Aitor Alert! Manuballista found!

[Iulus]

I don't know,whether it was already said/written,but maybe we should pay attention to this:

FLAVI VEGETI RENATI VIRI INLUSTRIS COMITIS
EPITOMA REI MILITARIS LIBER IV,22,line 6-7:

"Scorpiones dicebant, quas nunc manuballistas uocant..."

Meaning: Scorpiones were called,which are now called manuballistae.

[Robert]

Salve,

I checked the site for you and have found no usefull reference to the manuballista. The site does not contain any great amount of factual information. Perhaps best to send them a mail, they read and write English very well (even for non-Americans :twisted: ). Sorry for the dig, but you did leave the goal wide open ..... :lol:

[P. Clodius Secundus]

It would seem strange to fire over the mules, as an elevated firing position would really hamper accuracy and this is just where these engines come into their own. For laying down suppressive fire, a group of archers would be far more useful, as they have somewhat the same range, but not the knock down, shield smashing power of a ballistabolt aimed at chest level. The heavy projectile of a ballista soon succumbs to gravity, greatly lessening it's effective range because of the flatter trajectory.

It's the old discussion on caliber versus speed. Modern rifles sacrifice mass of the projectile for speed and distance. As speed was limited by the mechanics involved, mass caused the destructive penetrating power of the ballista bolt in an equal range situation. The .44 has the greater stopping power, but the .22 with a long barrel and a good charge will kill well over the effective range of a .44. The .50 caliber single shot sniper rifle is probably the exception to the rule, but packs a massive charge.

Possibly, the artist took a liberty here, as showing a gun crew in action would be impossible if they were behind raised sides but could be well depicted when standing at the rear of the assembly.

Robert,
While attempting to find a mule team to work with my carrus I have asked several experienced mule-skinners how mules would react to bolts flying over their heads. The usual response is that they wouldn't care as long as it didn't fly right past their heads. This would seem to support my theory that the carroballista was primarily used for high angle plunging fire at maximum range. Your comment about the .50 cal is precisely what I'm talking about. What if some weapons designer (let's call him Hiramus Maximus) :lol: had a moment of brilliance and designed a catapult that had a significantly greater range than previous engines? (see Aitor Iriarte's cheiroballistra page concerning in-swingers). Previous "Vitruvian" design weapons (out-swingers) could only fire about as far as archers. This doomed them to defensive roles since they could never hope to match the archer's rate of fire and would be swamped by volleys if they attempted to take the field. Now they can can sit back out of arrow range and hurl bolts with impunity. Volleys of arrows coming in at high angle can be seen and shield raised in defense. Just like a .50 cal round, a ballista bolt doesn't care much about distance or shields. It's mass stays constant, and if you're in range..... you're dead. The best part is that now you can mount them in a mule cart, toss in a supply of ammo, and follow the infantry on the offensive. If the enemy manges to push the shield wall back so that his archers can engage, you just pull the cart back and set up on the next bit of commanding terrain. (can you guess who used to be a tanker?) Some folks have proposed that the "little arch" on the top frame in Trajan's, Orsova, etc. was intended to open the field of view and aid in aiming. I agree, but for a slightly different reason. Previous weapons often had decorative plating covering nearly the whole front of the frame. Obviously they didn't consider that an issue. When firing line of sight this would probably act as a scope, isolating one particular target. Widening the frame alone would open up the field of vision. The arch would only be need when one was firing at high angles/long range.
As they say, "that's my story and I'm sticking to it".... I'm working a "unified field artillery theory" that starts from the assumption that Trajan's Column is basically accurate and working from there. It's funny how people who will base their gear on one grave stone carved by some provincial artist are so willing to dismiss the work of artisans in Rome working under the direct supervision of the Emperor on the crowning masterpiece of his forum. :wink: ..... No offense to anyone in particular, especially you, but I'm sure I'll hear it about that last bit. :lol: To test my theory I will have to build an in-swinger catapult, mount it in my cart, hitch up some mules, and challenge an experienced archer to a duel. How's you composite bow coming Dane?

