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Werner Stiegler




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PostPosted: Sun 10 Apr, 2011 12:22 pm    Post subject:         Reply with quote

Kurt Scholz wrote:

http://emedia1.bsb-muenchen.de/han/HISTORYEBO...o=heb02369
mentions from page 73 to page 80 exports of deerskin from Taiwan under Dutch rule in the range of 62,000 per year and Japan as the major customer. Thailand is mentioned as an alternative source for the depleting reservoir of deerskins on Taiwan. The deer in question would be this guy: http://en.wikipedia.org/wiki/File:Cervus_nippon_taioanus.JPG
I think that's a lot of skin exported to Japan, enough to equip an army.
Sure he doesn't look like providing as thick leather as the wild boars native to Japan, but what exactly did the Japanese use for their leather armour?
I do not doubt that the trade did happen, I doubt that they were used to make armour. I would believe that they were used for uniform Happi. Deerskin remained a popular material for these coats, even during the Edo-Periode and it should give a material that's easily decorated with branding irons, aiding mass-production of these uniforms. That's the only reasonable explanation I can come up with, because people usually consider deerskin to be too thin to be any good for armour.

I think there were some folk believes that would usually prevent people not engaged in warfare from wearing those too, so dressing your soldiers with these would clearly mark them as a class appart from common peasants, but that's just speculation on my part.

The image is... I think a locksmith shop's happi made from deerskin.



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Timo Nieminen




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PostPosted: Sun 10 Apr, 2011 2:20 pm    Post subject:         Reply with quote

Larry Bohnham wrote:
Mr. Uchida was describing the whole of Japanese industrial history from first metal use forward.

For some reason you folks seem to think I'm putting the Japanese down, far from it, I think their design solutions to many problems are often unique and ingenious and they have the guts to not be afraid of ideas that come from places other than Japan and incorporate them into what they're doing. Also, you have me at a bit of a disadvantage as I am not familiar with the price and export tables that you refer to. One of the leading documented causes of Japan's military conflict with the Western powers in the late 19th - mid 20th century was directly related to her need to obtain increasing amounts of natural resources from outside her borders to supply her rapidly growing industrialization which speaks to Mr. Uchida's assertions quoted earlier.

Further, if there was an abundance of workable iron ore in Japan during the middle ages, how come they did not develop full plate armour? Their battle space environment was filled with lethal missiles to a far greater extent than the battle space of contemporary Europe, and yet those circumstances which drove Western armourers to develop full plate never seemed to click in Japan, why?


From up-thread, "In the early 1600s, Japanese iron prices were under 10 English pounds per metric ton (steel prices were higher, by a factor of 5-10 times). Late 1600s English iron prices I've seen mostly vary from just over 10 pounds to 18 pounds per ton, depending on quality." This is from East India Company records (Pratt), as cited by Perrin in "Giving up the gun" (Perrin uses this to show how wonderful the Japanese iron industry was - he overstates his case, but his reference is useful.)

As for Japanese plate, "plate" would nicely characterise a lot of breastplates and helmets. Given other Japanese metalwork (like articulated animals), the technological capability was there. Comparing the weight of iron in a typical Japanese armour, and the weight of a complete plate harness, shortage of iron isn't going to stop it.

Various suggestions earlier in the thread, from cultural and climatic, through to economic.

Some further thoughts:

Japanese archery was highly oriented towards armour penetration. The energy in a Japanese war arrow would be as high as the energy in an English war arrow, if not more - the armour penetration would have been just as good. Arms and legs on a plate harness were often not arrowproof to a sufficient level to stop this; breast and helmet were arrowproof. It's possible that the Japanese, just as the Europeans, didn't want to carry sufficient weight on the arms and legs to arrowproof them.

Brigandine performs very well against arrow penetration. The individual plates have some movement, and this allows them to give, helping prevent penetration. (See "Secrets of the English war bow" for some tests.) Results: better penetration resistance for a given thickness; a thickness that would allow arrows to whizz straight through if plate stops or almost stops them instead. Japanese lamellar shoulders and legs (and breasts, throats, etc) might be more arrow resistant than European plate.

The best Japanese lamellar armours used steel-faced lamellae. This would help stop penetration too.

The transition to heavy plate breastplates in Japan looks like it was to resist musket fire, not archery. Since musketry was a major reason for the disappearance of full harness from the European battlefield, it isn't surprising that the Japanese didn't adopt full harness due to musketry (looks like they were content to go with bullet-proof breast and helmet, and lighter limb armour).

