

[Gaius Julius Caesar]

Sorry, I don't see that! :?

[Spiridonov Alexander]

Sorry, I don't see that! :?

Do you see bow-arms at the Trajan column, for example? we dont see arms becouse it inside/mabe medieval rewriter miss it becouse he dont see arms which was inside/

[P. Clodius Secundus]

Unfortuately most depictions of mechanical things from the time of DRB until Leonardo DaVinci are rendered in such a tortured manner that they are nearly useless for the purpose of reverse engineering. At least the stonemasons who carved Trajan's and Marcus Aureliius seem to have just carved what they saw without trying to show mutiple views within the same image. Granted, they did play games with the relative size of objects. That's not as difficult to overcome as some of the bizzare artistic conventions of later times. One thing we are missing from Trajan's is the extensive metal decoration that once supposedly adorned the sculptures. The slider an an out-swinger does not need to extend far beyond the face of the frame unless it is pushed forward to capture the bowstring. In that case the arms would be to the side and easily rendrered as on The Tomb of Vedennius and The Arch of Pergamon. They were not. A more likely possibility is that they were projecting forward and therefore added as metal details. This would be appropriate treatment for such a novel innovative feature. A couple of the weapons appear cocked and loaded. Their sliders still project far beyond the frame. Although not definitive proof, these bits of circumstantial evidence favor the inswinger hypothesis. Perhaps the question should be asked .... What evidence is there that out-swingers existed after @ 96 AD? The last evidence I know of is from a tomb. Is it just a coincidence that one (or at least an image) was buried with Vedennius? Five years (an eyeblink in terms of Roman military fashion) later, the Emperor goes on campaign and apparently takes only a new kind of metal framed engine. It must have been significantly better to replace a proven technology so quickly. It's also seen being fired from the bed of a cart. Is there evidence that wooden-framers were ever used in that manner? While I'm causing trouble, :wink: What is the historical justification for the number of wooden framed engines with wheels and wheelbarrow handles attached to the base? These "barrowllistae" are well constructed, really cool, and look very easy to move around at events, but how well would they fit the needs of the Roman Army? To be taken on campaign they would probably need to have a wider track width to avoid toppling over or need to to be carried in a more conventional mulecart. carrying them up a ladder to defend a section of wall or tower might be a bit of a problem as well. Sorry if this upsets my fellow carroballista enthusiasts, but asking inconvenient questions often leads to the best answers.

[LUCIUS ALFENUS AVITIANUS]

What's the relationship between the length of the bolt and his caliber?

How many span were the Dura Europos bolts?

I have seen the Aitor's manuballista darts and there are very short. So, the proportions are diferent for the later ballistae?

[P. Clodius Secundus]

What's the relationship between the length of the bolt and his caliber?

How many span were the Dura Europos bolts?

I have seen the Aitor's manuballista darts and there are very short. So, the proportions are diferent for the later ballistae?

The use of "span" as a formula to determine the size and/or power of a catapult most likely changed along with everything else when iron frames were introduced. A more modern equivalent is the "caliber" of a weapon. In the days of black powder smooth bore guns a "twleve-pounder" meant about a 4.5" bore. Once rifling was introduced the equations were meaningless but the system persisted. Caliber can also refer to the length of the bore in relation to it's diameter. Even in the smoothbore days there were special types of ammunition used depending on the intended target. The power and size of a weapon have a great effect on how projectiles behave. Comparing a manuballista or cheiroballista with a three span is like comparing a musket with a cannon. Same general priciples, but once you get beyond hand-held weapons forces change quickly.

[Gaius Julius Caesar]

Sorry, I don't see that! :?

Do you see bow-arms at the Trajan column, for example? we dont see arms becouse it inside/mabe medieval rewriter miss it becouse he dont see arms which was inside/

I think I had already said it was a possibility that the mechanics were inside, but you see that strange thing snaking across the front of the box?
Possibly it had a totally different type of spring mechanism, other than bow arms...... but once again, I will also repeat the possibility that it is totally impractical, due to the positioning of the horses? :wink:

[LUCIUS ALFENUS AVITIANUS]

Well, so i redo my question:

What's the relationship diameter of the bolt/ lenght of the bolt in a 2 span and in a 3 span ballistae?

[D B Campbell]

I have photoshopped it into pictures of the reliefs to show how it appears in the various tactical situations depicted.

Nice work, Randi.

It's also seen being fired from the bed of a cart. Is there evidence that wooden-framers were ever used in that manner?

'fraid not. Tracey Rihll has a rather convoluted theory that wagon-mounted catapults were used at Cremona in AD 69, but her argument is basically wishful thinking. There's nothing in Tacitus' account to suggest that the catapults were anything other than normal stand-mounted machines.

