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Bolts retain energy better down range where an arrow sheads it much faster.


Even at extreme range, a heavy longbow arrow will have around 67% of its initial kinetic energy. How much more will a crossbow bolt have?

Some authors say crossbow bolts are prone to losing speed. W. L. Rodgers, for example, wrote, "Many offer great resistance to air." He also didn't think a 1,640 lb crossbow could shoot a five-ounce bolt faster than 160 fps. That's about 169 J. More punch than your average longbow shot, sure, but not vastly more.

Quote:
Also remember a crossbow can fire a much heavier missle then a bow could.


Longbow arrows could weigh over four ounces. I've heard of five-ounce bolts, but never much more than that.

Quote:
Steel bolts were used back then - this becomes a pure armor piercing round much like a 50 cal.


I'm not really sold on the idea of crossbows as armor piercers, at least not in the 16th century and on. I'm sure they hit at least a little harder than longbows, and could pierce some armor, but they weren't guns. Supposedly Fourquevaux considered both the longbow and the crossbow only effective against unarmored targets. I've read a fair bit of 16th century military history. I don't remember any battle or siege in which crossbows were very potent (except in the New World, but that's a whole different story). I don't remember any accounts of bolts blowing through armor.
By the 16th Century I don't think any really heavy siege crossbows would be worth using even IF they were good at piercing armour as it would make more sense to just use a heavy musket or wallgun sized musket with more effect.

One question I had about bows and crossbows is what kind of target can one use with a full power longbow or one of those 450 pound crossbows ? It would be embarrassing to have a bolt blow through a regular archery target back stop and end up a few inches into the concrete wall behind ! :eek:

The kind and thickness of backstop needed for safe use with a long bow compared to what is needed with the above heavy crossbows should give us an idea as to comparative penetrative power ? ( Maybe not armour piercing ??? )

If a crossbow bolt needs a lot thicker backstop for safe use it should tell us something about comparative potential armour piercing potential.

From doing a bit of archery with an 80 pound recurve bow some years back, I do remember that pulling arrows out of the target was not always easy with arrows close to halfway the length of arrow embedded in the backstop: With very heavy crossbows and with expensive bolts, that one would want to re-use with as little damage as possible, I wonder what target backstop would work ? Too soft the bolt would just disappear into it and too hard, very difficult to remove ?
David Ruff wrote:
[
FYI, on the big 1700lb crossbow i am making - it will fire 3/8" steel rods fletched with leather and a bodkin tip ground into the front. Steel bolts were used back then


Can anyone be so good as to provide photos of an antique all steel crossbow bolt?[/b]
George Hill wrote:
David Ruff wrote:
[
FYI, on the big 1700lb crossbow i am making - it will fire 3/8" steel rods fletched with leather and a bodkin tip ground into the front. Steel bolts were used back then


Can anyone be so good as to provide photos of an antique all steel crossbow bolt?[/b]



Will get to the forge and look in the reference books we have there, i remember hearing a story about them. Not that it applies to heavy bows, the assassins crossbow used a steel dart as well.



David
there were a similar discussion on the Fire Stryker forum last year.

http://www.wolfeargent.com/cgi-bin/ultimatebb...p;t=000332

The conclusions are quite differents...
Marc-Antoine Jean wrote:
there were a similar discussion on the Fire Stryker forum last year.

http://www.wolfeargent.com/cgi-bin/ultimatebb...p;t=000332

The conclusions are quite differents...



There seems to be question in what is safe for what and at what poundage. My experiance is like this:


0 - 150lbs - hand span
0 - 300lbs - belthook
150 - 450lbs goatsfoot
400 - 850lb windlass (depends on pully numbers used
600 - 3300lbs - crank

I say 3300lbs as this is the strongest crossbow i know of that is being built and used. I believe that crossbows of this strength exsisted in period as well but were VERY rare to ever see/face.



As far as composite prods go......


I make fiberglass composites, one type is fiberglass lay up and these i make to 170lbs. The other is laminate made exactly like a modern hand bow. These prods are "safe" until about 300lbs and then the stresses start blowing things up. It also should be noted that due to modern materials and the increased speed of the laminates a 300lb prod is about the power of a 500lb steel as far as impact and range.

I have done period composite prods to about 200lbs. They start getting very finicky after that and i have NEVER had a success over 300lbs - I.E. the two i tried blew apart. That doesn't mean they didn't do them - lord knows the masters have thier secrets. But im not sure i EVER saw a windlass type composite crossbow. I have seen tons of belt hook and goatsfoot types in collections.

