It pleases me that, somewhere in the world, there is a man with crossbows willing to answer all the questions I've ever had about their use and operation. He even answers questions I never would have thought up.
@@breembo I've got 2 Tod Cutler daggers, they're nice and am considering a commission when he starts taking them again. A late14th century falchion would be more my jam.
@@tods_workshop I've been going through your old videos and noticed the difference, been meaning to ask about it for a while. I guess sometimes the simple things make a big difference.
@@tods_workshop I always put it down to you not being used to talking to camera. I seem to remember Jill Bearup talking about this, it's hard to get emotions across a lot.
I had nothing against Tod's quieter style. It was obvious there was no lack of enthusiasm there. Not that I mind his animated "let's shoot stuff!" lockdown pick-me-ups :-)
Having a scene, in which three rival Condottieri face each other across a piazza, attempting to draw their crossbows with windlasses, and get of the first shot, while Morricone's, "The Triple Duel", booms out of the speakers; that would be awesome. Of course, Tuco would find that Blonde had tied a knot in his windlass string while they slept the night before.
@cable "Verily, it is a commonly held belief, that there be just two types of spurs in this wicked world; those that entereth the chamber by the portal [crosses himself], and those that doth risk defenestration." Tuco Ramirez, 1526, near Governolo
Unless someone invents a crossbow with a revolving bolt magazine. Remember that 2004 van Helsing movie? I bet if Tod and Adam Savage work together, they can make that contraption real.
I find stuff like this a real eye-opener when looking at how much great characters in fiction lug around while sneaking past guards and scaling castle walls.
When I went to high school, the physics teacher did spend 20 minutes or so on bows and bolts, as an aside from the couple days on artillery shells and how they fly and are affected by things like air resistance and the rotation of the earth. But that was over 50 years ago, and I'm pretty sure things have changed in education practices since then.
@@tods_workshop all this is just fascinating, isn’t it. It’s the reason why you make your videos and the reason we watch your videos. Weaponology, as I call it. I look forward to your videos and so does thousands of other people.
Thank you for addressing this question, because from the arm chair i have often argued with other YT users about this! :) Love to you from across the Pond, Todd.
When comparing weighs of a bow, a string and a bolt one has to take into account relative mechanical advantage in the system. The ends of a bow move twice as slow as a bolt does. And the center of a bow doesn’t move at all. So the effective mass of the bow would be about 1/5 of it’s real mass. For the string it’s something like 3/4 of it’s real mass. The bow is still the most relevant part. But one has to be careful comparing the masses like this.
A possible explanation for why the lighter string gives less power: It's stretchier than the heavy string. So for the same draw distance you get more string stretching and less steel bending, meaning you have a lighter draw weight and less power. It's exactly the same impact has having a longer string, but not visible until you pull the bow back. Can this be something you measure in your workshop?
Yeah, it's very possible that the 140 g string was just a bit too weak, so it stretched immediately, Tod's says it's probably ended up bit too long at around 6:30
@@lscibor I thought he said that it might have always been longer? Either way, measuring the draw weight at full extension with both strings would be very interesting and resolve this quandary!
@@QuantumHistorian Even measuring that might not fully capture the issues at play; depending on whether its and issue of length at rest or an issue of string stretch. If the lighter string just happened to be fractionally longer, but no stretchier, then your draw weight measurement idea should tell the tale. But If the lighter string has more stretch to it then I'd both static and dynamic stretching; and a draw weight test would only capture the former. Because if the string stretches even more once the trigger's pulled and it's accelerating the bolt then that'd be a further reduction in energy transfer compared to whatever the draw weight test showed.
@@aarong-s4954 Probably not, but he's pronouncing it within the allowances of the rules of English pronunciation (which are VERY wide!), and we understood what word he was saying, so it's as "right" as it needs to be.
