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Will S
Location: Bournemouth, UK Joined: 25 Nov 2013
Posts: 164
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 Posted: Sun 30 Aug, 2015 10:14 am Post subject: |
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Shoot, not fire - there is no gunpowder involved in archery 
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Cs. Norbert
Location: Romania Joined: 21 Aug 2015
Posts: 27
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| Posted: Sun 30 Aug, 2015 10:21 am Post subject: |
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After this post I won't fuel this type of debate on this forum I will gladly debate it (with arguments based on references with links) on the bodybuilding forum or other related type!
| Quote: | | I think you may be approaching this from the wrong angle somewhat - have you shot a heavy bow yourself? Most healthy young guys can get 100lb bows back with ease after less than a year of the right training and the right guidance. That's with no special diet, exercising or determination. |
I have no problem believing that, but it's quite a different matter when going from 100lb to 200lb or 260lb for the asian archers, I will try to explain this with the following analogy : x amount of hp will get you to 100 km/h, but 2*X amount of bhp won't get you to 200km/h.
| Quote: | | There are videos such as the one above of Joe shooting bows over 200lb, so it's not fiction at that weight. He certainly doesn't look like a weight lifter either (nothing at all like the guy in that video), and if you met him in the street I can assure you that you would never know he was immensely strong. You would not be able to pick him out of a line of normal, non-athletic healthy adult males. |
When speaking of strong you need a reference system like strong for his body frame and weight, as I mentioned earlier climbers do not resemble strength athletes, but are able to lift their own weight with one finger (referring to ~60 kg climbers) and are able to do one hand chin ups with an added weight of ~30kg so it's 1.5 times their own weight. Also like you mentioned "You would not be able to pick him out of a line of normal, non-athletic healthy adult males" As you gain more body weight you cannot maintain that 1.5 ratio of strength/body weight. I will get to the part where I will elaborate on the differences between power lifters (and the derived) and bodybuilders!
| Quote: | | Also, the old "medieval archers were peasants" and "people in the middle ages had poor diet and health" myths have I believe long since been disproved - medieval archers were very highly paid soldiers by the time you're in the 15th/16th Century. Their diet would have been healthy and good, and they would all have been training - just like Joe today - from very young. It was in the country's best interest to have them strong, healthy and capable of drawing the most powerful bows possible. They're not being picked out of old, weak farmers and given a bow to go and fight with. |
I used the word "peasants" not to describe their social status or their wealth, but only to have a fare comparison of physical activity. It doesn't matter I your rich/poor or of higher/lower social status if you compare individuals by their activity. So i suggested that a medieval archer (regardless of status) should have been as active as some of today's peasants!
I didn't mentioned anything of "old, weak farmers". Their nutrition was according to their body needs (the body "tells" you what it needs to recover it's self after physical work, that's why you sometimes feel that you want to eat food rich in protein, like meat) they didn't knew about hypercalorie diets to bulk up and what specific ratio of macro nutrients would work the best.
"If Joe can draw over 200lbs in his late 20s, to assume that this is rare seems to me slightly odd. The only reason he's so special today is because nobody else is pushing themselves to his level. In the middle ages, this would of course be completely different and I think it's perfectly safe to suggest that a huge number of archers would have been at exactly the same level as Joe is today, if not even stronger."
That is like assuming that most of the medieval archers had body frames and genetics similar to Joe's and most would be over 200 lbs! Knowing a bit of how genetics work's today, I would not estimate that the majority of population or physically active population to be in that range of lbs!
| Quote: | | Even if ALL of this is incorrect, and even if you disagree with everything above, none of that is relevant when looking at the actual evidence we have. We have the MR bows to make copies from, we have the arrows. We know without any doubt that if you make replicas of the slab-sided MR bows using almost identical timber, they come out around 190#. It's been done before. We know that it's perfectly achievable to shoot bows up to and over 200lb if training and discipline (something no army is alien to) are followed. |
I agree that, "if you make replicas of the slab-sided MR bows using almost identical timber, they come out around 190#"
and maybe more lbs, and that "We know that it's perfectly achievable to shoot bows up to and over 200lb if training and discipline (something no army is alien to) are followed", but I can't agree on: many archers would have been able to use those 200lb bows or as I interpreted (maybe wrongly) the majority of archers would have been able to use the 200 lb bows, or as Dan Howard interpreted "...they would have been common". I think the word "many" in the above context (and how we each interpret it according to personal reference systems) created the confusion which ultimately led to this debate. I want to use another analogy that would represent my point of view: today we have incredibly strong people that can do amazing strength feats, but that doesn't mean they are the so called "majority", we also have gyms with incredible weights, but that doesn't mean that any individual even with a lifetime of training would be able to use those weights.
Regarding arrow weights I would like to use the 1/4 lb arrows (from what I understand, that would have been close to the maximum back then) as example when referring to high lb bows and their performance.
I will repeat the example I used earlier:
https://www.youtube.com/watch?v=MN2jAsE9ics Joe Gibbs, English Warbow Society, Quarter Pound Arrow Record Shot vs http://www.theenglishwarbowsociety.com/records2013_EN.html with same arrow, 155lb bow, max 240 yards.
According to some studies, efficiency of medieval longbows was estimated at 70% with 9 grains / pound of draw force
so in the above examples we have the 155 lb bow with an estimated efficiency of 0.723 that delivered the 1/4 lb arrow at 240 yards, and the 175 lb bow with an estimated efficiency of 0.71 that delivered the same arrow at 241 yards.
Assuming that, both of the bows have identical mass( which I don't think they do) there should be a difference of ~10fps in arrow velocity
From the above I would conclude that the greater loss in efficiency would come from the heavier bow limbs.
A 200lb bow would have an estimated efficiency of ~0.697 with the 1/4 lb arrow, and it's close to what I arbitrary consider a good balance between arrow weight and speed. This bow should have (if the bow mass is the same) a ~20fps increase in velocity over the 155lb with the same arrow. From the previous example we can conclude that this is not how it works, so I really doubt if the increase from 155 lb draw to 200 is worth, considering the diminishing returns!
In theory it should be worth only if the ultra skilled bow maker is lucky enough to find the "best" yew and the most efficient bow limb dimensions to maintain a low limb mass for 200lb bow! I think that Joe or Mark would be qualified to answer these questions. If you know their recent findings please post some links, I would be glad if my assumption is proven wrong!
I will use this post to make a general reply that is not focused on a single person!
| Quote: | | I have studied Strength Training through the National Personal Training Institute. There are some things.... firstly, a Dumbbell Row is a compound exercise, yes, but it still does use only one arm. A Barbell Row, or Bent Over Row, uses both arms. Theoretically, you could Row with both of your arms at once with a dumbbell... but that is just not how it's done. |
I've studied strength training and nutrition ~16 years, and practiced what I learned ~3 years (not in a row) this doesn't make me specially qualified to answer questions about advanced body mechanics and bio chemistry! I can only reproduce what I learned [from scientific (more or less official)] data (based on my interpretation of the data) and from other professional bodybuilders with whom I had the pleasure to interact and also the experiments conducted on myself !
Yes a dumbbell row is a compound exercise and yes you use the biceps of one arm when pulling, the other arm is used only as support and the weight distributed on the other hand is dependent on the core strength and back strength (you can choose to wrongly execute the exercise and also risk injury and apply more load on the supporting hand by "relaxing your core) so most of the load is on the working side of the back. Yes a barbell row, or bent over row uses both arms (since the arm is not the main part that is worked it would be more correct to say both sides of the back) and are worst examples than the dumbbell row when referring to the muscles used in archery. When you hold the bow "or push into it" with your left hand and draw with your right hand the muscles are used like this: right hand biceps, right portion of upper back, (abdomen lower back and hips and legs, are used isometrically to balance and maintain for), left part of the back is used isometrically (does not contribute to the pull motion) left part of the chest, front delt and left arm triceps are used hold the bow (isometric) or "to push into it" like when you do one hand push ups" (that is if you decide to not hold the hand straight, and bent it at the elbow and bring the elbow close to the torso). No matter how you use the left part, the load on the right part (back+hand) will gradually increase to 200 lbs. So when you do dumbbell rows, your core takes most of the load from the supporting hand (it's easier when you distribute a high load on the big muscles than the hand), when you draw a bow the load is distributed on the left chest, shoulder and triceps (this is more demanding and exerts greater pressure on the spine). I believe I estimated correctly the motion used and the muscles targeted when I used the dumbbell row example, but I didn't use the proper type of load. The dumbbell exerts a constant load, it would have been more correctly to use an elastic cord that gradually increases load, or a 200lb chain that also increases load as you lift more of it. This is where you can cheat the most and be able to use the speed of execution to create momentum, this could help you allot, but for the untrained individual wouldn't make to much difference since you can snatch the string to be able to gain more draw length, but ultimately you wont be able to hold it more than a fraction of a second. So at maximum draw length no matter how you twist it, it still gonna be 200lb of load but the muscles will take the load differently (it will be isometric) and I didn't quantify how much easier is to hold that weight (=isometric, and is certainly not divided in half like when you use both hands and the full back for the same motion) for a specific time vs the other dynamic type of work, to pull the same weight.
