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Reconstructing Ancient Linen Body Armor
BOOK LINK

They say that :
70 joules is required to defeat 20 laminated layers of linen.
2 mm of bronze provide same protection than 12 mm of glued linen.
Nearly cut 50% of the weight for the same protection.
but we can see 131 Joules (175*0.75) to penetrate 2 mm mild steel in the knight and blast furnace, and we can see in the begining of the book that cold worked bronze have an hardness close to mild steel (air cooled).
I am a little bit confused. Did they just underestimate the level of protection provided by bronze ?
The experimental setup might have been very different. For instance, it'd take much less energy to penetrate armour mounted against a rigid and strongly-supported backing, and more energy if the mount is soft and/or yielding. The alloy chosen for the bronze could also have had a factor since the correct alloy for ancient weapons and armour is no longer commercially produced (so somebody who wants bronze armour would have to either mix the alloy him/herself, buy an expensive customised mix, or make do with less appropriate modern alloys).
I've critiqued this book a few times now. These days I just cut and paste a summary.

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The latest research suggests that what we thought we knew about the linothorax was pretty much all wrong. The armour that we commonly see in Greek illustrations that is known as a "tube and yoke" corselet has erroneously been called a "linothorax" but was actually called a spolas. It was probably what the Spartans called an aegis as well. The word "aegis" implies that it was made from animal hide and we have Pollux's Onomastikon specifically telling us that the spolas was made of animal hide. We have no evidence for Greek linen armour during the classical or Hellenistic periods but there is evidence of it at the end of the Bronze Age.

Regarding Aldrete's book on reconstructing Greek linen armour, it has five fundamental problems:

1. All of the sources he cites for Greek linen armour during the time in question are actually talking about foreigners using linen armour, not Greeks. As mentioned above, what little evidence we have about Greek tube and yoke armour suggests that it is made of leather, not linen.

2. He relies on an outdated hypothesis by Connolly who suggested that glue may have been used to make their linen armour because their shoulder flaps appear to be "springy" in some illustrations. Firstly, properly quilted linen is just as springy and rigid as glued linen (take a look at kendo arm guards). Secondly, we now suspect that those shoulder flaps were more likely made of leather, and not linen at all.

3. Layered textile armour has been used in battle for at least three thousand years all over the world from the Americas to Europe to Asia. There are dozens of extant examples and many descriptions of how it is made in various texts. Every single one is quilted. There isn't a shred of evidence to suggest that glue has ever been used to make layered textile armour in all of that three thousand year history. The two articles that Aldrete cites as evidence for using glue in his reconstruction are discussed here.
http://bookandsword.com/2014/02/14/did-the-gr...-armour-2/
As can be seen, they do no such thing.

4. His team doesn't seem to have bothered to examine any of the multitude of extant examples of textile armour and so their quilted test pieces are woefully substandard compared to how real textile armour was made. Because of this they come to the false conclusion that their glued construction was more protective than quilted armour. When the quilting is properly done, a good case can be made for quilting actually providing better protection than glue.

5. They overbuild their reconstruction. If they really wanted to reproduce Hellenistic linen armour then they should not have made it so thick that it was completely arrowproof. Pausanias said that linen armour was better for hunting because it was susceptible to a strong weapon thrust, and Alexander was almost killed by an arrow that punched through his armour. We know that linen armour can be made arrowproof; there were European examples with as much as 30 layers in their construction, but the linen armour described in Greek texts seems to have been a lot lighter.

According to his figures, his linen construction seems to provide better protection than a similar weight of hardened steel! In the real world we had to wait for the invention of kevlar to do that. Plus, the so-called bronze plate he tested was 20% less dense than real bronze, suggesting either his measurements were sloppy or he never used bronze at all. In addition, he said that the metal was annealed, which destroys the work-hardening and seriously compromises the metal's ability to stop weapons.

Their experiments regarding glued linen are actually well thought out and carefully documented, but ultimately it was a pointless squandering of resources until someone comes up with evidence that historical armour was ever made like this. It would have been far more useful if they put those resources to examining how various types of quilted armour performed. Quilted linen makes a very effective armour. It actually provides better protection than a similar weight of layered leather - even if it is hardened into cuirbouili. Personally I believe that the Greeks may have made limited use of linen armour during the classical and Hellenistic periods but it definitely wasn't glued and it may not have been of the tube and yoke typology.

