Draw weights of medieval crossbows, longbows and modern crossbows

[@commander31able60]

Came to watch crossbows and bolts. Learnt some maths that I never paid attention to in school. Double nice.

[@PDeRop]

Only rare people like Tod can teach Maths. Schools cannot afford that level of skill.

[@PDeRop]

Generał WP if you learned it in school. Either you had a rare teacher, or you did not need the teacher. Which were you?

[@commander31able60]

@@moscuadelendaest you calculated foot-pounds of energy in primary school? must've been nice.

[@katt2002]

@@commander31able60 I think he didn't know which math you're talking about, the first part of the video is indeed talking about area of the triangle which is indeed primary school.

[@darinduchev9315]

This guy just captures my attention every time I watch his stuff. Love the precise, thoughtful experiments, and that he's a brilliant master of his craft. Cheers!

[@gozer87]

Great video. The numbers really put things in perspective.

[@MisterKisk]

The other thing to consider in regards to the actual numbers, is the material of the arrowhead/bolt head. Hardened steel, soft low carbon steel, is it sharpened, and even the cross section/shape of the head. While the numbers themselves are not that high in comparison to firearms, there's a whole bunch of other aspects that are also important when considering the lethality of a bow or crossbow. .22 LR might kill a person, but it would take proper shot placement, and a very unlucky individual. It has very low probability to hitting a vital structure of the body bringing about incapacitation or death. While getting shot with any one of the projectiles from the crossbows and bow you shot, the probability of killing or seriously wounding is significantly higher. Just for some additional comparison; a standard MLB regulation baseball thrown at 95 mph has a kinetic energy of 117.5 Joules. Batters get hit fairly regularly, and thankfully they aren't dying anymore (in large part due to batting helmets and other rule improvements).

[@elgostine]

i'd say on your l;ast point definately where projectile elasticity and surface area come into play. also a modern crossbow is often of materials that cant handle the very high stress of impact, since id likely say they arnt designed for it compare thast though to jeorg sprave the shloingshot guy and his 'plumbers nightmare' arrow shooter, launchinngg projectiles at aroundf 700-900 joules, ive no doubt that would pierce plate armour no trouble.

[@Tananjoh]

IIRC Alan Williams in his book "The Knight and the Blast Furnace" did comparisons of arrows and bullets (in this case round balls which would be worse than modern bullets) capabilities to penetrate metal plates. The balls needed a lot more energy to penetrate the same plate and of course had more energy.

[@2bingtim]

That makes sense. Bullets aren't as pointy & usually of softer metals.

[@MDgunship]

When I taught Hunter Safety, we would demonstrate the difference in the mechanics of the projectiles and the impact on penetration. We would shoot at a 5-gallon pail of sand with Winchester .243 and .308 caliber rounds. The pail would always trap the rifle projectiles. When the same pail of sand wash shot with a modern compound hunting bow at 65 lb. draw weight with a broadhead arrow, the arrow would always protrude through the bucket (plastic 5-gallon pail). Projectile design and physics are very important in determining terminal ballistics.

[@ToothbrushMan]

What about momentum? The damage done to a target is not just the energy, but also the force applied. Which is roughly the momentum divided by the time to stop the projectile.

[@nickverbree]

Fantastic video! Just curious, do you need to unstring a steel bow to prevent set, or are they fine left strung?

[@ramennight]

isnt that longbow hunting bow draw weight not war bow draw weight? I kind of wonder if you should have put medieval hunting longbow, instead of just longbow, as people may take it to mean what the warbows where like. Understand why you didnt use a warbow though, those things are super hard to use without life long training. Enjoyed the video. EDIT: Thanks for covering what war weights did later in the video.

[@thalivenom4972]

he did mention it was lighter.

[@bulcsuv]

Drag is proportional to the square of speed, therefore quick projectiles loose more energy on their way to the target. Heavy and slow crossbow bolts start with less energy but preserve more during their way.

[@ViperVenom16]

However they fall "faster". Meaning that the archer had to account for more drop.

[@thewinterasp]

Not to mention a function of damage isn't necessarily the same for firearms and crossbows. A slow moving bolt just needs to penetrate armor and flesh and cause bleeding. The larger the diameter of the bolt head the larger the wound, the more bleeding occurs. Bullets have small diameters even when dealing with huge cartridges like .50bmg (around 12.5mm). Thus when it strikes a target the initial hole isn't necessarily that large. The speed however, is enormous comparatively, and counts for much more of the damaging potential (never judge a bullet solely by its diameter, aka caliber). This means when it hits a target and dumps even a portion of its energy into a target the hydrostatic shock which creates a large temporary cavity and a smaller permanent cavity. In essence your looking at tearing a hole mostly by energy of impact to create a lot of bleeding and damage versus versus piercing a hole with a relatively large diameter. As a side note you can see this in action by watching ballistic gel tests with a slower round, say .45 acp versus a fast round like a 5.56x51 NATO.

[@DmdShiva]

@@thewinterasp Long, narrow bullets create more physical trauma than shorter fat bullets, because all bullets tumble on entry (see the work of Dr. Martin Fackler et al.), but a greater increase in the permanent wound cavity (as opposed to the temporary wound cavity) is caused by fragmentation of the projectile.

[@filianablanxart8305]

Well, long narrow bullets behave * Differently * than short fat bullets in Terminal Ballistics ( and external balistics for that matter ). But there are a whole bunch of additional factors , and you can't make generalizations from just one factor . The design goal of non-expanding FMJ bullets is to at least tumble upon impact, and ideally subsequently fragment . This is effected by the stability of the bullet ( rpm of spin), and multiple factors of internal bullet design . Center of gravity front to back , jacket thickness , jacket hardness , external or internal scoring of jacket, presence or absence of cannelure , and actual impact velocity . There are inherent compromises in bullet stability . To oversimplify , for maximum tumbling on impact , a bullet should be just barely stable enough to be flying point first . But for long range accuracy , accuracy in all climate conditions , and penetration of hard barriers , the more stability the better . ( Stability being a factor of bullet RPM , which is effected by both twist rate, and muzzle velocity .) ( Insert long history of evolution of U.S. ammunition, twist rates, and barrel lengths for 5.56 weapons, with terminal performance going up & down . ) If small caliber bullet performance isn't ideal , big non tumbling bullets are better than small non tumbling bullets . And throughout history generally , there have been lots of small bullets that performed poorly , or at least been designed with greater emphasis upon factors other than terminal performance . And of course , this is all within the arbitrary context of International Treaty , requiring nominally non expanding ammunition against certain Recognized Combatants . For hunting, personal defense , law enforcement , and certain Counter Terrorism , it takes a really tricked out FMJ , performing exactly as designed, under ideal conditions to match a rather mediocre expanding bullet .

[@adams651]

True but not very relevant at distances under 200 meters or more likely under 100 meters that most warbows are regarded as being prime effective range.

[@SymbulYT]

Always love the trademark zero bullshit production on Tod videos.

[@chase_h.01]

If modern crossbows are the best in the end, i wish they'd make them less ugly lol

[@skategreaser]

That's why they're camouflaged, so its harder to see how ugly they are.

[@Giblet12]

They aren’t ugly at all?

[@lultopkek]

@@Giblet12you are just a nerd

[@yorkshire_tea_innit8097]

They know their market :D @Memeologist

[@prjndigo]

They really aren't. There's a problem with manufacture and engineering and light-weight arrows/darts that is just retarded.

[@madichelp0]

Exceptional video Tod. Really informative.

[@linmal2242]

@nd the motion. Great explanation.

[@Chasmodius]

I asked this on another crossbow video of Tod's, but it would probably fit better here: Do you know if there is a materials-engineering reason they didn't use compounding pulleys on bows and crossbows in the medieval era, or was it just that no-one had thought of trying off-center pulley wheels? It's a really weird idea to wrap your head around, from a geometry perspective, but they had some pretty inventive people between Pythagoras and the middle-ages, and LOTS of experience with making and using bows.

[@Llongbow52]

The first compound bow was invented in the 1960s, i guess they didnt have the technology in medievel times.

[@zramirez5471]

You made an interesting point at the end but I think you're just shy of the mark: are your bows or Joe Gibbs bows as good as the BEST bows of the time--probably not. Are they as good as the run-of-the-mill mobilize the country to arms quality of weapons that were likely made during a period like the hundred years war? Probably as good or better. The King's sword isn't measured the same as that of the yeoman, and bows I'm sure are much the same.

