Polybius, horse archers arrows, roman armour, oh my.

[Dan Howard]

no both weight and shape are important

Yes. Though weight is a far better indicator than shape. No light arrow can penetrate metal armour. They have trouble penetrating any armor.

but anything shaped like a bodkin would be for armour piercing

Hardly. Only the heavier typologies have any chance at all of penetrating metal armour.

Heavy arrows are intended for short range shooting. They need to be both heavy and have the right arrow-head for even a small chance of penetrating metal armor.

[Gregg]

Good stuff as usual, Gregg, but one brief caveat. Modern tests with ballistas show that bolts with any kind of broadhead will "plane"--the head acts as fins and the bolt sails wildly off where it wills. So the conclusion is that the bodkin point simply gives good streamlining and accuracy.

Matthew

Thanks Matt! Or is "Good stuff" Latin for "obnoxious blowhard"? :lol:

Yes, the wind planing phenomenon, which is what I meant when I said that trilobate arrowheads were more accurate than broadheads or leafblade heads. That's an interesting observation, though. But since, unlike arrows, crossbow and balista bolts have no spin stabilization, I'd think all you'd have to do is mount a broadhead horizontally instead of vertically to avoid planing (though I'm not sure about that). Still, the Romans did sometimes use leaf blade (maybe better described as diamond cross-section) balista bolt heads along with the standard bodkin forms. And I can't think why the Romans couldn't have used the same type of low profile broadheads that are used today with modern hunting crossbows. They aren't subject to planing like a standard arrow broadhead would be and would certainly do more damage to an unarmored man than a bodkin form.

And that still leaves the question of why the bodkind form was utilized on the pilum and some spear heads. It would have been MUCH easier to forge an iron pilum with a leaf blade head, even a barbed leaf blade (like the angon), than a bodkin head. And I seriously doubt a heavy short-range pilum would be subject to wind planing (and we're all aware of the various tests showing what a bodkin point pilum will do to a shield and armor). And a bodkin shape spearhead makes no sense if the only thing you're trying to punch through is unarmored flesh. That's what the nice wide standard spear blade is for, to leave a big wide wound that bleeds a lot!

the romans had faced horse archers with powerful bows before but the skill with which they were employed+crassus lack of preparation+the terrain and the heat contributed to the roman defeat.

There's no evidence that the Romans had ever faced the new type of Iranian composite bow before Carrhae, and there's a big difference between an archer sitting on a horse and steppe horse archers. The Romans had faced cataphracts before, but had never faced the fully developed steppe tactic of coordinated attack between heavy close combat cataphracts and harrasment shooting by highly mobile nomadic horse archers. Crassus could not have prepared for it because the Romans had never encountered anything like it before. The terrain was hardly the desert Plutarch made it out to be, the Romans had campaigned there the year before and were familiar with the territory, the battle was fought in early Spring where the lush grasses probably hadn't dried out yet, in an area of numerous rivers and streams, in the same subtropical Mediterranean climate as Southern Italy where Crassus' Legionaries had been born and raised.

It's good to remember that Plutarch's account of the battle was probably drawn from a highly distorted report by Cassius, who had fled the army after the first day's battle and probably feared prosecution for desertion. He almost certainly put a major spin on his account of the campaign to make himself look as good (and Crassus as bad) as possible.

Gregg

[Conal]

OK ... different tack on the pilum bodkin point ... was the pilum intended to pierce mail or was it designed to defeat what it would hit first ... the shield, hence the long tang to reach the bearer behind it? Weren't the first ones around before mail was widespread?

Could the bodkin arrow head have be intended to take on shields rather than mail?

[Sean Manning]

Hi Gregg,

I'm skeptical that the quality of the Parthian bows made a difference. Even if the Parthians did have new bows which were 10-20% more effective for the same draw weight, that's still just a minor advantage, and minor advantages in technology are usually less important in war than we think. I think that the unfamiliar Parthian tactics and the skill of their soldiers were more important. The Romans had fought professional horse archers before, but I think this was the first time they fought a whole army of them.

[Gregg]

I'm skeptical that the quality of the Parthian bows made a difference. Even if the Parthians did have new bows which were 10-20% more effective for the same draw weight, that's still just a minor advantage, and minor advantages in technology are usually less important in war than we think. I think that the unfamiliar Parthian tactics and the skill of their soldiers were more important. The Romans had fought professional horse archers before, but I think this was the first time they fought a whole army of them.