I am planning a composite for a Ulrich V Duke of wuttenburg bow soon.... awaiting the ivory to come in. This bow used a composite horn bow with a goatsfoot. Prolly in the area of around 200 to 300lbs judging by the mass of the original.

This to me suggests that they did not exsist over 300 to 400lbs Most likely for a very good reason.



David
Ok ok....are you sure you are right about the pounds of your crossbows? We have here a 500 lbs crossbow and it is just simply impossible to charge it with a goatsfoot... Teste were made with quite heavy bolts in a real breastplate and the bolt never passed completly through the armour,,,with 500lbs of pressure...
I think there are aome pictures on the web about those tests.
Do not take all you see on the web as reality...there are a lot of speculators on that subjetcs.
the speed of a bolt is not the only factor of the power of a shot.
the force equals the weight multiplicated by the acceleration. A bolt can go slower but if its weight is high it should cause more damage than a faster one wich goes faster. So, the distance traveled by a bolt is not that important to know the power of the weapon...
And more! You don't really want your bolts to pass through 10 men at ams. First, you want to recuperate your bolt. Secundo, the bolt will do more damage on a person if it stays on the body. if the bolt pass, the wound will be quite light (not really more than 1 or 2 cm. But if it stays in the person it will be cumbersome and the injury will often be much bigger. The difference is the same as the difference of a slicing wound causing by a sword or a wound caused by the impact of the blade on a member., or the difference between a full metal jacket bullet or a full lead one...

So for now it think there is no use of saying more about that... it is time to experiment, see pictures of crossbow tests, videos should be better!

my two cents
Can somebody explain exactly how to properly test the pull strength / power of a crossbow? I would also appreciate sending any links to 'net sites with a suggestion of the measuring tool needed so I don't have to search myself and then make a mistaken purchase.

Thank you.
you test the power (in pounds) of a medieval crossbow exactly the same way you should do with a modern one. It is exactly the same as a bow Usually the required equipment to do so is available in any good archery club... It is simply the pressure needed to a rope to get the total draw (mostly aroune 7-8 inches for a crossbow or 28 inches for a bow). SO for a crossbow with a power of 100 lbs you will have to apply a strenght of 100 lbs to charge it.
The difference between the bow is also simple. A 100lbs crossbow will have mostly a draw of 7-8 inches as I said before. That means that the acceleration of the bolt will be really short, the bolt will take acceleration just in those 7-8 inches. For a bow the draw is almost around 28 inches sont the arrow will accelerate in those 28 inches, that is longer than 8 ''. SO with a bow, to get the same "range" or "power" than a crossbow you don,t need that much pressure. For example, with a modern hunting bow 60lbs is really enough to go deer hunting.
SO for now if you plan to purchase a crossbow all you have to do is deal with someone who knows those basic principles...I think there is Dabek in Canada who has made some great ones. But, I absolutely do not know how to contact him.
Couple things to cover here.


Power in crossbows:

Yes i am sure of the weight, a properly made goats foot is a 3:1 to 5:1 lever. These can span upto 450lbs and i have seen 500lbs spanned with them. Altho when making them from 1/4" steel i would keep it at 450lbs max. I am not sure what the breaking load is of the joints of the goatsfoot is - never had one break - not sure i want to break one while spanning a heavy bow. The angles of the fingers of the bow have to be correct for the bow and you have to have a handle on it - thats where the advantage comes in, the longer - the more advantage - however you balance the lenght vs bending it at load. Mine are around 12 to 18" load. You can feel a difference when spanning at 1/2" handle and at top of handle.


500lbs with a bodkin should put you striaght thru armor - no questions. It is my understanding armor was in the 18 to 14 guage thickness in period. My 450lb will put a bolt thru a plate of 12gu and follow it thru a piece of 18gu behind it at 60 yards. Remember that 60 yards is just at point blank range for a war crossbow and 450lbs is not really a war weight. Its more of a heavy hunting weight. Now this also is a test without a human body inside the armor. I would imagine ribs, back bone and muscle would make a difference in a pass thru shot.

You have to remember - a tapered bolt with a bodkin only had to penitrate 4", once the wide part of the bodkin punched the rest of the bolt (being smaller) was of no concern. The bodkin itself is designed to be a chisle and it cuts VERY effectively.

also tips for the most part were not fastened to the missle, except with tar or the like. The bolt hit and many times the wood bolt stopped when it hit and the tip kept going.


Pass thru vs sticking:

I have to disagree on sticking a person vs a pass thru. You DO want to blow thru several people. First, a pass thru creates two wounds that are going to bleed out fast. The channel has nothing in it (bolt) to stop blood loss.

