Armor Penetration and Armor resistance.

[hoplite14gr]

Dan is right on his theory about cloth.
I used linen of the type that they use for furniture covers not garment construction in my experiment.
The only thing that penetrated was a thin steel blade of a punching tool so
David Wills has a very strong point in my opinion.
Also when you close your shoulder guards it is 15layers plus 15 layers on your chest 30.

I saw a documentary of the silk "subarmalis" of the Mongols.
They also showed a test where a reconstructed silk vest resisted .357slugs.
Sorry dont recal the layers. Thai police is using such vests according to the documentary(!!!!!!!!!!!!!!!)

Matt the square holes can very well be from the dreaded Saka "saggaris"
One of this helmets is Athenian and dates from the time of Marathon battle.

Kind regards
Kind regards

[Dan Howard]

The Thai police are today being issued with layered silk vests. They resist anything up to a 9mm. The local availability of silk means that these vests are cheaper than imported kevlar.

You can't use a puich to make holes in textiles. The weave unravels. What was done was an awl was used to carefully spread the weave so that a rivet or large needle could pass through without breaking any threads.

[Dan Howard]

Crossposted from the leather cuirass thread.

To Dan ; I should have explained myself better - leather/textile armours are more resistant than metal to some types of weapon ( but less resistant to others ).All three types I mentioned have been shown to adequately resist blows between 30-40 Joules of kinetic energy.

I'm willing to bet that the so-called test piece has nothing in common with what was actually worn on the battlefield. What was the metallurgical content of this plate? What was its hardness? Bronze with a tin content of around 8% that has been workhardened (the type of material that was used on Greek shields and armour) has a hardness over 200VPH. 1mm of this material can withstand blows well in excess of the 30-40J you have cited. By "blow" I am referring to the tip of a steel spike, not the edge of a blade. 5mm of hardened leather doesn't go close to this level of protection. Swords often had tin contents closer to 10% and work hardened edges can produce hardnesses of 270 VPH. This is superior to all but the best quench-hardened steels which were in very short supply in the Iron Age.

[hoplite14gr]

If we trust this source:
From Plutarch´s "Life of Demetrios"(The Besieger)
"Whilst Demetrius was at this same siege, there were brought to him two iron cuirasses from Cyprus, weighing each of them on more than forty pounds, and Zoilus, who had forged them, to show the excellence of their temper, desired that one of them might be tried with a catapult
missile, shot out of one of the engines at no greater distance than six-and-twenty paces; and, upon the experiment, it was found that though the dart exactly hit the cuirass, yet it made no greater impression than such a slight scratch as might be made with the point of a style
or graver. Demetrius took this for his own wearing, and gave the other to Alcimus the Epirot, the best soldier and strongest man of all his captains, the only one who used to wear armour to the weight of two talents, one talent being the weight which others thought sufficient.
He fell during this siege in a battle near the theatre."

Kind regards

[Dan Howard]

Wonderful source. A 40 lb iron cuirass would be over 2mm thick. Bronze of this thickness would be at least as protective, though it would weigh a little more since bronze is denser than iron.

[hoplite14gr]

Hmm...weight in Hellenistic period for a General would not be much issue since they were all (or almost all) horsemen riding with their HETAIROI in battle a and could afford big horses.

And a question can a hand-propeled weapon (i.e javelin) attain 30-40J from an average thrower?

Kind regards

[Thersites]

AFAIK tests performed by different people, from Napoleon III to modern scholars and reenactor groups consistently show that a heavy throwing javelin, such as a soliferreum or pilum will be effective, and armor-piercing capable at a range of 20 to 25 or even 30 m. Lighter javelins will be effective at the same range on unarmoured or lightly armoured targets, but seldom really armor-piercing capable. These same light javelins will still be useful at ranges over 40 m. and up to 60 m if thrown with the aid of an amentum and in salvoes or dense clouds, but their killing capacity will be very reduced. They can be useful for harassing and disordering enemy formations, wound horses and some men and generally 'soften' enemy formations. I am however a bit sceptical at the longer end of these ranges, as in real combat conditions all weapons tend to be normally used at the lower ranges, even nowadays.
Cheers

[Paullus Scipio]

For Stefanos :- One of the major problems in trying to take a scientific approach to this subject is the number of variables !

Comparisons with modern javelin throwers are hopeless, because they use an aerodynamic javelin made of modern materials, not to mention modern specialist training techniques !

Nevertheless, here are some figures for javelins of the original type.....

Mens olympics,1908 ; wt 0.8 kg, range 60m, velocity 24.5 m/sec, initial kinetic energy, 240 joules.