@@tods_workshop It's cool to learn new stuff though, innit? It took me a few moments to get "wait, what did he mean there? Oh!" when you said that. "Parabellum", as in the proper name of the firearm cartridge, is a hell of a word because it's an English portmanteau of the _Latin_ words _"para bellum,"_ shortened from the phrase _si vic pacem, para bellum;_ if you seek peace, prepare for war. And of course there's all the wonderfully confusing malarkey about _how_ to pronounce Latin in the first place! So it's totally understandable that someone who didn't know it was "Para-Bellum" would look at it, immediately liken it to "Parabola," and pronounce it that way.
i read on a trad bow forum something like: not to think about the limbs transfering energy into the arrow, but about the arrow sucking energy from the limbs! To resist the limbs bending back to neutral you need an opposing force, that is inertia. Basically heavy stuff resists efforts to change its velocity. In moving objects its often called momentum. So a heavier bolt will always absorb a higher % of the energy stored in the limbs than a lighter bolt, because it resists the limbs for longer due to its higher inertia, giving it more time to absorb their energy. Regarding the string: If we compare the kinetic energy of each type of bolt, we can determine that the crossbow has at LEAST 4% less energy stored with the longer (lighter) string. That is assuming that the lighter string does not change limb efficiency, which it definitely WOULD. I think the lighter string being longer actually diminished the amount of energy stored in the limbs FAR more. Here is why: Lets assume during the shot the string at the nock doesnt move, and the string at the height of the bolt moves as far as the bolt, a bit like a rubber band. If the mass of the string is evenly distributed as you move along the string from nock to nock, the mass of the string moves half as far as the bolt does during the shot. That means the mass of the string moves at half the speed of the bolt at any given time. That means it carries half the momentum a bolt of the same weight would, as momentum=mass*velocity. Meaning a 80g bolt + 140g string have about the same combined inertia as a 60 g bolt + 180g string acting on the limbs, and would be draining the same amount of energy from the limbs, and would be shot at the same speed. That means a lighter string of the same length should cast the 80g bolt about as fast as the 60g bolt shot with the heavy string, giving it 16% more energy and bumping it up to 4.4 kg*m/s. So a 10% increase in momentum aka penetration power.*** ***Assuming my simplifications werent too sacrilegious. Regardless of my quick maths, Im quite confident you could have lost 10% of total energy stored in the limbs.
Loving these videos Tod. You (along with Ranch Fairy who's big into heavy, high FOC arrows) have inspired me to build the heaviest bolts I can for my (modern) crossbow to see the difference. Not hunting with them as I'm in the UK, but an interesting experiment all the same.
I would highly recommend Tuffhead products, (which if you watch Ranch Fairy you’re probably already familiar with them) as they offer a wide variety of high-FOC heads and points. You should give their 400 grain dangerous game heads a try, they really have some punch! Also, if you’ve got a higher budget in mind Bishop archery makes broadheads and points in the 500-600 grain range, but unfortunately they have priced their products insanely high. Hope this information helps, and good shooting! 🏹👍
@@garrettevans8863 Cheers Garrett! I am actually about to order some of the Tuffheads (+ inserts). Sadly they have to be shipped over here from the US so I'll have a little wait. I'll check out the Bishops also - I've heard them mentioned before.
started the video and couldnt stop laughing at the T-shirt, Love it! and loved this eagerly awaited follow up on the bolt distance vid! keep them coming!
I love this sort of content and I'm so very happy to see numbers explaining the mechanics going on with shooting bolts. When you shot using the lighter string and you got less velocity, at first I was very surprised. After you proposed an explanation, it all became clear. Now it seems quite obvious that if the final string length varies (with crossbow drawn), the bow will be differently deflected, affecting the deformation energy it's storing before release. And I say final length, because the string can be longer or shorter, but also more or less elastic. Accounting for this might be out of the scope of these videos, I think, but it's probably good to know for a better understanding of the whole thing. In any case, cheers!
The crown bolt is not just a big load, it's going to have a really efficient energy transfer and low penetration. Should drop things really fast with minimal damage to meat/hide.
Interesting fact; this 850lb crossbow got a very similar performance with a 93g bolt compared to the 960llb crossbow you tested a while back with a 90g bolt. The 960 had the same momentum, 4 more joules, and 2 more meters/second.