Under 200,000 men at Sekigahara, one of the largest battles in pre-modern Japan. How much iron to put them all in full plate? A lot. How much iron was around? Also a lot. (How heavy were the big iron Buddhas of medieval Japan?) But it takes more than just iron; it also takes a lot of gold. From Japanese arms export prices gives by Pratt (as cited in Perrin), a good katana sold for about the cost of 55kg of iron, an inferior katana about the same as 25kg of iron. Armours cost from the equivalent of 60kg of iron up to 120kg of iron. (Prices are posted here.)

"In addition to being efficient, all pole arms were quite nice to look at." - Cherney Berg, A hideous history of weapons, Collier 1963.
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PostPosted: Sun 10 Apr, 2011 2:33 pm    Post subject:         Reply with quote

Timo Nieminen wrote:
Japanese archery was highly oriented towards armour penetration. The energy in a Japanese war arrow would be as high as the energy in an English war arrow, if not more - the armour penetration would have been just as good. Arms and legs on a plate harness were often not arrowproof to a sufficient level to stop this; breast and helmet were arrowproof. It's possible that the Japanese, just as the Europeans, didn't want to carry sufficient weight on the arms and legs to arrowproof them.

The chance of any arrow penetrating any kind of metallic torso armour regardless of whether it is solid plate or lamellar and regardless of whether it is a European or Japanese bow is very low. The vast majority of sources in all cultures talk about arrows penetrating the extremities where armour is lighter, such as arms and legs, or bypassing the armour completely and hittting exposed areas such as the armpit and face. Both a samurai and a knight would be very confident that any arrow that hit his torso would be stopped by his armour.
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PostPosted: Sun 10 Apr, 2011 2:41 pm    Post subject:         Reply with quote

Werner Stiegler wrote:
That's the only reasonable explanation I can come up with, because people usually consider deerskin to be too thin to be any good for armour.

A lot of Japanese plate was covered with leather. It is possible that some of the deerhide was used for this purpose. In any case, even leather-covered plate is still considered metal armour, not leather armour.
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Eric S




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PostPosted: Sun 10 Apr, 2011 9:16 pm    Post subject: Re: How do you defeat Japanese armour?         Reply with quote

Michael Curl wrote:
So this is similar to my japanese weight thread, question is how would one defeat japanese armour of an opponent?


This question can not be answered with out specifying which time period. Before firearms? During the period of firearms use? Or during the Edo period? Armors from these periods were completely different from each other and were built to deal with the conflicts of the times. Different weapons and tactics were used for each of these time periods. Any debate on this subject is meaningless with out knowing which period of time you mean.
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Michael Curl




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PostPosted: Mon 11 Apr, 2011 1:46 pm    Post subject:         Reply with quote

During the sengoku-jida. To be honest I didn't think firearms mattered since it seems that the japanese response was only seen on the do. How did the manj no wa or the kote change in response to firearms.
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Eric S




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PostPosted: Thu 14 Apr, 2011 12:21 am    Post subject:         Reply with quote

Michael Curl wrote:
During the sengoku-jida. To be honest I didn't think firearms mattered since it seems that the japanese response was only seen on the do. How did the manj no wa or the kote change in response to firearms.
For samurai that were in the position to afford such armor both the dou and the kabuto were changed in response to firearms. Something unseen and still not well know was the use of steel plate in conjunction with iron plates in the manufacture of samurai armor. The steel plate stopped projectiles while the iron plate underneath absorbed the shock. Not much research is available for auxiliary armors such as manju no wa, wakibiki and manchira that I know of, pictures of these items are hard enough to find. Layering different types of armor gave the wearer protection against several different weapons and attacks.

I have included a link to an article on the conservation of a samurai manchira from the 1600s and a link to an article from the Royal Armories of Leeds about the use of steel in samurai armor.

Also a picture of a rare manchira with kote, completely lined with small iron plates. Worn underneath a suit of armor this type of armor provided an extra level of protection.


http://docs.google.com/viewer?a=v&q=cache...MKDvxlBDPQ

http://www.royalarmouries.org/what-we-do/rese...ate-armour





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PostPosted: Thu 14 Apr, 2011 1:44 pm    Post subject:         Reply with quote

Wouldn't the addition of such defences make the armour heavier than their european counterparts?