[Paullus Scipio]

Whoa, there ! Whence came the idea that torsion artillery was only effective at archery ranges ? Effective archery range against an individual or small target (such as a cheiroballista ) would be of the order of 100-200 yds/metres.
Marsden concluded that stone-throwers and arrow-shooters were effective in excess of 400 yds, and arrow -shooters 500 yds plus, against mass targets, particularly Vitruvian and later types.

BTW I think "in- swingers", at least in general use, are a myth ! ( ducks from incoming)

[P. Clodius Secundus]

Paullus Scipio,
Don't duck on my account... I haven't even started building my catapult yet. As usual I have put the cart before the horse, and in this case the engine as well. I'm sure I'll hear it from all sides on this topic. :lol:
Seriously, I welcome lively debate, especially from those with experience or evidence I'm not aware of. My primary interest is in the carroballista as one of the first examples of a dual-purpose field artillery system (like the German 88mm). What puzzles me is why the first evidence appears after +100 and why the radical departure in design and construction. Is it coincidence? Trajan, or whoever "edited" the scenes on the column seems to have placed a great deal of emphasis on them. Of the seven catapults shown, three are in the mural defensive role. They are small images in the background of scenes. Ho-hum, nothing new about them. Of the rest, in "field" use, one is ground mounted in a much more exposed position, the other three are cart mounted. These are all in the foreground and much larger. Another coincidence, or intended? I started out accepting the opinion that Trajan's was only useful as general guide and that the artisans didn't know what a "real" catapult was supposed to look like. Sweating in the Maryland sunshine trying to chop down the "normal" height monopod I'd made to support George's ballista helped to change my mind. I could almost hear the stone cutters one hemisphere and two millennia away chuckling at me. "Why'd he make it that tall in the first place? Didn't he look at the column? Did he think we were stupid?" To me it shows that they knew something we didn't. That begs the question, what else did they know? :?
As far as the in-swinger/out-swinger question, a few quick observations.
1. Hatra. It would be a giant leap backwards as an out-swinger.
2. Sliders. They extend way beyond the frames. Unnecessary in a Vitruvian, but useful on an in-swinger where the string is still in contact with the bolt. If they are slid forward for cocking why aren't the arms visible in the at rest position.
3. Just speculating here, but weren't there metallic details (weapons and such) on the column originally. What if the arms and strings were rendered that way since the stuck out from the front of the weapons. The biggest one doesn't even have a slider at all. Where'd that go?
4. If we classify engines by how the arms move relative to the motion of the projectile ie. traction=in-swinger... counter-traction=out-swinger, the concept wasn't unknown to them. The onager is a traction engine. An in-swinger is essentially two onagrii set winch-to-winch and slung together.
Lets, hear more opinions folks. Especially those who've shot for distance with period technologies.
Regards,
Randi R.

[Gaius Julius Caesar]

I like your idea about the open sight for longer ranged, higher angled shots, but also think it would help the crew to keep from be coming tunnel visioned, and switch to a more important target more easily....


looking forward to your posts 8)

[D B Campbell]

I like your idea about the open sight for longer ranged, higher angled shots, but also think it would help the crew to keep from be coming tunnel visioned, and switch to a more important target more easily.

You're in good company, Byron. This was essentially Dietwulf Baatz's explanation of the wide cheiroballistra-type frame.

btw I don't like the idea of high-angle mortar-style shooting for catapults. The missile would suffer badly from air resistance over the course of its long trajectory.
Shooting along a reasonably flat trajectory, at a target around 200m away, the missile is in the air for 2 seconds maximum, and retains much of its initial energy.
But over a longer, arching trajectory, in order to reach targets of 400m+, the missile is airborne for much longer, and, besides losing kinetic energy with every passing second, it will be subject to lateral drift.
And how do you target individuals (who are presumably mobile themselves) with this style of shooting? I don't know about you guys, but I can barely see over 400m (but maybe I just need new glasses ).

