Armor Penetration and Armor resistance.

[Anonymous]

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Multilayered linen armor (especially glued) has been shown to provide excellent protection from most forms of attack, but is susceptible to cutting

That's interesting. I have been cited evidence that linen gives better protection if is not glued. Can you cite any sources/evidence for the view that it's better, glued?

[Archimedes]

Sorry, I expressed myself very poorly :oops: ...I meant that glued linen is especially susceptible to slashing cuts, from the evidence thats been posted on this board.

I'm a real believer in 'try it for yourself' however, and plan to do quite a bit of testing myself, now that I actually have a bunch of linen to test.

Archimedes

[hoplite14gr]

In my opinion lead sling bullets were not for penetration but rather to have a mace-like effect crushing for example your scull under the helmet.

As for keep going after being wounded lets say that adrenalin makes miracles sometimes....

Kind regards

[Paullus Scipio]

Thank you Wolfgang !
In the words of a popular T.V. program....."Myth Busted" !!!
As that program also showed, the Hollywood myth that powerful guns knock people off their feet is just that - a myth.
So, no 'superweapon' slings then.
It would appear that greek slingers of the Hoplite era were concerned less with 'armour piercing' than with range.
Several greek "glandes" made of lead are of the order of 50g, and some are known as light as 24g, and if we allow a range of around 250-300m for the latter, they have a kinetic energy of around 30-36 joules, which is around the same kinetic energy as the Asiatic bows they opposed.
Xenophon mentions that the Rhodian slingers ( using lead bullets) could outrange Persian ones ( presumably slinging stones, but maybe not ) and"further even than most of their archers" (Xenophon, Anabasis, 3,iv )

That slings, arrows and javelins were similar in effect, range, and performance is shown by the fact that all three were used throughout the greek and roman world, and it is not until both Asiatic and Western bows get more powerful in mediaeval times, that slings and javelins are displaced as missile weapons.

[Sean Manning]

2mm of work-hardened bronze could easily withstand 120J from a javelin. This is not enough to stop a modern Olympic javelin even at a fair distance but ancient javelins would have more trouble. However, many cuirasses seem to have been closer to 1mm in thickness. This is enough to stop most arrows but not thrown javelins (single-handed spear thrusts and sword stabs have no chance at all). IMO the growing prevalence of body armour at the end of the bronze age caused the bow to be discarded in favour of javelins.

Dan, I have heard you say a few times that javelins have better armour penetration than arrows or spear thrusts. Why do you think this? It sounds reasonable, but I don't recall seeing any evidence other than the surprisingly high figures for energy Paulus presents. It seems to me that spear throwers who could take a run up (skirmishers or a howling warband of Franks, say) would be much more effective than those who could not (Romans receiving a charge, or a Germanic shield wall).

[Archimedes]

Actually, slings don't work in a linear fashion...lighter ammo doesn't necessarily go farther. I sling fairly regularly and I find that my best weight for range is about 70 grams...lighter ammo drops in range pretty fast, especially under about 40-45 grams. I sling lead, rocks, and cement balls I handroll (and that weigh ~70 grams :twisted: ) and this is true for all of them. Incidentally, lead has three main advantages over rocks: 1-its manufactured, so aerodynamic shape and consistent weight 2- lead is denser, so less surface area to create drag 3- you can use a sling that is specifically made for the ammo...this is a far bigger thing than most people realize. A sling pouch for lead ammo can be very small and shaped for the ammo, increasing accuracy and especially reducing drag on the sling, increasing the release velocity.

Archimedes

[Dan Howard]

Dan, I have heard you say a few times that javelins have better armour penetration than arrows or spear thrusts. Why do you think this? It sounds reasonable, but I don't recall seeing any evidence other than the surprisingly high figures for energy Paulus presents. It seems to me that spear throwers who could take a run up (skirmishers or a howling warband of Franks, say) would be much more effective than those who could not (Romans receiving a charge, or a Germanic shield wall).

I have figures for one-handed and two-handed thrusts wirth various weapons. I have figures for various types of bows. I had no real data on thrown javelins. I relied on Paulus' figures for that. IIRC there were some figures posted on RAT about the Roman pilum. Of course I can't find them now I need them I agree with Paulus that the primary concern of any archer or slinger was range not armour penetration. However, the missile still needed to inflict some damage at the end of its arc. For example, there is no point using flight arrows on the battlefield.

[Sean Manning]

Actually, slings don't work in a linear fashion...lighter ammo doesn't necessarily go farther. I sling fairly regularly and I find that my best weight for range is about 70 grams...lighter ammo drops in range pretty fast, especially under about 40-45 grams. I sling lead, rocks, and cement balls I handroll (and that weigh ~70 grams :twisted: ) and this is true for all of them.

Archimedes

The same is true for bows, incidentally. There is an optimal weight of arrow for range, and another for kinetic energy, depending on the strength of the bow and the design of the arrow. Air resistance and the design of the bow give an upper limit to how fast the arrow can be accelerated between release and leaving the string, so a very light arrow will fly no faster than a light one (and it may even fly slower, due to the inefficiencies involved).

Thanks for the information, Dan. Where did you get your figures for the energy of spear thrusts (as opposed to knife thrusts)?