Womens olympics, 1908 ; wt 0.6 kg,range 61m, velocity, 24.5 m/sec, initial kinetic energy, 182 joules.

And here are some more figures for an ancient type javelin of 0.8 kg, thrown by a male non-trained athlete;
Thrown with run-up: range, 44m, velocity 21m/sec, initial energy 190 joules
Thrown taking one pace: range 29m, vel 17m/sec, initial energy 111 joules
Thrown with 'amentum' ( throwing loop),taking one pace : range 45 m, vel 22m/sec ,initial energy 200 joules
Thrown standing: range 15 m vel 12m/sec , initial energy 60 joules.
Due to measuring difficulties these figures might be out somewhat, and should be treated as approximate .
Now of course, you could go out tomorrow, using a different javelin, and yourself throw and obtain different results.........
We must also consider that much kinetic energy would be lost in flight. An estimate might be 10-30%.
This should help readers to appreciate some of the difficulties and variables involved in this whole subject !

[Dan Howard]

Hmm...weight in Hellenistic period for a General would not be much issue since they were all (or almost all) horsemen riding with their HETAIROI in battle a and could afford big horses.

And a question can a hand-propeled weapon (i.e javelin) attain 30-40J from an average thrower?

Kind regards

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.

[Paullus Scipio]

Before we start getting too technical on this subject, it might be as well if we set down some basics, so we all are aware of what is under discussion.
Let me begin with a disclaimer! I am not a physicist or an engineer, so if my terminology or understanding is not technically correct, please forgive me.
Also, I am trying to write for all, rather than a technically minded audience.
In considering armour effectiveness there are some basic forces at work, and we might as well remind ourselves of them:-
Firstly, Force=mass x acceleration (F=ma ), that is, the force exerted by a weapon will be governed by its mass, and the acceleration which it gets from the attacker. This may be direct , e.g. a hand blow, or by storing energy, as in an arrow.
A standing man is limited to exerting around 120 Newtons ( a newton is kg/metre squared ).
Force may be quasi-static, as in a direct blow (e.g a thrust or cut), or from a source of kinetic energy (e.g. missile such as arrow or javelin or sling bullet ), or a combination of the two.
Exertion of force imparts Kinetic energy = ½ mass x velocity squared (K=1/2 mv2 – the “squaredâ€

[geala]

Im not sure to post it here or in a new thread as it is not exactly about armour penetration (but armour performance). I decided to post it here after reading Pauls very good and interesting post about the performance of weapons and the formulars (laudes for this).

I have some problems with the ballistics of slings. I like that weapon, tried it a bit (I'm very bad with it btw ) and have read astonishing things about it. On the other hand my preoccupation with the ballistics of modern projectiles sometimes makes it hard to believe everything said about slingshots.

I have read different statements for terminal ballistics of slings. Some estimate about 75 J starting energy for a 60 gr. glandes, some about at least 100 J. I have read on www.slinging.org about distance shots as far as 500 metres, 200 to 300 being the norm.

Lets assume a glandes of 100 gr (50 - 70 gr. seem more to be used, but...) reaching an energy of 150 J. It must be shot with about 55 m/sec which seems difficult to achieve for me but is perhaps no problem for a skilled slinger (?). The energy would diminish quite a lot with the distance and a hit in about 150 m - would it be so bad?

But lets assume the glandes would hit a soldier with the full 150 J. What would happen if he has a cuirass of bronze or layered linen and a helmet? Devastating things if we can thrust some ancient sources or the leading opinion amongs slingers. Words like "armour-piercing" came to my mind. Even if the armour would not be pierced or shattered the "force" of the hit would maim, blind or kill the victim.

But in the same energy area would be the javelins, as we have seen in the post from Paul. Arrows shot from a very strong longbow or recurve bow may also reach 150 J (but would be more close to 100 J). A warrior hit by a javelin or arrow must experience the same as if hit by a glandes. Or not?

But what would happen if an armoured soldier on a modern battlefield would be hit by an object with 150 J energy? Not so much. A very strong .22 lr bullet has a muzzle energy of about 120 to 150 J. A 9mmx19 (9 mm Luger or Para) has about 500 J, same for a .45 ACP. If you have a solid plate in your hand (lets say 4 mm of a ballistic solid fibre) and a bit soft backing (a thin piece of cloth f.e.) you can snap the bullets of a 9 mm Luger/.45 ACP from the air without much inconvenience. Therefore I strongly doubt that a missile with 150 J can kill or maim a soldier with a cuirass or helmet if it is not able to enter the body and injure important inner organs or blood vessels.