My impression is that the japanese aproach is very perfectionist. Lots of little, specialized details to give maximum performance; Just enough mail to cover the weak spots, flexible Kote sleves, and so on.
In the end, though, it might be a bit "over-engineered". Are all those little pieces THAT much better or lighter than a mail hauberk with a breastplate on top?

The europeans has a more "brute force" approach to armour. Cover EVERYTHING in metal. Sometimes several layers of metal. Which, again, can be a bit over the top when a more optimized suit would give the same battlefield effect with less weight. Late plate armours, like the high gothic or maximillian style probably represents the most optimized of european armours, before they become to heavy to be practical in response to firearms.

I'm not very familiar with japanese heavy infantry doctrine, but their lighter armour would sugest that they to a lesser degree based themself on "tanking it out" in the european 15th c fashion?

"this [fight] looks curious, almost like a game. See, they are looking around them before they fall, to find a dry spot to fall on, or they are falling on their shields. Can you see blood on their cloths and weapons? No. This must be trickery."
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Werner Stiegler




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PostPosted: Thu 14 Apr, 2011 3:37 pm    Post subject:         Reply with quote

According to Anthony J. Bryant's Online Manual, the Kote began their career as bags that held the long sleeves of the kimono, and they're probably not the only part that was born from an interaction of fashion and the needs of mounted warfare, rather than from a 20st century sensibility of efficient and optimized design.
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Lafayette C Curtis




PostPosted: Fri 15 Apr, 2011 10:33 am    Post subject:         Reply with quote

Hugh Knight wrote:
Lafayette C Curtis wrote:
Japanese agriculture might have had something to do with the less extensive coverage of their armour too--a European soldier could have walked clean through a ploughed European field without getting anything but his shoes soggy (and maybe his sabatons a bit clogged with sod), but a Japanese warrior would have had to be wading if he wanted to cross a rice paddy. Slogging through a paddy with a full suit of European plate...well, let's just say that if you could pick up a ton of mud and water in a pair of combat boots (before the advent of ventialted jungle boots) crossing a rice field, just imagine how much you'd accumulate inside a pair of metal shoes, with metal greaves, and all that kind of stuff....

(Not to mention that the Japanese--along with many other East Asians--used to fertilize their fields with human excrement. Try getting that inside your greaves.)


I'm not sure we can really see that as a factor. After all, consider the glutinous mud at Agincourt: It has been cited as a major contributing factor in the exhaustion of the French men at arms because of the way it pulled on them as they marched in full harness across the field.


While I agree that agricultural practices could in no way have been the sole deciding factor, I don't see why it can't be one of several (or many) contributing factors. We know that some Japanese armours were fitted with detachable kusazuri (tassets), which is normally attributed to river-crossing purposes, but i can't help thinking that it might have had something to do with crossing paddy fields too. And that brings up one interesting issue--wet-rice fields aren't just mud. They're artificial marshes. With standing water. And I doubt the Europeans had that, even at Agincourt....

(In any case, wasn't the mention of mud at Agincourt made because it was so unusual for a European battle? I'm not saying that Japanese warriors fought in rice fields all the time, but given the fact that wars were often fought over and on rich agricultural lands then I wager Japanese warriors would have had a hard time avoiding the need to wade into a paddy every now and then!)
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Lafayette C Curtis




PostPosted: Fri 15 Apr, 2011 10:40 am    Post subject:         Reply with quote

Larry Bohnham wrote:
Their battle space environment was filled with lethal missiles to a far greater extent than the battle space of contemporary Europe, and yet those circumstances which drove Western armourers to develop full plate never seemed to click in Japan, why?


"Far greater extent" would be far too great an exaggeration. After all, Europeans had their archers and crossbowmen too. And I believe it has been mentioned before that Japanese bows were optimized for armour penetration at short ranges--the beaten zone in front of a pavise-protected line of Japanese archers wouldn't have been very deep and, while more armour would probably have helped somebody survive the crossing, more speed would have been able to improve their chances just as well.
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Timo Nieminen




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PostPosted: Fri 15 Apr, 2011 2:59 pm    Post subject:         Reply with quote

Speed won't help as much as armour to cross the Japanese "archery zone". Book of Five Rings has 40 paces as the maximum effective range. Ideal range is about 15 metres. If you lighten your armour, you lengthen the effective range, and even if you can move faster, you have further to go. That's without even getting into just how much does armour slow you down.