[@vanivanov9571]

Looking at the efficiency of Joe's longbows in the Agincourt test, it was rather disappointing. A good bow can put out about as many joules as it has pounds of draw weight, at about a 1:1 ratio. His was at a 100:74 ratio. I once saw a 180 lb bow that barely put out any more energy than his 160 lb bow, admittedly (of course, arrows make a big difference to readings).

[@Intranetusa]

@@vanivanov9571 Were those recurve and/or compound bows? Longbows are self bows and are not as efficent at transfering the energy into the arrow as other types of bows.

[@filianablanxart8305]

I'll readily concede that Joe Gibbs ( or other other quality Bowyer's ) long bows have efficiency on par with military issue bows from back in the day . The big difference is the test bow has a draw weight well below historical .

[@adams651]

@@filianablanxart8305 If we go by the Mary Rose samples then 95 is underweight with the average being around 140-150lbs but the math works similarly so long as we keep in mind what Tod says about ignoring efficiency which is actually super important and an area which causes most of the controversy from what I have seen. The heavier warbows in the 180-200lb range have thicker cross-sections which gives more potential energy but lowers the efficiency. They use heavier arrows than lighter bows which increases the amount of potential energy transferred into the arrow but still losses efficiency and all tests I have seen indicate loss of 10-20% fps but the heavier arrows have more momentum and did have higher potential energy than lighter warbows. Compared to a horn/sinew Manchu bow that has 150lb draw but is 25% more efficient but also has a shorter stroke the math indicates really similar energy delivered to a target by a slightly lighter, shorter arrow that moves at a higher initial velocity which translates into less drop (more accuracy). The result... the top end warbows of English archers and steppe warriors were really quite similar in armour penetration with the steppe bows being smaller and more accurate but also more expensive to make and more difficult to maintain. For steppe cultures that is not a huge drawback because bows were the main weapon of the steppes and there was no need for ordinances such as England created to mandate men to practice archery.

[@thundercactus]

In regards to whether a great modern bowyer can match the *best* medieval bowyer, well we simply can't know for certain. But given that they're both humans doing a task with a clear goal, the answer is undoubtedly yes, what makes this question unanswerable is the fact that we don't have a point of comparison. What we do know, is that we actually have the math to PROVE that we can make the best bow possible. We can factor in all the variables; things like hysteresis, the return of the limbs, drag mechanics, the application of force over distance, etc. And we can look at that number, determine what the *theoretical* maximum efficiency of a 160# longbow should be, then keep building longbows until we get the closest tested number to the theoretical number. What we DO know about the medieval method of crafting, is that perfection was not only complete mystery, but also often times a trade secret. So the "best bow of the time" was almost certainly very regional, and literally limited to the best bow that anyone was able to produce at the time. That could have been the maximum theoretical performance of a longbow, or it could have been 70% of what a longbow is actually capable of. But they didn't have the formulae to math it out, they didn't really have the measuring equipment to quantify the results precisely (other than range and penetration), and the records of "best longbow ever made" are tenuous at best, since once an event has been removed from 1st person account, it becomes less of an actual fact and more of an arguable point: Your great grandfather claims he knew a man that could make longbows that shot 300 yards! But you tell your friend who's been made hundreds of longbows over the last 20 years, and he's never made a bow that shot more than 260 yards, and none of the bowyers he knows have ever made bows that shot more than 250-270 yards. The bias of experience results in the 300 yard claim being dismissed as crazytalk, regardless of it being true. But now, we have official records backed by photographic or even video evidence, much harder to dismiss. That being said, as Todd has mentioned, they didn't have the math, they didn't have the equipment, but they had the same brains. So a bowyer could continue to make bows, changing little things here and there, until they found the best result. So simply by trial and error, they were bound to make some pretty impressive bows eventually, as long as they kept trying. So in summary, COULD a modern bowyer make a longbow that replicated the BEST longbows made in medieval times? Absolutely. We can use the same materials, and we have the same brain. We have some scientific advantages to gauge how close we are to the end result, but ultimately it just comes down to making bows until you get the best result. And that end goal, maximum perfect result, has not changed in 600 years.

[@johnsteiner3417]

I just want to say, as someone who has tutored college students for eighteen years, you did an excellent breakdown of the physics and math calculation, as well as comparison to modern weapons.

[@chrisabraham8793]

How efficient is the Mongolian type bow over the Long bow, i was going to ask this in another video you showed.

[@kovi567]

You mean recurve vs long bow?

[@Tyr1001]

i read a study done by some university students awhile back that went in to just that. They concluded that in terms of efficiency, the chinese bow was about as efficient as any traditional bow can get. Not much of a surprise considering they used it for so long, even long after european firearms outclassed the bow in terms of battlefield efficacy.

[@snafu2350]

Presumably you mean the recurve design (as opposed to the compound construction)? Both had significant benefits & drawbacks Recurve bows of that period are expensive to manufacture in both cost & time & pack about as great a punch as English simple longbows. /However/ the significant comparison to draw was (?is) in the different styles of warfare: Orientals tended to prefer horse archers whereas Europeans preferred foot. Obviously a longbow is an impractical weapon to use from horseback, while the recurve can be designed to optimise the slash/attack cavalry tactics of the Eastern style /in a major battle/ (prolly a 'memento' of Ghengis' hordes: 'It worked then, so we did it this way!')

[@kovi567]

@@snafu2350 ...They were used by the scythians in the antiquity already. Nothing about ghengis' memento or whatever. Also just cavalry tactics in general. Can't use any other warbow effectively on a horse. Too big, or too weak.

[@Daylon91]

@@snafu2350 longbows were used on horseback just not very often. They had mounted archers but they mostly used the horse to bring them quickly to a location

[@Luciferofom]

What I learned from this is that .22 LR is surprisingly effective.

[@comradesoupbeans4437]

.22 lr can kill deer and people (not humanely tho)

[@TheIlidius]

@@comradesoupbeans4437 how do you kill someone humanely tho?

[@comradesoupbeans4437]

@@TheIlidius i meant the deer lol, people are just basically the same in terms of firepower needed

[@franzelias5368]

Extremely effective at very close range, reference the Bain family murders :-(

[@jerryjantola]

A .22 revolver was considered a fine self defense weapon a century and change ago.

[@leopoldsamsonite1750]

outstanding video. well reasoned and articulate. very informative. thank you.

[@Matt_The_Hugenot]

Thinking about the quality of materials the steel you use for the prods is almost certainly better than was available to medieval craftsmen whilst it seems likely there is less optimum quality yew available to contemporary bowyers.

[@AKlover]

Yew is used in expensive furniture, more money to be made there because women throw wads of money at useless trivial shit. It is that simple.

[@YTRulesFromNM]

@@AKlover Yew is ground up and used in very expensive pills now too.

[@totherarf]

A good video! One small point you did not cover too well though was type of Arrow / Bolts! The purpose of them was to put holes in things .... bodies, armour, horses .... and mere energy of the arrow does not compare in this respect. There were many different tips from scimitar like heads designed to disembowel horse to basic points for "normal people" to armour piercing heads. All of these were great at their design targets but poor in others. Also there is much loss in the archers paradox (flexing of the shaft in flight) which is one of the great advantages of compound bows. The draw weight varies from high at the start of the draw to light at the end. This makes the arrow speed up more as it moves to the end of the draw rather than the longbows more flat speed curve!

[@GamingWithHasty]

It's funny how you say Tod did not cover something too well, and on your comment you don't even know what archer's paradox is.... The flexing of the shaft in flight in not the archer's paradox, but a result from it, I could explain to you what it is but I will let you search the information by yourself, so you could be more considerate next time you bash on someone else's video without even knowing what you are talking about.