| Quote: | | Drawing a Bow is very much simply a Cable Row. In many gyms, there is a cable machine called a matrix which allows you to basically, draw a bow, plus a bunch of other things. Now, this would be half of the bow draw, in reality. So you would not gain the benefit of your other half. |
I've explained above the mechanics and load on muscle groups, and cable row is another bad example since force is constant (if your talking about the ones with pulleys and not flexible cords).
| Quote: | | Back then, they did not know about strength training, you are correct. But, without knowing it, they did strength training every day. Strength and resistance training is more than lifting weights. It is even more than lifting heavy weights. Training with a sword, shield, armor... and especially training with a bow, would have provided a lot of strength. Mostly power, except in the case of the Bow, I image it is a lot of strength and power. |
Strength is known as a consistent, slow, exertion of force over a period of time, Power = Strength x Speed.
Strength is trained with: high resistance and low repetitions;
Power is trained with: low resistance and high repetitions, and is mostly defined by explosive motions
Also don't confuse endurance and aerobic training with weight training and anaerobic (it does not activate the same muscle fibers and the energy pathways are different). Fighting with swords while carrying armor is physical demanding but it is not strength training is more aerobic and endurance. Today's peasant's activity would be ~90% aerobic.
"Strength and resistance training is more than lifting weights. It is even more than lifting heavy weights." Training for raw strength is only about slowly lifting heavy weights(regardless of the type: own weight vs free weights). Regarding the bow, unless you draw the bow very slowly (and the weight is close to you maximum 1 rep potential), this type of exercise would not fall in the strength training class, but does contribute to one's overall strength, especially the isometric part of the exercise.
| Quote: | | If you look at the way our soldiers train today, you'll notice it relies heavily on endurance. This is because a lot of what they do involves long periods of time walking and standing, also lots of long distance running and short distance running. All with variable amounts of weight. This would easily be true for people back in those days. But the difference lies in the fact that their weapons required a lot of energy to wield, unlike guns. A life of constant training would really bulk and/or lean them up. These people would be getting their strength training out of their every day lives. They would not look like professional strength athletes. This is mostly due to their diet, health, training efficiency, and also the fact that they were not Power lifters. |
I agree that the soldiers that train today mostly train for endurance. This could be true for medieval archers, since I believe they were also substitutes for man at arms, in most of the battles. Yes their weapons required a lot of energy [fulled by muscle glycogen or fat depending on the type of activity or intensity (less than 50% VO2 max)], also today's soldier can mostly match that energy expenditure, doing diverse types of exercises that consume a lot of calories.
A life of constant training would / wouldn't "bulk" them, this are particular cases that depend on many factors : genetics (frame size, joint width, muscle composition fast vs slow fibers....), metabolism, heavy weight lifting (archery won't bulk you up), differences in energy expenditure/work type by individual, difference in nutritional requirements, difference in their possibility to provide their nutritional requirements (this leads to overtraining and the degradation of muscle), difference between their endocrine systems, difference in the amount of rest, the list is very long... . They would be as different as today's individuals are regardless off their training.
"These people would be getting their strength training out of their every day lives. They would not look like professional strength athletes. This is mostly due to their diet, health, training efficiency, and also the fact that they were not Power lifters" You previously mentioned that most of their training was focused on endurance, endurance and strength training are not the same, so most of them weren't strength athletes and of course they didn't look like them if they weren't. Power lifters are : as the name suggest, strong people that use their strength, leverage and speed of execution to generate power. The guy on the video I posted is not a power lifter he is strongman competitor at world's strongest man competition, a competition that displays raw strength. The trials are made so, that the individual has limited possibilities of using leverage and speed to achieve the result, so it represents(or at least strives to represent) raw strength. Power lifting would represent the power required to achieve that effect and it would be defined by strength x speed!
| Quote: | | That guy you posted is a power lifter. He looks like he does steroids, I am not saying he does, I have no idea who he is, and I do not want to be slanderous, but I've never seen a man of that stature who was not on steroids. |
He's not a power lifter, as I mentioned earlier, but you are correct about the usage of steroids. Most strongman and professional bodybuilders and even wrestlers use steroids to be near to their max genetic potential. This isn't necessarily a bad thing if you know what your doing and don't abuse them you wont get permanent side effects. Also is mostly considered cheating, but is it really cheating when everybody uses them?
| Quote: | Firing a bow is not Brute Strength. In fact, Strength does not even mean brute strength. There are many subsections of Strength Training. Power Lifting is the strength training term for brute strength. Where you want to live as much as possible, once. I say, Archery is Power and Endurance.
I've found a decent definition of Power online.
"Power is defined as the amount of work performed per unit of time. Power is an element of skill-related fitness that is needed to excel in athletic performance. Increased strength does not always translate into increased power. For example, a strong upper body lifts a high amount of weight. However a strong upper body does not always have the ability to throw a shot put very far if enough speed cannot be generated." |
Yes drawing a bow is not all about raw strength, in fact the strength related part is where you hold the fully drawn bow.
Strength training is training for strength, power lifting is the name of the competition, the competitors are called power lifters because they use their strength and leverage and speed to generate power, so it's strength related but not a display of pure strength but a combination of the previously mentioned. You can look at it this way: how much strength would you need to lift those weights very slowly, how much do you need when you snatch the weight?
I agree that archery is mostly about power, but what happens whet speed is out of the equation and you need strength to hold the draw? Well the strength in isometric exercises varies with limb mechanical advantage. You can hold allot of weight when siting in a bench press position with the arms straight, but you will not be able to hold that weight once you bend the elbows. You don't need 200 lb strength to draw the bow if you have enough strength and use high speed of execution, but once you have drawn the bow you will not be able to hold it at that position if you don't have the necessary strength. Also you don't have a mechanical advantage in the drawn position, you will most likely use close to 200lb strength to hold the draw. Consider this: you can lift past your 1 rep max ex for bicep curls, if you cheat and snatch the weight, but don't complete the motion stop in the middle, now see if you are able to maintain that weight in that position, most likely not!
"However a strong upper body does not always have the ability to throw a shot put very far if enough speed cannot be generated" yes this is true where the sport is more speed dependent, but in power lifting if you don't have enough power to quickly lift the weight then it doesn't matter how fast you can do the motion.
"Strength does not even mean brute strength" my bad on this one for creating confusion by not describing what I was referring to so: I used brute strength or raw strength as a quantification of the strength used in disciplines where power is used to achieve the desired effect, so I was mainly referring to strength used without the aid of speed and leverage, which in a combination (strength x speed) results power. I didn't mean to use that word as if I'm referring to multiple types of strength, there is only plain and simple strength when speed and other factors don't affect the result.
| Quote: | | Power is used to swing a baseball bat, sword, or to pull the string of a bow with any sort of haste. Power is a form of Strength. |
Power is related to strength, but I don't know if it's correctly to say that is a form of strength.
| Quote: | | You have a very huge misunderstanding of what "skill" means in terms of Strength. Power Lifters do use leverage, they use leg drive, and they change their posture to make their range of motion smaller. All of this would be considered cheating if you were doing it as training, but, during a competition, it is used to gain an edge. That is simply a result of the practicality of the rules created by the sport. Skill, in terms of Strength, is referring to Neuromuscular communication. |
Skill would be the means of manipulating strength, to make the best of it or to put it to good use, to use it effectively! Skill doesn't affect the strength that you have but does affect the power you can generate with that strength. Your right about how power lifters use leverage, and rapid change of posture to not only make the range of motion smaller, but also to use the momentum their own mass generates, to help snatch the weight. I agree on this as well "That is simply a result of the practicality of the rules created by the sport." if the rules didn't allow them to use those advantages that generate power, using strength to slowly lift the same weights would be impossible.
