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Randall Moffett
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 Posted: Mon 06 Aug, 2007 12:23 pm Post subject: |
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I am not a math or physics but I'd guess that equation your friend gave might not be quite right. Force is equal to mass times acceleration (F=m x a). I think that is one of Newton's law of motion and I think that is what would apply here but anyone is welcome to correct me here. I do not think it comes out the same between the two even with the drag from a larger/heavier projectile.
I think something to consider is that not all mail shirts are the same in wire diamter link internal and external diameter etc. The same goes with arrowheads and bolts in question. Under the right variables your outcome changes.
RPM
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Michael Edelson
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| Posted: Mon 06 Aug, 2007 3:50 pm Post subject: |
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| Randall Moffett wrote: | I am not a math or physics but I'd guess that equation your friend gave might not be quite right. Force is equal to mass times acceleration (F=m x a). I think that is one of Newton's law of motion and I think that is what would apply here but anyone is welcome to correct me here. I do not think it comes out the same between the two even with the drag from a larger/heavier projectile.
I think something to consider is that not all mail shirts are the same in wire diamter link internal and external diameter etc. The same goes with arrowheads and bolts in question. Under the right variables your outcome changes.
RPM |
Hi Randall,
A 150lb bow is suposed to shoot a 1600 grain arrow at about 115fps. I am not the source of these numbers, I got them here or at SFI. The speed of the ligther arrow is supposed to compensate for the momentum of the heavier one....or something like that. 
The Indian import mail I tested with the same bow stopped a 50lb compound bow, same arrow, at 25 yards, but a 70lb bow punched right through. It also only stopped the 50lb 3 out of 4 times.
At 10 feet, the good mail stopped the 50lb bow every time. 10 feet! The import mail did not, though it did rob the arrow of a lot of it's force.
I think someone wearing good quality mail would have been fairly safe on the battlefied, and let's not forget the shield....
New York Historical Fencing Association
www.newyorklongsword.com
Byakkokan Dojo
http://newyorkbattodo.com/
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Randall Moffett
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| Posted: Tue 07 Aug, 2007 11:01 am Post subject: |
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Well you just convinced me not to by the indian riveted shirt I was after... 
Yeah like I said I really am not sure about the mechanics of it but it seems odd still but I could be wrong.
Did the 70 pound bow piece the good mail ever? You were using the round target heads right? Did any of the arrows explode? I am sure against certain arrows a guy in a good mail shirt would be well off on the field. You read the accounts of the crusades and realize the interesting situations that came from it, Richard I bristling like a porcupine because he had so many arrows stuck in his mail and he was fine under it.
Interesting tests. We have been thinking of doing some testing here with some pretty good weight bows but with arrow loops..
RPM
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Michael Edelson
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| Posted: Tue 07 Aug, 2007 11:17 am Post subject: |
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| Randall Moffett wrote: | Well you just convinced me not to by the indian riveted shirt I was after...
Yeah like I said I really am not sure about the mechanics of it but it seems odd still but I could be wrong.
Did the 70 pound bow piece the good mail ever? You were using the round target heads right? Did any of the arrows explode? I am sure against certain arrows a guy in a good mail shirt would be well off on the field. You read the accounts of the crusades and realize the interesting situations that came from it, Richard I bristling like a porcupine because he had so many arrows stuck in his mail and he was fine under it.
Interesting tests. We have been thinking of doing some testing here with some pretty good weight bows but with arrow loops..
RPM |
Randall...by all means buy the Indian mail. They have gotten so much better at it...I have a new hauberk that uses wedge rivets and while the rings are overly flattened in the rivet area (typical of power hammer or other machine work), the riveting itself is excellent. This 20lb hauberk (haubergeon really) might not be as tough as one of Julio's or Erik's super mail, but then it won't cost 4 or 5 grand either.
Yes, the 70lb bow did pierce the mail, but only at 10ft, and yes, I am using those bullet shaped field tips. When it pierced the mail, however, the mail took so much energy from the arrow that the gambeson underneath was barely pierced. In other words, the guy underneath would have been fine, especially if his gambeson was layered instead of padded. None of the arrows were damaged...the mail/gambeson robbed them of life and they sorta jus fell down.
The poleaxe, now that was interesting.
New York Historical Fencing Association
www.newyorklongsword.com
Byakkokan Dojo
http://newyorkbattodo.com/
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Benjamin H. Abbott
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| Posted: Tue 07 Aug, 2007 11:31 am Post subject: |
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| Quote: | | A 150lb bow is suposed to shoot a 1600 grain arrow at about 115fps. |
The initial velocity of a 1663-grain arrow from a 150-lb bow should be around 171 fps. Its kinetic energy is 146 J. These numbers are from The Great Warbow. 115 fps is extremely slow for an arrow.
A 400-grain arrow at 300 fps has 108 J of kinetic energy.
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Michael Edelson
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| Posted: Tue 07 Aug, 2007 11:38 am Post subject: |
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| Benjamin H. Abbott wrote: | | Quote: | | A 150lb bow is suposed to shoot a 1600 grain arrow at about 115fps. |
The initial velocity of a 1663-grain arrow from a 150-lb bow should be around 171 fps. Its kinetic energy is 146 J. These numbers are from The Great Warbow. 115 fps is extremely slow for an arrow.