[@SimonsDiscoveries]

Great job. I've been thinking about those differences for a long time. However, I don't think comparing energies of firearms to bows and crossbows makes much sense, as these projectiles work in very different ways. Unlike bolts and arrows, firearm rounds don't rely on simply piercing the target and causing blood lose through relatively small, clean cuts. Instead their tips are often blunt or even flat and hollow (and if their not, it's to do with aerodynamics as they're often designed to flatten or tumble upon impact) and tear through tissues causing massive shock waves and extensive damage. The whole process is very efficient at killing but requires far more energy to even occur. Comparing arrows/bolts to gun bullets would only make sense if done in the armor-piercing context. In therms of so-called soft targets, it doesn't really matter how much energy a projectile carries as long as it's enough to penetrate and reach the vital organs. For instance, a long knife, or any pointy object, can be slowly pushed into a body and even poke out the other side causing almost instant death even though it probably won't have more kinetic energy than a cheap air-riffle. On the other hand, a heavy rock can be thrown with more energy than many air-riffles will produce, yet won't be able to do quite as much damage.

[@Sangth123]

I always wondered about the power an old crossbow might have in comparison to other weapons. I looked online and never really found anything conclusive. This video was great. I still do wonder about the projectile itself, and if that actually plays a bigger role in how "deadly" the weapon ends up being. Like you said with the heavier crossbow at 1250 lb, the joules would seem to be close to a modern .22, but I imagine the bolt itself would cause a heck of a lot more havoc on whatever it ended up hitting than a .22 round. I never tested this, of course, so I can't say for sure.

[@bozo5632]

Arrows and bullets are really different.The wound types are different. The terminal ballistics are very different. I think it's hard / unrepresentative to compare them using just "muzzle" velocities. An arrow mostly pokes a little hole through you. A bullet makes a much messier hole, and stirs up adjacent tissues more than with arrows. If you look at the numbers, one .308 round is equal to (I forgot the numbers) seventy or a hundred longbow arrows. Bit if I had to choose, I'm pretty sure I would be better off being shot once with a .308 then 35-50 times with arrows, let alone 70-100. (Neither sounds enticing.)

[@bozo5632]

One factor is the surface area of the missile. A pointy arrow might well have more joules per cm2 than a bullet. It might penetrate deeper despite less KE and momentum. (A 1 kg pillow going twice as fast as a bullet wouldn't penetrate much.)

[@Sangth123]

Yeah, it's interesting. Because when I think of someone getting hit with a .22 pistol round to the chest, I'm not thinking "Well he's done for", but a bolt or an arrow to the chest makes me think of a much worse injury. The caliber/ammunition weight, shape and size seem to play a big part in what's going to happen when it hits, compounded by that force behind it.

[@budahbaba7856]

*Sangh* i am just an armchair enthusiast, & so i am going to be as vague as possible to cover my tracks! :) In a very general sense, i am going to hazard that to a significant degree, some comparison of side-arm versus rifle ballistics can be instructional. Mainly in that even for most pistols, which fire bullets traveling much faster than a crossbow bolt, the single biggest operative factor to damage is the diameter of the bullet in relation to shot placement. They are still low enough velocity that wounding from fluid displacement from cavitation as the bullet passes through isn't all that significant until you start dealing with some of the magnum loads, which are more typical of revolvers than pistols. Then, overwhelmingly so with rifle loads. But, with that backdrop, i would think that by the crudest of definitions, the diameter -size -of the crossbow bolt is going to be similarly operative here too, as it is still much slower than a pistol bullet. In fact, so much so that the design of the bolt -& its ability to cause cut & bleed is going to be the biggest factor in its lethality. But that trait is where the bolt design suddenly gets funny. It might be surprising that military bolts were often not nearly so refined as good hunting bolts. Military bolts commonly have minimal fletching, utility rather than razor tips, and are weighted more for penetration rather than accuracy. In many respects i think the rough & ready design of the military bolts emphasizes wounding/disabling as the priority beyond outright bleeding/killing. This would make sense, as wounded soldiers require a lot more resources to maintain than dead soldiers, & so efficient killing function is not necessarily the most important consideration in the design of the crossbow bolts. Taking them out of the fight is. And in general, i think the design of the heavy crossbow bolt is something that i have always questioned. I am just an armchair enthusiast, but i always have this sense that they tended to not be as optimized as a projectile like, the bodkin arrow of the warbow, or even a dart & atlatl. But i could very well be wrong about that -and would venture that is more likely the case than not. But considering the abysmal rate of operation of a heavy crossbow, i would hope that designing the perfect bolt for the function of the machine would be a critical priority, as each shot counts all the more. But it appears to me that the finest bolts were probably those designed for hunting and target shooting rather than war. And like i said... don't take me too literally. All this is my sense of things! :)

[@Hirvee5]

As a hunter the principals taught to me go something like this: With a bow the death is caused by the cutting that the broadhead does to the animal. All the energy you need is for the tip to just pass through the heart and that isn't that much with a modern cutting broadhead especially if you don't hit bones. Cutting diameter of the tip is what causes massive blood loss and death. With a gun the damage is based on the crushing shock effect that the bullet causes. If you have ever seen a water jug for example being shot, they usually just explode even though the bullet diameter can be relatively small. If you shoot with a very low powered rifle I imagine the effect would be similar to shooting with a target tip arrow where it just cleanly goes through and easily leaves big blood vessels intact. In the past they didn't really have any ways to heal these kinds of wounds and they could easily get infected but they would probably seriously lack any kind of immediate stopping power. I guess there is still a good change if you have an arrow sticking out of your side that you would stop bullying the dude in the castle and search the local shaman for help.

[@wyattw9727]

It's important to remember that missile weapons up until advanced firearms were never really used for raw stopping power either. Their role on the battlefield was as a support weapon for the main melee troops. Even the Hussites, famed more-so than the English for excessive use of missile weapons, ultimately finished off the charges with their massive flails and halberds and not their crossbows or handgonnes.

[@generic8891]

@faultroy I personally can't speak for a medieval javelin or spear, but modern olympic javelins are thrown at up to 30m/s, and weigh 0.8kg, for an initial energy of about 360 J. I'm not sure how a historical one would compare to that, but I assume it would be lower.

[@dgthedwarf5133]

Look at this chronograph Every time I do it makes me laugh

[@kylethedalek]

How did that bullseye get so red? And the hell is on William Tells head?

[@alexanderhinman4454]

excellent video Tod, but I feel I should mention that while energy is important for punching through thin, hard materials i.e. plate, it is less important than momentum for penetrating thicker and more flexible materials, e.g. Kevlar, gambeson, and indeed flesh and bone. Sectional density is of course relevant for all materials. I bring this up because penetration is the most important data point for the "stopping power" of a round, with wound cavity a proportional secondary point. Shooting these weapons into ballistic gelatin would tell us more, though again would be inconclusive. Anyway, great vid!

[@Donkeyearsa]

I did not realize that modern crossbows where so much more powerful than medieval crossbows. I still think modern crossbows are entirely butt ugly! I will go with the medieval crossbow becauze they look so awsome.

[@herc34es]

Another amazing video! Thank you for all the information! We should take in mind that they didn't have the same metalwork as we do today. Also they did tend to exaggerate about their works. Your bows are among the most beautiful ones ever.

[@PolluxA]

Great video. You did a great job on explaining this. Kudos for the parts about warbows. Heavy draw weights around 140 to 150 lb reaches 140-150 joules with middle to heavy arrows. Important detail there. According to a video on the Medieval Crossbow channel, composite horn crossbows in the 1276 lb range reaches 488 joules with 348 gram bolts. It's rather big in comparison to the crossbow you have here. The bolt left at 52.92 m/s. It shows that composite horn is a much better material to make a bow of than steel. The 260 gram bolt left at 57.74 m/s and gave 433 joules.

[@adams651]

Yes, Han and other Chinese records go into quite a bit of detail on crossbows and the distances for various weights achievable and how to use the various types of crossbows. As more of these records are translated, verified, and accepted by medieval hobbyists some of the work examining the few medieval crossbows extant and reproductions will focus on how to make steel prods more efficient because while the European crossbows never quite measure up to the Chinese sources they do much better in comparison to Tod's reproduction and actually are not that different from LaCombe's results. Han crossbows had a longer stroke which as Tod demonstrates makes them more efficient but there are also many small tricks in making the limbs of bows more efficient, not only in materials, but design, and other very small factors which I do not believe we have any bowyers currently working who have fully mastered crossbow manufacture.

[@AFCAWorldBodybuildingArchive]

Glad that you made this Video so detailed. The mathematic back up may calm down those people who say that a 1200lb crossbow could shoot through the moon.

