Polybolos

[aitor iriarte]

Not very much, I'm afraid...
I should search for Marsden's second book to re-read Philon's description. Has anybody got it at hand? DUNCAN, please :!:

Aitor

[Tarbicus]

I don't see the comparisons to WW2 machine guns as being particularly valid, as their rates of fire, and therefore potential casualties per second, far outstrip the polybolos by a huge factor. Machine guns also have the advantage of more accurate aiming via the sights, which I doubt a polybolos had. Maybe good for defending a narrow causeway, or breach in a wall where the enemy had no choice but to cross a certain spot. But, I imagine not much use on the battlefield, compared to the more random spread of other artillery which made them more unpredictable, more importantly, to the enemy. Coupled with its low strength (can it even penetrate a shield?), I think I can see why it wasn't particularly popular. Great theory which on the face of it was 2000 years ahead of its time, but in practice probably not worth the effort due to the technology available.

OT, but still has some relevance to do with tactics and weapon choice: I have a friend whose uncle was in WW2 and carried a Bren gun. Apparently, if it looked like they were going to be captured the rule was to bury it and pick up any other available weapon, as the enemy hated it so much that any captured Bren gunner was shot on the spot. The thing I understand about its use is that it was no good for area fire, which was how the US troops used their BARs and thus Patton called the Bren a godawful weapon, probably as it didn't operate the same way. But possibly British troops used different combat tactics which made the Bren more useful to them.

[Crispvs]

Ambrosius,

I should probably point out that my knowledge of the polybolos is completely based on talking to Alan Wilkins and seeing his reconstruction. It was him rather than me who made the point about the Bren gun. I had not known about the Bren's accuracy or otherwise prior to that. My own grandfather was prevented from joining up as he was a farmer. He was in the Home Guard but as far as I know he never had anything as expensive as a Bren gun to play with. A quick search for the name 'Crispvs' on the BBC Poeple's War site should bring up all those things I know of my grandfather's experience of WWII. In the late 1950s and early 1960s my uncle carried a Lee Enfield No. 4 and proffesses to know little about machine guns.

Dan,

I don't know what the draw weight should be. Not being an artillery specialist I have to rely on what other people tell me. Alan's polybolos was intended to be a working model to test the reconstruction rather than a fully capable weapon. Therefore the draw weight of his reconstruction will have been considerably less than that of the real thing, whatever that was. When the reconstructed polybolos was demonstrated on the rather inaccurately named BBC progamme 'What the Romans did for us', the director wanted to show the range as well as the accuracy of the machine. On that day the machine was at a particularly low tension and was only shooting fifteen feet or so. The director therefore insisted we retrieve the bolts and stick them in the ground again in the same pattern some distance further on. This is how the range demonstrated on the programme was accurately achieved.

I agree that the achievable draw weight is more likely to be a factor in its demise than the accuracy. I will try and pass on this suggestion to Alan Wilkins next time I see him, although if he has continued working on the project he may have discovered it for himself already. I would expect Duncan Campbell to know.

Tarbicus,
"The thing I understand about its use is that it was no good for area fire"

I thought that the Vickers gun was still used in this role. :?:


Crispvs

[ambrosius]

OT, but still has some relevance to do with tactics and weapon choice: I have a friend whose uncle was in WW2 and carried a Bren gun. Apparently, if it looked like they were going to be captured the rule was to bury it and pick up any other available weapon, as the enemy hated it so much that any captured Bren gunner was shot on the spot. The thing I understand about its use is that it was no good for area fire, which was how the US troops used their BARs and thus Patton called the Bren a godawful weapon, probably as it didn't operate the same way. But possibly British troops used different combat tactics which made the Bren more useful to them.[/i]

OT again (and the last of the Ellis family wartime exploits) but my
grandad said he would set his Bren/machine-gun post up on the _flanks_
of his own lines. That way, when the enemy line approached his own
line, he was firing _along_ the enemy line. So that (whichever kind of
MG you use) you don't need to worry so much about a narrow field of
fire. As, whatever shots miss/pass through the first man hit the next,
as they drop, and so on. It also means they have to worry about fire
coming from more than one direction. Though I doubt the polybolos
was powerful enough to do that.

Ambrosius

[D B Campbell]

I should search for Marsden's second book to re-read Philon's description. Has anybody got it at hand? DUNCAN, please.