"Skill, in terms of Strength, is referring to Neuromuscular communication" skill could mean a conscious rational decision that can help you generate more power from that strength, if you are referring to muscle memory then I wouldn't put =, as skill doesn't = muscle memory. Here's the wiki on muscle memory https://en.wikipedia.org/wiki/Muscle_memory#Strength_training_and_adaptations The neuromuscular adaptations and evolution based on movement patterns, are not skill affected. You don't consciously contribute to their evolution. And you cannot be more proficient (since you mentioned skills, skills have proficiency levels) in "neuromuscular evolvement and adaptation", you can however, be more proficient in a motion type as a result of that evolution.
| Quote: | | You become Stronger when you lift weight, not because you are building muscle, but because you are teaching your muscles how to more efficiently move. You are teaching your body and your mind how to better communicate. You will build muscle as long as you eat enough calories... and this will make your strength increase too, but not nearly as much, and at a slower progression. |
You become stronger when you lift heavy weights , because of neuromuscular evolutions and because of a combination of both type of hypertrophy (sarcoplasmic which focuses more on increased muscle glycogen storage, that I would call "energy tanks" (as in fuel recipients), and myofibrillar which increases the number of contractile proteins (actin and myosin) which are related to the neuromuscular evolution. The sarcoplasmic one, increases muscle volume, the other one increases the amount of contractile material which in turn increases myofibril size and strength as a result. I say a combination of those because you won't see professional strength athletes that would have only one type of hypertrophy, is just a matter of the predominant one (bodybuilders have the sarcoplasmic more predominant, strongmans and power lifters have the myofibrillar one predominant). I've bolded heavy weights because that is the only way to trigger this long term type of neuromuscular evolvement, the other low-med intensity, high rep (endurance) would benefit from muscle memory for proper muscle coordination, not to trigger the increase in contractile material, but to trigger the increase in muscle volume (as a result of sarcoplasmic hypertrophy). So in theory after proper stimulus is applied (first step: the use of heavy weights repeatedly with specific training) will trigger an increase in the neural drive's ability to stimulate muscle contraction, after this assuming you properly trained you achieve hypertrophy (myofibrillar predominant) as a result of muscle reaction from the increased stimulation. After adequate rest and proper nutrition the muscles regenerate, they have more contractile material and a small increase in size(after a "long" period).
You become stronger because you build muscle (increase in contractile material is considered building muscle, but it's not that evident in muscle circumference, as the other method). The increase in contractile material and receptors is responsible for long time strength gains, the central nervous system's ability to excite the receptors and activate the muscle fibers will vary in time(can be overworked with over-training, thus will decrease the stimulation, and is affected by lack of training). The rapid increase of strength due to nervous system's training "teaching" as you interpreted, will have short time gains, but is also responsible for triggering the events (muscle recruitment patterns, and the increase in sensors) that provides long term results. The muscle fibers recruitment pattern is affected by these stimulations, and in time the muscles will increase in stiffness (you can see the difference between muscle stiffness, or density when you compare young untrained animals that have tender muscles vs older active animals). In bodybuilding there is a term that would describe this(although is very controversial) "muscle maturity". You can also see that bodybuilder, that train with heavy weights will have a specific look that would suggest muscle "hardness", the granite aspect of Ronnie Coleman's muscles would be the result of heavy weight training for a long period.
| Quote: | | Muscle Mass =/= Strength. That is a huge misconception. When referring to different kinds of Strength, you cannot refer to different kinds of competition. That would be like me saying that Football Running is different from Baseball Running... because in baseball you can only run straight. The differences of the types of Strength are not defined by their respective sport. |
Yes muscle mass does not = strength, or more correctly muscle volume or circumference =/= strength, but strength is related to the cross-sectional area of muscle fibers (fast twitch type contributes the most)! I previously clarified that I wasn't referring to multiple types of strength, there is only one type and is often confused with power!
| Quote: | We should not even talk about Body builders, as they don't even have functional competitions. The large portion of their training is based on diet, and a large part of being a body builder is genetics.
Volume =/= Definition. Power lifters do not have dense muscles. A lot of them look kind of fat. Body builders have lean, dense muscles. With high definition. They lack raw strength and power, because... well, basically because that's the only way to get to 5% body fat. |
Most of the bodybuilders include strength training in their routine, it just isn't the predominant type. So a bodybuilder would have higher energy stores ( muscle glycogen), thus would not be able to match the strength of the strongman competitors, but they would have more endurance, they can achieve a higher rep count with weights under their 1 rep max. "Volume =/= Definition" I didn't state that volume = definition, I was referring to the muscle volume (from sarcoplasmic fluid in the muscle cell) from the off season, which is covered by adipose tissue, until the pre-contest "definition" period. That volume will further evidentiate muscle separation and striations (definition) when they are in contest shape. Power lifters do have dense muscles and they look fat because they are permanently "off season" their muscles are covered by fat, so you can't see their "definition", also you would have to take a biopsy to be able to see their muscle composition.
| Quote: | | Power Lifting, specifically, involved Bench Press, Squat, and Deadlift. But, more generally, it refers to lifting the maximum possible in a single rep. |
Yes those 3 are the main building exercises, and because they are large muscle groups, stimulating them with large weights increases the secretion of anabolic hormones. Lifting 1 rep max slowly would be a display of strength, lifting heavier weights with the help of speed would be a display of power.
Next reply to: Jasper B.
| Quote: | Also, I kinda fail to see how a discussion about power, strength and building muscles, etc is relevant to a question on:
"Most accurate formula for estimating longbow performance?"? |
Your right it's not relevant to the main question, it's just a debate that deviated because of our different interpretations!
So I will stop fueling this type of debate after this reply.
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Dan Howard
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| Posted: Sun 30 Aug, 2015 2:48 pm Post subject: |
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Dr Kooi used his computer modelling to estimate the draw weights of the Mary Rose bows. Robert Hardy had some replicas made and the draw weights of these supported the accuracy of Kooi's results. He also sent some other modern-made bows to Kooi to run through his modelling system and the results matched the specs of the bows exactly. There is no point speculating on what an English archer COULD have drawn because we already know what he actually DID draw. The draw weights of the Mary Rose bows ranged from 110 lbs up to 185 lbs.
The only question is whether these bows were a typical sample or were exceptional in some way. It has been said that 1511 is well past the heyday of the English longbowman and that earlier archers may have drawn heavier bows. However it should also be noted that the Mary Rose was the king's flag ship and that he would have had elite troops on board - the best archers available.
Whether a modern archer can draw a 200 lb bow is irrelevant. We know what they drew in 1511 and the heaviest was 185 lbs. A typical bow was closer to 150 lbs. A counter argument needs far more than empty speculation. It needs evidence.
Author: Bronze Age Military Equipment, Pen and Sword Books
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Cs. Norbert
Location: Romania Joined: 21 Aug 2015
Posts: 27
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| Posted: Sun 30 Aug, 2015 8:03 pm Post subject: |
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| Dan Howard wrote: | Dr Kooi used his computer modelling to estimate the draw weights of the Mary Rose bows. Robert Hardy had some replicas made and the draw weights of these supported the accuracy of Kooi's results. He also sent some other modern-made bows to Kooi to run through his modelling system and the results matched the specs of the bows exactly. There is no point speculating on what an English archer COULD have drawn because we already know what he actually DID draw. The draw weights of the Mary Rose bows ranged from 110 lbs up to 185 lbs.
The only question is whether these bows were a typical sample or were exceptional in some way. It has been said that 1511 is well past the heyday of the English longbowman and that earlier archers may have drawn heavier bows. However it should also be noted that the Mary Rose was the king's flag ship and that he would have had elite troops on board - the best archers available.
