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Dan Howard
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Posted: Sun 13 Apr, 2014 6:18 am Post subject: |
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Buff coats weigh 20-25 lbs. Williams reckons that it takes 30J for a bodkin to punch through his test piece of buff leather. So you'd need to wear four of these (80-100 lbs) to get the same protection as his mail and padding combination (which required 120 J to be fully compromised).
Author: Bronze Age Military Equipment, Pen and Sword Books
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Mart Shearer
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Posted: Sun 13 Apr, 2014 8:50 am Post subject: |
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Dan Howard wrote: | The thickness of the wire is less important than the ratio of wire thickness to link diameter. The higher the ratio, the denser the weave. |
Whether the aspect ratio is more important than the thickness would seem to be dependent upon the number of thrusts or penetrations vs. cutting attacks. Thicker wire should offer better resistance to cuts while denser weaves should offer better protection against penetration. Flattened rings give an artificially higher aspect ration without raising the weight by using thicker wire.
ferrum ferro acuitur et homo exacuit faciem amici sui
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Dan Howard
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Posted: Sun 13 Apr, 2014 2:31 pm Post subject: |
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Mart Shearer wrote: | Dan Howard wrote: | The thickness of the wire is less important than the ratio of wire thickness to link diameter. The higher the ratio, the denser the weave. |
Whether the aspect ratio is more important than the thickness would seem to be dependent upon the number of thrusts or penetrations vs. cutting attacks. Thicker wire should offer better resistance to cuts while denser weaves should offer better protection against penetration. Flattened rings give an artificially higher aspect ration without raising the weight by using thicker wire. |
True. That's one of the problems with modern Indian-made mail. The links are hammered way too flat. If you knew the wire diameter before the links were flattened you could still use [thickness:ID] ratio as a way to estimate its strength.
Author: Bronze Age Military Equipment, Pen and Sword Books
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Mart Shearer
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Posted: Sun 13 Apr, 2014 2:56 pm Post subject: |
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That should be calculable with a micrometer and sample of Indian mail. Presuming the ring has a basically rectangular section, area of a rectangle and circle being simple to determine for comparison. I suppose there is also some tendency for flattened rings to fold across their section. Wallace A2 rings having a flat front and rounded back D-section IIRC.
ferrum ferro acuitur et homo exacuit faciem amici sui
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Karl Randall
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Posted: Sun 13 Apr, 2014 3:00 pm Post subject: |
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Forgive me for the side question, but I have noticed a number of people quoting "Williams" in the discussion with regard to leather armor testing.
What is the title of his work, and where can I get it, please?
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Dan Howard
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Mart Shearer
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Posted: Sun 13 Apr, 2014 5:26 pm Post subject: |
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Dr. Williams' examination of the metallurgy of medieval mail also included one presumed Roman example. He doesn't state hardness in VPH for Sample 1, but it is presumably the same mentioned for wrought iron in the preface of 80 kg.mm^-2.
http://www.themailresearchsociety.erikds.com/pdf/tmrs_pdf_6.pdf
ferrum ferro acuitur et homo exacuit faciem amici sui
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Jaroslav Jakubov
Location: Slovakia Joined: 26 Aug 2008
Posts: 48
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Dan Howard
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Posted: Mon 14 Apr, 2014 1:36 pm Post subject: |
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Just because a plate was partially penetrated or a couple of links were broken doesn't mean that the wearer was injured. Williams says this himself. The whole point of armour was to absorb as much of the weapon's energy as possible. Part of that involves distorting or even breaking the armouring material. Williams believed that the wearer wouldn't have been seriously injured wearing the mail and padding combination until 120J with a bodkin and 140J-200J with the lance.
Author: Bronze Age Military Equipment, Pen and Sword Books
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Dan Howard
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Posted: Mon 14 Apr, 2014 2:07 pm Post subject: |
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This is the exact quote from Williams, pp. 942-943.
"Some modern (mild steel) mail, backed by a quilted jack, was tested. A piece of 15th century mail was also tested. This was made of a low-carbon steel hardened by quenching. The performance was closely similar but slightly inferior.
[Table of results]
"(a) with a simulated halberd (40mm blade); at 200 J impact, one link was broken, and three dented. So the mail was damaged by no means defeated.
(b) with a simulated lance head (60 deg point); at 200 J impact, two links were broken. So again the mail was damaged but by no means defeated.
(c) with a simulated bodkin arrowhead (18 deg point)l at 80 J two links were broken; at 100 J, in addition, the jack was holed completely. At 120 J the mail was completely defeated. that is. two links were opened out, three others bent, a 5mm diameter hole put through the jack, and a 35mm dent in the plastilene behind.
(d) A bullet with an impact energy of 400 J defeated this mail.
A piece of 15th C mail was also tested. This consisted of a piece known to have been made of low-carbon steel hardened by quenching, and 17 x 22 cm in size.
(a) the simulated blade, an impact energy of 170 J defeated the mail completely. Two links were broken, two more were opened out, and five bent. The jack was completely penetrated.
(b) Simulated lance head: an impact energy of 140 J defeated mail completely. Three links were broken, two more opened out, and one bent. The jack was completely penetrated.
(c) Simulated arrow:L an impact energy of 120 J broke two links and completely penetrated the jack."
Further down Williams describes two different types of padding and is unclear which was used behind the mail. One was a jack made of 26 layers of linen, which he says was used in the test, but the other was 16 layers of layered linen which he specifically says was made "to simulate that under armour".
I've always assumed that he used the 16-layered padding under the mail because he never tests it by itself and would not have mentioned it at all if it wasn't involved in the metal armour tests, but I could be wrong. A letter to the author might clarify matters.
In any case, even at the worst interpretation, the mail resisted more than thee times as much energy as cuirbouilli.
Author: Bronze Age Military Equipment, Pen and Sword Books
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Raman A
Location: United States Joined: 25 Aug 2011
Posts: 148
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Posted: Mon 14 Apr, 2014 7:09 pm Post subject: |
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I don't mean to go too off topic, but what's the most affordable way to get a copy of Williams? I read it back in college but I don't have access to it anymore, and I'd really like my own copy to reference.
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Karl Randall
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Posted: Tue 15 Apr, 2014 4:25 am Post subject: |
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While I cannot condone copyright violations, at one point I have seen a copy on ebookee.org
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