Much depends on the draw weight of the bows in question. Draw weights of many long bows were as much as double the draw weights we consider standard for bows today.
Estimates for the draw of these bows varies considerably. Before the recovery of the Mary Rose, Count M. Mildmay Stayner, Recorder of the British Long Bow Society, estimated the bows of the Medieval period drew 90â110 pounds-force (400â490 newtons), maximum, and Mr. W.F. Paterson, Chairman of the Society of Archer-Antiquaries, believed the weapon had a supreme draw weight of only 80â90 lbf (360â400 N).[2] Other sources suggest significantly higher draw weights. The original draw forces of examples from the Mary Rose are estimated by Robert Hardy at 150â160 lbf (670â710 N) at a 30-inch (76.2 cm) draw length; the full range of draw weights was between 100â185 lbf (440â820 N).[9] The 30-inch (76.2 cm) draw length was used because that is the length allowed by the arrows commonly found on the Mary Rose.
A modern longbowâs draw is typically 60 lbf (270 N) or less, and by modern convention measured at 28 inches (71.1 cm). Historically, hunting bows usually had draw weights of 50â60 lbf (220â270 N), which is enough for all but the very largest game and which most reasonably fit adults can manage with practice. Today, there are few modern longbowmen capable of using 180â185 lbf (800â820 N) bows accurately.[10][11][12]
In an early modern test by Saxton Pope, a direct hit from a steel bodkin point penetrated Damascus mail armour.[31][32]
A 2006 test was made by Matheus Bane using a 75 lbf (330 N) draw (at 28") bow, shooting at 10 yards; according to Baneâs calculations, this would be approximately equivalent to a 110 lbf (490 N) bow at 250 yards.[33] Measured against a replica of the thinnest contemporary âJack coatâ armour, a 905 grain needle bodkin and a 935 grain curved broadhead penetrated over 3.5 inches (89 mm). (âJack coatâ armour could be up to twice as thick as the coat tested; in Baneâs opinion such a thick coat would have stopped bodkin arrows but not the cutting force of broadhead arrows.) Against âhigh quality riveted mailleâ, the needle bodkin and curved broadhead penetrated 2.8". Against a coat of plates, the needle bodkin achieved 0.3" penetration. The curved broadhead did not penetrate but caused 0.3" of deformation of the metal. Results against plate armour of âminimum thicknessâ (1.2mm) were similar to the coat of plates, in that the needle bodkin penetrated to a shallow depth, the other arrows not at all. In Baneâs view, the plate armour would have kept out all the arrows if thicker or worn with more padding.
Other modern tests described by Bane include those by Williams (which concluded that longbows could not penetrate mail, but in Baneâs view did not use a realistic arrow tip), Robert Hardyâs tests (which achieved broadly similar results to Bane), and a Primitive Archer test which demonstrated that a longbow could penetrate a plate armour breastplate. However, the Primitive Archer test used a 160 lbf (710 N) longbow at very short range, generating 160 joules (vs. 73 for Bane and 80 for Williams), so probably not representative of battles of the time.
Tests conducted by Mark Stretton[34] circa 2006 focussed on heavier war shafts (as opposed to lighter hunting or distance-shooting âflightsâ) mated to a variety of heads indicate that the adoption of the heavy bodkin head - similar in form to contemporaneous crossbow warheads - was not merely fashionable imitation: Strettonâs findings (based on experimentation using a variety of bows, arrows and heads based on historical examples but the results interpreted in the light of modern knowledge of the effects of blunt force trauma, via the good offices of Cranfield university) show the quarrel-like armour piercing shaft from a yew âself bowâ (with a draw weight of 144lbs at 32 inches) while travelling at 134 feet per second achieved 90% of the range of lighter broad heads while being 45% heavier and thus delivering more kinetic energy.
When translated these figures (102 grams moving at 47.23 metres per second) yield 113.76 joules, comfortably surpassing the 80 joule threshold at which a strike to a vital area is hazardous. (In fact all of the test arrows, fired from test bows, surpassed this potentially mortal limit). In tests Stretton addressed not merely depth of penetration against representative targets but strike angle and discovered that the short, heavy quarrel-form bodkin could penetrate a replica brigandine at up to 40° from perpendicular, and further, when fired at such a target mounted on a travelling rig at 20 miles per hour and thus appropriate to a war horse at the charge, the added forward momentum of the target added a full inch of penetration.
If not sufficient to kill a man in plate armour outright - so long as he is protected by thick and substantial energy-absorbing intermediate layers - would have a severe, possibly fatal, blunt trauma effect. (As Stretton acutely observes, if the purpose of the war bow and war shaft was to neutralise opponents as combatants precisely the same logic holds as on a modern battlefield: a wounded man demoralises his fellows and absorbs resources that might otherwise contribute to the battle and, as is still the case today, survivors tend to be those best protected and thus more profitable when taken alive and held hostage or for ransom.)
It is interesting to note that in many cases of hits from high-pull weight longbows, penetration might not be necessary to incapacitate or even kill, as blunt-force trauma was capable of disabling or even killing. I can imagine a shot to an armored head, even if penetration did not take place, would be similar to a blow from a club, based on the 80 joule threshold being far surpassed by bows like those found on the Mary Rose. Also, only those elite troops who could afford steel armor were really (mostly) immune to the penetrating effects of long bows, as most had iron armor which was penetrated. So I guess it was a real mixed-bag.
[2] Kaiser, 1980
[10] Strickland & Hardy 2005, pp. 13,18.
[11] A review of The Great Warbow âThe power of a bow is measured in its draw-weight, and these days few men can pull a bow above 80lb⊠and skeletons retrieved from the wreck show spinal distortions, indicating just what it took to be a proper archerâ (Cohu 2005).
[12] In the English language there is the expression that someone âwas not pulling their weightâ. This is thought to infer that someone was using a longbow that had a draw weight that was less than that personâs body weight.
[31]Pope 2003, Chapter IV.âArchery in general, p.30.
[32] âRoyal Armouries: 6. Armour-piercing arrowheadsâ.
[33] Bane 2006.
[34] Soar, Hugh; Gibbs, Joseph; Jury, Christopher; Stretton, Mark (2010). Secrets of the English War Bow. Westholme. pp. 127â151. ISBN 9781594161261.
Edit*** An interesting point is that most states in the United States require archers to use a bow with a minimum pull weight of 40lbf for hunting deer.
Thanks for the feedback. Tweaks and changes will happen to a degree. Just nothing to announce at the moment!