Whether a modern archer can draw a 200 lb bow is irrelevant. We know what they drew in 1511 and the heaviest was 185 lbs. A typical bow was closer to 150 lbs. A counter argument needs far more than empty speculation. It needs evidence. |
I have a similar point of view, and I would add that: the assumption, that before 1511, they would have drawn heavier bows, would be contradicted by the fact that, bow performance seems to suffer greatly past the ~160#, you don't need to be an engineer to figure out that, if two high lbs bows with considerable difference in draw weight, deliver the same arrow at the same distance, the small gains in ke might not be worth the increase to 200lb. This would be my (unproven) personal opinion, and maybe a skilled bowyer could make an efficient 200 lb bow, but I doubt that even so, the gains in KE is worth that increase in draw weight. From my previous calculation I estimated that a 200 lb bow will have ~ 20 fps over the 155 lb, with the same arrow(1/4lb), but in my calculation, I considered the 200lb bow to have the same mass as the 155 one, and the same tip mass!
Regarding Dr. Kooi's computer simulated models, I've read on a forum, that some engineer has some mathcad simulation methods of bow static and dynamic performance, and he wrote: "I have checked my work against Bob Kooi’s detailed PhD thesis results and we are in close agreement."
I don't know if supertiller is similarly accurate, but I did find another bow simulation software that should be worth testing:
bow simulation tool - http://st-321.github.io/
and supertiller - http://www.buildyourownbow.com/build-alongs/h...ild-along/
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Will S
Location: Bournemouth, UK Joined: 25 Nov 2013
Posts: 164
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| Posted: Mon 31 Aug, 2015 4:47 am Post subject: |
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I'm afraid that's wrong. We certainly do NOT know that the "heaviest" bow was 185lbs. All we "know" is that a computer model, which has been LONG since disregarded amongst warbow makers (as it's ludicrous to assume a computer model can predict the natural tendencies of a piece of wood bending, plus the skill of different bowyers, plus the effect certain tiller shape has on draw weight at different draw lengths) and a few replicas (using wood very different to the MR bows due to availability at the time - it wasn't even the same species of yew) peaked at 185lbs.
To take that as the maximum is ignorant of bow making and the variations within. We KNOW (since that seems to be the key word here) that other replicas of specific MR bows such as MR 81A 1607 made using European yew of a very similar quality came out at 196lbs at a draw length of 32". That immediately makes the idea of the maximum poundage being 185lbs absolutely incorrect.
As for the idea that the 1/4lb arrow being "the average" or at least the one that the OP is using for all of his theories, that's quite frankly ludicrous as well. It shows a fairly large ignorance towards the actual equipment used, and displays knowledge built purely on certain people's theories plus a skim-read of the EWBS flight records. No practical experience whatsoever, I would imagine. I don't mean that to be condescending in any way, but these theories have been bandied around for countless years, and this is just repeating the same stuff.
The problem with the theories readily available in books etc are that they have all been written a long time ago. Long before real experiments with natural fibre strings, long before timber of a good enough quality was readily available, and long before certain bowyers were proficient enough to provide opposing evidence. Today, almost all of these theories have been disproved, but unfortunately very little has been written about the new findings. The same ideas circulate on forums for years due to that, and nobody learns anything new until they actually turn up and watch these guys making and shooting real replicas.
Don't forget - not so long ago, Pip Bickerstaffe published a book that was given extremely high regard, and was considered one of the most important books in the manufacture of English warbows. In this book, he stated (and I quote) "I have come to the conclusion that the TOP END weight limit for these bows could have been no more than around 100lbs draw weight at 30." This was due to his "theory" regarding natural strings. Now we know for a fact that natural strings can support bows over 180lbs, but this book is still out there, being bought and read by every aspiring archery historian and bow maker. The Kooi results are just the same, as are the very early replicas made by Roy King for Hardy, shot by Simon Stanley. They are not accurate, they are not finite. We are still learning, and because of people like Joe we are also able to test the much higher weight bows than nobody could have tested a few years ago.
Unfortunately it seems very apparent that the OP has a clear idea of what he WANTS the answer to be, and no amount of argument will change that opinion, so I'm out. There are plenty of incorrect theories about warbows and their potential out there - another one will probably do no more harm.
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Dan Howard
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| Posted: Mon 31 Aug, 2015 5:11 am Post subject: |
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| Will S wrote: | | To take that as the maximum is ignorant of bow making and the variations within. We KNOW (since that seems to be the key word here) that other replicas of specific MR bows such as MR 81A 1607 made using European yew of a very similar quality came out at 196lbs at a draw length of 32". That immediately makes the idea of the maximum poundage being 185lbs absolutely incorrect.. |
That is a variation of around 5%. If you add 5% to all of the MR results, you get a range of around 115 lbs to 200 lbs. If we assume that the bows on the MR were typical then most archers in 1511 were drawing about 160 lbs, not 200 lbs.
Author: Bronze Age Military Equipment, Pen and Sword Books
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Will S
Location: Bournemouth, UK Joined: 25 Nov 2013
Posts: 164
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| Posted: Mon 31 Aug, 2015 7:46 am Post subject: |
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Yes, but I don't believe the MR bows were typical.
You only need to look at the arrowheads of the Tudor period to arrive at a logical argument - small, light and designed purely for penetrating textile armour such as gambesons. Compare that to the large, heavy, plate-cutting heads found at Crecy for instance, and the notion that the MR bows were as heavy if not heavier doesn't make sense.
In layman's terms (and forgive the simplicity - I'm well aware of your expertise here), stronger armour = heavier arrowhead. Heavier arrowhead = heavier arrow. Heavier arrow = heavier bow. Why use the heaviest bow of all time to shoot one of the lightest heads at textile armour? Surely the heaviest bows would have been used during the period when the heaviest heads were in use? If the MR bows DID peak at 200lbs it stands to reason that that peak was quite a bit higher during the HYW which of course brings the average up with it.
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Dan Howard
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| Posted: Mon 31 Aug, 2015 7:59 am Post subject: |
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There were no "plate cutting" heads at Crecy. In order to have even a small chance of penetrating plate armour an arrow had to be heavy, it had to be shot at short range, and its head had to be made of hardened steel. Nobody has produced any of the "bodkin" typologies that have turned out to be made from hardened steel.
I think you seriously underestimate the effectivenes of properly quilted textile armour. The padded jacks worn during the Tudor period were just as effective at stopping arrows as solid plate.
Is there a study surveying the weight of extant arrowsheads between the 14th and 16th centuries? I'd like to see proof that there is a trend towards lighter arrowheads.
Author: Bronze Age Military Equipment, Pen and Sword Books
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Will S
Location: Bournemouth, UK Joined: 25 Nov 2013
Posts: 164
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| Posted: Mon 31 Aug, 2015 10:42 am Post subject: |
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I don't think you're overly familiar with the arrowheads being made and tested at the moment. The information is out there, I can assure you.
It doesn't take a huge amount of research (practical research that is) to learn about the relative weights of arrowheads and their uses. A well made Tudor bodkin (for instance a replica of the one found at Portchester Castle) such as the one below is almost always less than 15g (and many less than 10g.)
(Arrowhead on white background is one of my own, made by Miloslav Lasky Krizan and weighs 9g. The arrowhead on the black background is from the London Museum and weighs 11g)
Replicas of earlier lozenge-shaped heavy bodkins will easily reach the 40g - 60g weights.
(Again, head on white background made for me by Milos, and weighs 42g, arrowhead on black background from London Museum and weighs 63g)
To assume that the same bow would have been used for these two vastly different arrow types is (in my opinion) nuts.
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Cs. Norbert
Location: Romania Joined: 21 Aug 2015
Posts: 27
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| Posted: Mon 31 Aug, 2015 2:24 pm Post subject: |
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| Quote: | | I'm afraid that's wrong. We certainly do NOT know that the "heaviest" bow was 185lbs. All we "know" is that a computer model, which has been LONG since disregarded amongst warbow makers (as it's ludicrous to assume a computer model can predict the natural tendencies of a piece of wood bending, plus the skill of different bowyers, plus the effect certain tiller shape has on draw weight at different draw lengths) and a few replicas (using wood very different to the MR bows due to availability at the time - it wasn't even the same species of yew) peaked at 185lbs. |
Why was the computer simulated model theory, disregarded amongst warbow makers? It's not ludicrous to assume that a computer simulator can predict (with a certain tolerance) bow properties and performance. From what I understand the software was tested against different bow types, with different compositions and the test results have been close to the real bow tests. If the " MR 81A 1607" (MR replica, made from different yew of "similar" quality ) turned out to be 196 lb vs 185 lb in Dr. Kooi's simulation, than this would not contradict the validity of Dr Kooi's simulation, but it would turn into a debate like: which yew type properties (moe,mor,density) would better represent those bows back then, the one in Dr Kooi's simulation or the "similar" one from europe? If an expert would analyze the "similar" european yew for: moe,mor,density values, and input them in Dr. Kooi's simulation, the simulation result should be close to 196lb!