Steel-faced armour was mentioned above. AFAIK, the use of steel-faced lamellae predates Japanese musketry. Very good for making arrow-proof armour lighter, so there's a good motivation. I don't know if it helps much against musket balls.

"In addition to being efficient, all pole arms were quite nice to look at." - Cherney Berg, A hideous history of weapons, Collier 1963.
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PostPosted: Fri 15 Apr, 2011 9:14 pm    Post subject:         Reply with quote

Timo Nieminen wrote:


Steel-faced armour was mentioned above. AFAIK, the use of steel-faced lamellae predates Japanese musketry. Very good for making arrow-proof armour lighter, so there's a good motivation. I don't know if it helps much against musket balls.


Tameshi armor is samurai armor which was bullet tested before being sold. Usually you will see proof marks on several if not all panels, the proof marks were left in the armor and lacquered over. Of course no one is taking any samurai armor in their personal collection apart to test for the use of steel panels but the tameshi zunari kabuto I own is very heavy compared to a normal zunari and it can reasonably be assumed that steel and iron laminated panels as described in the 1800s book by Sakakibara Kozan were used on these tameshi armors.

''The manufacture of armour and helmets in sixteenth century Japan'' or ''Chukokatchu seisakuben'' Translated by T. Wakameda ; Rev. by A. J. Koop and Hogitaro Indada, 1912 ; Rev. and edited by H. Russell Robinson, 1962.
Publisher London : Holland Press, 1963.

http://books.google.com/books?id=MBvWAAAAMAAJ...CC0Q6AEwAA

Pages 23-27 throughly discuss the different methods and types of iron and steel to be used in samurai armor and both arrow and bullet proofing is mentioned. The lamination and folding of iron and steel plates was know and manipulated in order to produce armor that could repel penetration of both arrows and bullets.

The only thing that is not know on existing armors...which ones were made with steel plate and which ones were not. It is not know is if armor plates on kote, sode, etc were made with steel also, or just the dou and kabuto that got the bullet proof treatment.

Tameshi armor.





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Timo Nieminen




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PostPosted: Sat 16 Apr, 2011 8:15 pm    Post subject:         Reply with quote

Eric S wrote:
Timo Nieminen wrote:


Steel-faced armour was mentioned above. AFAIK, the use of steel-faced lamellae predates Japanese musketry. Very good for making arrow-proof armour lighter, so there's a good motivation. I don't know if it helps much against musket balls.


Tameshi armor is samurai armor which was bullet tested before being sold. Usually you will see proof marks on several if not all panels, the proof marks were left in the armor and lacquered over. Of course no one is taking any samurai armor in their personal collection apart to test for the use of steel panels but the tameshi zunari kabuto I own is very heavy compared to a normal zunari and it can reasonably be assumed that steel and iron laminated panels as described in the 1800s book by Sakakibara Kozan were used on these tameshi armors.


First, I mentioned steel-faced lamellae/kozane in particular, not plate (which you mentioned earlier). I read about these quite a long time ago, and don't have a reference at hand, but, iirc, the source noted the use of broken sword blades for the steel facing. It would have been a secondary source, not a primary source. If you have anything on iron/steel composite lamellae, I'd be interested.

Iron/steel composite construction was known and used (in China as well as Japan) for blades, long before guns saw major use in Japan, so the technology was there to use for armour.

A recent paper (Grazzi et al., Ancient and historic steel in Japan, India and Europe, a non-invasive comparative study using thermal neutron diffraction, currently an online first paper in Anal Bioanal Chem, DOI 10.1007/s00216-011-4854-1) includes an Edo-period "neck protection" piece among their samples - looks like an iron/steel composite.

Second, steel-faced lamellae look like a very good anti-arrow armour. Lamellar armour appears to be better against arrows than plate of the same thickness, from modern testing. A hard face help stop arrowheads from cutting into the armour, the harder the face, the better.

Stopping bullets is a different story. The mechanism of penetration is different, and the energies are enormously greater. Perhaps about 100J for a high-energy arrow, versus over 1000J for a bullet. Using a softer material that will deform further may well stop the bullet better. Hardened steel armour was used in Europe, but the preferred armour for bullet-resistance looks to have been thick wrought iron. Cost might be part of it, but you don't want an armour that will crack and fragment when shot.