Also as in modern military its better to wound one as it takes 2 to drag that one off and away. You want a pass thru in hopes you get another person. The screaming and such creates fear ect - cuase disarray and panic and you start losing your fighting force.

Now in the case of sticking someone - yes (depending on the tip used) the bolt inside the body will cuase pain and such, if using a swallowtail or a sinew twister it will cuase more cutting as the body moves, this will cuase internal damage, bleeding and death. But i think all will agree the point then was to kill as many as possible in a short amount of time with as little resource as possible. So the thinking would be to fire and blow a hole thru 2 or more poeple. Also you have to understand the crossbow fired bodkins - armor piercing tips that were ment to pierce armor - NOT cuase massive internal bleeding. A bolt that hit your - went through you and hit someone else was going to kill you - regardless. This is due to the infection and lack of medical expertise. So as the reciever of the bolt - you hoped it killed you instantly.


Getting the bolt back -

Was never a concern, bolts are fire and forget. If you got them back - great. But they knew that they were not going to get them back. First - off a crossbow (anything over 100lbs) your gonna bury them into grass, mud, dirt, ect. When they fired them off of the heavies, they shattered, they blew through things and they buried into dirt, grass and the like. You were not going to find them. The smae holds true to these heavy modern reproductions - your lucky if you find the bolt. Now, as i said before - if your firing target tips you can get the bolts back using loose pack plastic bags in a sack. But fire bodkins - and your gonna chase bolts and bury them.

Arrows were the same way - they did not fasten tips to the arrows very well. The tip was designed to come loose in the body. However arrows being longer could be recovered after a battle. Look at the referances in history explaining how a battle field looked after the battle "like a field of snow"



I have a video on my sight from last year using a 150lb crossbow (modern prod) that i made. I fired it against a piece of 1" plywood at 60 yards or so. The bolt can be heard striking and it sunk sum 11" into the board using a modern target point. Later tat year i used a bodkin - just to see what it would do. We stopped at 3 boards as we ran out of bodkins. In other words the bodkin makes a HUGE difference in blowing holes through things.




Now lastly, i do not claim to be right about everything crossbows, infact i am learning everyday. But i do know what i have done with them, and continue to do when i build new ones. At the end of the year i will sit with historians and better learn what they did in period and hopeful temper my learning with fact of an age we all love and want to learn about. In time i will post more videos of stronger bows we are building and see what those can and can not do. So long paragraph short - i welcome ideas and experiances that are not mine as again i am merely a student learning all i can about a weapon i love.



David
Quote:
500lbs with a bodkin should put you striaght thru armor - no questions. It is my understanding armor was in the 18 to 14 guage thickness in period. My 450lb will put a bolt thru a plate of 12gu and follow it thru a piece of 18gu behind it at 60 yards. Remember that 60 yards is just at point blank range for a war crossbow and 450lbs is not really a war weight. Its more of a heavy hunting weight. Now this also is a test without a human body inside the armor. I would imagine ribs, back bone and muscle would make a difference in a pass thru shot.


Have you actually made tests with real armour? most modern replica-armour is made from untempered mild-steel, a test with such a breastplate shows nothing. If we trust Dr. Alan Williams plate-armour was "bolt-proof".
( http://www.rdg.ac.uk/engin/home/material/ancient/AW_poster.jpg ). It was even proof against early firearms which had much more power.
I've seen a mail-shirt that was pierced by a a bolt that went straight through the body ( http://www.hermann-historica.de/auktion/hhm50...b=A-50.txt ), but plate-armour is in a completely different league.
Wolfgang Armbruster wrote:
Quote:
500lbs with a bodkin should put you striaght thru armor - no questions. It is my understanding armor was in the 18 to 14 guage thickness in period. My 450lb will put a bolt thru a plate of 12gu and follow it thru a piece of 18gu behind it at 60 yards. Remember that 60 yards is just at point blank range for a war crossbow and 450lbs is not really a war weight. Its more of a heavy hunting weight. Now this also is a test without a human body inside the armor. I would imagine ribs, back bone and muscle would make a difference in a pass thru shot.


Have you actually made tests with real armour? most modern replica-armour is made from untempered mild-steel, a test with such a breastplate shows nothing. If we trust Dr. Alan Williams plate-armour was "bolt-proof".
( http://www.rdg.ac.uk/engin/home/material/ancient/AW_poster.jpg ). It was even proof against early firearms which had much more power.
I've seen a mail-shirt that was pierced by a a bolt that went straight through the body ( http://www.hermann-historica.de/auktion/hhm50...b=A-50.txt ), but plate-armour is in a completely different league.