[@sum41foreverown]

Fantastic vid! Found it absolutely wonderfull, its a shame crosbows are illegal where I live, would love to have a medieval one. There's something very alluring with the thought of practicing marksmanship with a medieval cross in a sligthly secluded part of the countryside. Just me, my crossbow and an unfortunate assortment of fruit.

[@shanek6582]

Johan where do you live that crossbows are illegal? You can’t even make one and have it in your house?

[@foolwise4703]

Oh Todd I LOVE IT! In fact, I was just thinking about how somebody should draw out the draw weight over powerstroke curves of some bows to calculate their energy output, and right then I see this video where you do just that! I do however have two points of criticism: 1. You are looking purely at the energy of the projectile, because this is used to characterize modern rifles. I wonder however, if the deadliness of an arrow isn't better characterized by its momentum, rather than its energy. Of course, this makes the comparison to rifles difficult, but this is to be expected, because the damage-mechanism is also a different one: An arrow cuts through the target, while a bullet pushes the mass in front of it away. The former should be far more energy-efficient. This claim could be tested by shooting bolts or arrows with different masses from bows with different draw weights, and simultaneously measuring penetration and bolt-speed. If penetration scales linearly with speed, its the momentum that counts, if it scales with the square, its the energy. 2. You remarked already that it is incorrect: You are assuming linear relationshipts for draw weight over powerstroke. Although I appreciate that this should not become too complicated and it was probably right for this video to keep it that simple, this neglects the whole purpose of the curved shape of recurve bows for example. I think it would be really interesting to measure these curves directly - for example by filming how you slowly draw the bow over a tape measure using a bow scale. (If you happen to want to do that, you are welcome to send me such a clip and I will can evaluate it and send you a nice graph and energy value ;-) ) After all, the graph for a "perfect" bow would not appear as a triangle, but as a rectangle: From zero, it would directly jump to the maximum draw weight that the archer can draw, stay there until the full draw length, and then drop back to a low value to make it easy to hold the bow drawn. I expect that the modern bow will approximate this behavior much better than the medieval ones. If such a measurement were done and compared to the actual arrow speeds, one could also calculate the actual energy efficiency of the bow :) I believe that both these points contribute to why the modern bow performed so much better than the simplified math suggested.

[@Dinoenthusiastguy]

Excellent empirical calculation of kinetic energies. Just for interest's sake I thought it'd be interesting to calculate the momenta as well (from your numbers). For the modern crossbow, 2.86 N*s; longbow is 2.00 N*s and medieval crossbow is 2.54 N*s (the same qualitative order as kinetic energies). What I don't understand (maybe someone with an engineering background can explain this) is why longbows typically have longer ranges, even though by your test crossbows have larger momenta and kinetic energies. Is this purely a function of how streamlined the projectile is?

[@Camcolito]

'You couldn't make a longbow twice this length' - Au Contraire! Meet the VERY longbow!

[@InSanic13]

Longerbow!

[@Camcolito]

@@InSanic13 :)

[@HaNsWiDjAjA]

Did Todd just shoot a 95 LB BOW?!!! Dude is a beast!

[@alexwang2419]

Yes he is hehe

[@RoyceLerwick]

@@alexwang2419 Yes. A lighter Danish longbow draw...

[@CharlesOffdensen]

Heavier and slower objects lose less energy to friction in comparison to faster and lighter ones. So modern crossbows are not 3 times as good as medieval ones. Right?

[@warrax111]

Medieval heavy crossbows were made more for penetrate at closer range, than for accuracy. Because, almost every warrior, wore at least gambeson. The key was to be able to penetrate average chainmail with average gambeson, at close range. Without it, it would do simple nothing on battlefield. These crossbows were also very effective during the siege, because there were many oportunities to shot at close range, while you could reload in safety behind the walls. So the key was to make so much penetrating force, that could penetrate armor at close range, lets say to 30 yards. And for it, you need heavy bolt (often weighted 150-220 grams), and very high draw weight (1000+ windlass crossbow).

[@2bingtim]

Lighter arrows will shoot further & faster, but heavier arrows use more of the bows energy efficiently. That's why war arrows where usually heavier. Tod used a 45g arrow, but a 2oz(56.7g) war arrow would be more typical of the majority of arrows shot in war. The lighter ones were used to harrass at longer ranges, but the real killing zone would be under 100m or so.

[@2bingtim]

Roger Ashcam decried the use of Poplar wood(lower density) for arrow shafts(early 1500s) rather than ash which was much heavier & gave the arrow, "a good strippe". i.e. The arrows hit harder.

[@thorwaldjohanson2526]

it's not just about the kinetic energy, but also the momentum of the projectile, which is m*v (not v²), there the heavy bolts are actually quite good.

[@gracesprocket7340]

Sectional density and (in war or hunting heads) sharp edges promote puncturing and incision wounding in-situ, very different from the 'tearing and bruising' seen in bullet penetrations, with their considerable cavitation and (temporary) displacement of soft tissue. A handgun and arrow have similar penetration depths (at low draw weights - the 'wounding study' I have shows results for ~ 52lb bows only - and a bow of around twice the draw weight with heavier arrows (these were only 30-40g arrows - much lighter than what a heavy bow would be firing from what I understand) would show at least as good performance. Indeed, medieval/renaissance texts warn of taking broadside shots on deer because of the risk of a through shot striking hunters on the far side of the quarry on a hit - and it was preferred to take an oblique shot to maximise wound channel length.

[@janmorup9407]

Kinetic energy is far more informative than momentum because it is that energy that is 'used' to impact the target, ie break molecular structures. Obviously each molecular bond is far smaller in strength than a joule so it is sort of a count of how many molecular bonds it can break.

[@paulbaumer8210]

Incorrect. It is the energy that is important in a killing projectile. A large mass moving at a slow speed is nowhere near as effective as a small mass travelling at high speed. That is why is a bullet is preferred to a thrown rock.

[@darthplagueis13]

@@paulbaumer8210 Well.... In the end a bullet isn't the same thing as an arrow, however. For instance, picture getting hit in the thigh. A sufficiently fast bullet is going to travel through and if it will kill you mostly depends on if it hits an important blood vessel or breaks your bones. If it doesn't you are left with a comparatively clean wound that can be patched up without too many complications. If you have a projectile or a bolt that isn't as fast and gets stuck instead your are in a world of trouble. Removing it can cause additional tissue damage and damage an arterie but not removing it is likely going to result in an infection of some sort or lead poisoning if it was a bullet. People dying not from getting hit with the arrow but after having the arrow removed from the wound was rather common. In the end, whilst energy does of course play a big role, it is not the sole determining factor as the type of the projectile will determine the kind of injury you receive. A full metal jacket may carry the highest overall kinetic energy but a soft point is still gonna be more lethal if you get hit by it.

[@gehtdianschasau8372]

the mass is already in the calculation. The slower medieval bolt had more energy than the faster arrow. He doesn`t multiply speed with speed to get to joule (v²) like you suggested.

[@ifthebeltiscrackedor]

I don't really intend to be picky but why is crossbows always "always" referred to as "medieval" although they were used (this small handheld one, not the ballista in the roman empire) roughly between 1300 and 1900. Wouldnt it be more accurate to roughly call them "renaissance crossbows"?

[@TheOhgodineedaname]

How do composite prods compare to steel ones? I really wonder how much more efficient those would be, would they beat plain wood? An accuracy test would also be extremely interesting.

[@TheOhgodineedaname]

Awesome! Great to hear you're making more quality videos. Who is going to be shooting the 160lbs longbow if I might ask?

[@kenmichener8439]

DushinSC not you

[@damijanruzic9128]

all depends on weight and disztribution of weight per power..

[@poppywarner177]

DushinSC I’m guessing Joe gibb...

[@nelumbonucifera7537]

Drag is proportional to squared velocity, so the difference between modern and medieval bolts may not be so great at 100+ yards.

[@frantic299]

Yeah but actually hitting what you are aiming at at 100 yards is a whole other story. But you are right. Weight trumps speed at any distance really as long as you can get it where it’s supposed to be. I compound bow hunt deer and have hunted with what I consider light arrows (350 grain) and heavy-ish arrows at 450 grain and that little jump makes a world of difference in penetration. Guys I know that use traditional equipment rarely are under the 600 grain mark. They will zip those arrows through a deer at or less than 1/2 the speed my compound is shooting.