Hi Sean!
The 10-20% improvement in the bow may have been the difference between an arrow that just bounced off armor and one that defeated it. Again, the one thing both Dio and Plutarch agree on (drawing from different sources), is the unexpected power of the Parthian bow and its ability to defeat Roman armor. The minor improvement may not, in other words, have seeemed so minor to the Romans who were on the receiving end of it.

OK ... different tack on the pilum bodkin point ... was the pilum intended to pierce mail or was it designed to defeat what it would hit first ... the shield, hence the long tang to reach the bearer behind it? Weren't the first ones around before mail was widespread?

Could the bodkin arrow head have be intended to take on shields rather than mail?

I know that early examples of the pilum had flat arrow-shaped heads, but I'm not sure if that design predated or paralleled the standard bodkin-tipped iron shank pilum, and I believe that earlier design had dissapeared by the late Republic. You might be able to make an interesting case for the introduction and spread of mail armor and the evolution of the pilum head. On the other hand, I don't think the bodkin arrowhead was designed to defeat shields. Shields at the time seem to have been too well designed and robust for arrow strikes, even large numbers of them, to render them unuseable.

Still, that admitedly leaves the question of whether or not the pilum head could pierce armor. I suppose in the end we can't accept that a bodkin-head pilum (or a bodkin arrowhead or a bodkin crossbow bolt head or a bodkin ballista bolt head) could defeat, or were intended to defeat, armor until we've had tests where an ultra-authentic pilum is thrown at ultra-authentic armor. Until then we have to assume that the bodkin tip on the pilum was not designed to defeat armor, and when a pilum hit a man wearing armor it would simply bounce off. Though, personally, I tend to doubt it.

Gregg

[marka]

Good stuff as usual, Gregg, but one brief caveat. Modern tests with ballistas show that bolts with any kind of broadhead will "plane"--the head acts as fins and the bolt sails wildly off where it wills. So the conclusion is that the bodkin point simply gives good streamlining and accuracy.

Matthew

There's no evidence that the Romans had ever faced the new type of Iranian composite bow before Carrhae, and there's a big difference between an archer sitting on a horse and steppe horse archers. The Romans had faced cataphracts before, but had never faced the fully developed steppe tactic of coordinated attack between heavy close combat cataphracts and harrasment shooting by highly mobile nomadic horse archers. Crassus could not have prepared for it because the Romans had never encountered anything like it before. The terrain was hardly the desert Plutarch made it out to be, the Romans had campaigned there the year before and were familiar with the territory, the battle was fought in early Spring where the lush grasses probably hadn't dried out yet, in an area of numerous rivers and streams, in the same subtropical Mediterranean climate as Southern Italy where Crassus' Legionaries had been born and raised.

It's good to remember that Plutarch's account of the battle was probably drawn from a highly distorted report by Cassius, who had fled the army after the first day's battle and probably feared prosecution for desertion. He almost certainly put a major spin on his account of the campaign to make himself look as good (and Crassus as bad) as possible.

Gregg

did the greeks not possess some horse archers-the hippo toxitai?
the armenians and syrians both possessed horse archers.
the egyptians and assyrians possessed chariot archers

horse archers are mentioned in a judean battle

but i take your point the numbers were quite a bit lower

i think all the sources agree that crassus had not prepared a secure line of retreat or fall back position (carrhae was n't provisioned for instance).

[Dan Howard]

OK ... different tack on the pilum bodkin point ... was the pilum intended to pierce mail or was it designed to defeat what it would hit first ... the shield, hence the long tang to reach the bearer behind it? Weren't the first ones around before mail was widespread?

Could the bodkin arrow head have be intended to take on shields rather than mail?

Why would the Romans design a weapon to overcome mail? Hardly anyone they faced would have worn it, whilst every man carried a shield. Any armour-piercing capacity the pilum might have had was incidental to its true purpose.

[marka]

OK ... different tack on the pilum bodkin point ... was the pilum intended to pierce mail or was it designed to defeat what it would hit first ... the shield, hence the long tang to reach the bearer behind it? Weren't the first ones around before mail was widespread?

Could the bodkin arrow head have be intended to take on shields rather than mail?

Why would the Romans design a weapon to overcome mail? Hardly anyone they faced would have worn it, whilst every man carried a shield. Any armour-piercing capacity the pilum might have had was incidental to its true purpose.

a few enemies would have worn it.
interestingly i read (i forget the reference)about numbers of late roman bodkins being found in rhine forts.while in britain the finds tend to be trilobites

[Dan Howard]

a few enemies would have worn it.