I don't have any problems believing that: today we can make MR warbow replicas that exceed 200lb with different yew, and back then, they could have also exceeded 200lb, and some(not the majority) of the medieval archers would have been able to use them.
| Quote: | | As for the idea that the 1/4lb arrow being "the average" or at least the one that the OP is using for all of his theories, that's quite frankly ludicrous as well. It shows a fairly large ignorance towards the actual equipment used, and displays knowledge built purely on certain people's theories plus a skim-read of the EWBS flight records. No practical experience whatsoever, I would imagine. I don't mean that to be condescending in any way, but these theories have been bandied around for countless years, and this is just repeating the same stuff. |
I never stated that 1/4 lb arrow would be "average", if you read the post again you'll see that I was referring to the 200lb bow when is stated: "I arbitrary consider a good balance between arrow weight and speed" if this is what led you to believe that I consider "average". For a 200lb bow, a 1/4 lb arrow would be almost average. If you were referring to the examples I used (155lb vs 175lb, with 1/4 lb arrows) I don't consider 1/4 lb arrows, average for 155lb bows, but these examples were the most relevant (to the main OP) that I could find. It would make sense to test the heavy bows with the heaviest arrows from EWBS, because that is how you can see the greatest increase (or lack off in that case) in bow performance!
We have Joe and Mark that tested 200lb longbows, but there isn't data on their performance (or it wasn't made public (why?)) ! I didn't find any cronographed tests of a 200 lb bow! Well we don't know the performance of the 200 lb bows (Joe and Mark most likely do), but we do have some performance examples [those that I repeatedly mentioned (and more, but not that relevant): 155lb vs 175lb, with the same arrow]. If my assumption is correct ( the diminishing returns in KE, would not be worth the increase in lbs to 200lb) then it would make a very strong argument for the under 200 lb limit.
| Quote: | | Unfortunately it seems very apparent that the OP has a clear idea of what he WANTS the answer to be, and no amount of argument will change that opinion, so I'm out. There are plenty of incorrect theories about warbows and their potential out there - another one will probably do no more harm. |
I still want what I mentioned in the OP( the estimative performance of bows with arrows that have the same ratio of gr/lbs, and it doesn't matter if it's 7 gr/lb or 11). What interests me the most is: the 200 lb warbow performance, and I've chosen 200 because that's the official record, not because I wouldn't believe that longbows could go over 200lb!
| Quote: | Yes, but I don't believe the MR bows were typical.
You only need to look at the arrowheads of the Tudor period to arrive at a logical argument - small, light and designed purely for penetrating textile armour such as gambesons. Compare that to the large, heavy, plate-cutting heads found at Crecy for instance, and the notion that the MR bows were as heavy if not heavier doesn't make sense.
In layman's terms (and forgive the simplicity - I'm well aware of your expertise here), stronger armour = heavier arrowhead. Heavier arrowhead = heavier arrow. Heavier arrow = heavier bow. Why use the heaviest bow of all time to shoot one of the lightest heads at textile armour? Surely the heaviest bows would have been used during the period when the heaviest heads were in use? If the MR bows DID peak at 200lbs it stands to reason that that peak was quite a bit higher during the HYW which of course brings the average up with it. |
Yes It would make sense that: if the arrows from the tudor period were lighter, and those that were used at Crecy were heavier, then bows from tudor period had lower lbs, and those that were used at Crecy had higher lbs. But it doesn't make sense to have high lbs (200+) in the tudor period to shoot light arrows! Also at 200lb draw it wouldn't be logical to use light arrows (1/4 lb arrows that were probably near the max ever used in any period, would be considered almost medium at 200lb draw, because of the gr/lb ratio that would be close to 9, and the estimated efficiency of 0.7).
In theory you can send a heavy arrow a bit faster with a high lb bow vs medium lb, but when you use a light arrow you wont make to much of a difference, because bow limb speed doesn't increase as much as draw lbs. The gains in KE from heavy bows would come from arrow mass, not from arrow speed. So what would make sense is: that in both periods (tudor and crecy) they used heavy and light arrows (same with bows) according to their needs!
What would be more absurd is: using tudor period (MR 81A 1607 MR replica) bows with light arrows only!
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Dan Howard
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| Posted: Mon 31 Aug, 2015 2:43 pm Post subject: |
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| Will S wrote: | | I don't think you're overly familiar with the arrowheads being made and tested at the moment. The information is out there, I can assure you. |
None of these arrowheads are made of hardened steel. You need hardened steel arrowheads to have even a small chance of compriomising plate. Even this is only for light plate. Once the plate gets over 2mm, it doesn't matter what arrowhead you use.
I do agree that lighter arrows suggest lighter bows but there are lighter arrowheads dating a couple of centuries earlier as well. Until you produce a study demonstrating that there was a general trend towards lighter arrowheads over two-three centuries, you have no case.
Author: Bronze Age Military Equipment, Pen and Sword Books
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Cs. Norbert
Location: Romania Joined: 21 Aug 2015
Posts: 27
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| Posted: Mon 31 Aug, 2015 2:57 pm Post subject: |
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I forgot to mention something!
If I'm not misunderstanding, the OP focuses on high lb bow performance (max KE, max arrow speed) and not the maximum lb limit of the MR warbows! It doesn't matter if they were 300lb draw weight, if we don't have any modern replicas of that lb, to test the performance. Also we do have 200lb bows replicas and they were tested, but we don't (at least I don't) know the performance data! If you know some cronographed tests of 200lb MR type longbows, or the maximum range with x gr/lb arrows delivered by that bow, please poste some links! I would also be interested in your estimation of max KE that an arrow (I would assume 1/4 lb to be a good example since is the max at EWBS, and we have something to compare it to) could generate when shoot from that (200lb) bow, and your calculation steps so we know how you ended with that result!
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Cs. Norbert
Location: Romania Joined: 21 Aug 2015
Posts: 27
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| Posted: Mon 31 Aug, 2015 3:43 pm Post subject: |
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| Dan Howard wrote: |
None of these arrowheads are made of hardened steel. You need hardened steel arrowheads to have even a small chance of compriomising plate. Even this is only for light plate. Once the plate gets over 2mm, it doesn't matter what arrowhead you use. |
I agree with you regarding plate penetration (it would be more correct to specify the quality). There are some inconsistencies in "The Knight and the Blast Furnace" and maybe some slight exaggerations. To have a more accurate calculation of the amount of KE needed to pierce a x mm plate (of y quality and hardness on V's scale) we should compare that data to the "Defence Academy warbow trials" (this one isn't to accurate as well). So we have:
Mark Stretton with a 140 lb longbow @ 32" with 87grams lozenge arrow (I chose this one since it has the best penetration on this test, and also the highest hardness) shoot at 46m/s, this generated a KE of 92J, and penetrated (at close range) a charcoal-rolled wrought iron plate of 2 mm (180 Hv) to a depth of 13mm from an angle of 20 degree "Bounced out on first attempt but strike was very close to deformation in plate caused by previous penetration. Second strike penetrated and remained in". This would be a superficial penetration, since the padding (the test lacked) would prevent injuries!