Third, if your helmet is very heavy, why assume a steel/iron composite? The advantage of steel/iron composites versus wrought iron is the same protection at a lighter weight. "Very heavy" suggests to me plain iron. Assuming "very heavy" is heavy enough to provide significant bullet protection with plain iron construction.

Certainly the Japanese knew and used iron/steel composites, including in armour, but I wouldn't just assume that bullet-proof(ed) armour is such a composite. Assuming honest proofing, the lightest proofed armours are the most likely to be composite, and the heaviest the least likely. Assuming equal and honest proofing, you only need to destructively sample one armour (or perhaps use neutron or X-ray diffraction), and the depth of the dents will tell the rest, but, alas, I don't believe we can assume equal and honest proofing.

Hardness testing might be good for judging whether or not composite construction was done for arrows or bullets. If we know the carbon content, we have a good idea of the trade-offs for hardness vs toughness. If toughness is significantly sacrificed to gain more hardness, it's probably anti-arrow armour (or anti-spear, anti-sword, etc.). If hardness is kept low to enhance toughness, then perhaps bullets.

(Anyway, nice pics!)

"In addition to being efficient, all pole arms were quite nice to look at." - Cherney Berg, A hideous history of weapons, Collier 1963.
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PostPosted: Sun 17 Apr, 2011 8:09 am    Post subject:         Reply with quote

Timo Nieminen wrote:
Stopping bullets is a different story. The mechanism of penetration is different, and the energies are enormously greater. Perhaps about 100J for a high-energy arrow, versus over 1000J for a bullet. Using a softer material that will deform further may well stop the bullet better. Hardened steel armour was used in Europe, but the preferred armour for bullet-resistance looks to have been thick wrought iron. Cost might be part of it, but you don't want an armour that will crack and fragment when shot.

(Anyway, nice pics!)

The "steel armour was more prone to fracture against bullets" theory is ingenious, but when I tracked down the original article by De Reuck et al. they didn't seem to have any evidence except "European armourers gave up using steel after the late 16th century; hardened steel can be more prone to fracturing; the 1911 Brittannica advises using wrought iron rather than steel against shells." Williams' model suggests that 3-4 mm of medium-carbon unhardened steel would stop arquebus and caliver shot at close range.

It would be nice if their theory were true; are you aware of any better evidence?
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PostPosted: Sun 17 Apr, 2011 3:00 pm    Post subject:         Reply with quote

Sean Manning wrote:
Timo Nieminen wrote:
Stopping bullets is a different story. The mechanism of penetration is different, and the energies are enormously greater. Perhaps about 100J for a high-energy arrow, versus over 1000J for a bullet. Using a softer material that will deform further may well stop the bullet better. Hardened steel armour was used in Europe, but the preferred armour for bullet-resistance looks to have been thick wrought iron. Cost might be part of it, but you don't want an armour that will crack and fragment when shot.

(Anyway, nice pics!)

The "steel armour was more prone to fracture against bullets" theory is ingenious, but when I tracked down the original article by De Reuck et al. they didn't seem to have any evidence except "European armourers gave up using steel after the late 16th century; hardened steel can be more prone to fracturing; the 1911 Brittannica advises using wrought iron rather than steel against shells." Williams' model suggests that 3-4 mm of medium-carbon unhardened steel would stop arquebus and caliver shot at close range.

It would be nice if their theory were true; are you aware of any better evidence?


The effect of toughness on penetration by bullets doesn't appear to be very well known. Atkins, "The science and engineering of cutting", states that much in his review of armour penetration. To avoid penetration, the energy has to be absorbed within the armour, so you want the armour to be able to sustain a large plastic deformation. But you also want a large force before the onset of plastic deformation; the energy will scale as (deformation distance)x(deformation force). Atkins gives some references that might be relevant, but I haven't looked at them. Atkins' summary of the results doesn't lead me to expect any gems.

That a hard face will help stop something hard from cutting through is known. For bullets that are already softer than the armour, less relevant.

Fracturing of hardened steel mail, with unpleasant consequences for the wearer, is known. H. R. Robinson, "Oriental armour", has a brief discussion of this regarding late British-made mail in Egypt and the Sudan.