@@Kokoonutz I cant know the limit, if you want a steel short limb long draw you will need a really springy steel,and a really strong chassis. It will be super hard to make if not impossible.
I had sent a suggestion for graphics, I sent an example along with it. I'm not sure if you decided to do it independent of my suggestion it if you saw it, but I'm glad you started putting up the stats, makes it easier to follow along
One thing to consider with the choice between light and heavy quarrels is that weight of them doesn't matter only in flight. There is going to be the cost of metal, but of course, even to carry them. Which is a massive concern even today. Some quick math and rounding made me realise that with a 60gram bolt you will fit ~83 into an arbitrary allowance of 5kilograms. With the 93gram one? Only ~54. You only get two thirds of number of bolts downrange! I am sure each crossbowman had a different preference and probably even had multiple types of bolts on his person, just thought that it is a good argument for consideration of the light bolts, even though I like lobbing big hunkin' chunks of steel myself as well. Lovely video and looking forward to more of them as always! Have a good one, Tod!
Yep, that's a significant concern even today. I suspect that the crossbowmen would have maybe a dozen or so specialty arrows and a fixed weight of war shots. Total equipment weight is going to be about 35lbs/15kg
Been waiting for this video for years! With regards to the string, a possibility is that a heavier mass is more effective at energy transferal. Heavy mass accelerating heavy mass = lots of energy transferred Lighter mass accelerating heavy mass = less energy transferred A heavy string would accelerate slower meaning the acceleration phase is longer.
I would love to see another collaboration where Joerg Sprave, from The Slingshot Channel, tests your swords and daggers on a ballistics' jell dummy. That would be awesome!
Maybe you should concentrate a wee bit, Lad. Because if do, you can go ahead and learn how to spell “more” correctly. PS: please read this with a Scottish accent, cause then it would sound like I’m talking directly to you. leis gach deagh dhùrachd, Mithrandir.
@@simonmorris4226 As an accountant myself I have found that my curiosity was a blessing more than a curse. Although if you are pointing the crossbow at me then I confirm that I will temper my curiosity about the effect it might have on my physical (and other) integrity.
The way to see that is on Mister Watts' big ballista. Firefly is a beast, 5000lb draw weight and some 30" draw length! With a sawtooth/gear tooth rig for variable draw length. wattsunique.com/blog/
The engineer in me loves these videos. I also think it would be great in a physics class. It teaches a lot of very important things, design of experiment, hypothesis, statistics, etc. You should take you gear to a local school!
Hello. Tod from my observation and background (material science) it seems that the main limitation of xbows is the elasticity (rate of deformation) of the metal bow. Depending on the metal (or other material) a vast amount of the stored energy in the bow is lost to internal friction and the maximum deformation speed also limits the maximum speed the bolt can reach. Because of this the lighter bolts only move a bit faster than heavier bolts. If you would really put money into R&D I bet you could design a modern xbow with terrifying power and momentum. But at the same time we have fully automatic firearms, so nobody will put down the money for such an adventure.
@Michael Smith Hello. I set the performance of the bolt as standard for the comparison. Of course there are ways to improve the bolt too. My main focus was the xbow and why the lighter bolts did not show a far greater speed. Modern xbows solve a lot of these problems already (I'm aware of that) but they are doing this with more or less basic materials. CFRP's are by today's standard basic materials by the way. Besides that Michael your intuition was not wrong, the effects you describe are important too and are based on material properties and mechanical solutions. It takes a whole bunch of different engineers and technicians to produce a top rated product.
I wonder if there was another way of stringing a crossbow; or if, armies on campaign had a cart kitted out with various rigs necessary to maintain the army's weapons.
@@euansmith3699 There was certainly an armorer's cart (or several) as part of the train of any substantial army. What exactly was in it would have varied with the army and age, but for most of history you can assume it would be a combination of a blacksmith's shop and a woodshop. I would also suspect there were field expedient methods of restringing a crossbow, since you likely didn't have a lot of spare bows when you were in the middle of a battle or seige.