[@goldmole1]

All the things i a bowyer of primitive, self bows never figured out in such a scientific way,.... Low tip mass, shortest possible limbs, thin string and all that is known to increase efficiency. But this vid gives a very clear and broad insight into the matter. Thanks for posting.

[@yorkshire_tea_innit8097]

A point about the energy of the projectile. Low weight, high velocity will slow down more from air resistance, so perhaps down range the medieval crossbow would fair better. Bullets do ofcourse have a much smaller cross section for air resistance, but the speeds are vastly higher and the weight is vastly less so they probably lose velocity more than the medieval crossbow bolt also. Probably the gun energy is measured at the muzzle.

[@LocalDiscordCatgirl]

In addition, Kinetic energy isn't how arrows and bolts kill or do damage unless you're using rubber/wood blunts. Broadheads as a set of inclined planes are able to amplify the amount of work doable by a given force (which is measured in momentum/impulse, not KE). Related to your point, as impact velocity of any projectile increases, the resistance forces faced increase exponentially. Here's a neat research paper that talks about it in depth cpw.state.co.us/Documents/Hunting/EHU/Momentum-KineticEnergy-ArrowPenetration.pdf

[@spikeguy33]

Man.. Those medieval archers must have been bulky as hell :)

[@Kosh800]

Probably skipped leg days, though.

[@johngrealey1894]

UrbanTarzan Duh there were the body builder's of there day they trained from boyhood they had to train by law .king Edward lll made a law forbidding all ball games and you had to train with the bow every Sunday .

[@totherarf]

Archaeologists say they can readily identify two historic types of employment (not always for money) Miners and Archers. The repeated tensioning of muscle makes the tendon build up which affects the skeleton it is anchored to!

[@jordanreeseyre]

I'll have to look at the momentum change of these weapons & see how that affects their relative relationships. As the .22 comparison shows, the effectivness of a projectile can depend as much on its momentum and sectional density as it does on its kinetic energy.

[@BillTheScribe]

This was my thought as well. Momentum is the resistance to slowing down. a train rolling at 1 m/s is harder to stop than a compact car at that same speed, because it's heavier. Heavier things want to keep doing what their doing. I know American math, so check for conversion errors. Momentum is just mass x velocity and give us kgm/s. Using his values the momentum of the Compound crossbow was 2.9 The Longbow was 2.0 The Medieval Crossbow was 2.5 A .22 bullet (2.6 g, 361 m/s) was 0.9 A 9mm bullet (8 g, 381 m/s) was 3.1 A .308 (7.62 x51) (10.9 g, 770 m/s) was 8.4 A 12-ga slug (35.6 g, 488 m/s) was 17.4 A .22 isn't more deadly than an arrow or bolt. That energy value only matters the instant it makes contact. After that, the much higher density of the target will begin to slow the projectile down. Things with a higher momentum slow down more slowly, so they penetrate deeper. The compound crossbow may not have anywhere near the energy of the 9mm bullet, but it has a very similar momentum, making them comparable as far as close range damage goes. The Slingshot Channel did an old video comparing momentum of one of Joerg's slingshots to a number of handguns using a swinging metal plate to test. The only gun tested that beat the sling was a .44 Magnum. kzbin.info/www/bejne/qn3bn4GGYt6WjLM

[@omgwtfbbqstfu]

Bar for lethality was lower, didn't take much damage to reduce the fighting effectiveness of a person back then. Now you have to stop someone from being able to move a single finger.

[@DmdShiva]

Counterbalancing that is that wounded were usually left on the field for whoever carried the day to collect and care for the survivors, while modern warfare places a premium on getting care to wounded personnel as quickly as is practical -- besides the fact that smaller ammunition lets a soldier carry more rounds, a high-powered weapon that kills its target reliably takes one soldier out of combat, while a less-powerful weapon that wounds its target beyond being able to continue combat takes them and up to four other personnel out of combat to recover and care for them.

[@EnKiDou666]

I'd really want to see someone make medieval style armor piercing bolts for modern crossbow and test them vs armor. It would show us how efficient the system could be at it's peak. Tests using modern arrows are pointless yet so many people still do them.

[@EnKiDou666]

Amazing. Should be interesting.

[@Rucky888]

Mass of the arrow an important aspect. Great video

[@VRichardsn]

Very informative, and rationally backed by numbers. Top quality content.

[@Grymbaldknight]

Medieval crossbows were never the most mechanically-efficient weapons around. In terms of equivalent poundage, conventional bows are markedly superior when it comes to power output. With crossbows, however, the relative inefficiency of the system simply doesn't matter. You can build a medieval crossbow to have colossal poundage, such that the raw power output cannot be matched by even the most efficient bow.

[@manlyadvice1789]

True, but that will significantly increase the difficulty of drawing to cock it.

[@chaumas]

This had me really wondering: could you build an effective compound bow using medieval technology? How much of their effectiveness depends on modern material science and manufacturing, and how much of it was just a matter of understanding how bow efficiency works and having the insight to use pulleys to exploit that?

[@chaumas]

That's awesome. I watched that catapulta video - so cool and pretty terrifying. Do you think the compound mechanism would have been achievable at hand-held scale? I don't have a great sense of what the limitations were with medieval techniques.

[@KamiRecca]

The one number that REALY means anything: The ammount of time it takes to learn how to concistently put arrows through targets. And thats where the medieval crossbow shines. Spend years training a longbowman so that he can spend years to train more, Or spend a day to train a crossbowman so that he can spend years training a vast number of people a day each.

[@KamiRecca]

@incinerator950 Go for it. Archery is fun ^^

[@danielburgess7785]

That's the curve that means the most. Modern firearms (10 years before WWI to present) have been beaten down in their complexity to deal with volunteers/conscripts.

[@KamiRecca]

@John dear John, i feel you are underestimating the impact that the Crossbow had on military history. The very fact that you could field a great number of people with limited training and expect a reasonable result was a real gamechanger. In many ways, crossbows lay the foundations of how firearms were used, it most likely defined the Look and Funktionability of firearms from handcannons and shouldermounts (Bazooka style) to Stock against Shoulder. About the Stick VS Automatic analogy; I dont see your point here. Or rather i think its a false analogy. But lets use it anyways: Say that you need 10.000 drivers for your country to succeed on a task. They dont need to be great drivers, only competent enough to get the car from point A to Point B. And you need them trained fast. Like Yesterday fast. Do you train them with Stick or with Automatic? You would probably go with Automatic gearshifts, right? We can skip a whole process of the driving lessons and get right into how to manouver the car safely. This is the advantage of crossbows. And it is a big thing. Do you get better precision with a bow? Yes. Can you fire more arrows (Or bolts, in the case of crossbows) per minute? Yes. But to achieve that you need a heck of a lot more time than to teach a person to basicly Point and Click. From Sweden with Love - Kami

[@KikoTheLumberjack]

Still can't make the crossbow shoot as fast as a bow. Don't know about the longbow, but reflex bows -Scythian, Avaro-Bulgar, Mongolian, Turkish bows ect. can fire an arrow a second in the hands of a trained archer. Also the crossbow can't reach half the distance of a longbow, let alone a reflex bow.

[@Chasmodius]

I also wonder about the amount of time it takes to train the crafts-people to make a bow vs. a crossbow, and how long each takes to make, as well as the cost. Then how much maintenance each takes, and whether it requires special knowledge, materials, or equipment?

[@SevenDayGaming]

The reality is, kinetic energy is utterly meaningless when talking about weapon damage. Momentum is more important, and even it really only impacts penetration. All these have the momentum to fully perforate a human body with any arrow or bolt you choose. The reason these things kill you is the hole they put in you. That's what matters for lethality. Unless armour penetration is a factor, or you start shooting extremely far away, the best killer is the broadest arrowhead.

[@SevenDayGaming]

@Brian Hensley And we know that's possible, because religious texts are very accurate and never absurd at all.

[@WColdblooded357W]

The thing about the 22 vs the crossbow bolt is that bolt tends to have a very sharp and sometimes wide tip meant to slice into the target where as 22 round is like trying to push an unsharpened pencil into the meat.

[@vegantoxophilite2594]

A 95lb longbow shooting a 45 gram at 146 fps? I would expect around the 190-200 fps mark. Or that to be an arrow around the 70 gram mark?