I don't believe that a thin hard face would hurt at all, provided it has a good, thick, iron backing. Perhaps this just doesn't help enough to make the extra cost worthwhile. By the time the whole thing is thick enough to stop bullets reliably, an arrow isn't going to go through it, so you don't need a hard face to stop arrows.

Addendum: I haven't found anything that looks at the effect of hardness of steel plates on the penetration of soft (e.g., lead) projectiles. The studies on the effect of hardness I found used hard projectiles/penetrators, and usually much thicker steel plates than one would see in a breastplate. However, some of the work appears relevant, even if a little removed from the exact case we'd like to see.

S. Dey et al., "The effect of target strength on the perforation of steel plates using three different projectile nose shapes", International Journal of Impact Engineering 30, 1005-1038 (2004), tests 12mm thick steel plates, of varying hardness and toughness, with hard projectiles with blunt and pointy ends. For pointy ends (conical and ogive), the harder steels were better, while for blunt ends, the harder steels were worse, needing 25% less energy to penetrate.

S. N. Dikshit et al., "The influence of plate hardness on the ballistic penetration of thick steel plates", International Journal of Impact Engineering 16, 293-320 (1995), tested 20mm and 80mm thick plates, of steel of the same composition and different heat treatment, resulting in hardnesses of HV300, HV350, HV440, and HV520. For the 20mm plates, the HV440 performed best, with the HV520 performing similarly to the HV300 at the lower impact velocities they used, and significantly worse than the HV300 at the highest velocity (500m/s).

There's work by Woodward and Crouch (Google Scholar with their names and "penetration" finds various relevant reports) on penetration of laminates. Separation of layers and deformations of the layers away from the impact (i.e., the layers on the far side) absorbs a lot of energy and helps prevent penetration. So you can benefit from laminates even if all the layers are of identical hardness and toughness.

"In addition to being efficient, all pole arms were quite nice to look at." - Cherney Berg, A hideous history of weapons, Collier 1963.


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PostPosted: Sun 17 Apr, 2011 10:15 pm    Post subject:         Reply with quote

There is a lot more European duplex plate than anyone ever suspected until a few years ago. It consisted of two layers of plate of differing hardnesses welded together. It seems that this was the most popular solution to the firearms problem. Other options such as trying to find the ideal heat treatment couldn't be done reliably enough usnig the available technology
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Jean Thibodeau




PostPosted: Mon 18 Apr, 2011 12:16 am    Post subject:         Reply with quote

Dan Howard wrote:
There is a lot more European duplex plate than anyone ever suspected until a few years ago. It consisted of two layers of plate of differing hardnesses welded together. It seems that this was the most popular solution to the firearms problem. Other options such as trying to find the ideal heat treatment couldn't be done reliably enough usnig the available technology


In the era of late 19th century and early 20th century Ironclad and steel battleship armour where a hard surface breaks up a projectile and a more ductile inner layer diffuses the energy.

Of course by this time period quality control of heat treat was less an art than a science but not as much a sure thing as today !

The same science was applied to the projectiles in return in having a hardened armour piercing tip.

If I remember accurately a lot of the British shells of WW I ended up too brittle and shattered rather than penetrate on impact.

A bit off topic of course except that it relates to the same principles. Wink

http://en.wikipedia.org/wiki/Shell_(projectile)#Armor-piercing

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PostPosted: Mon 18 Apr, 2011 2:14 am    Post subject:         Reply with quote

Dan Howard wrote:
There is a lot more European duplex plate than anyone ever suspected until a few years ago. It consisted of two layers of plate of differing hardnesses welded together. It seems that this was the most popular solution to the firearms problem. Other options such as trying to find the ideal heat treatment couldn't be done reliably enough usnig the available technology


Is there some good source other than A. de Reuck et al., "Duplex armour: an unrecognised mode of construction", Arms & Armour 2, 5-26 (2005)? The hardnesses given in de Reuck are on the soft side (compare the duplex plate hardnesses with the harder armours in fig 2), and there are almost as many harder on the inside as are harder on the outside. Also over 1/3 are close to the same hardness on both sides.

From de Reuck's numbers, I'd only go so far as to say "two plates welded or rivetted together". But even if of equal hardness, being duplex (or triplex) will let it deform more when shot, stop cracks from propagating between layers, and absorb energy as the weld breaks. All will help stop a bullet.

