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Trevor Borden




Location: Phoenix az
Joined: 05 Sep 2013

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PostPosted: Sat 07 Sep, 2013 6:38 pm    Post subject:         Reply with quote

Tod
I just got done with some measurements
the ssaa10 leaf spring is 56in from where the string will sit on the prod
1/2in thick and is tapered. I measured 3 times, my scale only gose up to 550 lbs
@ 1/2 in I got 157lbs
@1in I got 298lbs
so I do not know as much as you do, which is why I am happy that you have chosen to give me you opinion and I do look forward to your advice on other matters but it seems that 300lbs per in is a good guesstimate.


I did shoot the SCA style arbalest ballista today and here is what I got. And I remeasured everything.

47in prod (from where the string sits) 32in backer and a secondary 18in backer
410lbs draw prod with 4in deflation and the string deflation 24in (if that is what its called)
36in long, 12 oz bolt and 48in long 15 oz bolt
both sets averaged out to 125 yards @ 45 dr angle
The problem with the center serving breaking seems to be in the trigger very crude it keeps slapping the string on the stock causing miss fires


is what I would like to get info on is how the strings are being made for the larger bows that have been listed on this forum
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Trevor Borden




Location: Phoenix az
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PostPosted: Sat 07 Sep, 2013 6:40 pm    Post subject:         Reply with quote

https://www.youtube.com/watch?v=rurswz_774Y&feature=youtube_gdata_player

ps that should be an attachment of it shooting
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Jojo Zerach





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PostPosted: Sun 08 Sep, 2013 11:20 am    Post subject:         Reply with quote

I haven't read through most of this thread but I want to ask, what's the point of an 850 pound arbalest if it can barely punch though 1.6 mm thick steel? (Like in the photos on the first page?)
A lot of bows would easily outperform that.
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Jean Henri Chandler




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PostPosted: Thu 26 Sep, 2013 1:52 pm    Post subject:         Reply with quote

Any new tests Todd?

J

System D'Armes Historical European fencing in New Orleans

Essays on Hroarr

Introducing the Codex Guide to the Medieval Baltic
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Dan Howard




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PostPosted: Thu 26 Sep, 2013 2:59 pm    Post subject:         Reply with quote

Jojo Zerach wrote:
I haven't read through most of this thread but I want to ask, what's the point of an 850 pound arbalest if it can barely punch though 1.6 mm thick steel? (Like in the photos on the first page?)
A lot of bows would easily outperform that.

Which bows would those be? Stretton could barely compromise 2mm of low grade munitions plate with a 150 lb warbow at a ridiculously short range. The deepest penetration was 16mm, which would barely be noticed by the wearer. Better quality steel, a longer range, a weaker bow, or some underpadding would have resulted in no penetration at all.

1.2 mm segmentata made from mild steel can easily stop Parthian bows. Even an arbalest merely dents the plates.

Blythe's analysis shows that 1mm of bronze could stop any bow that the Greeks had to face.
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Jojo Zerach





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PostPosted: Thu 26 Sep, 2013 4:57 pm    Post subject:         Reply with quote

Dan Howard wrote:

Which bows would those be? Stretton could barely compromise 2mm of low grade munitions plate with a 150 lb warbow at a ridiculously short range. The deepest penetration was 16mm, which would barely be noticed by the wearer. Better quality steel, a longer range, a weaker bow, or some underpadding would have resulted in no penetration at all.

1.2 mm segmentata made from mild steel can easily stop Parthian bows. Even an arbalest merely dents the plates.