So, perhaps it is the momentum of the slingshot? The momentum is a variable which is more or less without any meaning in modern terminal ballistics discussion. Old theories based on the very problematic Thompson/LaGarde tests and theories of so called "Stopping power" by Hatcher or Tailor are fortunately out of order. Instead energy (and the behavoir of the bullet in the target, but that's another theme) is the most interesting factor.

But sling bullets are a lot heavier than modern ones. Is this the solution? So lets have a look. I think momentum is the same as Impuls in German, so the momentum is P = M x V. For the above mentioned slingshot it would be P= 0,1 kg x 55 m/sec = 5,5. A glandes of 60 gr with a velocity of 50 m/sec and 75 J energy (more realistical I think) would reach a momentum of 3. A 9x19 would have a momentum of 0,008 kg x 350 m/sec = 2,8; a .45 ACP of 0,0149 kg x 260 m/sec = 3,87; a .308 Winch. (former 7,62x51 Nato, reaching 3500 to 4000 J as E0) of 0,011 kg x 800 m/sec = 8,8. The momentum of a javelin with 0,6 kg and 24,5 m/sec (that's very much velocity...!) would be 14,7, of an arrow of 60 gr. and 60 m/sec = 3,6. The very heavy slingstone mentioned to be used sometimes by Balearic slingers with 0,436 kg and perhaps a velocity of 35 m/sec (too much I think) would reach 15,26.
Again:
glandes (extrem performance): 5,5
glandes (normal) 3,6
heavy stone 15,3
javelin: 14,7
arrow: 3,6
9x19: 2,8
.45 ACP: 3,8
.308 Winch. 8,8

(Btw: the formular for the return motion energy (?) would be: E=P² / 2 x M. Lets assume a 70 kg body hit by a glandes. For the extrem glandes that would be 5,5² / 2 x 70 = 0,22 J. That is the energy you need to lift a weight of appr. 20 gr. to 1 metre height. The body could compensate that with ease. So no knock down hits through sheer "force".)


If a .308 Winch. bullet is stopped by a vest with plates there is no devastating effect to the soldier as far as I know. I know some guys from a police special unit who told me that being hit with a 9mmx19 from 10 m on a kevlar vest (without plates) is not that bad, like a strong stroke with a fist. I have read of French police officers telling the same for the (stronger) .357 Magnum. You don't fall down, you get a bruise, nothing more. But never experienced it myself, luckily. I know a lot of incidents where people were hit with heavy clubs, bottles etc. on the head (with comparable momentum as in a sling shot but less energy) and were able to react, f.e. draw a gun and shoot the attacker.

Is somebody there to give a medically based rule what momentum will result in what injury? Unfortunately my connections to forensic medicine doctors have ceased the last years.

The only conclusison for me in the meantime is that the performance of sling shots on armoured targets is a bit exaggerated in some sources and statements. A hit on the armoured body would not kill or maim the warrior. A hit on the helm could knock him down and perhaps let seldomly to blindness (also sometimes mentioned from the Spanish in the American Conquista.) And a hit from a glandes would be the same as a hit from an arrow or a javelin. Or is there a mistake in my thoughts?

[Gaius Julius Caesar]

Well I was hit over the head with a ski pole in my teenage years.....if it had not been someone who I shouldn't have been fighting with, the person who did it would have been a lot worse off than me! It cut to the bone but I was still capable of carrying on!

[caiusbeerquitius]

You can read all about slingshoths and their energy here:

Baatz, Dietwulf, Schleudergeschosse aus Blei - eine waffentechnische Untersuchung. Saalburg-Jahrb. 45, 1990, 59ff.

Also, there are a couple of articles published in Slingshot, a wargaming magazine, the reference can be found here:

www.soa.org.uk/

[geala]

I don't have Baatz article by the hand but I have read it (partly I have to confess) and I remember that he is rather critical about the performance of slings, reducing the effective range to about 50 m. I did not want to quote this therefore. I don't remember medical details in the article, so I have to try to find it again and reread it. I will have a look to the other source, thanks.

[Archimedes]

Khairete!

Has anyone else considered that the scales that we often see added to the linothorax may have been more to protect the armor than the wearer?
Multilayered linen armor (especially glued) has been shown to provide excellent protection from most forms of attack, but is susceptible to cutting attacks, especially slashing cuts that 'slice' at the armor instead of 'chopping.' What if the scales were very thin, with the purpose of protecting the armor itself from slashing cuts?

Archimedes