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Dan Howard
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| Posted: Mon 31 Aug, 2015 5:43 pm Post subject: |
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| Cs. Norbert wrote: | | Dan Howard wrote: |
None of these arrowheads are made of hardened steel. You need hardened steel arrowheads to have even a small chance of compriomising plate. Even this is only for light plate. Once the plate gets over 2mm, it doesn't matter what arrowhead you use. |
I agree with you regarding plate penetration (it would be more correct to specify the quality). There are some inconsistencies in "The Knight and the Blast Furnace" and maybe some slight exaggerations. To have a more accurate calculation of the amount of KE needed to pierce a x mm plate (of y quality and hardness on V's scale) we should compare that data to the "Defence Academy warbow trials" (this one isn't to accurate as well). So we have:
Mark Stretton with a 140 lb longbow @ 32" with 87grams lozenge arrow (I chose this one since it has the best penetration on this test, and also the highest hardness) shoot at 46m/s, this generated a KE of 92J, and penetrated (at close range) a charcoal-rolled wrought iron plate of 2 mm (180 Hv) to a depth of 13mm from an angle of 20 degree "Bounced out on first attempt but strike was very close to deformation in plate caused by previous penetration. Second strike penetrated and remained in". This would be a superficial penetration, since the padding (the test lacked) would prevent injuries! |
Which is why I specifically said "compromise", not "penetrate" and why I said "over" 2mm. According to Williams, the best plate in the Stretton test was the worst quality plate available at the time and, even at ridiculously short ranges, those arrows would not have injured someone wearing 2mm, even though the arrowheads used were far harder than any that have been found to date. The bow would have fared even worse if the plate was over 2mm, if the plate was better quality iron, if the arrows were shot from more realistic ranges, or if the arrowheads were made from the same material as extant examples. It is pretty clear that 2-3mm of plate is proof against these warbows unless there is a flaw in the metal.
Author: Bronze Age Military Equipment, Pen and Sword Books
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Cs. Norbert
Location: Romania Joined: 21 Aug 2015
Posts: 27
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| Posted: Mon 31 Aug, 2015 8:01 pm Post subject: |
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| Quote: | | Which is why I specifically said "compromise", not "penetrate" and why I said "over" 2mm |
Technically it did penetrate (superficially) the armor, but not the wearer, so compromise would be the better way of describing this. Yes it was the worst type of plate quality, and 2-3mm would be the thickness of the plate on vital areas (like the chest).
If we add padding and the specific rounded shape of the plate, I would imagine that you would need to generate a considerable extra amount of KE to achieve the same effect. The extra KE from "The Knight and the Blast Furnace" (that Williams added to the amount of KE needed to compromise armor) required to penetrate trough padding and flesh, is excessive in my opinion. I didn't calculate how much would charging speed affect penetration, but I think it would be safe to say that, over 2mm (of the worst quality) would be relatively enough to protect the vital areas (depending on: arrow profile and hardness, arrow KE, the amount of arrows received by the same person, time of exposure, the deformation caused by the arrows and a slight chance that another arrow would find it's way through the compromised spots on the armor, this would be unlikely at greater ranges because of the heavy arrow drop angle, so those arrows would mainly affect horses). At close range they would be playing "russian roulette"! To be able to make it (in effective time) at that close range, they would need lucky horses! After they (the knights) make it to that close range, they wouldn't be able to disrupt the formations (which would be the cavalry's primary goal and advantage) if the archers were prepared with wooden stakes in the ground. Allot of factors were working against the knight, especially at close range.
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Cs. Norbert
Location: Romania Joined: 21 Aug 2015
Posts: 27
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| Posted: Mon 31 Aug, 2015 10:01 pm Post subject: |
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| Quote: | | You only need to look at the arrowheads of the Tudor period to arrive at a logical argument - small, light and designed purely for penetrating textile armour such as gambesons. Compare that to the large, heavy, plate-cutting heads found at Crecy for instance, and the notion that the MR bows were as heavy if not heavier doesn't make sense. |
I assume that you refer to lozenge when your using the term "heavy, plate-cutting heads".
Crecy - 1346
100 years war - 1337-1453
war of the roses 1455-1485
MR ship 1510-1545 in tudor period, Henry VIII
This is what I've found in the Defence Academy warbow trials:
| Quote: | All arrowheads were made by experts with a large degree of professional
experience. The heads were made from Victorian iron. The lozenge arrowhead
was intentionally hardened using a traditional technique of heating in a pot of
bonemeal. Lozenge heads like these were in use from the end of the Hundred
Years War and were employed throughout the Wars of the Roses. They are
similar in appearance to heads commonly found on crossbow bolts |
So we have: "the large, heavy, plate-cutting heads found at Crecy" (1346) and "Lozenge heads like these were in use from the end of the Hundred Years War and were employed throughout the Wars of the Roses" 1453 - 1485.
Would the later statement contradict yours? Or we could assume that those heavy heads were used at Crecy and in the war of the roses! It doesn't specify that those heavy heads weren't used after the war of the roses (1485).
The race between armor and weapons and the improvements in metallurgy, would also lead us to believe that, most probably those arrowheads were improved and used in the 15 century (not to pierce med to high quality plate of course).
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Cs. Norbert
Location: Romania Joined: 21 Aug 2015
Posts: 27
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| Posted: Mon 14 Sep, 2015 2:38 am Post subject: |
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I cannot edit the OP and I want to include the subject "estimating armor performance" in this topic. The OP focuses on longbow performance and the data will be compared with armour effectiveness data from "The Knight and the Blast Furnace" and the "RA's Arms and Armour Journal" studies. The new title should be "Estimating longbow performance and armour effectiveness", therefore, discussions on armor penetration will be on topic (it might have been on topic with the OP, since armor penetration is related to longbow performance).
To integrate this subject, I will divide the topic in 2 parts: Part I - estimating longbow performance and Part 2 - estimating armor effectiveness.
PART I - ESTIMATING LONGBOW PERFORMANCE
Discussed in OP and no final conclusions can be drawn (work in progress...), but I can summarize what I know so far:
-the MR longbow max draw weight is estimated by Dr. Kooi (with software that simulates bow performance) at around 180 lbs,
-recent MR warbow replicas, made with italian yew (or similar high density) exceeded 190 lb (and probably 200 lb),
-we currently have 2 archers that can draw warbows close to 200 lb (Joe Gibbs and Simon Stanley) and one that can exceed 200 lb (Mark Stretton),
-we have no performance data from 200lb bows, only in the med-high lb range,
-the med-heavy EWBS war arrows used for testing are in the 980-1750 grain range,
-the current EWBS distance record with the 980 grain arrow is 306 yards, performance achieved with 170 lb bow and arrow speeds of ~210 fps,
-the above warbow set the 1/4 lb arrow distance record of 241yards (previous was 240 yards with 155 lb warbow),
-I don't have a cronographed 1/4 lb arrow speed, but considering the 155 lb and 170 lb bows had similar performance with that arrow, I would presume that, the generated KE would be ~ 150 J,
-the bow from the primitive archer armor penetration test was 160 lb, and generated 156 J(don't know if arrow speed was measured),
-considering the above, we can conclude that, warbows in the med to high lb range, can shoot arrows that can generate up to ~160 J (theoretically at least).
I would appreciate if someone would provide the profile dimensions (with n number of segments, x and y horizontal and vertical segment dimensions, and width and thickness in each segment) of the highest lb MR longbow (or 180-200 lb replica), so I could estimate the mass of the bow (I will increase the density of the material until I get to that lb range)!
PART II - ESTIMATING ARMOUR EFFECTIVENESS
RA's Arms and Armour Journal
Warbow
-140 lb warbow @32"
Arrows
3 arrow types:
-long bodkin - 71grams, hardness 190-200V, tip 300V,
-short bodkin - 70g, hard 230-250V,
-lozenge - 87g, hard 480-500V, "The lozenge arrowhead was intentionally hardened",
Armour
3 iron flat plates backed by 90mm "Plastalina":
-"Thin puddle wrought iron* 1.15 mm, good quality Victorian provenance, Vickers hardness: 206 Hv (max 221, min 191), microstructure: large, irregular grains, slag inclusions. *Iron ore smelted in coke furnace to cast iron, then furnaced and reheated to remove impurities through stirring (about 98% pure iron with slag)",
-"Charcoal-rolled wrought iron 1.95–2 mm*, probably similar to medieval quality, about 99% pure iron with slag. Vickers hardness: 180 Hv (max 187, min 170). Microstructure: fine, regular grain structure with few slag inclusions. Good quality, strong material. *This would probably represent some of the thickest parts of the breastplate"
-"Thick puddle wrought iron 3.25 mm. As 1.15 mm plate but of lesser quality (required numerous attempts to get good hardness readings due to inconsistencies), Vickers hardness: 172 Hv (max 182, min 163). Microstructure: large amounts of slag inclusions, the through thickness structure of the material is lamina in its appearance"
# What would be the estimated fracture toughness for the above plates (would it be similar to "Swedish" wrought iron -parallel to rolling or perpendicular to rolling)?