[@WillBlueAnimalTraining]

how much did your arrow weight/? 146 seems bit low for longbow of that power very well built tho indeed

[@MarsPHLO]

Your longbow is under draw, and the arrow is under (significantly) weight, my longbow 95lb@28 draw to 31",32", arrow weight 65g (>1000gr, 10GPP), shoot 155,160fps at least, at 45g arrows its 180,190fps... Huge difference, in bows, underweight arrow drop energy transfer (efficiency) in an extreme way..

[@Kalishir]

the 25inches refered by Todd are the power stroke and not the draw length. A 31" draw length minus a 6 inches fistmelee is a 25" power stroke. You're right about heavy projectile being generally more efficient thought.

[@stevedjurovich194]

@@Kalishir I don't think Mars PH was referring to the power stroke, we know you subtract brace height + thickness of the bow from arrow length to get power stroke, I think he meant the bow was not at full draw at the moment of loose. It looked about three inches under drawn, which is significant in terms of power loss. If we assume it is linear in power delivery, then that ammounts to over 11lb of draw weight short of the 95lb draw weight at the rated draw length assuming the arrows are the correct length for the bow.

[@strongback6550]

Extremely informative, thank you very much.

[@carldavies4776]

Absolutely fascinating... Be interested to know your thoughts on the modern reverse draw crossbows??

[@MrMonkeybat]

Ancient people had long traditions and more experience in their speciality. But they did not have access to all the information we have today trade both in history and science books and internet enthusiast share there information openly while ancient craftsmen and guilds kept their secret close to their chest away from their competitors in other towns.

[@ironpirate8]

If only they had all written their knowledge down and it survived today.. !

[@ifv2089]

Great video👍🏼 Personally I enjoy a field recurve and some stumping

[@tlsgrz6194]

I know this video is quite old, but I wanted do do some calculations for myself to see if I could quantify the efficiency of the bows. I took the bow strength, the powerstroke and the weight of the projectiles for the medieval long- and crossbow from this video, as well as the Skallagrim-crossbow (I got the values from other videos: 976lbs, 160mm, 96g). I calculated the theoretical acceleration (a = F/m) for the three bows, and used that to get a theoretical projectile velocity ( v = a*sqrt((2*d)/a) ). Point is, a 423N (95lbs) longbow with a powerstroke of 0.64m (25 inch) should be able to accelerate a 45g arrow to 109m/s. You measured it at only 44.5 m/s, which is about 41% of the expected velocity. The lighter crossbow (2002N, 0.11m, 60g) should reach 87m/s but reached only 42.4m/s which is 49% of the expected velocity. Skall's heavy crossbow (4341N, 0.16m, 96g) should in theory shoot bolts at 120m/s but was measured to shoot them at 47.9m/s (39,8% of the expected velocity). Since I think, that the kinetic energy is a better measurement for the efficiency of those bows, I calculated the energy both, based on the theoretically expected and the experimentally measured velocities (the latter were basically the same that Tod calculated in the video). Because we calculate the energy by squaring the velocity and the other parts of the formula (mass of projectile and the factor 0.5) stay the same, the efficiencies of the energy were just the squared efficiency of the velocity (I should probably have seen that coming...). The surprising thing is, that the longbow appears to be less efficient than the lighter crossbow, and that even though the longbow's projectiles should in theory have more kinetic energy (268 vs 228 Joules), in practice the crossbow has the advantage here (45 vs 54 Joules). The heavy crossbow has about the same efficiency as the longbow, but with more than ten times the draw weight and twice as heavy projectiles, those projectiles have more than double the energy of either the longbow or the lighter crossbow (110 Joules). I'm kind of curious how a warbow would perform, so if anyone has the draw weight, powerstroke and projectile mass for a representative bow please let me know :)

[@DanielChristensen81]

Am i the only one who heard 195 lb draw weight on the longbow ?

[@BushcraftTexas]

Neat video. Not sure how versed you are in a .22? Out here in Texas, the .22 is used for a lot and is quite an under estimated round. I think the .22 is listed as a round that has killed a lot of people, likely because “it’s just a .22”. Years and years ago the us army did experiments with 1/2” plywood stating if it went through the 1/2” ply it was lethal. Would be an interesting experiment to see what that 450 pound does on 1/2” plywood at 100, 150 and 200 yards - assuming you could connect.

[@Gothmetalhead13]

Very interesting and enjoyable save one bit >Buy a bow Why buy what I can make?!

[@Rasmus1603]

10:18 am i the only one who realized that medieval is written wrongly

[@Rasmus1603]

doesnt matter still a Great video my friend

[@JackGordone]

No. I kept hearing my 2nd grade teacher sing "I before E except after C"

[@androot69]

... And my father told me years ago that crossbows could penetrate armour... Silly

[@ipullthepork]

what is the level requirement for that compound bow?

[@andrewschroeder4167]

I'd say that this is all very informative, but you skipped some important metrics, which may be more difficult to test. For the damage of each weapon, what matters most is the energy of the arrow when it reaches the target, not when it leaves the bow. So a more massive, narrow arrow or bolt will lose less energy to drag forces during flight. Perhaps measuring velocity at the end of flight would be a better indicator. Next, I think the main strength of the crossbow was not that it did more damage than a longbow, but that it was much easier to learn and use than a longbow. Additionally, a crossbow does not require the user to hold the weight of the bow when preparing to fire, allowing them to be much more accurate with little training. They can take a moment to line up the shot and aim down the sights, while a bowman has to hold the bow drawn back until they fire, which is very tiring. Obviously a well trained longbow user would be greatly superior to a run of the mill crossbow user, but wars are won by economics and logistics, and it is much easier and less expensive (at least training wise) to field a large group of crossbow users. Ultimately, being able to train and arm more soldiers more quickly and achieve perhaps just slightly worse results from each individual is a better strategy. All this is to say that a longbow may be a superior weapon when used to its full potential, but a crossbow's full potential is passable and much easier to achieve. Wars are not won by a single skilled individual, but by a large group of well equipped, well supplied, and well trained soldiers. The average effectiveness and expense of your soldiers is very important.

[@pippohispano]

I do enjoy your videos, they are very informative, you are quite clear and honest about your research. Thank you!

[@Rowanbows]

would be interesting at wich drawweight the yew bow hast 190lbs cause I build bows and this bow looks like normal 100lbs warbow at 29lbs

[@educatedmanholecoverbyrich8890]

Modern Crossbow = 302ftps (92.049 mps) = 205.9 mph : Long Bow = 146 ftps (44.5 mps) = 99.545mph : Medieval Crossbow = 139 ftps (42.367 mps) = 94.772 mph

[@jamesk8730]

Well done, this is truly an excellent video. I just have 2 things to add: Firstly, one of the biggest inefficiencies of the longbow is that it isn't cut past center, like a modern recurve is. That causes the direction of the force applied by the bowstring to not be directly in line with the arrow, wasting energy. Secondly, I don't think it's fair to compare the kinetic energy of arrows to the kinetic energy of bullets. Arrows have sharp blades and points, and kill through blood loss. I think they're a much more efficient projectile design than a bullet (especially a slug) for penetration.

[@maninalift]

Also, in interested in whether momentum may be important as well as energy in penetration/damage. This would mean heavier projectiles with the same energy (and lower speed) might be more effective.

[@rodparsons521]

James K The effect of a modicum of offset potentially has less effect on the cast than it does on lateral accuracy and dispersion. It is a fact that poor decisions on such factors as pass width, brace height, spine, even shaft diameter and of course shooting style and competence will to a significant degree affect how efficiently your chosen combination can be aimed and shot. How do I know this? From years of close observation combined with recording my all scores in open competition and relating demonstrable improvements in performance to what was learned and applied to the process of geometry in set-up and subsequent results. I'm not just repeating a piece of received wisdom from modern archery as a generalisation. I can tell you what works for me and why, but figure that you can learn more if you work it out for yourself. Simply put I work within the constraints of a certain degree of offset created by a combination of avoiding excessive pass-width, selecting an efficient cross-sectional shape, setting an appropriate brace-height and by employing an arrow selection for any given task that I have proven to my satisfaction. An excessive degree of static offset at brace height or mismanagement of relevant factors can prevent being able to aim directly at the mark at full draw.. It should also be noted that lateral centre-shot in a bow held vertically (or nearly so) is in comparative terms a very recent innovation. Q 1. What is the greatest degree of static offset at your brace-height that will allow you to aim directly at your mark and have the arrow always go there, all else being equal? Q 2. What are the other contributing factors in bow geometry and set-up and how do they effect the outcome? Q 3. What are the principle factors in consistently accurate shooting? "it's meant to be simple. not easy".

