Glued Linen Armour- a simple test

[Astiryu1]

I have seen an article in Primitive Archer about simply drawing lines above where the arrow would rest to gauge yards I have tried it it seems to work best in around 25 yd increments. Anyone try it?

[Sean Manning]

I liked that experiment in "The Cutting Edge" too. They used several bows, types of arrow, and shields and described their methods clearly. The book is poorly edited though- there are typos, sources missing from the bibliography, mis-captioned and missing photos, and so on. And the lack of tables of data is a nuisance.

My only serious disagreement with the experiment was their short draw of 60-65 cm. Apparently some Greek art shows short draws, but the Munich wood, an Achaemenid seal carving published in The Ancient World at War p. 69, and one of the seal impressions at Persepolis all show long draws with Scythian bows (by long I mean that the right hand is pulled back past the ear). Perhaps short arrows were used on the steppes, if most of the finds are short. I'm not familiar with the archaeological evidence for short arrows, but I don't know much about steppe archaeology. If anyone can give me references I'll add them to my reading list.

Blyth's estimates for an 'average' arrow look plausible when compared to some of the other sources I have. I'm just saying that unusually strong or skilled archers would have used stronger bows, and that archers would use different types of arrows in different situations. I'm sure there were archers using Scythian bows with 60 and 70 lb draws and heavy arrows, but they probably weren't typical.

[Astiryu1]

One should always think about the supply of wood on the steppes and in the desert. The Chinese for instance found making boats out of wood to be too expensive;so In proper form they used concrete. This was published in National Geographic and was photographed.

[MeinPanzer]

My only serious disagreement with the experiment was their short draw of 60-65 cm. Apparently some Greek art shows short draws, but the Munich wood, an Achaemenid seal carving published in The Ancient World at War p. 69, and one of the seal impressions at Persepolis all show long draws with Scythian bows (by long I mean that the right hand is pulled back past the ear). Perhaps short arrows were used on the steppes, if most of the finds are short. I'm not familiar with the archaeological evidence for short arrows, but I don't know much about steppe archaeology. If anyone can give me references I'll add them to my reading list.

I looked up some info on arrowshaft lengths after reading this thread, and it seems that while it was the norm in the east during the Scythian period for arrows to be c. 80 cm in length, in the west among the late Scythians and Sarmatians well-preserved arrowshafts which have been found are between 50 and 60 cm long.

[Astiryu1]

I tend to use the shortest arrows I can find because I have fairly long arms and my bow is old.

[Benjamin Abbott]

I have to say I find those energy figures for classical projectiles laughably low. It looks like the myth of the shortbow all over again. What evidence leads people to assign such weak draw weights to Scythian and Persian bows? We know cultures across time and space used much stronger bows made with similar technology. It's extremely dangerous to apply modern notions about material progress to ancient and medieval times. Things really didn't change much. There's no reason whatsoever to assume the existence of fabric armor implies feeble bows. The English wore quilted jacks on battlefields teaming with 130-joule arrows. Crusader shields and armor performed similarly to the ancient Greek kit against swarms of arrows. You see the same in countless cases. The dynamics between armor and projectiles remain constant for hundreds of years.

[Paullus Scipio]

The science behind archery is fairly well understood. The energy figures have been carefully calculated in studies such as P.H. Blyth's "Effectiveness of Greek Armour against arrows in the Persian War ", an in-depth study of over 300 pages now available on-line, which calculations have so far stood the test of time.....

He covers early 'short' Scythian bows too, whose 50-60 cm arrows were drawn merely to the chest....which fact alone tells you they were not particularly powerful.

Similar studies exist analysing Egyptian simple and compound bows found intact(ish) in tombs.....

[Benjamin Abbott]

I remain unconvinced. Dubious scholarly work often dominates a field of inquiry until questioned and revised. All sorts of strange notions about classical and Hellenistic warfare have had their day in the sun. Extraordinary claims, such as the ancients using bows five times weaker than in later periods, demand extraordinary support. What do you and Blyth bring to the table? Detailed reconstructions of a number of surviving examples? Remember, a single find isn't necessarily representative. You have to careful with how you interpret data. Short arrows don't always mean feeble bows. Den Erickson says he can draw 230+ pounds at 26.5 inches. Textual sources from the period in question stress the strength required to be an effective archer. That doesn't match the idea of most folks drawing only forty or fifty pounds.

Bows aside, your figure of 30 +/- 15 joules is simply too low. That wouldn't even stop a strong dagger thrust. In a modern test of stabbing performance, males averaged 28.6 J per underarm attack. The best managed 64 J underarm and 115 J overarm. Most of the folks tested had no martial inclination or experience with knife thrusts. The researchers gave them only one or perhaps two attempts, allowing no time to improve technique. As such, I suspect the maximum values correspond better to what you'd find on an ancient battlefield. With swords and spears, warriors would surely produce higher energies. We lack solid data on the power of such weapons but know Olympic-level javelin throwers manage around 360 J with their missiles. Classical armor had to protect against a variety of potent threats.

[Giannis K. Hoplite]

Classical armor had to protect against a variety of potent threats.