This kind of research can't be done by Arts students. You need multiple disciplines including engineering, physics, metallurgy, and hoplology.
I'm seriously grateful to Dan for doing the legwork on this! I've never had the guts to read the book, it would just be too painful. After all the meticulous research that other people have done on the subject, discovering that Peter Connolly's theory of glued linen was all wrong and had no basis in the evidence, Aldrete simply ignored all that, twisted or overlooked crucial evidence, and set the field of Greek armor studies back 40 years. We'll be at least another generation digging ourselves out of this hole, and it makes me want to cry.

The main problem with reconstructing or testing ancient linen or leather armor is that we simply don't know enough about it. Thickness, for starters. There must be hundreds of surviving fittings from organic armor, but none have been examined either for traces of leather or linen, or for how thick the material was (which can be judged by rivet length). We don't know if the linen was sheer and fine, or heavy like canvas, let alone how many layers might have been used. We don't know what *kind* of leather or hide was used, nor if it was layered, thicker in the front, etc.

We know what it *looked* like, but every dot and line in the artwork is hotly debated: Is it showing rivets? Quilting? Decoration? We don't know. There is an understandable tendency to make reconstructions that are quite substantial, weighing 10 to 20 pounds. It's supposed to be armor, after all! But then there are several depictions of someone casually holding a cuirass that has been rolled up like a newspaper. Gah! We can see a lot of cuirasses that are reinforced with scales, but almost no scales have been found in Greece, or at least published. And then we notice that the scales are often on the *sides*, but not the *front*--does that mean the front is thicker? Reinforced with a plate? How does THAT roll up like a goll-darn *newspaper*?? That a woman can hold in one hand?

We also keep hearing about how organic armor must have been preferred because it was lighter than metal. While I have yet to see a reconstructed leather or linen cuirass that weighs less than 10 pounds, *original* bronze cuirasses seem to weigh 5 to 7 pounds!

The more we learn, the less we know. But Aldrete's book is a huge step backwards.

Matthew
Ok, many thanks, so the experimentation and numbers on glued linen was probably right but don't prove anything on the existence of such things. And bronze resistance test was made with bad bronze or they fake it.
Talking about linen resistance vs leather there is a recent studies that explain leather provide a little bit more protection vs wide blade arrow head than linen for the same weight.
Just to have your though:
https://www.academia.edu/5520314/Arrows_Against_Linen_and_Leather_Armour
It's not that much but its seems well done.
Sure, that looks reasonable. And he's careful to say that he's just generally looking at mechanics, not trying to demonstrate that a particular material or thickness WAS used, etc. (Of course, that kind of test gets misinterpreted and misused by other people all the time!) A little more detail on the type and thickness of leather would have been nice.

It would be interesting to see similar tests with various types of leather, made with historical methods: vegetable/oak tanned, rawhide, smoke-tanned, alum tawed, etc. Again, those might give us some comparisons, but not a lot else.

Matthew
I wanted to thank Sean Manning for tracking down those two obscure articles that Aldrete cited. This happens time and again. A writer makes a claim and cites an article to back it up but when you consult that article, you find that it says nothing of the sort.
Alexis Bataille wrote:
Ok, many thanks, so the experimentation and numbers on glued linen was probably right

I doubt it. We've demonstrated sloppy measurements elsewhere in the book so there is no reason to trust any of the data. I would want to see someone else reproduce Aldrete's results before taking them seriously. If you take it at face value then his figures suggest that glued linen provided better protection than a similar weight of hardened steel! There have been a lot of very well funded companies trying very hard for a century using every combination imaginable to make body armour that protects better than hardened steel and they came up with nothing before Kevlar. It doesn't matter what sort of glue you use, linen simply doesn't have the required tensile strength. Flax has a maximum of 1500 MPa (usually a lot less) while Aramid is over 3000 MPa and is a lot more elastic as well. Silk is stronger than flax but it loses tensile strength when exposed to water, sunlight, or impact and so could only be worn a handul of times before its protective capacity is compromised.
Ok so 70 joules for glued linen is fantasy.
Dan Howard wrote:
5. They overbuild their reconstruction. If they really wanted to reproduce Hellenistic linen armour then they should not have made it so thick that it was completely arrowproof. Pausanias said that linen armour was better for hunting because it was susceptible to a strong weapon thrust, and Alexander was almost killed by an arrow that punched through his armour. We know that linen armour can be made arrowproof; there were European examples with as much as 30 layers in their construction, but the linen armour described in Greek texts seems to have been a lot lighter.