[hoplite14gr]

Paul Xenophon in the original Greek texts says that Greek slingers from Rhodes outranged Tissafernes Persian slingers NOT archers and he mentions that Pesrians cast fist sized stones instead of the Greek lead bullets.
Kind regards

[geala]

Dan, I have heard you say a few times that javelins have better armour penetration than arrows or spear thrusts. Why do you think this? It sounds reasonable, but I don't recall seeing any evidence other than the surprisingly high figures for energy Paulus presents. It seems to me that spear throwers who could take a run up (skirmishers or a howling warband of Franks, say) would be much more effective than those who could not (Romans receiving a charge, or a Germanic shield wall).

I have figures for one-handed and two-handed thrusts wirth various weapons. I have figures for various types of bows. I had no real data on thrown javelins. I relied on Paulus' figures for that. IIRC there were some figures posted on RAT about the Roman pilum. Of course I can't find them now I need them I agree with Paulus that the primary concern of any archer or slinger was range not armour penetration. However, the missile still needed to inflict some damage at the end of its arc. For example, there is no point using flight arrows on the battlefield.

M. Junkelmann gives some data in his book "Die Reiter Roms" part III from 1992, p. 166ff. I think it is known to the most? The performances for the thrown weapons are much worse than that Paul quoted. Unfortunately I cannot get out how the data was aquired. I presume a velocity measure tool for bullet velocities was used.

For example the used hasta of 0,8 kg reached a velocity of (just) 12 m/sec if thrown standing still but (also: just) 17 m/sec with a short running up, resulting in 58 J versus 116 J, quite a big difference. They also made short tests of penetration power against flat steel panels and mail (not riveted) and a performance test against a material called "soap" used for testing of temporary wound profiles from bullets. Maybe that is partly wrong as ballistical soap was normally used to show the final wound profiles; but that's not important because the both wound profiles of low energy weapons like arrows, javelins, swords etc. are mostly the same.

The arrows from the used bow performed better against armour than javelins. That is no surprise because the energy in relation to the surface of an arrow is much higher than that of a javelin (it's Querschnittsbelastung in German, I don't know the English word), resulting in much better penetration power relatively to the energy of the projectile. Pila or similar javelins are something special however.

[Paullus Scipio]

Sorry, Stefan, but my quotation from Xenophon is accurate ( I've checked both the penguin and Loeb editions ).
To Wolfgang :
Another very interesting post ! It would be very interesting to know the circumstances and methodology of Junkelmann's tests.
As soon as I saw your post,an obvious possible explanation occurred to me in respect of the performance discrepancies.
As any "old soldier" can tell you, when performing fitness tests, the same soldier will turn in very different results from P.T order ( shorts and training shoes), and Battle order ( boots, weapon,light equipment) and even running in boots and camouflage trousers.
The results I quoted earlier were all carried out in "athletic dress". Were Junkelmann's carried out in armour/ ancient dress ?
I can't think of an english equivalent word - but I love those german compound words! For readers generally, an arrow needs much less energy than,say, a spear due to the difference in area over which the force is applied ( and the fact that the arrow is penetrating, while the spear/javelin head slices through ).--- see the formulae posted earlier. [/b]

[Dan Howard]

Depends upon the arrowhead. Broadheads react very similarly to spear or lance heads. Bodkins seem to have better penetration of metal armour. However they perform worse than broadheads on textile armour. Bodkins tend to bounce off quilted linen while broadheads are more likely to cut through. Felt seems to offer the best protection agasinst all types of arrowhead (though obviously not as good as metal plate).

[Paullus Scipio]

That brings up an interesting point, Dan. Formulae are not particularly good at predicting armour /weapon interaction. Kinetic energy and momentum calculations would not have predicted bodkins bouncing off textiles! Clearly other surprise factors can be at work (e.g. the 'limiting velocity' phenomenon referred to earlier ).
Could you elaborate on your comments about felt? I know the whole subject of differences between ancient/modern felt has been debated before, but what type of felt are we talking about here, and as used by whom ?

Lastly, I had trouble posting to this thread earlier and opened a parallel one with some lengthy posts, with a request to a moderator to move them across to here - there are some things there that you could shed a great deal of light on.

[Paullus Scipio]

To Stefanos : sling glandes were certainly capable of penetrating bare flesh - a roman mecical description of how to remove them still exists !

To Geala/Wolfgang ; I've just looked again at those javelin figures - they are not so different after all !

If you compare the two Junkelmann gives, that you quote (standing and after 1 or 2 pace run-up) with those I gave for non-trained athletes, they are all but identical !!

[Paullus Scipio]

Archimedes[/quote]"The same is true for bows, incidentally. There is an optimal weight of arrow for range, and another for kinetic energy, depending on the strength of the bow and the design of the arrow. Air resistance and the design of the bow give an upper limit to how fast the arrow can be accelerated between release and leaving the string, so a very light arrow will fly no faster than a light one (and it may even fly slower, due to the inefficiencies involved)."

Similar considerations apply to 'heavy' arrows. A famous expert on archery had cause to examine a Tartar bow which had an extreme pull, and fired a heavy arrow to a range of little more than 100metres, which he then pooh-poohed and denigrated as 'useless'. In fact, if he had calculated the kinetic energy, he would have realised the bow was an exceptionally powerful armour-piercer at ranges up to 100metres !