I haven't seen a hardness for the Japanese laminated armours. The "neck protection" in Grazzi (cited earlier) is about 0.2% carbon, 95.7% ferrite, 2.7% cementite, 0.9% martensite, similar to the tachi blade in Grazzi (the tachi would also be composite construction), so it's possibly as hard-faced as a sword blade. OTOH, this is an 18th century Edo piece, so not a 16th century battlefield armour.

"In addition to being efficient, all pole arms were quite nice to look at." - Cherney Berg, A hideous history of weapons, Collier 1963.
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Eric S




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PostPosted: Mon 18 Apr, 2011 3:26 am    Post subject:         Reply with quote

At the bottom is an example of the type of armor plates that were used before firearms were introduced in Japan. This dou is made from a large form of small scales, this type of scale is called iyozane. Each scale was punched with holes and and lacquered and then the scales were laced together. This dou looks like the entire outside was also covered with leather and then lacquered. By overlapping the scales, (which would be made from Iron and or leather), an extremely strong strong chest armor was produced, this was a very time consuming and expensive process which used a large amount of individual scales. This type of dou did not use a hinge and the wearer would just pull it open making it a maru dou as opposed to a ni-mai dou which used a hinge to open. The advent of firearms in Japan caused the armor makers to change their armors from small scale armors to large plate armor. It would make sense that at least some scale armors were made with some steel, but I do not know of any research on this subject. This dou was probably made in the 1600s but the scales are large enough to see as an example of scale armor. The Royal armories of Leeds did an examination on Japanese armor plates and found this information.




Quote:
The question

Compared to European armour, a very limited amount of Japanese armour has been examined metallurgically. Documentary sources, such as the text of Sakikabara Kōzan published in 1800, suggest that, particularly with the introduction of firearms in the 16th-century, Japanese armourers went to considerable lengths to increase the protection offered by their armour.

Could metallographic examination of some stray plates donated for scientific analysis, tell us more about the metallurgical quality and effectiveness of Japanese armour?

Results of analysis

This section of armour is of composite construction, comprising an outer face of steel (shown as the dark-etching phase in the micrograph above) and an inner lining of pure iron (the bright phase, ferrite). The steel is distinctly harder and tougher which would help prevent the penetration of projectiles, whilst the softer iron behind is ideal for absorbing the energy of the impact.

The content of slag inclusions is exceedingly low compared with other traditionally produced ironwork and the ferrous plate is protected from corrosion by numerous coats of lacquer.

Significance

This armour has clearly been constructed from two different carefully chosen and skilfully worked materials, such that even with a thickness of about 1mm the armour would provide the best possible level of protection for the wearer.

A piece of cheaper armour, examined at the same time was constructed entirely of soft iron containing many slag inclusions so the quality of armour may be very variable.

Output

The results of this recent research were first made public in a series of talks that accompanied the Royal Armouries Shogun exhibition in 2005. A broader research project looking at the metallurgy of Japanese armour is now planned.

http://www.royalarmouries.org/what-we-do/rese...ate-armour


And some interesting research on European duplex plate armor.

Quote:
The question

During the 16th-century improvements in firearms and gunpowder led to the wearing of fewer, but thicker pieces of armour. In recent years it was realised that some of the surviving breastplates had been made by combining two thinner plates. X-radiography was undertaken to identify makerís stamp marks on the rear plates or those that are obscured by paint or corrosion on the front.

Results of analysis

X-radiography very successfully allowed many makerís marks to be identified so that the date and provenance of the breastplates could be determined. However, the X-radiographs also revealed an entirely unexpected feature. Some of the ďduplexĒ armour contained three breastplates. Others had further scrap iron or even armour, such as a tasset from a pikemanís leg armour, sandwiched between the inner and outer plates.

Significance

In an additional twist it appeared that some duplex armour was not simply cobbled together old armour, but had been newly made that way. Was this to provide more effective protection? A clue to the possible benefits of such armour may be found in 19th-century research into the protection of iron-clad ships. Penetration by the projectile is achieved through the propagation and growth of a crack in the metal. Where two layers are used the interface between the two acts as a barrier to the crack and thereby prevents failure.

Output

Since publication in the Arms and Armour Journal, many more examples of duplex armours have come to light worldwide. It is hoped that recent collaboration with the Technical University of Delft into the impact resistance of armour will be expanded to test the relative merits of single and double layers of armour.

http://www.royalarmouries.org/what-we-do/rese...oof-armour


Iyozane maru dou

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