Only the most wealthy. At most maybe 1% of a host.

[marka]

a few enemies would have worn it.

Only the most wealthy. At most maybe 1% of a host.

i wonder if we are looking at this from the wrong angle
yes foreign enemies.....roman enemies ie rebels would have had mail or later scale and plate.after all caesar,octavian,pompeius,crassus fought internal enemies as much as external ones.
i have read that the pila goes back to at least 3rd C BC and probably further.

might it also be something to with the barbed head of the pilum.

[Dan Howard]

So if we follow this line of logic, the pilum was designed to be used against fellow Romans since no enemy that the Romans commonly faced wore enough heavy armor to justify its development.

Doesn't it make more sense to look for another reason for its development?

[Gregg]

FWIW Alan Williams tested two samples of mail. One was a surviving 15th C example. Another was a reconstruction made by Erik. Both samples required 120J to be penetrated by a bodkin-type spike. This tells us nothing about Roman mail but it suggests that McEwan's reconstruction would have little chance of penetrating the two samples tested by Dr Williams.

In fairness, this statement needs some correction. Williams calculated that 120 Joules was required to completely penetrate 15th c. mail (quench hardened mild steel so not equivalent to medieval or Roman mail) AND a padded jack (16 layers of quilted linen), something the Romans almost certainly would not have been equipped with. Williams used a drop tester rather than a bow, and the arrow head form was akin to the short squat bodkin type (something like a late medieval type eight, which some believe was developed in the late 14th c. to counter plate armor). He did not test the type 16 broadhead or type 7 needle bodkin, the two most common arrowheads of the age of mail. IIRC, the modern mail without padding behind it was penetrated at 80 Joules, and modern mail with a padded jack behind were penetrated at 100 joules.

At the ranges the Parthian horse archers were probably able to approach the Romans at Carrhae, penetration seems quite possible with an 80 lb composite bow, though other factors would clearly have played a role.

Gregg

[Conal]

roman enemies ie rebels would have had mail or later scale and plate.after all caesar,octavian,pompeius,crassus fought internal enemies as much as external ones.
i have read that the pila goes back to at least 3rd C BC and probably further.

might it also be something to with the barbed head of the pilum.

I have read that the pilum was developed that far cack too. Also if what read is correct then the pilum was a borrowing from the Italic tribes probably the Samnites circa 295BC. As these people developed it and had no tradition of mail, neither did their foes to a great extent then we may be justified to conclude that it was not developed specifically to combat mail.

The other borrowing from the Samnites was the scutum to replace the hoplon. As I have postulated maybe the pilum was designed to penetrate either the metal covered hoplon or a laminated scutum.... maybe even linen body armour.

[Dan Howard]

In fairness, this statement needs some correction. Williams calculated that 120 Joules was required to completely penetrate 15th c. mail (quench hardened mild steel so not equivalent to medieval or Roman mail)

Since when did 15th C Europeans make mail from mild steel? One of the two samples that Williams tested was a surviving example of 15th C mail. One might suspect that had it not been 600 years old it might have performed even better.

AND a padded jack (16 layers of quilted linen), something the Romans almost certainly would not have been equipped with.

We don't know what the Romans wore underneath their mail (personally I think their mail had an integrated padded liner). In this case Williams was being generous when he said the combination was defeated because the plastilene was only penetrated by 35mm. Hardly a serious wound.

Williams used a drop tester rather than a bow, and the arrow head form was akin to the short squat bodkin type (something like a late medieval type eight, which some believe was developed in the late 14th c. to counter plate armor).

The spike used in the test had a 18 degree point and was far harder than any extant arrowhead so far analysed.

IIRC, the modern mail without padding behind it was penetrated at 80 Joules, and modern mail with a padded jack behind were penetrated at 100 joules.

The Knight and the Blast Furnace p. 942 says that both the modern reconstruction AND the 15th C example required 120 J.

At the ranges the Parthian horse archers were probably able to approach the Romans at Carrhae, penetration seems quite possible with an 80 lb composite bow

Not if you use the data presented by Williams and the data presented by McEwan.

[Dan Howard]

And that still leaves the question of why the bodkind form was utilized on the pilum and some spear heads. It would have been MUCH easier to forge an iron pilum with a leaf blade head, even a barbed leaf blade (like the angon), than a bodkin head.

According to David Sim in Iron for the Eagles the difference in production time is negligible. One takes around 37 minutes the other takes around 36 minutes.