It's worth keeping in mind that you have a lot of men with little to do other than work at menial tasks most of the time. This gives you a huge reservoir of ability to make a bunch of field expedient pieces via a bunch of guys whittling the appropriate bits. At the end of the day, you could just get a couple of men, some rope, and a couple of closely spaced stakes or tree trunks to wedge the bow against while the men use the rope to pull the round side the bow against the trees. Enough men (or a draft horse) and even some of those HEAVY bows could be worked with in relative ease.
food for thought: no mention here of sectional density. Energy and momentum are part of terminal ballistics but only part of the story... A fastball and a .22 round have samey energies but different effects on target. Higher energies would matter more on the blunts you have there. Rifle shooters have argued energy versus penetration basically the whole time. Don't get all worked up like them but it might be good to take sectional density into account. fun study thanks for the video.
@@JorgTheElder the point impacts faster leading to more penetration allowing the mass to do more damage. it’s why modern tank shells fire a smaller arrow-like bolt than a large bullet-like shell, the force to penetrate is less but it also goes deeper and causes more damage on the backside of the point of entry: like flesh and body parts
I was watching this (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-KXfB59HenMA.html) @JoergSprave video earlier today, and was struck watching this video how similar the head width on the Crown bolt is. I would expect the results to be pretty similar.
According to Fragment Hazard Criteria, energy is meaningless when it comes to blunt impacts (at these low velocities, at least, it could be driving factor for hydrostatic shock with bullets) - so anything that doesn't go through mail. The findings were that there were three categories of blunt impact injuries, and the thing that mattered how badly it injured you were either m*v (so, momentum), m*m*v*v (both speed and weight squared) and m*m*m*m*v*v*v*v (speed and momentum to the fourth power). This is especially important with the heavy weight bolt, because that one will be fearsome in these three categories, much more so than the energy alone would suggest. If you are wondering, Fragment Hazard Criteria gives us even the lightest bolt above the 50/50 odds of causing a major injury (cracked skull, breaking ribs enough to lacerate insides), and has even odds of going through a thigh even when blunt. Wear armor when getting shot at, is what I take from that. Another thing I noticed is that the heavy bolt is about 150 grams at 45 meters per second - which is about as fast as I can sling a baseball, which weights 150 grams. And there were clay and lead sling projectiles found in that weight category, probably meant as a siege ammo or anti-armor. It's interesting to note that once you get to cranequin crossbows, you can use them to make all but the most elite slingers obsolete, and with almost no training required at that.
I’m very pleased to learn what the historical meaning of bastard was and how it applies. I know that high velocity stabbing would really be unpleasant, but I’d be way more scared of seeing one of those crown bolts flying through the air around me.
With energy and momentum being the highest on that blunt thicc one, I would like to see its performance with a normal botkin tip on armor or wooden doors. And make one rediculous heavy, like 400 grams and look if energy tranfer goes down again, currently it simply goes up with weight, but it would be nice to see what that strong bow can move, and when its power hits a border.
@@tods_workshop Yes, i saw that one. Sadly no Chrono to compare it to the other bolts, and since it is blunt, I don't know how effective a 'sharp' version (please mount a spearhead on a bolt 😅) would be compared to the 90ish grams bolts. Since crossbows are not the most mobile and range-defining things, i wonder if a 'breach commando' could have used some rediculous bolts like that, as range would be neglectable and pure energy transfer is all you need sometimes. (Full metal bolts perhaps? They probably are not as top heavy as the pommel one...)
That one is thicker, so more metal would need to be bent and the four 'cuts/leaves' would need to be longer, so I would think there would be diminishing returns. But having numbers to prove that would be sweet.
Changing the string had the biggest difference for the heavy bolt. That makes sense: if the lighter string is more elastic (reduces the force), then there should be less energy in the bow. We don't see this for the lighter bolt, since the weight of the string starts having a bigger influence.
It would be interesting to see the 3 war bolts with the same style head on them. I'm sure you'd have to add weights to get them the same as with the different heads.
my answer before watching the video: to the degree that making the bolt lighter makes the bolt faster, it should be the case that lighter bolts have more energy. The relationship between energy and mass is linear, but the relationship between energy and velocity is a curve.