[P. Clodius Secundus]

I like your idea about the open sight for longer ranged, higher angled shots, but also think it would help the crew to keep from be coming tunnel visioned, and switch to a more important target more easily.

You're in good company, Byron. This was essentially Dietwulf Baatz's explanation of the wide cheiroballistra-type frame.

btw I don't like the idea of high-angle mortar-style shooting for catapults. The missile would suffer badly from air resistance over the course of its long trajectory.
Shooting along a reasonably flat trajectory, at a target around 200m away, the missile is in the air for 2 seconds maximum, and retains much of its initial energy.
But over a longer, arching trajectory, in order to reach targets of 400m+, the missile is airborne for much longer, and, besides losing kinetic energy with every passing second, it will be subject to lateral drift.
And how do you target individuals (who are presumably mobile themselves) with this style of shooting? I don't know about you guys, but I can barely see over 400m (but maybe I just need new glasses ).

If you buy Baatz's "field-of-view" explanation for such a radical change in a proven design, you should first ask the question "Why did they ever block up what little view they had on the wood-framers with decorative metal sheeting?" IMHO it couldn't have been that important to them. Even if you believe it was, why did Heron specify that the width should be more that 2X arms length? Wouldn't one length have been enough? As a tank gunner shooting much longer ranges I would acquire targets using a 10X sight and fire using 3X. Neither had much field of view (kind of like looking through a toilet paper tube), but the all the Tank Commander had to do was get me in the general area. More importantly, why does everyone focus exclusively on the flat trajectory direct fire mode? Just because a weapon does one thing very well doesn't mean it can't do others. (88mm, .50 cal, FA-18 hornet, et al). Modern weapons are often rated as having two effective ranges. For example 350m vs point targets, 800 vs area targets. Even if the air resistance could stop the bolt in mid air, it would fall at terminal velocity with all it's mass. I guarantee you wouldn't want to be under it when it did. An individual may be able to see high angle fire approaching and dodge the round, but men standing in formation can't (area target). I was once too close for comfort to a barrage of incoming MLRS missiles. At the last minute they seem to get real small and they either fly over your head or kill you. By then it's in God's hands. Firing from an open cart within range 200m? of a group of archers would be suicidal. Stand off at your max range, not theirs and crank off a few bolts at their formation. If they scatter they're undisciplined rabble. If they stand fast they'll be well disciplined corpses. :twisted:

[Gaius Julius Caesar]

Yes, I think it would be used to 'lob' a round so to speak, over fortifications, (in a siege or what ever), as well as direct fire!

mind you, it would probably only be really practical if there were quite a few weapons firing that way, for maximum effect, if used against another field army. with only a couple on line, a flatter trajectory shot would be more desirable for maximum damage...just guessing

[Paullus Scipio]

