what lbs makes it a warbow insted of a longbow

[bow-toxo]

A couple of things I'd say in response to that. Your first assumption that "no man should shoot at a distance less than eleven-score yards" I believe is actually an incomplete part of the statement, I do not have access to the actual statute, but as I understand it it goes something like "no man should shoot at a distance less than eleven-score yards with prickling/flight arrows", an important difference I'd say.

Also in response to: "(As an aside: Many archers fail at this point, then start to look for evidence for a shorter 'medieval' yard (for example, the Pace) so they can say they've achieved the correct distance.  This is called changing the conditions of the test, or 'cheating'!)"

I can't really see how that could be construed as cheating? If indeed the medieval yard was shorter than the modern one then why should we not be measuring by that unit? After all if we wish to replicate Medieval requirements of military archers then why would we not use the original measurements of the time? It seems ridiculous not to do so, as wouldn't that be "changing the conditions for the test"?

To be fair, EnglishArcher did specify the EWBS livery arrow, not a flight arrow. The mediaeval pace was longer than a yard. It was the so-called Roman pace measured between footfalls of the same foot. A 15 th century source says"The pace contayneth five feet." The mediaeval yard was not shorter than the modern yard. The best research indicates that it was the same or one inch longer than our present yard. Check with the British Board of trade. As you say we should "use the original measurements of the time" if we want to honestly compare our performance rather than boost our egos.

[Et_tu_brute]

Perhaps what I said came across in the wrong way, I understand EnglishArcher did specify the 220 yard distance to be shot with a heavier arrow, but what I'm saying is that the original statute was in regard to prickling arrows, not heavy ones so I don't see how we can say that being able to shoot a heavy arrow 220 yards was a standard of the time that archers must be able to achieve when that is not what the quote was in reference to. As for the varying length of the yard, I suppose that discussion could just go on and on, but again perhaps what I said came across in the wrong way. What I was saying was that if the medieval yard was different to the modern yard then we should be using the medieval yard to compare our achievements to rather than the modern one if we want to see how close we are getting to the requirements of the time.

[bow-toxo]

I did agree with you that we should use the original distancees. As I understand the statute, the archer, practicing for war, was not to use the lighter prick shafts [ the ones used in clout shooting] or flight arrows at the shorter distances { less than 220 yards}.
At those distances he was to use the heavier arrows designed for maximum penetration. Really, I agreed with you.

[Yewboy]

Dave is right on the quote about prickling arrows and the 220yd statute - the fact is that no one knows what such an arrow would look like but arrows made to MR specs out of aspen and armed with hardened points which are the right weight to optimise flight (an important point this, no pun intended) don't come in at 70-75g or even near. Closer 60-65 if you apply some no nonsense scientific thought to it. Many bows in the 90-100lb range can achieve 220yd with this sort of weight.

I was at Leeds armouries on Thursday and was struck by the meagre diplays on archery related things - but one thing was obvious and that was that there is no relationship whatever between the modern replicas of equipment shown (doubtless informed by people who owe much of what they believe to some cloud cuckoo land concept of aerodymamics and arrow flight -  a good story for schoolkids but lets not buy it here) and the actual arrowheads shown - almost delicate, well made, no doubt hardened and clearly designed to do the job without making the arrow 'end heavy' beyond what was absolutely needed.

EWBS? Not a scientific organisation of which I'm aware and therefore can't comment on what they've discovered. I hear wonderful - almost magical things from them but without scrutineering or any authentication, can't possibly comment. I will say this though - get the facsimile arrows even a bit wrong, and the equipment you need to drive them will inevitably sky rocket.

C

The EWBS has some members that have researched the MR finds probably more in depth research than anyone else, including some of the more notable authors and the EWBS Livery arrow is probably closer than you think to an MR arrow and yes the weight is as you say between 60-65g and makes that 220yds quite attainable for bows of moderately heavy draw weights. However that is only to be able to reach the distance whilst shooting at a 45deg angle, this obviously does not mean it is capable of reaching the required distance with a consistant accurate shot, this would need a heavier draw weight bow which will be shot at a reduced angle for accurate shooting.

[ChrisD]

Well, thats a graceful reply to a potentially provocative post - so hats off! Actually, If I was shooting a 60-65g arrow and trying to get 220yds, I wouldn't need to shoot at 45 degree with either of the 100lb or so hardwood laminate bows of which I have significant experience. With those, I would expect 240yd or so.  I don't know if you were at the Finsbury shoot at Sandon recently, but if you were, you would have seen me shooting 220yds yd with a 110lb swiss yew bow with 86g arrows, but that was at 45 degrees.