Apologies, Aitor et al. -- I just noticed this thread.
As Aitor said, the source for this machine is Philon, a Byzantine Greek writing (probably) around 225 BC, so the relevance for the Roman army seems questionable.
After noting that the "polybolos katapaltês" was invented by a certain Dionysius of Alexandria, Philon gives a very detailed description. So detailed that (as others have already noted) Alan Wilkins was able to reconstruct it, presumably following Marsden's interpretation of the Greek text. I haven't seen a detailed report by Alan, but I have no doubt that the machine performed more or less as Dionysius expected it to.
Philon himself appreciated the ingenuity of the device, but states that "it was not applied to any use worthy of notice" (76.22). I take this to mean that no one ever used it in warfare.
The observations on the use of the bren gun have been fascinating, but Philon evidently had a different set of criteria for judging missile weapons: he is concerned that rapid shooting doesn't allow the gunner time and opportunity to accurately target each shot (thus giving us an insight into the usual dynamics of ancient artillery warfare); and he is concerned that blindly shooting at the same spot will simply provide the enemy with more spent missiles to use against him (a very real concern in ancient warfare, where we hear of the opposing sides gathering up missiles during the night for use on the following day).
It is worth emphasizing that there was no known link between the "polybolos katapaltês" and the Roman army, and no other author ever mentions the machine. It is my opinion that the Romans were usually more interested in efficiency than ingenuity; so they would probably not have been impressed by Dionysius's machine, even if the experiment had ever been repeated.

[conon394]

D B Campbell

As Aitor said, the source for this machine is Philon, a Byzantine Greek writing (probably) around 225 BC, so the relevance for the Roman army seems questionable.
After noting that the "polybolos katapaltês" was invented by a certain Dionysius of Alexandria, Philon gives a very detailed description. So detailed that (as others have already noted) Alan Wilkins was able to reconstruct it, presumably following Marsden's interpretation of the Greek text. I haven't seen a detailed report by Alan, but I have no doubt that the machine performed more or less as Dionysius expected it to.
Philon himself appreciated the ingenuity of the device, but states that "it was not applied to any use worthy of notice" (76.22). I take this to mean that no one ever used it in warfare.

True, but would the Rhodians really have told Philo(n) every detail of their device (they could be a bit touchy about the docks and arsenal). I can think of one area were the device might have served Rhodes well – aboard her fleets. The motion of the ship would deal with the fixed fire problem (and spent missiles are not a problem either) and a high volume of fire for a sort time would be very useful if a ‘4’ was trying to ram and disengage from a larger polyreme (which would normally ‘out-gun’ the smaller vessel if you will). In some ways the polybolos is a perfect example for economic theory (even if it did not work): Rhodes had lots of capital but limited manpower and was thus very likely to try to substitute automation for labor; Rome had no real reason too since it had lots of labor. Of course argument from silence is not really very strong, But Philo(n)’s criteria for successful artillery might not be the same as the those of the Rhodians.

"it was not applied to any use worthy of notice"

Good point but it seems worth considering that for Thucydides the effects of the plague on the Athenian fleet, her most important military force was also not worthy of notice. Perhaps Philo(n) was just not that interested in good concept that was not his own, or one he though was not generally useful.

[Moderatus]