A 400-grain arrow at 300 fps has 108 J of kinetic energy. |
Thanks!
So that would mean the bow I tested was more than 2/3s as powerful as a 150lb bow, and slightly more powerful than a 100lb bow, which would mean that it is valid for determining how effective the longbow was against mail. After all, 150 is just the top extreme. It is my understanding that weights around 100lbs were the most common.
New York Historical Fencing Association
www.newyorklongsword.com
Byakkokan Dojo
http://newyorkbattodo.com/
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Benjamin H. Abbott
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| Posted: Tue 07 Aug, 2007 2:59 pm Post subject: |
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According to The Great Warbow, 150 pounds was the average draw weight.
Lighter arrows, however, have less kinetic energy. I believe the lightest arrows tested had 111 J when shot from a 150-lb bow.
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Jean Thibodeau
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| Posted: Tue 07 Aug, 2007 3:15 pm Post subject: |
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| Benjamin H. Abbott wrote: | According to The Great Warbow, 150 pounds was the average draw weight.
Lighter arrows, however, have less kinetic energy. I believe the lightest arrows tested had 111 J when shot from a 150-lb bow. |
Maybe you mean " momentum " rather than kinetic energy ?
Some of the kinetic energy is wasted in heat production i.e. friction on impact and the formula for momentum doesn't favour velocity as much as the formula for calculating momentum.
Ke= M x V 2 Mass multiplied by velocity squared.
M= M x V Mass multiplied by velocity
At the velocities of rifle bullets kinetic energies of a 3000/sec. projectile versus a 1000/sec. pistol bullet of fairly light weights sort of favour velocity highly as far as effectiveness on target.
With much lower velocities but much higher masses of arrows momentum might be a bigger factor.
But the actual effect is probably something in between as both Ke and momentum are involved and can't be taken as completely isolated or used as if the other was not important to the results i.e. using just kinetic energy gives a false idea of how effective an arrow should be.
You can easily give up your freedom. You have to fight hard to get it back!
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Robin Smith
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| Posted: Tue 07 Aug, 2007 4:46 pm Post subject: |
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| Michael Edelson wrote: | | Randall Moffett wrote: | Well you just convinced me not to by the indian riveted shirt I was after...
*snip* |
Randall...by all means buy the Indian mail. They have gotten so much better at it...I have a new hauberk that uses wedge rivets and while the rings are overly flattened in the rivet area (typical of power hammer or other machine work), the riveting itself is excellent. This 20lb hauberk (haubergeon really) might not be as tough as one of Julio's or Erik's super mail, but then it won't cost 4 or 5 grand either.
*snip* |
Sorry bout the derail, but I gotta agree with Micheal here. The wedge riveted stuff thats on the markets now is certainly worth the price. Its not on par with Erik's work, but at less than one fifth the price, you get your money's worth. And it's light years ahead of the riveted maille that was on the market a few years ago...
A furore Normannorum libera nos, Domine
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Benjamin H. Abbott
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| Posted: Wed 08 Aug, 2007 6:52 am Post subject: |
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| Quote: | | Maybe you mean " momentum " rather than kinetic energy ? |
No, I mean what I posted. Maybe kinetic energy isn't the best way to judge penetrating power, but it's what Strickland and Hardy use.
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Hugo Voisine
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| Posted: Wed 08 Aug, 2007 11:54 am Post subject: |
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Hi guys,
Pardon me if I disgress further away from the main topic but, can I ask you about what maker (or makers) of wedge riveted mail you are all talking about ?
« Que dites-vous ?... C'est inutile ?... Je le sais !
Mais on ne se bat pas dans l'espoir du succès !
Oh ! non, c'est bien plus beau lorsque c'est inutile ! »
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Mikael Ranelius
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| Posted: Wed 08 Aug, 2007 1:12 pm Post subject: Re: Brigandines Vs Mail |
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| Dan Howard wrote: |
The problem with this is that historical mail was very very rarely made with links this large. Internal diameters were more often closer to 5-6mm. No arrow will penetrate this type of mail unless fired from a very heavy bow at short range. Not that I think that mail is superior to brigandines, except as has been said, for flexibility. |
I would question that. You may be right in that most maille was made with a smaller ID, but I've seen plenty of maille and maille fragments with rings 8-9 and even 10 mm ID. Thin, netlike maille like this is not uncommon
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Dan Howard
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| Posted: Wed 08 Aug, 2007 1:39 pm Post subject: Re: Brigandines Vs Mail |
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| Mikael Ranelius wrote: | | Dan Howard wrote: |
The problem with this is that historical mail was very very rarely made with links this large. Internal diameters were more often closer to 5-6mm. No arrow will penetrate this type of mail unless fired from a very heavy bow at short range. Not that I think that mail is superior to brigandines, except as has been said, for flexibility. |
I would question that. You may be right in that most maille was made with a smaller ID, but I've seen plenty of maille and maille fragments with rings 8-9 and even 10 mm ID. Thin, netlike maille like this is not uncommon |
The problem is five hundred years of corrosion. Links wear during their lifetime also. Virtually all extant samples of mail will have IDs that are larger than when they were initially made.