Blythe's analysis shows that 1mm of bronze could stop any bow that the Greeks had to face.

http://www.youtube.com/watch?v=hIUUIc6RBpE
Not a historical arrow, but from 80 yards it punched through steel that is probably 3 times as thick as in the arbelest test.
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Dan Howard




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PostPosted: Thu 26 Sep, 2013 6:30 pm    Post subject:         Reply with quote

You are citing a video from Youtube as evidence. Take minute and think about that.
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Randall Moffett




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PostPosted: Thu 26 Sep, 2013 8:41 pm    Post subject:         Reply with quote

Dan,

I'd still careful with my conclusions with that study.... there are several issues with it as all of them. One was the bow was an older one and should have been tested for draw weight at the start instead of them asking him what the bow was when it was new. I am not sure how much draw is lost over years of use but I suspect it is significant. I have seen with my own eyes him and others do some pretty awful things to 16-14 gauge breastplates. I'd like to know what the key differences were between them. That said the testing did show penetration and that is I think important as we are getting toward realistic expectations. Truth is none of the testing is what it'd need to be to prove anything either way in a definitive way.

I still have ideas on what I'd like and once I get some funding and time I'll have to shoot some ideas to you for your thoughts.

And yes.... youtube may be a poor bit of evidence but that still looks rather remarkable. Guess he should be grateful it did not miss and hit something important.

RPM
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Leo Todeschini
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PostPosted: Fri 27 Sep, 2013 12:56 am    Post subject:         Reply with quote

HI Jean,

Sorry no new tests to date, but I am pursuing a couple of thoughts and will report in due course.

As for that youtube clip, I have looked at the VPA arrows on their site and they use a pretty chunky compound bow (80lb?) at point blank and put one of their arrows through 1" of ply. That fence post is at least 4mm thick mild and I suspect 3/16 = 4.8mm and the shaft hit, penetrated with a round point and the shaft remained intact. There is something going there that we don't know about.

Tod

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Jean Henri Chandler




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PostPosted: Fri 27 Sep, 2013 8:42 am    Post subject:         Reply with quote

Thanks Tod.

Guys if the armor vs. arrows debate grows into the usual intensity maybe it should go on another thread...we are interested in crossbows here specifically.

Speaking of which, does anyone know of any other recent antique / historical / replica crossbow tests, papers, youtube videos, anything?

I have an invitation to a crossbow shooting contest in Augsburg from the late 16th Century, the target was about 2' and the range was 276 Augsburg feet (not sure how long an Augsburg foot is but it's specified on the invitation apparently)

J

System D'Armes Historical European fencing in New Orleans

Essays on Hroarr

Introducing the Codex Guide to the Medieval Baltic
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Bartek Strojek




Location: Poland
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PostPosted: Fri 27 Sep, 2013 10:21 am    Post subject:         Reply with quote

Leo Todeschini wrote:
HI Jean,
As for that youtube clip, I have looked at the VPA arrows on their site and they use a pretty chunky compound bow (80lb?) at point blank and put one of their arrows through 1" of ply. That fence post is at least 4mm thick mild and I suspect 3/16 = 4.8mm and the shaft hit, penetrated with a round point and the shaft remained intact. There is something going there that we don't know about.
Tod


It looks like quality carbon shaft. They tend to be really resistant, when done properly, that's the whole appeal of carbon based materials after all.

I've broken plenty of wooden arrows on stuff, while thin carbon ones take lots, and lots of abuse.
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Jojo Zerach





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PostPosted: Fri 27 Sep, 2013 1:55 pm    Post subject:         Reply with quote

Dan Howard wrote:
You are citing a video from Youtube as evidence. Take minute and think about that.

You can criticize youtube as a source but that still doesn't refute the video.

Randall Moffett wrote:
Dan,
I'd still careful with my conclusions with that study.... there are several issues with it as all of them. One was the bow was an older one and should have been tested for draw weight at the start instead of them asking him what the bow was when it was new. I am not sure how much draw is lost over years of use but I suspect it is significant.
RPM

I seem to remember the bow in that test having a surprisingly low velocity even for its reduced draw weight. Is it possible a well shot bow of a given poundage could have a lower velocity than a new bow of the same materials and draw weight?