The discussion seems to have suddenly moved to needing to shoot 220 yds relatively flat. Well pardon me, but I've always had the view that engagements opened with a volley at about 45degrees and gven the relative standardisation of the MR arrow, this would appear to be with a 60-65g arrow for longest range, and if the distance at the marks was 220yd, then one would guess that this, or somewhere thereabouts,  is what was done with those arrows. I can see the point which you are making of accurate shooting by shooting straighter - but it isn't a given. I certainly shoot more accurately that way, but the people who win at clout competitions generally do so with an aim at or about 45 degrees using lighter bows, so it isn't by definition inaccurate to do it that way. Much has been made of the skill of archers of old and this has been used to infer that they might have been able to use much higher draw weights than we are accustomed to. I have always preferred to argue that this would have made them better archers (at a variety of draw weights) and this would have stood them in better stead than being able to use, for example,  150lb bows.

C

[alanesq]

BTW - Don't forget that shooting an arrow at 45 degrees will result in the arrow having much more speed at its target than a more flat shot will have, so it is preferable for that reason

[ChrisD]

BTW - Don't forget that shooting an arrow at 45 degrees will result in the arrow having much more speed at its target than a more flat shot will have, so it is preferable for that reason

I very much doubt that this is the case Alan. I'm no physicist and maths is not my strong point but my logic goes thus. An arrow has most energy when it leaves a bow, converts kinetic energy into mostly potential energy at the apex of its flight and converts that potential energy back into kinetic energy when it comes back down again aided by gravity. No system is completely efficient however and the arrow loses energy to friction with the air when it flies. An arrow with a longer flight path therefore has more opportunity to lose energy to friction than an arrow with a shorter one and therefore, the flatter shot arrow will maintain a bigger proportion of its kinetic energy when leaving the bow than the high shot one.

A flatter shot, is therefore probably a 'stronger' shot - in fact this might be the basis of the idea of 'strong shooting' in which we are all interested. Having said all of that, the longest shot is the one at 45 degrees on flat land and its still likely that this is what was employed in long distance harrying with lighter arrows and this distance is what archers had to be able to reach with those arrows, which kind of makes it reasonable to suppose that it was in or about 220yds or the minimum distance with prickling arrows.

C

[alanesq]

The theory I am going on is that if you shoot a arrow very high it will be doing something close to the speed it left the bow at by the time it comes down again (because its falling from a very great height)

I have tried shooting arrows as high and far as I can and measured the speed of the arrow coming down using my high speed camera and they do come down very fast

so if you shoot say 100 yards as flat as you can the arrow speed will be reducing all the time it travels, if you shoot the same distance very high it will be travelling much faster when it hits ?


BTW - In fact here is the video http://homepage.ntlworld.com/alan.blackham/ewbs/hscam/incoming.avi
not an ideal video I know but it was a proof of concept - I then never got round to doing anything with it
The video is filmed at 420frames per sec, the arrow if 34" total length and it takes about 10 frames to travel its length so its doing 120 feet per second on the way down
the arrow was shot from a 120lb bow around 210 yards at a very high angle

[ChrisD]

I understand your theory - its just that I think its wrong for the reasons outlined. What you are arguing is akin to saying that an arrow has somehow become a perpetual motion engine which goes faster the longer its in the air. This is physically impossible. The more time its in flight and going up, the more energy it will lose to friction and there isn't any way to get it back!

Heavier arrows suffer less than light - they carry more momentum, but in general terms I believe what I say to be true. Thinking laterally, the same reasoning makes downhill skiers avoid time in the air when they do jumps - they lose too much speed to friction whereas on the snow, they can glide well and remain aerodynamic by minimising drag by posture etc.

In all these things, friction with the air is the killer.

C

[Yewboy]

Mark Stretton did some similar tests regrding penetration at various distance and these were measured at the Defence academy test centre at Shrivenham, the results were that:

0-40 yds maximum penetration
40-80 yds minimal reduction in penetration, 2-4% less
80-100 yds penetration was down by 8-10%
100-180 serious reduction in penetration at its worst at 180 yds, approx 15% less
180 -200 a marked increase in penetration from the 180yds penetration approx 8%
200-240yds again an increase in penetration, this time only approx 6% loss from maximum penetration.