Test results
Velocity and KE
-long bodkin - velocity 46 m/s, KE 75 J,
-short bodkin - velocity 49.68 m/s, KE 86 J
-lozenge - velocity 46 m/s, KE 92 J
1.15 mm plate penetration:
-all 3 types penetrated 100 mm at 0 degree angle,
-short bodkin and lozenge have the same penetration (86 mm and 92 mm) at 10, 20, 40 degree,
2 mm plate penetration:
-short bodkin penetrated 9 mm at 0 degree "Araldited head penetrated, then bounced out",
-short bodkin penetrated 7mm at 10 degree "bounced out",
-short bodkin penetrated 6 mm at 20 degree "bounced out",
-lozenge penetrated 16 mm at 0 degree,
-lozenge penetrated13 mm at 10 and 20 degree,
-lozenge penetrated 5 mm at 40 degree ...
3 mm plate penetration:
-no penetration
I've bolded the short bodkin, because it will be the most relevant example for comparison with the data from A. Williams "The Knight and the Blast Furnace".
The Knight and the Blast Furnace
Section Nine
Chapter 9.4 (page 927)
| Quote: | | Jones (1992); A 70 lb draw longbow was used to shoot bodkin arrows from 10 m at targets of "Victorian wrought iron" (presumably puddled iron). The average initial energy of the arrows was 46 J. |
.......
Initial energy - 46J, target thickness - 2 mm, angle of attack - 0 (deg), result = penetrated by 11 mm # this is almost the same penetration length as the short bodkin on RA's Arms and Armour Journal, with ~half the energy!
THICKNESS
| Quote: | | The energy needed by missiles to defeat mild steel plates is summarised in the Tables of Resistance below. "Defeat" implies penetration of a point by 40 mm, or a complete hole made by a bullet |
Table of Resistance to ARROWS
Thickness of plate - normal (0 deg), 1 mm - 55J, 2 mm - 175J, 3mm - 300J, 4 mm - 475J
| Quote: | | These results are extrapolated from experimental data with 2 mm mild steel of 0.15%C, having hardness 152 VPH (100g load) and toughness 235 kj/m2. |
| Quote: | | Data was obtained by the author (and some of his students) carrying out impact tests on a variety of modern (and therefore expendable) materials, using a Rosand IFW5 tester in the Department of Engineering at Reading University. They were carried out on a variety of modern steels and "Swedish" (so-called) wrought iron—which is approximately comparable in metallurgy and thickness (1.8-1.9 mm) to munition armour of low quality |
(i) simulated bodkin arrows against mild steel plate:
1 mm 30 J (1.5 mm 80 J) just starts to penetrate, but if 40mm depth of penetration is also required to take place, then
1 mm requires 55 J; 1.5 mm requires 110 J; 2 mm requires 175 J;
| Quote: | So if the energy required to defeat a 1 mm plate is E, then the energy needed (E') to defeat a greater thickness (t) would be found by multiplying E, not by the thickness, but by the thickness enhanced,
E' = E x (t)^1.6 |
SLAG
APPENDIX 5: EFFECTS OF VARYING SLAG INCLUSION CONTENT ON FRACTURE TOUGHNESS (DETERMINED BY COTTRELL-MAI TESTS).
| Code: |
"Swedish" wrought iron (parallel to rolling) - slag 1.5%, carbon 0%, fracture toughness R = 228 KJ/m2,
"Swedish" wrought iron (perpendicular to rolling) - slag 2.2%, C 0%, R = 170,
puddled wrought iron (parallel to rolling) - slag 4.7%, C 0%, R = 120,
puddled wrought iron (perpendicular to rolling) - slag 7.5%, C 0%, R = 28,
modern "Armco" iron - slag 0%, C 0%, R = 195 |
| Quote: | Compared with modern (virtually slag-free) material the presence of 1% or 2% of slag would have reduced the fracture toughness by anything up to a quarter.
Armour with a low slag content like that found in the best products of North Italy and South Germany, might have lost only 10% of the toughness of a modern metal, while munition armour of high slag content might be diminished by 20% or more. The energy required to defeat such armour would consequently be reduced considerably. It should be noticed that reduction in slag has a much greater effect than increasing the carbon content. |
# If you look at the diagram on page 932 "Fracture toughness and slag content", you will see that the curve between the different irons is almost uniform [0% = 210 kj/m2, 2% = 185-190kj/m2, 2.2% = >180kj/m2(instead of 170kj/m2) and 8% = 0 Kj/m2], so 210 (max) - 185 (2%slag) = 25kj/m2(11.9% reduction) or 210 - 170(well below the curve at 2.2%) = 40kj/m2 (19% reduction)! I've reproduced the diagram in more detail on a larger scale with a symmetric curve(that almost touches all the points), and the maximum reduction from 0 to 2% slag is 11.28% and not 20% to 25% (0 slag would correspond to "armco" iron - 195 kj/m2, and the difference to 2% is 22 kj/m2)!
| Quote: | R - 200 - 5.S^2
where R is the fracture toughness,
and S is the slag content, expressed as a percentage of the cross-sectional area. |
# Using this formula for 2% slag and 0 carbon we get: 200 - 5 x 2^2 = 200 - 20 = 180 (10% reduction not 20%-25%)!
If my above assumption is correct, the 50% and 75% estimated ratios for *iron and **low-carbon armors, might not be valid!
CARBON
APPENDIX 6: EFFECTS OF VARYING CARBON CONTENT ON FRACTURE TOUGHNESS MEASUREMENTS
(DETERMINED BY COTTRELL-MAI TESTS
| Code: |
modern "Armco" iron - slag 0%, carbon 0%, fracture toughness R = 195 KJ/m2,
modern mild steel - slag 0%, C 0.1%, R = 235,
modern 1050 steel - slag 0%, C 0.55%, R = 320,
modern 1075 steel - slag 0%, C 0.71%, R = 330,
modern gauge-plate steel - slag 0%, C 0.85%, R = 392 |
APPENDIX 3; EFFECTS OF VARYING HARDNESS ON IMPACT TESTS
| Quote: | | Four modern plain carbon steels were tested (in the form of 2 mm sheets) with simulated bodkin arrowheads, at a constant energy (100 J) of impact. |
| Code: |
Steel Mild 1050 1075 gauge-plate
carbon(%) 0.1 0.55 0.71 0.85
penetration(mm) 22.3 8.9 6.3 6.1 |
| Quote: | | So increasing the carbon content of mild steel to 0.25%-0.3% reduces the extent of penetration by perhaps a quarter, and increasing it to 0.5% halves the penetration at least. Or, to put it another way, if 175 J was required to completely defeat 2mm mild steel plate, then over 400 J will be required for 0.5% carbon steel. |
| Quote: | | But impact tests on heat-treated 1050 steel (quenched and tempered to 460 VPH) indicate that the energy required to just penetrate it was increased by between a quarter and a half. This steel in the form of 2mm sheet (as received) was just penetrated by a point with 180 J, but needed 250 J for penetration (and just over 300 J for defeat) after heat-treatment |
# Assuming that "defeat" is still >40mm penetration, then we have:
JSP (just started to penetrate) - defeat
-1mm mild steel (1%C, 235 kj/m2 FT) needs 30J to JSP and 55 for defeat (I would speculate that 30J are needed to plastically deform the steel until the point just penetrates or creates a crack, and up to 25J are needed to gradually increase that crack until the base of pyramid head penetrated),
-1.5mm of the same mild steel needs 80J to JSP and 110 for defeat,
-2 mm mild steel needs x joules to JSP and 175 for defeat,
-2 mm of 1050 (not heat treated) needs 180J to JSP and x for defeat,
-2 mm of 1050 heat treated steel needs 250J to JSP and 300 for defeat ( apparently not over 400J, assuming defeat is the same at over 40mm with the same pyramid head angle)
If we input the known values on a XY Chart, we have: x axis(horizontal) - 55, 110, 300, y axis - 30, 80, 250.
If you connect the points, you'll see that it generates a straight line (from this, I assumed that the relation is a linear one).
So for 175J defeat, we have ~138J to JSP, and for 180 JSP, we have ~222J.
With extrapolations from that chart I was able to generate the following formula: if JSP = P , defeat "D" = P x 1.1136 + 21.592 and P = (D - 21.592) / 1.1136
# If we have: 2mm mild steel with ~138JSP and 175J for defeat and ~86J for 9mm penetration (which I would estimate it to be close to JSP) in 2 mm charcoal-rolled wrought iron, then charcoal-rolled wrought iron would be ~60-65% of the mild steel toughness.