[@rodparsons521]

@@maninalift There will be better or worse shaft combinations for a given outcome that can be found by methodical testing.

[@Not-Just-Cars]

That's why the ancient Chinese crossbows, though unwieldy, were one of the most effecient crossbows used in historical combat due to similar draw lengths as a handbow with much larger draw weights like 400 lbs

[@GymChess]

People, inventors, weren't stupid back then either. Surely they must've realized that the short power stroke would slow down the arrow significantly.

[@ExecutionSommaire]

The work done to the projectile is the integral of F(d) over d. Assuming the force F varies linearly with the drawing distance d, and brace height = 0, then it's just the triangle area calculation Fmax x dmax / 2. For the crossbow: 3825 N x 0.1651 m / 2 = 315 J For the warbow: 711 N x 0.6096 m / 2 = 216 J Same order of magnitude indeed. In real conditions the warbow packs more joules so I guess there are additional factors such as yew being a superior spring material than steel, or F(d) highly convex for the crossbow whereas the warbow shows a more linear curve? ....

[@nothim7321]

Okay, but what is the mechanism of injury? Meaning how much does foot pounds actually matter? How does the projectile actually cause damaga?

[@bgurtek]

The "Taylor Knockout" number, while essentially broken physics, may be a better criterion for projectile killing power. TK# = projectile weight x projectile velocity x projectile "caliber". But that's et up for firearms.

[@lylachristopherson865]

I like the "look" of the English Longbow. It's tatty and natural looking. Americans would think it no threat, "Ugly Thing".

[@vyl4650]

Joe Gibbs "Stick bender" by profession lol

[@ifthebeltiscrackedor]

Could you compare with a BIGGER medieval crossbow? But the point is interesting. The metallurgy of the time gave them this. I'm building a "medieval/ reinessance" myself (composite prod until everything else is set).

[@speckledjim_]

Imagine putting 450lb into today's modern compound xbows!!!

[@Marmocet]

Something is off about your longbow results. A longbow with a 95# draw weight, a force draw curve typical of that type of bow, an efficiency of somewhere around 60% to 80% typical of longbows and a 25" powerstroke should be able to launch an arrow weighing 45 grams at a muzzle velocity of somewhere between 55 and 63 meters per second (that's ~68-90 joules of kinetic energy). If you're actually drawing a 25 inch powerstroke, your bow really has a draw weight of 95# at that draw length and your arrow weight measurement is accurate, then your bow's efficiency is something like a measly 40%, which would make it less efficient than bows of a similar design made out of PVC pipe or fiberglass. You look overbowed, so my guess is you're not actually getting anywhere close to a 25" powerstroke. A powerstroke of around 20" would give you arrow velocities in the ballpark of what you measured.

[@DarkVeghetta]

Just today I was thinking of modifying my house rules for DnD 5e in order to better incorporate draw weight and accuracy for ranged combat and, as such, I found this video at just the right time! It's always bothered me how you don't need any strength as an archer and bow type is all that matters. The reality is much more nuanced and bowmen actually needed quite a bit of strength in order to be viable archers, in addition to being able to shoot accurately. Edit after watching the video: So, I might need an efficiency stat thrown into the mix for my DnD bows. Damn it, I was trying to keep this simple, but I guess I can't have nice things if I want realism. >.>

[@mountainman38]

I wish more games would account for recoil, bullet drop, bullet type, etc. Same with bows and their use. It was quite telling to see the gentleman in this video work mightily to pull his 95 pound long bow. There was no slow pull, then hold the bow while you sight carefully, then wait for just the right moment to release it - at that draw weight, you pull fast, get a quick idea of the target, and let the arrow fly. Having pulled and fired a 60 pound traditional bow, I can attest to how challenging it is!

[@janviljoen7001]

In big game rifle hunting momentum (MV) is more important than kinetic energy (1/2 MV^2. That is why elephant rifles like 577 Nitro Express, 505 Gibbs and 404 Jeffery shoot a heavy bullet but at slower speed than the Magnums. Now I wonder, is Kinetic energy in bow hunting not more important? Because penetration of the shoulder blade to reach the vitals is more important than overall momentum. All you big game hunters please chime in. I use to hunt some eland and kudu here in South Africa, never shot an elephant or buffalo yet, but lately I fancy the medieval bows much more. The nostalgia fascinates me. I have compound and recurve crossbows.

[@CandidZulu]

The .22Short (the original rimfire .22) was actually first a round for revolvers, ie not a hunting caliber. I liked this video a lot though, and understand what you mean.

[@JinKee]

what would happen if you used modern materials and medieval cocking systems to draw a 1200lbs modern carbon fiber compound windlass crossbow?

[@Jimbojenkins]

the 'string' drags on the stock. therefore it is not efficient and losing power. Read "The Medieval Crossbow" by Ralph Payne-Gallwey, refer to page 107 which describes how the prod should be set.

[@danajohnson5993]

Used to shoot metallic silhouette (firearm sport). The most fun calibers for me were the .375 H&H mag and the .458 winchester mag. Both would flatten the 50 pound or more half inch steel targets at any range you could hit them. Our range only had a clear view of 250 yards. Both would leave a decent dent where they hit. The .375 was at about 3000fps, and the .458 was more like 2000. However we had to ban calibers like the .22-250 or the .22 swift and even the .223 because they would consistently blow big holes in the half inch steel. Tiny bullets traveling at 4000fps plus requiring hours of welding the holes shut again. Even then, the targets didn’t even always fall down. Huge energy with the small fast projectiles, but very bad transfer of momentum. Most of the energy goes into vaporizing the bullet and creating the crater in the plate. For reference, the momentum of the .458 slug was about 5 times higher than the .22-250 50 grain bullet.the little round has about half as muck kinetic energy as the big one. Down range performance really depends on what effect you want. The .22=250 is a varmint round and will disintegrate inside a ground hog, where the .458 or even the .375 will easily go right through the long direction of a deer or crosswise in a bear if you are using a full jacket round.

[@katt2002]

he mentioned medieval crossbow effective range from the book says 400+yds probably was shot at high angle like 40-45deg from a tower 'downwind', probably? when you have a bunch of army capable of raining fire you don't have to worry about accuracy, you know, even one of the bolt flying at you could kill.

[@jimnickles2347]

Well. This Explains why .22 Long Rifle is a SUPER Deer-Poaching weapon....

[@bozo5632]

I kinda knew it wasn't as simple as draw weight = effectiveness, but I learned something about why from the video - thanks Tod. (Erm, I also learned an alternative spelling for 'medIEval... You're a far better archer and armsmaker than I, so let me have my spelling skilz lol.)

[@megacandid8789]

I think something that's important to consider is the change in context of stopping power. Modern fighting involves weapons that even heavily injured soldiers can still use effectively, as opposed to all pre-firearm weapons which required much more physical labour from the user. A minor arm or hand injury would make a bowman essentially useless, a puncture anywhere on the body would make melee combat excruciating. The standards of damage caused by a weapon would have been much lower back then, and the ability for instant kills would be basically pointless, out of the fight is out of the fight.