According to the Aldrete and company, 11.5-12.25mm of their glued linen armor requires 65-75 J to defeat with a iron or bronze arrowhead. A modern hunting arrowhead of hardened steel requires much less, perhaps as little as 30-40 J. That's far from completely arrowproof. Even an 80lb composite bow with a heavy arrow might easily manage 80+ J up close.

Also, this test suggests that making linen arrowproof may have been difficult.


Last edited by Benjamin H. Abbott on Sun 21 Jun, 2015 5:45 am; edited 1 time in total
Alexis Bataille wrote:
Ok so 70 joules for glued linen is fantasy.

Only because of the low weight they give. One would expect their construction to be heavier. As I said, thirty layers of linen wasn't unheard of in later times and something that substantial would likely need even more than 70J to penetrate.
Benjamin H. Abbott wrote:
Dan Howard wrote:
5. They overbuild their reconstruction. If they really wanted to reproduce Hellenistic linen armour then they should not have made it so thick that it was completely arrowproof. Pausanias said that linen armour was better for hunting because it was susceptible to a strong weapon thrust, and Alexander was almost killed by an arrow that punched through his armour. We know that linen armour can be made arrowproof; there were European examples with as much as 30 layers in their construction, but the linen armour described in Greek texts seems to have been a lot lighter.


According to the Aldrete and company, 11.5-12.25mm of their glued linen armor requires 65-75 J to defeat with a iron or bronze arrowhead. A modern hunting arrowhead of hardened steel requires much less, perhaps as little as 30-40 J. That's far from completely arrowproof. Even an 80lb composite bow with a heavy arrow might easily manage 80+ J up close.

Good point. I'll remove that section from my response in the future.
Does anyone actually know of a primary source describing textile armor as being "proof"?

I heard the term: "proof" being used for Milanese armor but I don't recall some sort of quality rating being used for anything other than metal armor. At any rate it does seem like quilted linen might better be referred to as arrow resistant.
Anything can be made arrowproof or even bulletproof if you make it thick and heavy enough but there is a point at which a material becomes too thick or cumbersome to be practical.
Pieter B. wrote:
Does anyone actually know of a primary source describing textile armor as being "proof"?

I heard the term: "proof" being used for Milanese armor but I don't recall some sort of quality rating being used for anything other than metal armor. At any rate it does seem like quilted linen might better be referred to as arrow resistant.


I suspect one would have to find original armourers' advertising to know if they practiced truth in advertising or engaged in "mere puffery"...
Dan Howard wrote:
Alexis Bataille wrote:
Ok so 70 joules for glued linen is fantasy.

Only because of the low weight they give. One would expect their construction to be heavier. As I said, thirty layers of linen wasn't unheard of in later times and something that substantial would likely need even more than 70J to penetrate.


in David Jones experiment a 80 lb bow (65 ich joules ?) pierce 40 layers of linen (365 grams*m- each layer) by 254 mm with a large arrowhead.
And big 150 lb bow get 64 J at maximum range.
If you mix leather and linen for the same weight you get only 38,5 mm of penetration (still large arrowhead)
That seems very poor protection against warbow arrows ...
At this deep of penetration i don't know the average chance of survive (infection included).
Perhaps medieval linen protection was mostly used for the melee protection instead of arrow protection.
Well it can do both :] but 4 cm of penetration at only 65 joules it can be easily deadly i guess.
You can't just pile a bunch of handkerchiefs on top of each other and call it armour. This construction gets its strength from the quilting - very dense quilting involving a great deal of labour. I have yet to see anyone bother to quilt their test pieces the same as historical textile armour. I have yet to see anyone involved in these tests even bother to examine these armours to see how they were made. The last time we discussed this was only a couple of weeks ago.
http://www.myArmoury.com/talk/viewtopic.php?t=32076

Edit: If you want a modern example then take a look at the arm guards on good quality kendo armour. This is the density of quilting that is required to make armour.


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kendo-kote_02.jpg

Nice, So in David jones experiments the linen protection is not optimal, can be better. Perhaps 30 layers of stiched linen was just enought to prevent bad wounds from long range warbow shot.
Depends on the type of cloth. 30 layers of the linen used to make quality tablecloths would be completely proof against longbows if they were quilted like the above kote.
Ok, in David jones tests 30 layers can barely take 30 j with a broad arrow
With heavy quilting can we say same material can take like 65+ J before failure ?
Sorry to be so picky i just need to be sure :p
Thank a lot again !
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