# Regarding this:
| Code: |
Steel Mild 1050 1075 gauge-plate
carbon(%) 0.1 0.55 0.71 0.85
penetration(mm) 22.3 8.9 6.3 6.1 |
we could consider that, mild steel is 40% the toughness of 1050 or 1050 is 2.5 times the toughness of mild steel, since 22.3 is ~2.5 x 8.9! So in theory you would need ~ 437J to defeat 2mm of 1050 steel if you need 175 for mild!
I would speculate that a constant load of 100J was used under a specific amount of time, that would equivalate x amount of joules. With x amount of joules you can achieve a 22 mm penetration on mild steel, but you don't need 1.8 times the x amount of joules to penetrate to 40mm (for 1.5mm mild steel you need 110D-80JSP =30J for 40mm), so 1050 steel might not be 2.5 times mild steel!
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Benjamin H. Abbott
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| Posted: Mon 14 Sep, 2015 10:14 am Post subject: |
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Like Dan, I find the measurements and tests published in The Great Warbow fairly convincing. I typical go with the idea that the standard high-quality English archer drew a 150lb bow that managed 110-146 J, depending on arrow weight.
However, various points of evidence suggest that the Mary Rose bows - which are from 1545, not 1511 - aren't necessarily representative of other historical English warbows. While they may have been elite troops to some extent, naval archery may not have require as powerful bows. The arrows recovered from the Mary Rose certainly don't seem well-suited for defeating armor; Roger Ascham considered poplar inferior ash, and some tests of replica popular arrows have produced poor results (one was under 100 J with light arrow shot from a 150lb bow). Writing near the end of the sixteenth century, Sir John Smythe claimed that a significant number of archers could shoot 400-480 yards with flight arrows, though he didn't consider this range militarily useful. And other period sources claim the similarly long ranges. Assuming bows of similarly efficiency to the Mary Rose replica tested for The Great Warbow, shooting even 400 yards would require either quite light arrows or a very heavy bow. Simon Stanley only managed 424 yards with a 53.6g arrow from a 170lb fiberglass flatbow that's more efficient than the Mary Rose replica - and with a favorable wind. So the flight range of 400+ yards stands consistent with the notion 200lb bows.
It's also possible some or many historical bows performed a lot better or a lot worse than the replica tested in The Great Warbow. Certainly many present-day longbows perform worse, while some supposedly perform better.
Going well beyond England, there's that Qing account of an archer winning a contest with a roughly 240lb bow.
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Cs. Norbert
Location: Romania Joined: 21 Aug 2015
Posts: 27
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| Posted: Wed 16 Sep, 2015 10:18 am Post subject: |
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| Benjamin H. Abbott wrote: | | Like Dan, I find the measurements and tests published in The Great Warbow fairly convincing. I typical go with the idea that the standard high-quality English archer drew a 150lb bow that managed 110-146 J, depending on arrow weight. |
I don't know in what category to put the "standard high-quality English archer" (in 15C), the above average (in built and strength) or close to high! If they would be in the above average, then I suppose that, those in the high strength category would draw bows with >180lb force!
| Quote: | | However, various points of evidence suggest that the Mary Rose bows - which are from 1545, not 1511 - aren't necessarily representative of other historical English warbows. |
This might be true (or not), but I do believe that, if they didn't improve the performance (considering the arms vs armor race), they certainly didn't make them worst than those before!
| Quote: | | While they may have been elite troops to some extent, naval archery may not have require as powerful bows |
This also might be true, since they didn't encounter fully armored knights at sea, but that doesn't mean they used the same equipment when engaging other targets at land!
| Quote: | | The arrows recovered from the Mary Rose certainly don't seem well-suited for defeating armor |
It depends on what armor, you don't need heavy arrows to defeat good mail, you might need medium to heavy arrows to defeat low quality plate at close range! I believe that a tudor period livery arrow(>63.5g) shoot from a very efficient 170 lb MR bow would have good chances to penetrate (at close range) low quality munition breastplate, and even better chances to injure the non vital (but important) areas where armor is less thick! As you suggested, you don't need to penetrate heavy armor at sea battles (that is if they didn't plan to engage the enemy on land, and the sea might have been the best route to the enemy), thus the reason why they didn't need heavy arrows in that context! There is no proof that they only used light to medium arrows in 15C, I would imagine that, they used arrow types and weights according to enemy protection! If you were referring to arrow head weight and type and not the shaft, then this https://www.youtube.com/watch?v=KR0pvYkZy7A is a good example of a light arrowhead similar to those from tudor period, that can penetrate low quality munition armor when shoot from a powerful bow (assuming that it was not backed by mail or at least a tough gamberson) !
| Quote: | | Writing near the end of the sixteenth century, Sir John Smythe claimed that a significant number of archers could shoot 400-480 yards with flight arrows, though he didn't consider this range militarily useful. And other period sources claim the similarly long ranges. Assuming bows of similarly efficiency to the Mary Rose replica tested for The Great Warbow, shooting even 400 yards would require either quite light arrows or a very heavy bow. Simon Stanley only managed 424 yards with a 53.6g arrow from a 170lb fiberglass flatbow that's more efficient than the Mary Rose replica - and with a favorable wind. So the flight range of 400+ yards stands consistent with the notion 200lb bows. |
I would also agree that, over 300 yards would not be a military useful range, considering the lack of accuracy and the low KE generated at that range from the light arrows, that wouldn't even benefit from the increase in KE that heavy arrows have when the drop angle is high enough (terminal velocity). I think that, range does not accurately reflect the bow performance in penetration! "Assuming bows of similarly efficiency to the Mary Rose replica tested for The Great Warbow, shooting even 400 yards would require either quite light arrows or a very heavy bow" I can agree on the light arrow part for the 400 yards range, but not the heavy bow part! Heavy bows are not used to shoot light arrows, if you are referring to medium arrow weights that by your assumption, can reach over 400 yards if shoot from a heavy (>180lb traditional) bow, then I can't agree on this either! I will use for my arguments the EWBS range records:
Note: Simon Stanley achieved 424 yards with an arrow weight that is considered standard by EWBS, and a 170lb bow that has a considerable efficiency advantage over the traditional ones, so it wouldn't fall in the traditional category!
-with standard arrows (52g), Joe Gibbs managed 315 yards with 137 lb MR warbow replica made from USA yew;
-with the same arrow , and non historical warbows (160lbs and 170 lbs) he managed 281 and 288 yards;
-with livery arrows (63.5g) and 170 lb MR warbow he managed ~306 yards at over 210fps arrow speed,
-with flight arrows (under 50g) and 132lb MR bow, Alistair Aston managed 370 yards;
-with flight arrows and 130lb non historical bamboo bow, Alistair Aston managed 438 yards,
As you can see, only the 130 lb bows with flight arrows managed ranges close to Simon's 170lb bow and 53.6g arrow, and the most efficient MR replica only managed 315 yards with arrows in the same class as the one shot from Simon's bow! You don't see any bow in the 180-200 lb range breaking any record, not even the 200lb bow that Mark Stretton used for the 200lb draw record! Joe Gibbs also used bows over 190lb and it appears that he didn't set any flight record with them! Considering the above, a 200lb traditional self bow, wouldn't have a considerable advantage (there is a great possibility that it would underperform) over the 137, 160 and 170 bows ! From the other 2 previous examples with the 170lb MR bow that Joe used to break the 300 yard record (with livery arrows) and 240 yard record (with 1/4lb arrows) and the 155 lb MR bow that had a similar performance with the 1/4lb arrow, we can conclude that, a 200 lb selfbow wouldn't have any considerable advantage over those bows either!
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Benjamin H. Abbott
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| Posted: Wed 16 Sep, 2015 11:01 am Post subject: |
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Heavy bows are indeed used to shoot light arrows. People archive velocity and/or distance records by shooting the lightest arrows they can from the heaviest bow they can. The best Turkish flight bows were 150+lbs. Contemporary velocity records come from shooting absurdly light arrows from extremely heavy (180-195lb) compound bows.
However, given Aston's records, I guess some English-style bows can effectively shoot very light arrows and maybe many heavier ones can't. So perhaps Smythe's archers were managing 480 yards with 130-160lb bows and very light arrows.
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