What evidence is there that out-swingers existed after @ 96 AD?

There's simply no sign of them after the Vedennius tombstone. But we need to be a little careful here, Randi. There's a well-known maxim that "absence of evidence doesn't necessarily constitute evidence of absence".

In Donald Rumsfeld's immortal phrase, there are "known knowns" (things we know that we know): Trajan's army had the new iron-framed catapults that many people think are inswingers. But there are also "known unknowns" (things we know that we don't know): the sculptor of Trajan's Column did not depict the old-style "euthytone" wooden-framed catapults, but that doesn't necessarily mean that they no longer existed. (That's probably about as clear as mud! :roll: )

Similarly, there's no mention of two-armed stone-throwers, either. Many people think that the Hatra ballista was a two-armed stone-thrower, but it could actually be an arrow-shooter. It may be that, for stone-throwing, there was a wholesale changeover to the onager. We just don't know for sure.

[Gaius Julius Caesar]

Well, so i redo my question:

What's the relationship diameter of the bolt/ length of the bolt in a 2 span and in a 3 span ballistae?

Well I am not an expert, but someone training us on firing a ballista, said the span of a three span, meant that the arms length, the height of the spring, and the length of the bolt, would all be 'three hand spans'.....
Certainly made sense in a simple way to me!

not sure where the diameter came in though! :?

[P. Clodius Secundus]

I have photoshopped it into pictures of the reliefs to show how it appears in the various tactical situations depicted.

Nice work, Randi.

It's also seen being fired from the bed of a cart. Is there evidence that wooden-framers were ever used in that manner?

'fraid not. Tracey Rihll has a rather convoluted theory that wagon-mounted catapults were used at Cremona in AD 69, but her argument is basically wishful thinking. There's nothing in Tacitus' account to suggest that the catapults were anything other than normal stand-mounted machines.

What evidence is there that out-swingers existed after @ 96 AD?

There's simply no sign of them after the Vedennius tombstone. But we need to be a little careful here, Randi. There's a well-known maxim that "absence of evidence doesn't necessarily constitute evidence of absence".

In Donald Rumsfeld's immortal phrase, there are "known knowns" (things we know that we know): Trajan's army had the new iron-framed catapults that many people think are inswingers. But there are also "known unknowns" (things we know that we don't know): the sculptor of Trajan's Column did not depict the old-style "euthytone" wooden-framed catapults, but that doesn't necessarily mean that they no longer existed. (That's probably about as clear as mud! :roll: )

Similarly, there's no mention of two-armed stone-throwers, either. Many people think that the Hatra ballista was a two-armed stone-thrower, but it could actually be an arrow-shooter. It may be that, for stone-throwing, there was a wholesale changeover to the onager. We just don't know for sure.

Thanks Duncan. It won't win any woodworking prizes, but it'll serve well enough for further testing. The photoshopping was just a reality check to make sure that I'm not straying too far from Trajan's. I can't wait to get the rest of the weapon started to see how it all works together. I'm figuring on about 75-80 mm washers (Lyon). You'll notice that I said they "apparently" didn't bring any wood-framers along. I know what you and Rummy mean. I spent a few years in Military Intelligence so oxymorons don't bother me. If you haven't noticed, I like to flip arguments and accepted theories upside down evey once in a while. Interesting things tend to fall out and it keeps folks on their toes :lol: It might do the outswingers some good to play defense for a while. Now that you mentioned the Hatra ballista, couldn't the carroballista have thrown stones as well?

[D B Campbell]

Now that you mentioned the Hatra ballista, couldn't the carroballista have thrown stones as well?

Provided it's a ballista, Randi!

Some of the other guys -- like Emmanuel -- have been playing around with mounting a wooden-framed arrow-shooter onto a wagon. But that's not a ballista.

At the risk of being labelled pedantic (again :roll: ), this wooden-framed machine is what the Romans called a catapulta or scorpio (i.e. scorpion). Its design -- technically called "euthytone" -- is subtly different from the ballista. The important point is that the catapulta/scorpio has a very narrow aperture in front for the arrow to shoot through. Obviously, this would be completely unsuitable for a stone. (And it can't be widened, because that would mess up the whole design of the "euthytone" spring-frame.)

On the other hand, the ballista -- technically called a "palintone" to emphasize the difference in design -- has a wider spring-frame, and a wide open aperture for the missile to shoot through. You can see this clearly on Trajan's Column. This means that, in theory, the grooved slider (tailored for the arrow) could be replaced by a wider one, the bowstring could be replaced by a wider strap (or "sling"), and -- hey, presto -- you have a stone-projector.