I have only just found this website and all the comments on the Polybolos. I am alarmed at the errors in statements attributed to myself, Alan Wilkins, about my reconstruction of the machine,originally for Adam Hart-Davis' programme, and about the Bren Gun. About the latter, I have never stated that the Bren was damaged to make it less accurate; this is utter nonsense. Someone may have heard me talking about the Bren's flayed zone i.e. the area struck by the Bren's bullets as they spread out. I once put 32 phosphor tracer rounds into a Bren mag at Altcar ranges to demonstrate this spread - a possible court martial offence because of the wear on the barrel !! My reconstruction was never intended to demonstrate the range of the polybolos. In fact I deliberately undertuned it for safety reasons and so that it could be safely used in public. Its range is about 6 metres, as Adam's programme showed (and the bolts were not moved by the producer, as someone has claimed). The claim that it was too accurate is made by Philon ("...the missiles will not have a spread..."), and has been well discussed by Duncan Campbell in his detailed contribution. I just wonder whether Philon ever saw the machine in action, because there is no way that successive bolts would stay in a tight group except at close ranges. Well before the maximum range quoted by Philon - "...little more that a stade"- the bolts would have spread out, as they can be seen to do when shooting modern reconstructions of standard, non-automatic, bolt-shooters. Those contributors who are not sure what Philon said about the details of the mechanism should read Eric Marsden's excellent translation in his second volume. I only disagree with his version in one detail - he alters the Greek text's "the groove under the case" to "a series of notches under the case" (p.151, para 2), unnecessarily. There is, as Duncan points out, no evidence that the Roman army ever used the machine, though it would be surprising if they had not heard of it, and they may, just may have tested it. It is clearly a much more complicated machine, with many more constituent parts, than the standard bolt-shooter. It would have been be more costly to construct and maintain. I used about 150 pins joining the links of the two chain drives, and that may be the Achilles heel that led to its not having "found a noteworthy use" by Greek, or indeed Roman armies. It is the old adage about the weakest link : every pin would have to withstand the strain of drawback, and when one pin snapped the machine would be out of action. I will write more on the machine soon. I have completed the tripod stand described by Philon, which would have allowed the weapon to be locked on to a target, as with the tripod mount for the Bren and many other modern machine guns. I hope to post a video later this year. Moderatus

[jkaler48]

Sinew Sinew Sinew I suspect every one of the reconstructed machines would reap benefits in range/draw weight by being strung with sinew rope.

[D B Campbell]

Welcome to RAT, Alan. I hope you are well and thriving.

I will write more on the machine soon.

Looking forward to it (and also to a report on "Bestia", which I hope you will publish).

[Moderatus]

Thank you Duncan. I hope you are well. The improved Mk 2 bestia is well under way. My detailed article on the machine is about two thirds complete. It will be published, I hope, as a pdf. Just back from Jordan and Syria. Took measurements of the missile slits on Palmyra's horseshoe shaped towers.

[P. Clodius Secundus]

It is clearly a much more complicated machine, with many more constituent parts, than the standard bolt-shooter. It would have been be more costly to construct and maintain. I used about 150 pins joining the links of the two chain drives, and that may be the Achilles heel that led to its not having "found a noteworthy use" by Greek, or indeed Roman armies. It is the old adage about the weakest link : every pin would have to withstand the strain of drawback, and when one pin snapped the machine would be out of action.

Along with the complexity factor, the chain-drive system introduces another self-limiting effect on the potential power of the machine. Philon states that, "It did not have a cord pull-back system." thus it could not use pulleys to increase the mechanical advantage of the winch. That alone would limit it to smaller calibers. In addition, making the links of the the chain larger to reduce their number and increase their strength would require a corresponding increase in the circumference of the pentagonal sprockets. This would further increase the effort required to turn the windlass. Compared to even a straight-pull cord system with a much smaller spindle, it would be like tying to pedal your bicycle uphill in high gear.

[Crispvs]

Moderatus (or perhaps that should read 'Moderate' to be grammatically correct :wink: ),

I would like to take this opportunity to apologise for unintentionally misrepresenting your comments on the Bren gun. Presumably I either misheard you talking about it or remembered your statement incorrectly. Regarding the statement about repositioning the bolts for the television programme, I was present for the sections of the programme filmed at the Lunt but was not present for the artillery filming so was going on what I had been told by someone else who I understood to have been present. I was using the pronoun 'we' in the sense of it having been performed by the group I am a member of. Given that I was aware that the machine was deliberately set at a low tension I accepted what I had been told as seeming reasonable for the purposes of filming. Whatever the case, please accept this as a public apology.

I hope that apart from these two issues my descriptions of your polybolos were otherwise faithful to your statements to me and in my presence.

I usually refer to your Shire Archaeology book and the 'Scorpio and Cheirobalistra' JRMES article when carrying the Wilkins banner into the artillery debates here on RAT. Unfortunately here of course, I had no source to refer to other than my own recollections of the times I had seen your reconstruction with my own eyes, principally during the artillery demonstrations at Dover Castle. I trust that in other threads on matters pertaining to wood framed bolt shooters, metal framed bolt shooters and stone throwing artillery I have more accurately represented your views.

It is perhaps unfortunate in terms of the development of this thread that my wife was pregnant throughout most of 2006 and I was being woken up to make her omlettes several times each night, which may have affected my ability to recollect things correctly at that point in time. Again I offer my sincere apology for any offence I may unintentionally have caused.

Crispvs