The short answer is no. I have always shot at mild steel. Our forge makes period type armor from carbon steel ect and that is on the to do list with this 1700lb we are making vs a breast plate made from tempered steel at 80 yards. Thats the one we are going to video.


David
So perhaps it would be best to refrain from making unfounded claims on how effective your crossbows are against historical armour. There is more than enough misinformation around already. What is your definition of "tempered". Perhaps you mean "quench hardened"? If you are using modern steel and modern manufacturing techniques then the test will still be invalid. What are you using as a backing? If you are not using a decent fascimile of an aming doublet then the test will be invalid. Does your target move like a human or will it be rigid/immobile? It seems to me that most ofthe "back yard" tests I've seen considerably bias the experiment to produce results that favour the weapon.
Lets say we do a test with the best armour piercing steel stock we can currently make and a crossbow bolt from a heavy 1700 crossbow sails through it as if it was tissue paper !? We could still say that the test is invalid because period plate was somehow a whole order of magnitude better than what we can make today !

If the said target stop the bolt easily then we know that stopping such a bolt is at least credible and period plate may have been at least as good as our modern example.

In the middle ground were some bolt penetrate marginally or bounce off a high percentage of the time then the test conditions can have a great impact on the results and all the historical materials / gambison / human body mass etc ..... can completely change the results.

Lets say at a ridiculous extreme we find that a case hardened plate 1/4" thick backed up with a 1/4" soft steel plate is at least seriously dented or even pierced by a maximum power crossbow, it is at least reasonable to have doubts about a 3 or 4 mm thick breast plate being proof against all crossbows. ( We could decrease thickness of plate until the bolt does pierce the target, and work from there our conclusions )

Since there is a lot of historical evidence that some breast plate were proof against crossbows and even fullpower muskets finding the upper limits of this proofing might finally answer some questions. :confused:

Oh, and if the best period plate was proof against a heavy siege crossbow it doesn't mean that all breast plates would be proof ! Why bother with proofing plate if all plate could easily stop all arrows or bolts.

O.K. I'll admit that I may be being argumentative here and not offering any proof beyond some thought experiments, but I am wary of any dogmatic statements that, even if they must be considered seriously, shouldn't stifle debate or disagreement.
Shooting at someone whos wears a full plate armour with a crossbow, even if it has a power of 500lbs is exactly like shooting a deer in modern hunting...you have to shot it at the very good place...
A great breast plate is blolt proof. L'Archevêque made a mild steel breastplate that was quite bolt proof, we've shot on it, we call that experimental archeology, to better what we are talking about...
You should share with us pictires of your tests. Pictures (better than those you have) of the crossbows, pictures of the metal pieces you will shoot at (wich shows thickness, etc...) pictures of the bols. etc...
We ask nothing more than agree with you, if you have proofs of what you say, because actually most of the archeological sources are goin' at a far other side...
[ Linked Image ]

The Harness of emperor Maximilian I. .......seems like someone tried to shoot him down several times with a crossbow. Yet nothing but little dents in the breastplate *g*
Marc-Antoine Jean wrote:
Shooting at someone whos wears a full plate armour with a crossbow, even if it has a power of 500lbs is exactly like shooting a deer in modern hunting...you have to shot it at the very good place...
A great breast plate is blolt proof. L'Archevêque made a mild steel breastplate that was quite bolt proof, we've shot on it, we call that experimental archeology, to better what we are talking about...
You should share with us pictires of your tests. Pictures (better than those you have) of the crossbows, pictures of the metal pieces you will shoot at (wich shows thickness, etc...) pictures of the bols. etc...
We ask nothing more than agree with you, if you have proofs of what you say, because actually most of the archeological sources are goin' at a far other side...


Marc-antoine;

When you do a test like you mentioned against a breast plate with a 500 pound crossbow and the breast plate stops the bolt you have extremely good evidence that a good breast plate can do this: Evidence to the contrary is difficult to accept if you have witnessed the results with your own eyes ! And the obvious conclusion is that something is very different in the test conditions / materials / power when getting very opposite results.

When you have in other tests, David's not mine, interesting results against thick steel plate as he described it does give at least pause to be impressed with what a crossbow bolt will pierce easily ? But I will conceded that we get more questions than answers when we compare these very different results.

By all means some controlled tests using the closest to historical materials and conditions should be done. :D

I'm just taking all this information in but keeping an open mind about it. :D

The difficulty can be if we cannot agree on what conditions are needed to have historically valid test(s).