Interesting theory. With air guns usually the heavier projectile the more power due to the extra time the heavier projectile has under load before leaving the weapon. In airsoft we call this joule creap
I think the one of the reasons the heavy bolt is slower, is because it has a less aerodynamic tip. I'd recommend putting a pointier head on the heavy bolt and see what happens
So, the system has x amount of energy it can give up. If you add more mass then the energy is offset by the mass. Think of yourself throwing increasingly more massive rocks. As the mass gets larger the distance gets smaller. Same energy, different outcome. I strongly recommend that you enjoy some basic physics demonstrations as they can be a very helpful tool to understand what many people take for granted.
The Crono is very close by, so there is little distance for the bolt to decelerate. Then also the bolt is heavier and not as fast - so even a bit less drag. And it is heavier, so while the air-resistance is certainly higher, the extra mass means it will still not slow down as fast. To put that to extremes: A Feather as less air-resistance than a car, yet even at just 50 km/h a car could be shot way further than a feather at 200 km/h.
I know I'm really late, but the thinner/lighter bowstring might also have a bit more flexibility. I know bowstrings are made from rather inflexible material (interestingly, in Germany it's called "Sehne" which translates to "sinew", but material like sinew or guts or other animal-derived strings weren't used much in central and western Europe; according to any evidence they preferred hemp or flax for its rigidity) but hardly any material has zero lateral give. And the thinner you make it, the more it can (slightly) stretch, which then reduces the efficiency. So basically I'm saying: unstrung the length of the two strings may have been virtually identical, but once you put them on the bow the lighter one may have ended up a few millimetres short - and once you've loaded the crossbow, that effect may have increased to the point where you lose a significant amount of power.
Also, medieval techniques, everything is going to be approximate, they aren't going to be weighing strings to the gram, potentially the ounce, but more likely they just make them to a pattern and set, especially as every village in Europe had its own slightly different measures. Same goes for the crossbowmen on the field, he isn't going to be measuring angle with a protractor , he is going to aim roughly 45 and shoot.
So, my lay-understanding takeaway here, is that the crown bolt is Ye Medieval equivalent of a shotgun loaded with deer slug; the heavier bodkins are akin to lighter or less-lighter rifle rounds, and the lightest of all would be something like a heavy revolver? In terms of the sort of things you'd want to use them for, anyway?
I watch these videos compulsively now. I don't even know what Tod's talking about half the time. I for sure don't know before I click the video. Doesn't matter. All cool.
I think I made a similar comment when you posted your range tests on these bolts, but I'd be very interested to see the results of a bolt as heavy as your crown bolt but a deliberately aerodynamic shape. I suspect what kills the range on it is air drag. I also (for the same reason) wonder what difference polishing or varnishing the bolts might make.
A interesting test would be to see how fast the bow can move an effectively weightless string. Perhaps use a string made of kevlar or similar very light modern material with effectively no stretch, or measure the movement of the bow with no string at all - that might need a fancy jig, measuring kit, and some equally fancy math. This would establish the limiting velocity of the steel bow itself.
You should consider to record shooting both strings with ultra slow motion. It may be that lighter string is smashing the arrow and bouncing back a little and not accelerating the arrow over full draw length. Maybe stiffness of both strings are considerably different?
Hey Tod! I had an idea, have you ever considered how they might build a compound bow in the medieval era if they would've known it was possible and effective? Just something I was thinking about recently, I'm not even sure it's possible to make a proper compound bow with those types of materials, but I figured if anyone knew, it'd be you or someone else here. Honestly I'd be surprised if you couldn't make something halfway decent though, but I'm no bowyer nor engineer TBH. Big fan, I appreciate the data in these videos. Very interesting, probably hardly anyone would know these things without channels like yours. Also I'd curious to see these crossbow bolts against plate armor (like in the arrows vs armor vid), not sure if you've done this yet. I'd be curious to see how they compare to Joe Gibbs's longbow.
Your videos are always so informative. I really love them. But seeing all the numbers you have provided with your vids, I started to wonder why crossbow are considered so much more powerful than bows. Easier to use I can understand, but talking about speed and energy, they looks very close to bows, if not inferior. Am I missing something?
