Longbow VS plate.

[JeffGentry]

Hey Shane

I would like to test this out myself, see how heavy a draw and how far away you would have to be to even penetrate steel, little lone a piece of plate armour, i don't know of anyone who would make a longbow now that would have a draw weight of a hundred pound's or more then you need arrow's made for that kind of draw weight, that might be the easiest part, wonder if any museum's or collector's would be willing to let someone use one of there longbow's to do it, that would be an interesting test though.

Jeff

[Shane Smith]

If we could somehow determine the velocity at which a 100+ pound draw longbow would launch a heavy war-arrow,we could perhaps find a suitable high-performance compound bow that will throw a shaft at the appropriate velocity in spite of draw weight and modernity. Striking velocity and it's chief by-product kinetic energy, are all that is required for this purpose with a proper period-style arrow regardless of how that is achieved...Now, who knows what that velocity may be?Also, what is the air-speed of an unladen European swallow? <img src="/forum/images/icons/grin.gif" alt="" />

[JeffGentry]

I was kind of thinking that too part of the velocity equation is related to the weight of the arrow, blah blah blah so much to consider, the only way i know would be too fire an arrow with one through a chronograph, i don't know of too many compound bow's that will even handle a 100lb draw weight, usualy 60-75 lbs is the max on most compound's doesn't take much to drop deer, bear, elk and such.

Jeff

[Shane Smith]

True enough,but the compound bows often provide much higher velocities than stickbows per pound due to more efficient limb design.I think this is doable in the absolute sense although a period-authentic longbow would be more to the liking of most purists.

[JeffGentry]

Hey Shane

It is very doable all we need to know is the feet per second of a certain weight of arrow(in grain's) and it would probably be pretty easy to replicate with a modern compound and aluminum arrow's or even wood, the weight of wood might be hard to do, aluminum would work though, it definately could be done.


Jeff

[Jaron Bernstein]

Phillip,

What is your email address? I have an inquiry for you.

Regarding the arrow experiment. I don't know of anyone who owns a 120# yew longbow. I DO know many who have 60-70# hunting compounds. Although it wouldn't be a purely historical experiment, it might at least give us some sense if they were to try out their compound against a good period accurate replica armor plate and see what happens...

[Jack Lynn]

You might just want to use a decent fasimile of armor at the same thickness as the play. Doesn't really even have to be wearable except by a side of beef. If you want to use really good armour its ok, but you could save yourself some cash. It would be more accurated to do it with real armor but you mentioned that you would not be using an accurate bow either. I think if your just trying to get a basic idea then you could save a bit of cash on the side. It could even allow you to do more experiments.

[philippewillaume]

here you go mate
willaume@eti.com
just so you know, i am leaving on holliday the 22-XII and com back the 07-I

[Stacy Clifford]

It would have to seriously crush the plate, maille and the gambeson to do you considerable harm and I don't see that happening.

I was specifically referring to the situation Jeff described where the arrow actually did penetrate the breast plate, but the head deformed in the process and didn't go through the gambeson. Even if the force from the penetration is dissipated and doesn't do much damage, suddenly you have a pointy thing jamming into your body underneath your armor which might not be easy to remove, assuming you have a combat-free moment to try. It would be like having a rock in your shoe, only a lot worse.

As for the projectile, if I remember it right, the arrow used on that NOVA program looked like it had a shaft at least a half-inch thick or more. I don't know if that's to withstand the shock of a heavy bow or to do more damage, but it probably doesn't matter. War arrows might have been heavier than we think, so for anybody doing some experimentation, that's worth a bit of research.

[JeanryChandler]

There are some guys who make authentic longbows, I think in the Northwest somewhere.

JR

[JeffGentry]

Hey Stacy


The draw weight and draw length do determine the thickness of the arrow shaft, the shaft of an arrow actualy does flex on release and the heavier the draw weight the thicker the shaft must be to handle the energy transfer and allow the arrow to flex without breaking and straighten out in flight, there are actualy alot of physic's in archery as to how energy transfer's from bow to arrow and the flex of the arrow and even the fletching on an arrow effect's how it flies, whether it is striaght or has a twist around the arrow, how long the feather's are, it can get complicated quickly that is why good archer's were so sought after and not easily trained.

Jeff

[DavidEvans]

From the Mary Rose find and a find in Westminster Abbey roof. War bows (Longbow is not the right term!) by the 1540's could be found as heavy as 240lbs pull (the heavist found) The average is about 180lbs. Arrows are shaped for the bow that fires them. The shaft tapers and thickens in different ways for different draw weights. From the shape of the arrow the bow draw weight can be worked out. Against Plate at close range with steel heads (they were made by at least the 1400's) with a flat angle shot they will whip thro. The motion on impact is interesting. The point remains static-ish against the armour the shaft whips backwards and forwards, moving the point very slightly. In effect the point is drilled through...

[JeffGentry]

Hey David

Arrows are shaped for the bow that fires them. The shaft tapers and thickens in different ways for different draw weights. From the shape of the arrow the bow draw weight can be worked out.

Well to a small extent this is true, the draw length also has something to do with it a guy drawing say 29 inche's the arrow will not be the same as a guy drawing 30 inche's, you can get an approximation you cannot realy be sure, an arrow for a 29 inch draw length when at full draw in 180 pound bow is going to be a little diffrent that a guy drawing 30 inche's because the mass and how it is distributed of the arrow will change and this will effect it's flight characteristic's, there are alot of subtle thing's in archery that only someone who know's how to shoot and know's what should be happening will be able to see.


Jeff

[Stacy Clifford]

Jeff, what you say makes a lot of sense, and I kind of figured that the draw weight would have an effect on arrow configuration. Given that knowledge, I would imagine arrows designed for the heavier bows would hit with an impact like a javelin, because that's about what they would be. As for a 240 pound bow, I have a hard time imagining anybody short of Mr. Olympia being able to draw one of those things more than a few times, let alone keep up a continuous fire rate on the battlefield. That is definitely not somebody I would want throwing an elbow at me. (Picturing some beefy English archer looking at a puny compound and saying "That's not a bow. THAT'S a bow.")

[Casper Bradak]

Just out of curiosity, do any of you know what a good equivalent exercize to drawing a bow would be? Maybe 1 arm rows? That's definitely a lot of weight.
Some of those draw weights make me wonder what psi it takes for a bowstring to cut off human fingers <img src="/forum/images/icons/wink.gif" alt="" />