So I'm afraid Chris I do agree with Alan on this one.

[alanesq]

I guess the only way to know for sure is do some experiments?
I may give it a go myself some time

As posted above as I was typing this; Mark Streton published some great results on the arrow speed at different distances in The Glade a good while back which shows a graph of arrow penetration against distance which shows nicely how arrows can have more energy at greater distances but I dont think he compared same distances shot at different elevations?
e.g. it shows an arrow shot 180 yards penetrated 6" where as an arrow shot 200 yards penetrated nearly 8"

but this would suggest that shooting 180 yards he would get more penetration if he had shot a much higher arrow ?
so at least in some cases this shows my theory would be true (how often this is the case is another question?)

[adb]

An object (an arrow or a sky diver or a rock) when falling will reach terminal velocity. It can not and does not accelerate. Terminal velocity is around 90 mph. Objects will deviate from this due to air friction or drag. So, an arrow can not magically accelerate beyond terminal velocity while it is falling. After reaching its apex, the arrow will begin to fall and reach this terminal speed. It will have the most energy upon realease, so in fact, you're both correct. It will have its greatest energy upon realease, its least at apex, and then something slightly higher after reaching terminal velocity upon returning to earth.

[alanesq]

I agree, this means the arrow has an ultimate max speed it can attain when falling
in fact I have thought in the past it would be good to drop an arrow from a great height to find out what its terminal velocity is

The question is; is terminal velocity (assuming they fall from high enough to reach it) greater than the speed the arrow would be doing if shot flat

From Mark's results it suggests an arrow shot high to 200 yards is doing about the same speed an arrow shot flat at 40 yards will be doing, so an arrow shot flat further than 40 yards will presumably be doing less than this (from the same bow etc.)
btw - this is just from looking at the graph so is estimates

[ChrisD]

Mark Stretton did some similar tests regrding penetration at various distance and these were measured at the Defence academy test centre at Shrivenham, the results were that:

0-40 yds maximum penetration
40-80 yds minimal reduction in penetration, 2-4% less
80-100 yds penetration was down by 8-10%
100-180 serious reduction in penetration at its worst at 180 yds, approx 15% less
180 -200 a marked increase in penetration from the 180yds penetration approx 8%
200-240yds again an increase in penetration, this time only approx 6% loss from maximum penetration.

So I'm afraid Chris I do agree with Alan on this one.

Thank you for sharing. What we were actually talking about was impact velocity last time I checked - penetration would be affected by many variables although I accept that velocity would be the prime factor involved.

I have to say that I would view those results as eye opening, even bizarre and I'd be grateful for the reference in a peer reviewed journal if you have one as I've never been tempted to buy the DVD. The reasons for my scepticism are

1 because it isn't what I'd expect given what I've said before and
2 it is wildly different to the impact velocities & energies given in the experiments run through a chronograph in the appendix to 'Great Warbow' which quote velocity losses of 19-24% (less for the heaviest arrow) at the end of the trajectory of a 45 degree shot  with a variety of arrows and bows- which is what I would expect given the above.
3 Predictions based on coefficient of drag and velocities later in the same paper indicate falling impact energy with increasing range in a more or less linear fashion for all arrow types

Much as I admire Marks writings on other topics, I agree with Alan that an attempt at replication would be worthwhile - but using a chronograph rather than a hand held camera.

C

[alanesq]

The problem is you cant really use a chronograph to measure the arrow speed at the target (unless you are VERY accurate at 200 yards)
this is why Mark used the penetration method as this was the only option available to him at the time
I understand the radar they were using couldn't measure it but I think this will be because you need a radar looking straight up at the incoming arrow

I have spoken to him about this in the past as I think there are more options available now
I first considered using a radar speed gun pointing up at the target to measure the incoming arrows speed and I even converted my radar gun so I could trigger it by radio control (as I didn't fancy standing at the target ;-) but never got round to actually trying it (story of my life ;-)

but since then I have got my high speed camera and I think there is a lot of potential to use this as you can use the zoom to film the incoming arrow from a reasonable distance and as the frame rate and arrow length is known you can figure out its speed
it would also be interesting to have the oportunity to test this against a chrono to see how accurate it is

BTW - If you watch a arrow coming down which has been shot at a high angle, one thing is clear - its coming down at a very high speed !