Leo Todeschini wrote:
HI Jean,
As for that youtube clip, I have looked at the VPA arrows on their site and they use a pretty chunky compound bow (80lb?) at point blank and put one of their arrows through 1" of ply. That fence post is at least 4mm thick mild and I suspect 3/16 = 4.8mm and the shaft hit, penetrated with a round point and the shaft remained intact. There is something going there that we don't know about.
Tod

3/16" was what I figured too just going by the arrow diameter. I don't know if that was a one-off freak shot or something easily repeatable.
Anyways I didn't mean to derail the thread.
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Dan Howard




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PostPosted: Fri 27 Sep, 2013 2:38 pm    Post subject:         Reply with quote

Jojo Zerach wrote:
Dan Howard wrote:
You are citing a video from Youtube as evidence. Take minute and think about that.

You can criticize youtube as a source but that still doesn't refute the video.

I suppose you believe everything you see on TV too? There are thousands of youtube videos that have turned out to have been staged for the camera. Mythbusters get plenty of ratings demonstrating this.
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Timo Nieminen




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PostPosted: Fri 27 Sep, 2013 5:59 pm    Post subject:         Reply with quote

Jojo Zerach wrote:
Leo Todeschini wrote:

As for that youtube clip, I have looked at the VPA arrows on their site and they use a pretty chunky compound bow (80lb?) at point blank and put one of their arrows through 1" of ply. That fence post is at least 4mm thick mild and I suspect 3/16 = 4.8mm and the shaft hit, penetrated with a round point and the shaft remained intact. There is something going there that we don't know about.

3/16" was what I figured too just going by the arrow diameter. I don't know if that was a one-off freak shot or something easily repeatable.


That's a skinny arrow, but I think 3/16" is about right. The 70# version of that bow can deliver about 120J; if this is the 80# version, then 135-140J.

30J will put the tip of the point through 1mm of iron plate at normal incidence. The usual power of 1.6 scaling would give about 300J to start to penetrate 3/16" iron plate. "There is something going there that we don't know about" sounds about right.

"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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Jean Henri Chandler




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PostPosted: Wed 23 Oct, 2013 9:35 am    Post subject:         Reply with quote

So Ralph Payne-Galway supposedly shot an antique cranequin spanned crossbow 490 yards back in 1903 or whenever it was.

Do any modern replicas approach this kind of range?

G

System D'Armes Historical European fencing in New Orleans

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Jojo Zerach





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PostPosted: Tue 05 Nov, 2013 10:16 am    Post subject:         Reply with quote

Randall Moffett wrote:
Dan,
I'd still careful with my conclusions with that study.... there are several issues with it as all of them. One was the bow was an older one and should have been tested for draw weight at the start instead of them asking him what the bow was when it was new. I am not sure how much draw is lost over years of use but I suspect it is significant. I have seen with my own eyes him and others do some pretty awful things to 16-14 gauge breastplates. I'd like to know what the key differences were between them.


Draw weight by itself is a pretty poor indicator of how well a bow will penetrate, the efficiency of the bow is also important. Just because the 140 pound bow used in this test barely penetrated 2 mm of iron doesn't mean a 90 pound bow couldn't penetrate the same or better.
Looking over the test again, the bow used seems to have averaged from 150 fps (46 m/s) to 162 fps (49.68 m/s) with arrows ranging from 1080 grains to 1342 grains.
Some warbows are able to shoot faster than others, it just depends on the individual characteristics of the bow. A 1000 grain arrow at 178 fps would deliver slightly more energy than the bow used in this test, and might penetrate better.
(In the test article it was mentioned that the bow used pulled 140 pounds, and that it was a well shot bow that had come down from a new draw weight of 160 pounds.)


Last edited by Jojo Zerach on Thu 14 Nov, 2013 10:36 am; edited 5 times in total
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Jojo Zerach





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PostPosted: Tue 05 Nov, 2013 10:27 am    Post subject:         Reply with quote

Jean Henri Chandler wrote:
So Ralph Payne-Galway supposedly shot an antique cranequin spanned crossbow 490 yards back in 1903 or whenever it was.