( Note: I'm just playing Devil's advocate and I have no personal stake / side on what the ultimate answer might be about bolts piercing breast plates or not, so I may argue for or against in response to recent posts. Hopefully, I'm not boring or annoying too many of you guys out there. :eek: :D )
Jean Thibodeau wrote:
When you have in other tests, David's not mine, interesting results against thick steel plate as he described it does give at least pause to be impressed with what a crossbow bolt will pierce easily ?

Just because we call it "mild steel" doesn't mean that it should be classified as steel. It might be asked why one would never make a crossbow prod out of mild steel but breastplates are ok? Why are the projectile heads made from hardened steel but not the breastplate? And 12 gauge is hardly "thick." It would be close to the minimum one would expect in the chest area of a breastplate. Thickness tapers off as one moves out to the edges but these areas are hardly going to receive a direct hit.

How much does this 1700 lb crossbow weigh? Is there any evidence that these were ever actually used on the battlefield or are they siege weapons? If they are siege weapons, how realistic is a range of 80 yards?
Dan Howard wrote:
Jean Thibodeau wrote:
When you have in other tests, David's not mine, interesting results against thick steel plate as he described it does give at least pause to be impressed with what a crossbow bolt will pierce easily ?

Just because we call it "mild steel" doesn't mean that it should be classified as steel. It might be asked why one would never make a crossbow prod out of mild steel but breastplates are ok? Why are the projectile heads made from hardened steel but not the breastplate? And 12 gauge is hardly "thick." It would be close to the minimum one would expect in the chest area of a breastplate. Thickness tapers off as one moves out to the edges but these areas are hardly going to receive a direct hit.

How much does this 1700 lb crossbow weigh? Is there any evidence that these were ever actually used on the battlefield or are they siege weapons? If they are siege weapons, how realistic is a range of 80 yards?


Mild steel is steel: It's just too low in carbon to harden much if any. Then there is carbon steel that would be hardenable but is left in it's soft state. I don't know how these compare to each other in hardness when both are in un-heatreated state.

I assume you are talking of top of the line late hardened breastplate with varying thickness depending on area that was proofed against crossbows that would not be siege weapons and muskets below the size of musket like wall guns.

Well the sides of a breast plate might well receive a bolt at 90° if the crossbowman happened to be shooting from a flanking position or the armoured Knight turned his side to the enemy for some reason at an unfortunate moment for him.

A bolt through thinner arm armour would also be very distracting if we consider the effectiveness of crossbow fire even if the front of a breast plate was completely proof.

My example of thick mild steel doesn't mean that you are incorrect about what a good breastplate would stop, it just means that I wouldn't want to stand behind a mild steel plate being shot at by a powerful crossbow. :eek: :cool:

Oh, and if I had to I would choose a historically proofed breastplate and hope for the best. ;)


Last edited by Jean Thibodeau on Sat 27 May, 2006 9:37 pm; edited 2 times in total
Oh. just to change directions a bit as the discussion risks going around in circles or splitting of hairs ( Some of which is my fault: I enjoy splitting hairs. :p :lol: )

How about power and rate of fire and practicality of Chinese repeating crossbows ?

The little I know about them is that they did exist and that they used a top loaded magazine of un-fletched bolts.

Some form of lever acting I would guess like an attached goats-foots lever serving to cock the crossbow and feed or allow to feed a bolt at each pull. Some built to fire two bolts at each cycle ( Not sure about this least bit. )

To be able to have a rapid rate of fire the draw weight must have been low or the goats-foot leverage good or it would have been too tiring to maintain a high rate of fire.

Might have been a poor weapon in small numbers, but large groups of crossbowman would put a lot of bolts in the air at once. Might have some tactical advantages if supported by other crossbowman with slower but more powerful crossbows.

Other types of repeating crossbows or ballistas were also experimented with I think, but I have only read found a mention of one in one book:

ANCIENT AND MEDIEVAL SIEGE WEAPONS, A fully illustrated guide to siege weapons and tactics,
Konstantine Nossov, THE LYON PRESS © Konstantine Nossov 2005 Pages 143, 144 Construction of an automatic repeating arrow-firer, " polybolos "

Quote: " Dionysius of Alexandria invented a repeating arrow-firer. Bolts were pushed into a vertical magazine and entered the fighting position by means of a revolving drum controlled by a cam. The latter was fixed with string when cocked. A windlass set by a chain transmission in action; the latter spanned the machine, drew the string, sent the arrow from the magazine to the groove, and released the string at the next revolution. As a result, the machine could fire automatically until the bolts ran out ".

A very interesting book that goes in great detail about siege engines with numerous illustrations.
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