Classical armour had to protect against a variety of potent feable threats. Against all the others,it didn't have to protect!
The points that you bring are interesting.
And welcome to the forum!!
Khaire
Giannis

[Sean Manning]

Fortunately, Benjamin, Blyth's thesis is now available to the public online, so you can read it yourself and form your own opinion. I think you can download it at the ETHOS website. I'm part way through it, and he's starting to convince me.

Regarding the effectiveness of armour, several extant Corinthian helmets in excellent condition average less than 1 mm thick in front, and weigh well under 1 kg. It seems that ancient warriors were willing to wear armour which would be considered dangerously thin today. After all, it was better than nothing, and would frighten their enemies and encourage their friends.

[Dan Howard]

I think you can download it at the ETHOS website. .

Heh. The best website in the whoooole world (apart from RAT of course)

[Benjamin Abbott]

Thanks for the link, Sean. Interesting paper. Darn useful, but my verdict remains the same. Blyth underestimated the kinetic of weapons in general and arrows in particular. We now have access to a number of experiments he didn't have access to when he wrote the dissertation. In light of the stabbing test I mentioned earlier, his figure of 30 J for the sword in close combat can only be considered an extreme low end. Given the tremendous number of variables involved in close combat, it's not reasonable to provide a single number. There's a huge range. Simply in physical abilities, I imagine ancient warriors ranged from matching Olympic-level athletes to equaling modern sedentary civilians. I'd bet the troops doing the majority of the fighting came closer to the former than the latter, but we don't really know.

His scholarship on missile weapons appears even more dated. He gives a figure of 50 J for a longbow arrow, which might well have been a credible number at the time. No longer. The Great Warbow shows that kinetic energy ranged from 100-146 J for the average Mary Rose bow. Only in the earlier context do Blyth's results seem plausible. He derives his estimates of energy by looking the relationship between energy and arrowhead breadth in a weak longbow reconstruction, contemporary hunting archery, and Native American hunting archery. That's not a method that inspires any confidence, as any sort of arrowhead can be shot from any sort of bow. His other methods are only moderately less speculative. Based on evidence of bow efficiencies and draw weights from across time and space, the notion that elite Persian troops could manage but 35 J has to be considered absurd. His own analysis of arrow shafts allows for draw weights of up to a hundred pounds, a number far more consistent with the overall data. Depending on arrow weight and bow construction, that should produce initial energies on the level of at least 67-100 J.

[PMBardunias]

The physics of penetrating armor is not as simple as many of the "Force x penetrates armor y" scenarios conjured by authors on weapon performance. There has been some truly abysmal work on this topic. If you found Byth's thesis informative, you should read (all of which and more I can provide if needed):

Stabbing of metal sheets by a triangular knife. An archaeological investigation
International Journal of Impact Engineering, Volume 27, Issue 4, April 2002, Pages 459-473
P. H. Blyth, A. G. Atkins

and some newer work:

Perforation of sheets by pyramidal weapons such as arrowheads
International Journal of Impact Engineering, Volume 35, Issue 6, June 2008, Pages 457-470
Eddie Cheshire, Marco Rossi, Tony Atkins

Experimental simulation of non-ballistic wounding by sharp and blunt punches, Wong et al. 2008

And lest we forget that we are all armored by nature:

Dynamics of stab wounds: force required for penetration of various cadaveric human tissuesForensic Science International, Volume 104, Issues 2-3, 11 October 1999, Pages 173-178
P. T. O’Callaghan, M. D. Jones, D. S. James, S. Leadbeatter, C. A. Holt, L. D. M. Nokes

[Benjamin Abbott]

Given a specific weapon, looking at kinetic energy isn't so bad. According tests published in The Knight and the Blast Furnace by Alan Williams, penetration of sheets of metal by arrowheads can be reliably measured in joules and scales up exponentially according to thickness. Those are solid articles on the subject, particularly when combined with Williams.

[PMBardunias]

Given a specific weapon, looking at kinetic energy isn't so bad.

The key is that you have to define with great care your variables. Willaims does this well, but you can see from his data that arrow X will penetrate armor Y becomes at Z joules is pretty meaningless when we start to add in other variables such as the angle of impact. At best we get a broad range and without knowing the likelyhood of impact at each angle, we cannot even give a decent average penetrability. There is no reason to expect armor to be made to withstand the rare impacts that are ideal for penetration.

Williams takes care to define what he considers a "defeat", something not always done, because the real question is not will the armor be penetrated, but will the weapon get through far enough to wound. A point will make a hole in plate at far less force than needed to get the weapon through to wound. Then you have to add the skin behind it, etc.

When we start to add non-ballistic tests, things get more difficult because we now have the weight of the man behind the weapon to deal with and the impact becomes more complex on a reduced time scale. Some have treated such blows as ballistic, which greatly underestimates the penetration of a hand held weapon. Blyth dismissed the weight of the man behind a blow through a loss of "linkage", but this cannot be the case or a punch would be of force Zero. The strength of the friction force between gripping fingers and spear shaft, and not the amount of weight a hand can hold is what is important here to include the weight of the arm in the strike.

When done incorrectly you get such obvious fallacies as the edge of swords penetrating plate better than the point.