I think you have hit on something here. Per time period, I do not think there would be much difference in power between bows and crossbows, but crossbows could throw a heavier weight? I will have to go back to lockdown longbow vids to see the arrow weights, but even then not all armies used longbows, so the difference in projectile weight and energy transfer may have been a larger factor.
You're not missing anything, you need to practice for years and build up very specific muscles to shoot a warbow, you just have to wind up a windlass on a crossbow and point.
@@thomasjackson8737 that’s interesting. I will check darts and arrow weight again too, ‘cos energy wise they didn’t look so different. But your point could answer why crossbows were considered the most powerful between the two
@@ziggarillo yeah, easiness of use was clearly the main advantage of crossbows, even if genovese men had a mandatory training requirement like the english bowmen had (meaning they were highly trained soldiers and not some peasants levy troops of sort)
Generally those crossbows with huge draw weight but very short draw length are one piece of puzzle available to us. Probably because they're best preserved in museums, collections, etc. and best studied. But they are obviously limited design, because they just can't store than much energy when they're being bent just by about 6 inches. So I suspect they're quite misleading. Take a look at this magnificent bows by Andreas Bichler, it's about 1200 pounds, like one of Todd's crossbows. It has about 15 inches of draw lenght instead though, so energy ends up being 3 times higher. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-AA5M0QKXtWU.html
Regarding the lighter String: Maybe trying a different material could change velocity and momentum. So sinew, flax, hemp, bast, maybe even leather are all different in elasticity and could influence the dynamic of the bow and therefore the bolts. Worth a try?
Hi Tod loving the videos as always, question for you though. How much more “power” would you expect to be able to make if on one of these medieval replicas you made the draw length slightly longer say another 1-2 inches were it wouldn’t look outlandishly crazy compared to a modern version?
Hi Tod! Is there a chance for You doing a video on different types of dagger sheaths/scabbards and suspentions? I think it's an interesting topic that rarely (if ever, honestly) gets much coverage, and I would love to hear some more of Your thoughts on this!
Great suggestion! and luckily I have ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-_YT52eMWUsA.html and ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--W6vCahVKLU.html and ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-bHLh3VQGrHI.html and ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-79qheU3I8uE.html
The next question is what is the point of diminishing returns? At which point will the weight (and size) be so large that the resulting energy starts to drop, the range and/or flight speed fall so low that they wouldn't be useful anymore?
Cool cool work.. i wonder if you get more data from the experiment ( min 3 data from each weight of bow) will show you the same or at least simillar result. Then the result will be very statistically and scientifically reliable, but you would have a longer video😊.. But this is a very2 cool series of archeries video.. Looking forward to your next video
The thinner string is more elastic and thus stretches further when being cocked,it's this that produces less bending of the bow and thus the poorer performance on being shot.
@@tods_workshop Everything's elastic to some extent. But the tensile stiffness of the string _may_ be much higher than the bending stiffness of the bow, in which case it wouldn't make much difference. You could measure this.
Makes sense that the "plate cutter" would have the highest momentum, it needs that force for penetration. I suspect the big heavy bolts were good for crossbows used by siege defenders, where stopping power was the biggest priority, while the lighter, more aerodynamic needle bodkins were probably way better for precision shots at range. Have you ever done a test of group accuracy with each arrowhead type at long range? Like made 3-6 of each type, shot a group, and looked at what performed best at the different ranges?
While the second string did lower energies it also got them much closer to each other so it may still help with lighter bolts. The 80 and 60 lost virtually no emergy compare to the 10 the 2 heavies lost due to length
Great video! Assuming a flat plane and no air drag(could be accounted for if we knew the drag coefficients of the arrows), you could calculate their energy from the distance they traveled, no need to measure their velocity. Since their launch angle was 45 degrees, the energy can be calculated as m(mass)*g(free-fall acceleration)*d(distance traveled)/2. According to my calculations, the energy of the 159g bolt was 105J, 93g was 91J, 80g was 80J, 65g was 69J. So pretty close to yours. I'm sure taking air drag into account wouldn't be that difficult