Do any modern replicas approach this kind of range?

G

Yes, it would be interesting to see how modern replicas compare to this range. Shooting a bolt 490 yards would probably require the bolt to be shot very fast. Maybe the steel used in modern reproductions just doesn't have the right characteristics.
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Leo Todeschini
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PostPosted: Tue 05 Nov, 2013 11:47 am    Post subject:         Reply with quote

I do wonder about the claimed range for Payne-Galwey bow, which working from memory was 440yds with a 1200lb bow.

I am don't know what the bow speed should be to get that range, but Liebel quoted 240-260yds as the expected range; my bows at present shoot around 220-230yds, so perhaps a little under Liebels expected and deliver around 45-47m/s with a 120gram bolt.

The modern quality of a spring steel has been designed specifically as a spring rather than historically when a steel was 'kinda what I want, but I am not certain' so I think we can assume that modern steels are well suited.

The lower the temper temperature the higher the return rate of the bow and so in modern times we err on the side of caution and temper higher to be safe, historically the temperature may have been lower and so the return rate higher, but I am not sure how much higher.

Tod

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Jean Henri Chandler




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PostPosted: Tue 05 Nov, 2013 1:11 pm    Post subject:         Reply with quote

I'm not so certain about that ... the assumption is generally that modern steel is everything that medieval steel was and more, but I've seen some information to challenge that, Peter Jonnsons analysis of sword blade design (the 'sacred geometry' etc.) also points out some interesting details about their metallurgy (high and low carbon steel or wrought iron in different parts of the blade) which are thought-provoking and (for me) put into a very different context some of the test results of medieval swords (though I do not suggest that Peter himself would say that).

I particularly liked his remark that Medieval swords are less like the proverbial 'sharpened crowbar' so often described in academic and popular literature, but rather more like an airplane wing.

Much more recently, there was an analysis of a medieval spearhead by an Italian researcher, which was shown at a lecture in the Swordfish tournament in Gotheburg Sweden last weekend which apparently showed some truly astonishing characteristics. From what I understand this is hopefully going to be published next year it should turn some heads.

I've also read some analysis of medieval armor done during World War II in the context of tank armor design, and of course, we know the results of Dr. Williams analysis.

Based on all of that, and my own obstinate hunch, I am standing by my current theory that while modern steel is very good for making washing machines, rebar, and I-beams, it may not in fact be ideal for making Medieval or other pre-industrial weapons. And some (though not all) of what we think of as flaws in the metallurgy and other design features of many medieval weapons may actually be intentional and quite necessary features.

We also very clearly have another issue with the composite prods. Some researchers have made them but they were not able to retain their strength for more than 2 or 3 shots. I suspect we still have a lot to learn about how these weapons were made. Payne-Gallwey's account does not stand in stark contrast to the historical commentaries, to the contrary.

It's too bad we don't have an Ewart Oakeshott or Alan Williams of crossbows to go out and systematically test a whole lot of them.

J

System D'Armes Historical European fencing in New Orleans

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Fabrice Cognot
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PostPosted: Wed 06 Nov, 2013 12:43 pm    Post subject:         Reply with quote

Jean Henri Chandler wrote:
Much more recently, there was an analysis of a medieval spearhead by an Italian researcher, which was shown at a lecture in the Swordfish tournament in Gotheburg Sweden last weekend which apparently showed some truly astonishing characteristics. From what I understand this is hopefully going to be published next year it should turn some heads.


Hi

Care to say more about this (privately, if you prefer) ?

And I think you're right wen it comes to modern vs ancient iron alloys : what is now asked form them is not what was asked then - and the solutions and answers found differed a lot. One example I mention very often, and which is based on my own experience, is how well ancient iron/steel welds (in a charcoal fire) as compared to modern, so-called "high weldability" steels are. Knowing this, ang knowing how 'easy (all things relative) it was to work with these factors, a lot of doors can be open, or at least hinted at.

PhD in medieval archeology.
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