[@aryafeydakin]

You have to understand that energy comparison of a bullet vs an arrow is basically totally irrelevant. To quote Bredsten in the book "Handgun bullet stopping power" : "To equate energy per se with either killing or stopping power is a non sequitur." To quote the same Bredsten : "Arrow/Spear versus Bullet This particular type of comparison almost invariably causes many shooters to complain that the comparison is not fair. Why is it not ? After all, with the centerfire handgun cartridge exception of the 25 ACP and perhaps the 32 S&W, the energy comparison between an arrow and a bullet favors the bullet. In the above example, the 230 grain bullet develops about 485 foot pounds [357 Joules], while a broadhead arrow, weighing 300 grains, with a velocity of 300 fps develops only about 60 foot pounds. The bullet has more than eight times the kinetic energy of the arrow, yet experienced and skilled archers regularly hunt large and even potentially dangerous big game without trepidation. Whereas, one would have to search far and wide to find the hunter who would seriously consider and intentionally hunt - without backup - large big game (e.g., elk, moose or sable antelope, let alone potentially dangerous big game such a s Cape buffalo or grizzly bear) using a cartridge, the bullet from which develops only 485 ft lbs. Consider the results of a spear wound. During the battle in the Teutoburg forest (AD 9), three Roman Legions and auxiliary units (about 20,0000 soldiers) were annihilated by Germanic tribes. The spears used by the Germans weighed one and one-half pounds and were hurled at a velocity of about 55 fps [16 m/s]. The energy developed by the spear was about 70 fl lbs, yet this weapon easily penetrated the Roman shield and then penetrated into a Roman soldier to either kill or cause a wound of random severity (depending upon the part of the body penetrated). Without belaboring the point, either a broadhead arrow or a spear will usually penetrate deeper (possible exceptions are very large bones like a ball and socket joint), create a larger and more sever wound track and generally result in as quick or quicker kill than will an expanding bullet from most handgun and many rifle cartridge. By expanding bullet, it is understood to mean a bullet that expands to at least one and one-half times its original diameter, for example, a .308 inch diameter bullet would need to expand to at least .462 of an inch and a 9 mm would have to expand to at least .531 of an inch. Hmmm. Perhaps the type and extent of the physical wound just might be significantly more important than the theoretical number of foot pounds produced by the projectile - be it an arrow, a bullet or a spear. Julian S Hatcher made another very discerning remark regarding energy : "Thus the amount of energy actually expanded by the bullet in the body does not measure either the killing effect or the stopping power". An example that supports Hatcher's remark was given by Ross Seyfreid : "First bullet energy and its transfer to game animals really has very little effect on killing potential. I've watcher both impala and pronghorns soak up and stop 300 Magnums at short range, in both cases, bullet performance was perfect; the shots hits the front shoulders and stopped in the opposite hip under the skin. Both little critters, just over 100 pounds, took almost 4000 foot pounds of energy. Neither of the animals showed any visual signs of being hit." End quote. So, in reality we observe that a centermass broadhead arrow shot is even more lethal to big games than large caliber expanding bullets. We consider that for hunting big games animals you have to start from a 1500 Joules muzzle energy, yet people consistently hunt large game like does and wildboars with mere 40 pounders IFL bows and a 600 grains broadhead arrow. The arrow carrying not even the twentieth amount of the energy of a hunting caliber bullet. The arrow energy is not even close to a 22 LR bullet. Still the light bow and arrow has immense killing power; the only thing a forty pounder bow setup does is reducing the ideal shooting range because the arc trajectory quickly become unmanageable with such a low poundage and heavy arrow, and you need a higher poundage to get a flatter trajectory. With compound bows of higher poundage, people easily hunt from more than 50 meters. The conclusion is that in practical reality a mere 80 joules arrow has greater stopping power and killing power than a 1500 joules expanding bullet as long as it can be accurately shot centermass. What is the real killer is the wound size not projectile energy. The stopping power of even a small thrusting bladed weapon like a broadhead arrow is colossal in the right hands. As human are concerned, you have to understand that you can apply the captain Fairbairn timetable of death but with the reach of a bow and arrow. I guarantee you that even a small puncture to one lung that's called a pneumothorax with the a "puny" blade tip that's a broadhead arrow is highly debilitating, that's an instant knock out that even a small blade tip can easily deliver. Rolland Warzecha is onto something too with the reconstruction of viking sword fight that's becoming thrust centric not a great big chopping contest. That is why any type of bladed weapon is so deadly, from the boar spear to a puny "court" sword, to a pocket knife. A puncture to the lungs will stop a fight faster than a blunt shock weapon. A good movie that depicts how a sword fight actually works is the movie called Alatriste. The problem is that HEMA practitioners don't know what they are capable of, the only legal area where they could more or less test their skills would be bull-fighting or also some type of ancient hunting. Bull fighter don't use cutting attacks to kill the bull, they use thrusting attacks with a sharp double edged estoque that is fullered up to the point. A trained torrero can instantly knock down a 500 kg bull with a 1 kg estoque with concistency using three main strikes. A media estocada, it is a puncture into an large blood vessel. An estocada, it is a puncture into the heart. In case of panic against an extremely large and clever bull, a torero can also use the strike called golletazo (low estocada), now the sword groove is essential to cause instant death with this 'lazy' strike. When an air bubble eventually goes into the blood system, that's instant death when it reaches the brain, that's called embolism. Mammals lungs are enveloped in a double layer membrane that allow them to slide freely against the ribcage. Like a fist pushed into a baloon, or having pair of sockets upon another pair of sockets, there's less friction. With a thrust, when the blade is fullered up to the point or concave, a groove on the blade will act as an air admittance when the blade is burried into a wound. This means aggravated pneumothorax intensity and embolism. A broadhead arrow works the same way by rotating and creating an S shape wound. Puncturing that double membrane (aka pleural cavity) with a blade that's featuring a gutter or a rotating action means that the lungs collapse way faster because the double layer membrane fills even more rapidly with fluids and air at each breath. That's almost instant knock out with minimal force applied. That's a huge target area for immediate neutralization that's unlocked with this type of strike.

[@keithlarsen7557]

So the thing about energy, is its biased to light and fast projectiles, but momentum is biased to slow and heavy projectiles. High energy, but low momentum means an inefficiency when impacting the target.

[@stevedjurovich194]

at 12.03 minutes did you say 195lb draw weight for the longbow? Surely you meant 95lb? ;) Also that's a low FPS even for a longbow. Would it not have been better to average several shots? You weren't at full draw on that shot so the bow was underpowered...and not really of medieval draw weight anyway. Not really a fair test, considering the crossbows suffered no such handicap.

[@arikwolf3777]

I'm in a medieval reenactment group, we can not have modern crossbows, bows nor arrows. And we are limited in the power for safety. So your two crossbows are not allows, but your longbow is. Except, I don't think I could use it. (I don't have the strength any more.) Still, I like your videos. You have such interested stuff and information.

[@adriendecroy7254]

The analysis here misses one very important thing. As the projectile travels, it loses speed. The energy calculation that really matters, is the amount of energy at impact, not when it leaves the bow. The force of friction due to air resistance is proportional to the velocity squared, so fast light projectiles lose a lot more energy with distance than slower heavier ones. I think if you did the numbers but instead used impact velocity over say 50m you could get quite a different picture, and the medieval cross-bow would probably stand out more, due to the heavier bolt. It might be possible to calculate velocity at target safely using a high speed camera rather than trying to shoot a bolt through your chronograph at 50m

[@peasantmob1712]

I noticed that Gallwey said that his crossbow had a 38 inch prod but only 7 inches of powerstroke, whereas your 1250 lb crossbow had a 28 inch prod and 6.5 inches of powerstroke. Why do you think that Gallwey's crossbow had a design of such a long prod with negligible increase in powerstroke? Won't this decrease its power? Why would a crossbow be designed this way?

[@michaelpitt783]

So, knowing the limits of modern materials, just how powerful could a crossbow be? (This is a massive question really, but looking at the dimensions for say, the prod, how far could we bend it past what they would?)

[@LocalDiscordCatgirl]

Hey Tod, old video I know, but there's more to the story than you mentioned and I feel like it should be acknowledged. Broadheads don't kill through kinetic energy like bullets, they kill through penetration, which KE is NOT a factor of. Bullets push their way through tissue, which is why they have such high KE. A basketball carries far more kinetic energy than any of these tested mediums, for example. What matters is a mixture of physiological effects (muscles retract and lubricate arrow shafts with blood when cut while an animal is still living) along with the mechanical advantage of a broadhead (or to a lesser extent a bodkin) which amplifies the work the arrow or bolt can do with the available force. This is why an arrow will penetrate a sandbag deeper than a .357 magnum will.

[@jacobahn9998]

Considering that medieval folk used pulleys like the windlass to cock 1000+ lbs. crossbows, could they have made a compound crossbow, or even a reverse-limb compound crossbow, with only string, wood, & steel? If so, could it be made small and light enough to be used as a light crew-served weapon operated by a highly mobile team of 3 men on foot?

[@johnsteiner3417]

I think you're justified in suggesting the historical reference might be exaggerated, because a crossbow operating at ranges that high would've remained in use well into the centuries instead musket rifles started taking over. It's not until the 1700's that a musket rifle performed effectively beyond 200 meters.