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Robin Smith
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| Posted: Wed 08 Aug, 2007 3:44 pm Post subject: |
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| Hugo Voisine wrote: | Hi guys,
Pardon me if I disgress further away from the main topic but, can I ask you about what maker (or makers) of wedge riveted mail you are all talking about ? |
In order to avoid further derailing, I replied via PM...
A furore Normannorum libera nos, Domine
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Daniel Hawley
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| Posted: Wed 08 Aug, 2007 4:50 pm Post subject: Re: Brigandines Vs Mail |
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| Dan Howard wrote: | | Daniel Hawley wrote: | Yes arrows will penetrate small links and at long range. The bodkin will force open a link and penetrate with no problem. As for the range, an arrow is least effective at medium range where the arrow is being slowed down by the drag of the air. At longer range because the trajectory is higher the arrow reaches terminal velocity and it's effectiveness increases again.
Daniel |
The maximum velocity an arrow will reach is at the point it leaves the bow. There is no way that an arrow will penetrate any sort of mail at long range, let alone finer typologies. |
I suggest that you read the chapter on arrowheads in "The Secrets Of The English War Bow" by Hugh Soar ISBN 10: 1-59416-025-2 Mark Stretton has done extensive practical tests on this subject, and has found that arrows WILL go through high quality mail. A brig is the best armour for stopping an arrow. His tests were also published in the Glade Magazine when he also did tests on penetration vs distance, and found that long range penetration was as great as short range, but there was a drop over the medium ranges. He also tested how much difference it made to have the armour travelling towards the archer as if it was a mounted knight charging. Very interesting and informative, well worth a read.
Daniel
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Benjamin H. Abbott
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| Posted: Wed 08 Aug, 2007 5:36 pm Post subject: |
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While interesting, Stretton's tests are hardly definitive. He didn't even use any padding with that shirt of mail.
On the other hand, the bow Stretton used for the test wasn't nearly as powerful as Mary Rose replica Simon Stanley shoots. The best it managed was 113.76 J, which is only slightly more energy than the lightest arrow from the Mary Rose replica.
I'm looking at the book now, but I don't see anything about penetration at maximum range. The Great Warbow makes it clear that kinetic energy decreases significantly at maximum range. This should affect penetration.
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Dan Howard
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| Posted: Wed 08 Aug, 2007 6:27 pm Post subject: |
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Stretton did not use "high quality mail". Nor, as Benjamin said, did he bother with any sort of padding. The test was so heavily biased against the armour as to of little use.
The best test so far is the recent one in the RA's Arms and Armour. It has flaws but some of the data can be used.
http://forums.swordforum.com/showthread.php?t=79261
There has yet to be any test against mail that would stand up to scientific scrutiny - Stretton's included.
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Steven H
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| Posted: Wed 08 Aug, 2007 7:17 pm Post subject: |
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Dan Howard, Benjamin Abbott and Daniel Hawley-
In the interest of understanding can you elaborate on the tests Stretton performed?
What was his source of mail?
How was it mounted?
How did he simulate the movement of the knight?
How was range handled? (I ask because the medium range result is quite incongruous to my basic understanding of the laws of physics)
Specifics on the heads he used, especially hardness?
Daniel Hawley-
My greatest difficulty in believing that Mark Strettons test are well set-up is that his results are overwhelmingly contradicted by the historical record of the time. Simply put: why are there so many accounts of large numbers of soldiers surviving large numbers of arrows?
Kunstbruder - Boston area Historical Combat Study
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Randall Moffett
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| Posted: Thu 09 Aug, 2007 10:49 am Post subject: |
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Steven,
I think there are all sorts of explinations of the historical accounts but you'd have to go one by one. I do not believe mail always stopped arrows, there are plenty of accounts that mention this failure to show some percent did defeat the mail. So it is not so simple to just say the historic records do not agree with his testing as they are contradictory in themselves. Some of the things mentioned would vastly alter the results. The quality of mail, link diameter, link thickness, quality of arrowhead, type of arrowhead, distance, draw of bow and many more.
I agree with Dan that most testing seems to be biased but I think it goes in both direction favoring the armour as well. I do not agree with Dan that not one would not pass any scientific scrutiny. That is just to bold and broad a statement for my likings. There are flaws to be sure but I think many have clear merit.
RPM
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Dan Howard
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| Posted: Thu 09 Aug, 2007 3:56 pm Post subject: |
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Actually there is one. The mail tests in the Knight and the Blast Furnace are pretty good. Erik reckons that the mail he supplied for the test was substandard however, and Dr Williams seems to have underestimated the amount of energy a longbow can deliver.
I'm impressed by Julio's mail too. I would be interested in Mr Edelson's results. I fear however, that unless an English warbow is used (c.150 lbs), the results won't tell us much we don't already know.
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This is a standard topic