We are probably drifting off-topic in getting into torsion artillery technicalities ( Great Subject though ! :wink: )
To deal with a couple of points however :-
Torsion artillery gets it's power from twisted ropes or 'springs'. Obviously, more twist equals more power. Originally the spring frames were a simple bar "_" shape and once added to the stock/slider gave a "T" shaped (in plan )machine - this was called a euthytone machine.
The next development was to alter the frames by turning them inward, giving a shallow "V" shape to the bar/spring frame, and making the whole machine "Y" shaped rather than "T" shaped(called palintone machines). Although complicated to make, such frames meant the arms swung through a greater angle, = more twist,=more power. The complicated structure was not considered worthwhile for the smaller arrow/dart throwers, which generally remained euthytones . However, a similar benefit was gained by curving the arms. ( e.g the machines described by Vitruvius).
The next development we know of was the cheiroballistra described by Heron and which features so prominently on Trajan's column ( the kind of machine P.Clodius Secundus is interested in ). This machine was a great advance. It had a metal rather than wooden frame, it moved the springs further out, thereby increasing the angle the arms swung through ( like a palintone ) and it introduced the central arch as an aid to aiming, now that the aiming aperture between the springs, originally narrow, was now so much wider. The angle of the arm-swing went from 35 degrees (straight arm euthytone) to 47.5 degrees(curved arm Vitruvian euthytone) to 59 degrees (cheiroballistra).It should be remembered too that these arrow/dart throwers were fairly low velocity ( compared,say, to firearms ) and "direct fire" for them still meant elevations of 10-30 degrees.Modern re-enactors thus find the arch as useful as their ancient forbears.
For much more on the technicalities see Marsden "Greek and Roman artillery - technical treatises" particularly pp229 on, or a simplified version, Warry, "Warfare in the Classical World" p178 or Duncan Campbell's "Osprey artillery volume " which I don't have, so can't give an exact refence - but no doubt Duncan will oblige!
Which brings us to the Hatra machine, which gave rise to the myth of "in-swingers".
Once the cheiroballistra appeared, it would not take long for an astute engineer to realise that the same principle ( moving the spring frames further apart to increase arm swing angle ) could now be applied to stone throwers as well, resulting in the same effect as the "V" shaped palintones without the complex structure. It could thus be made stronger and lighter, and as a euthytone, but had to be wood as metal spring frames that large were impractical. The Hatra machine is one of these ( and for all sorts of reasons, which I won't go into now, cannot be an in-swinger ).
As to range, an army drawn up in battle order is an easy enough target at ranges in excess of 500 yards - just ask any Napoleonic artilleryman, who had similar sighting arrangements ! Or a modern machine-gunner !

[D B Campbell]

... the myth of "in-swingers".

How very dare you, Paul! :wink:

(This would be a good time for Aitor to weigh in.)

[D B Campbell]

"Why did they ever block up what little view they had on the wood-framers with decorative metal sheeting?"

It wasn't really a question of blocking it up. The narrow aperture was a consequence of the arrow-shooter's euthytone design. Setting the springs farther apart (to create a better view) would presumably have placed intolerable strain on the wooden framework (Heron's peritrêta). Remember, this design was the result of years of trial and error, and was judged to be the optimum by engineers like Heron.

Why did Heron specify that the width should be more that 2X arms length? Wouldn't one length have been enough?

I'm not sure what you're referring to here. Width of what?

More importantly, why does everyone focus exclusively on the flat trajectory direct fire mode? Just because a weapon does one thing very well doesn't mean it can't do others.

That's true. But I think I've explained why, in my opinion, a high trajectory is less desirable for an ancient gunner.

Even if the air resistance could stop the bolt in mid air, it would fall at terminal velocity with all it's mass. I guarantee you wouldn't want to be under it when it did.

But remember -- we're talking about an arrow, not a shell. By its very nature, a catapult targets individuals. Unless you actually hit an individual (and I would argue that indirect, high trajectory shooting reduces your chances of doing this), the catapult loses its effectiveness as a weapon of terror. You may as well use archers.

[Robert]

Hmm, I am still puzzled about the working (the mechanics) of an in-swinger and its benefits to the more well known out-swinger.
Anyway, I would tend to favour lobbing a projectile with abundant mass, such as a round rock, and a flatter trajectory for something aimed at piercing, such as a bolt. It does make me wonder why the onager was not used for lobbing and the bolt-firing ballista used for flatter trajectory fire. These would in my view make the best use of the different charcteristics of either weapon. Of course, loading the ballista with rock would enable it to lob mass as well. These weapons both have a low firing cycle, as opposed to a volley of arrows, which I would consider the best way of dealing with massed infantry. In the middleages, the pierade and such was used for lobbing rock, the bow for volleyfire and the crossbow for piercing. Both systems were used side by side. Oh well, I'm a marksman, not a tankgunner, so artillery is probably out of my realm .

[Paullus Scipio]

Yes, Duncan, I'm still cowering at the bottom of my trench, awaiting the 'incoming' ( from Aitor et al !! ) - but there is an eerie 'silence' :?

Psychological warfare perhaps?? hock:

[Robert Vermaat]

Aitor has not taken the bait, apparently.. I did send him an email alerting him to this thread though. :wink: