Chinese Crossbows were the most powerful crossbow ever

[Fanest]

Ask yourself, if the Han crossbow picture used a Medieval European trigger mechanism, could it possibly have the nut placed all the way towards the back of the stock? Red line shows powerstroke.

Ofc it could easily have nut where Han trigger is, and there are two ways to do that - first one would simply require just a bit longer stock (cca 10cm) while the second would require to design reverse trigger - which imo could be done with little difficulty. Instead of trigger being turned down the stock it would be turned upwards.

[HackneyedScribe]

Ofc it could easily have nut where Han trigger is, and there are two ways to do that - first one would simply require just a bit longer stock (cca 10cm)

Please read post 62. Plus, at least from the picture I provided, I don't see how you think adding only 10 cm of stock is enough. Most Medieval triggers are longer than that (distance from nut to the end of the lever), and if you want to be able to press your cheek against the stock for stability, then you should add even more inches to the stock past the trigger lever. And as crossbow stocks get longer, ergonomics suffers.

As for the reason for the long trigger:

"The "trigger pull" describes the force necessary to overcome this resistance-to "pull" the trigger (in fact, a trigger should be squeezed, not pulled). The more strength required to squeeze the trigger, the greater the risk of shaking or jerking the weapon. The introduction of one or more levers between the trigger and the part that releases the bowstring allowed the strength of the bow to be distributed along several axes restraining the internal levers, resulting in a notably reduced trigger pull. This development, begun in the decades before 1500, produced the two-axis lock and, in the second half of the sixteenth century, culminated in the internal-release mechanisms ultimately involving four axes. Readying a crossbow with a four-axis lock and set trigger was a complicated process involving a number of time-consuming steps and an additional instrument, the pricker, or cocking pin." - A Deadly Art, European Crossbows, pg 32

Ergo, you can probably get a good guess at the draw weight of a crossbow by looking at the trigger's length. You can have a shorter trigger to increase powerstroke, but that means you'll need a weaker prod so the trigger can be operated with the same level of ease.

If you want both long powerstroke and high draw weight, then you end up with something akin to this clumsy thing:

while the second would require to design reverse trigger - which imo could be done with little difficulty. Instead of trigger being turned down the stock it would be turned upwards.

If you are going to change the design so that it looks more like a Han trigger, then that defeats the purpose of the question as this is no longer a Medieval European trigger anymore.

[Fanest]

Please read post 62. Plus, at least from the picture I provided, I don't see how you think adding only 10 cm of stock is enough. Most Medieval triggers are longer than that (distance from nut to the end of the lever), and if you want to be able to press your cheek against the stock for stability, then you should add even more inches to the stock past the trigger lever. And as crossbow stocks get longer, ergonomics suffers.

well i guess it depends how many axes - internal "gears" or levers there are in trigger - when i said that i had in mind the three axes one that u posted before

As for the reason for the long trigger:

"The "trigger pull" describes the force necessary to overcome this resistance-to "pull" the trigger (in fact, a trigger should be squeezed, not pulled). The more strength required to squeeze the trigger, the greater the risk of shaking or jerking the weapon. The introduction of one or more levers between the trigger and the part that releases the bowstring allowed the strength of the bow to be distributed along several axes restraining the internal levers, resulting in a notably reduced trigger pull. This development, begun in the decades before 1500, produced the two-axis lock and, in the second half of the sixteenth century, culminated in the internal-release mechanisms ultimately involving four axes. Readying a crossbow with a four-axis lock and set trigger was a complicated process involving a number of time-consuming steps and an additional instrument, the pricker, or cocking pin." - A Deadly Art, European Crossbows, pg 32

Ergo, you can probably get a good guess at the draw weight of a crossbow by looking at the trigger's length. You can have a shorter trigger to increase powerstroke, but that means you'll need a weaker prod so the trigger can be operated with the same level of ease.

I saw windlass trigger and many have trigger made of only 2 axes. They are also fairly short - some 15cm-20cm, and later i saw some 12th century crossbow (made by tod) which had similar trigger ( 2 axes) and length. So its not that universal that longer trigger = higher drawweight.

I see the logic behind it though - longer lever, requires less force, internal gears can reduce this further etc.

If you want both long powerstroke and high draw weight, then you end up with something akin to this clumsy thing:

My guess is that crossbow on the picture above has only one axis (whole trigger just one piece of metal - long lever), hence so long a trigger, and secondly prod seems to be massive so the long stock also helps with having gravity center further down the stock.

If you are going to change the design so that it looks more like a Han trigger, then that defeats the purpose of the question as this is no longer a Medieval European trigger anymore.

A reverse trigger would work same way as other European triggers. Nut would be practically the same - sear would be on the other side of the nut though, and trigger would be just turned around. Problem is that little finger and ring finger that would press on such trigger arent as strong as index finger and middle finger. But there are ways to solve this as well - make a basket around it or smt like that.

[HackneyedScribe]

well i guess it depends how many axes - internal "gears" or levers there are in trigger - when i said that i had in mind the three axes one that u posted before

That's a two axis lock design. The axis for the nut don't count.

I saw windlass trigger and many have trigger made of only 2 axes. They are also fairly short - some 15cm-20cm, and later i saw some 12th century crossbow (made by tod) which had similar trigger ( 2 axes) and length. So its not that universal that longer trigger = higher drawweight.

I see the logic behind it though - longer lever, requires less force, internal gears can reduce this further etc.

I was talking under the assumption that trigger length comparison should be taken under an "all else being equal" besides draw weight scenario, which includes the number of axis' being equal.

Btw, the "fairly short" triggers of 15-20 cm you spoke of would make that longer than the 10 cm mentioned beforehand. Still, 15-20 cm do not seem right. Most crossbow stocks revolve around 30 inches in length, albeit the ones used for cavalry are shorter. The distance from nut to the end of the trigger lever should be closer to 15 inches rather than 15 cm. Remember, due to the trigger design system the beginning of the trigger would not be directly under the nut but rather behind it. And if you want to use your cheek as a stabilizer, the stock must be lengthened accordingly as well. Of course, a four axis lock could significantly decrease trigger length, but that only developed during the 1550s in which the arquebus became the dominant missile weapon of the battlefield.

My guess is that crossbow on the picture above has only one axis (whole trigger just one piece of metal - long lever), hence so long a trigger, and secondly prod seems to be massive so the long stock also helps with having gravity center further down the stock.

You never want a stock that long for handheld crossbows, no matter the weight of the prod. If the prod weight is so heavy that you need such a long stock length to "counterbalance" it, then your shooting position like shown above is incredibly awkward. At that point you either shouldn't use such a heavy prod, or you should use a stand/prop rather than shoot in that position. But in latter case I wouldn't term it as a handheld crossbow anymore.

A reverse trigger would work same way as other European triggers. Nut would be practically the same - sear would be on the other side of the nut though, and trigger would be just turned around. Problem is that little finger and ring finger that would press on such trigger arent as strong as index finger and middle finger. But there are ways to solve this as well - make a basket around it or smt like that.

If you are talking about reversing the medieval trigger mechanism 180 degrees, that would introduce the problem of the string slicing off your trigger hand upon activation.

Anyway here is the Medieval European 2 axis lock trigger compared to that of the Han crossbow trigger. The Han trigger also used 3 axis, the middle axis is hard to see but I labeled it as roller, while the axis for the nut is shared by the axis by the nut/locking lever. Whereas for the top trigger mechanism you pull on a string to re-activate the trigger, for the Han trigger you re-activate the trigger by pushing back on the grid sight.

[wulfgar610]

Actually, the picture I showed there was a suit of iron chainmail, lorica hamata, unearthed from South Shields, England, back in 1997, and dating to the Roman Principate era. You are correct that we have no surviving pieces of lorica segmentata, though, as far as I know (someone correct me or prove me wrong otherwise).

The Segmenta yes, but only pieces of the iron plate, but enough for some good info. Plenty of the brass fittings survived.

[Inst]

Just some comments to add. I have an ongoing disagreement with HackneyedScribe about the progression of Chinese crossbows; in my understanding, Chinese crossbows started out as absurdly heavy with long power strokes, but later progressed into lighter types with less efficient designs. The Song Shenbi Nu, for instance, was a steel-prodded crossbow, and from known examples, bearing a short powerstroke.

The peak of Chinese crossbows was probably in the Qin dynasty, when the Chinese used heavy infantry as a decisive factor of warfare. These troops were often armored with a type of early lamellar plate, and examples exist of, probably ceremonial, stone plate. To fight such heavily-armored shock troops, the Chinese needed extremely high energies to defeat their opponent. However, while such a crossbow would be effective against armor, it would be tiring to pull and consequently have a poor sustained firing rate.

My hypothesis is that subsequent Chinese crossbows became lighter, or more oriented towards speed and long-ranged fire, once heavy infantry became obsolete and there was no longer a need to defeat heavy armor.

Consider the early arquebuses in Europe, for instance. These arquebuses tended to have an extremely high weight, as well as high levels of power. Yet they were replaced by muskets, a firearm of lesser lethality. Why? Arquebuses were inaccurate and bulky. At long ranges, where they would have an advantage over muskets by having greater projectile energy, they were simply insufficiently accurate to be effective. At short ranges, muskets performed just as well, but were lighter and required less powder to load.

At the same time, however, some forms of armor were effective at resisting musket ball, but not arquebus hits. Yet the existence of the arquebus was sufficient to drive heavy armor out of the European battlefield, because arquebuses could be kept as reserves or as supporting elements against heavy armor, eventually driving both heavy armor and itself extinct.

I think a similar pattern occurred in China. The super-heavy crossbows of the Qin-Han era became obsolete, because the heavy infantry they were designed to counter also became obsolete. Warfare shifted to lighter and lighter troops due to the preponderance of firepower, and missile weapons became more optimized for other considerations than pure power and penetration.

However, what happened in China occurred over hundreds of years. Over that kind of time period, technology that becomes of marginal use can be lost, and that would explain why the Chinese lost the heavy crossbow designs and were forced to rely on steel crossbows like the Shenbi Nu to counter heavy armor, then firearms. On occasion, some of the technology would be recovered; I recall reading Song dynasty and Ming dynasty accounts of ancient crossbows being recovered, and discovering that they had materials innovations more sophisticated than their modern counterparts. Sighting, for instance, was rediscovered during the Song, but it's uncertain as to exactly when the technology was lost. In the Ming dynasty, crossbows shifted to deer antler trigger mechanisms instead of cast bronze, purportedly because the bronzeworking technology had been lost.

Lastly, we should discuss the reasons why the Japanese did not adopt the Chinese crossbow. For China, the crossbow was a civilization-making technology. It enabled the democratization of warfare, sort of like the rifle making every French peasant a lethal weapon during the Napoleonic Wars. The initial military elites of Warring States China were primarily chariot archers, and the fact that they'd have to contend with extremely heavy volumes of fire from peasantry rendered them obsolete.

The Japanese, however, failed to adopt a similar invention, resulting in the creation of a warrior elite, eventually threatened by the advent of gunpowder. Why was that? Two reasons. First, the crossbows of the contemporary era (Sui-Tang, after the Han, but before the Song) probably lacked a sufficient advantage over bows, although the Chinese claimed that Silla crossbows were more advanced than their own. Second, the linchpin upon which Chinese crossbows rested was the bronze trigger mechanism, with bronze-working being a highly-developed and sophisticated art in ancient China. The Japanese of the era, living on a metal-scarce island, lacked the technology to cast similar mechanisms, and with such scarcity of materials, it would be equivalent to literally gold plating your weapons.

From the reports I've read, the Japanese did have a sort of Nu (Chinese for crossbow), but in their case, it was a weapon more akin to field artillery, probably similar to a ballista. It was mainly used during the Heian era, after which I'd assume the technology was lost.

Also, recently a semi-intact Qin crossbow was recovered. Archaelogists are attempting to replicate the design.

See:

http://www.digitaljournal.com/scienc...article/429061

One other interesting fact is that according to some records, heavy crossbows were used as side-arms for sword infantry, not different than say, the pilum for Roman legionaries. It actually has a similar energy to the pilum, counting around 312 joules, putting it in the middle of pilum range (200-400J). However, the lighter weight of the heavy crossbow allows projectiles to fly further than pilum, but it should also result in worse penetration due to lighter weight. This may be offset by a better ballistic coefficient as well as the thinness of the shaft making it easier to penetrate armor. Some reports actually do suggest that heavy crossbows were used similarly to Roman pilum; some infantry types went into battle with a single loaded bolt, then switched to swords once the opponent entered melee range.

[HackneyedScribe]

1) I have not read from any primary source at all that Shen Bi Nu had a steel prod, nor are there any Song era examples showing a short powerstroke. The prod is supposed to be made of sandalwood whereas the stock is made of mulberry. I think the idea of a steel prod for the Shenbinu is just a rumor spread on the internet. Later Chinese crossbows did not get lighter (in draw weight), but I agree that from the mid-late Ming onwards (~1550s AD) Chinese crossbows decreased in efficiency very drastically. So given the same draw weight as that of a ancient Chinese crossbow, the Ming crossbow would be much much weaker.

2) Early muskets were way more powerful than an arquebus, not to mention way bigger and clumsier too. Later developments led to muskets getting much smaller, but they were still called muskets. I don't know why they didn't just resort to calling them arquebuses again.

Early musket:


Arquebus:


3) I don't know where you got the idea that infantry went into battle with only a single loaded bolt. But the early Western Han terracotta did show quivers that could only contain about six quarrels. The infantry with these quivers were also heavily armored, so they were probably meant to engage the enemy in close combat after a couple of volleys.

4) 400 Joules for javelin throws are basically Olympic level, except Olympic javelins were thrown by literally the best throwers in the world, with a running start, and the throwers aren't encumbered by a scutum.

[Inst]

Not going to an in-depth rebuttal, but I finally have an explanation for why Ming and European crossbows progressed to high draw-weight short power-stroke designs.

Timo Niemenen mentions in one of the Armoury threads that short power-stroke high draw-weight crossbows can achieve higher speeds with the same energy as a comparable long power-stroke mid draw-weight crossbow.

That seems plausible; while the energy transfer efficiency can be expected to be lower, the higher poundage over a shorter distance can be expected to result in a faster "snap". This is not to say, however, that crossbows designed to this specification would launch higher-energy projectiles or launch their projectiles efficiently however, merely that their projectiles would have higher speed and thus higher range.

It's not a matter of Chinese crossbows being generally superior or inferior to European variants; it's a matter of design. While Qin-Han crossbows were probably the pinnacle of armor-piercing capability, even considering modern times, as modern crossbows are hunting weapons, later crossbows progressed more towards functioning as fire support and long-ranged weapons instead of as armor-piercers.

[HackneyedScribe]

You need to have a source rather than just state what you find on the internet, because it's incredibly vague. Yeah, short powerstroke crossbows CAN achieve higher speed than long powerstroke crossbows of lesser draw weight, if the former's draw weight is high enough to offset it, or if it is using a light enough quarrel, or if the difference between the two powerstrokes aren't that great. No one said otherwise. As to whether some crossbow's other variables can offset its short powerstroke, you need to provide exact numbers rather than vague generalities for the two crossbows you are comparing against.

But if Timo Niemenen is speaking under an "all else being equal" scenario, then chances are either he's mistaken or you mis-read him. Energy is measured by velocity*velocity*mass/2. Increase the velocity and you get higher energy, all else being equal. If you say shorter draws gives a *snap* that increases velocity, but doesn't launch higher-energy projectiles, then that breaks the laws of physics. Given two cloned quarrels that are exact duplicates of each other, the quarrel that flies faster has more energy. You can't have one with more energy that flies slower. Maybe in another universe, but not in this one.

So all else being equal, it is the crossbow with the longer draw that can shoot a quarrel at higher velocity. The easiest way to get higher velocity is to shoot a lighter quarrel. Shortening the draw length is just counterproductive.

[Inst]

You need to have a source rather than just state what you find on the internet, because it's incredibly vague. Yeah, short powerstroke crossbows CAN achieve higher speed than long powerstroke crossbows of lesser draw weight, if the former's draw weight is high enough to offset it, or if it is using a light enough quarrel, or if the difference between the two powerstrokes aren't that great. No one said otherwise. As to whether some crossbow's other variables can offset its short powerstroke, you need to provide exact numbers rather than vague generalities for the two crossbows you are comparing against.

But if Timo Niemenen is speaking under an "all else being equal" scenario, then chances are either he's mistaken or you mis-read him. Energy is measured by velocity*velocity*mass/2. Increase the velocity and you get higher energy, all else being equal. If you say shorter draws gives a *snap* that increases velocity, but doesn't launch higher-energy projectiles, then that breaks the laws of physics. Given two cloned quarrels that are exact duplicates of each other, the quarrel that flies faster has more energy. You can't have one with more energy that flies slower. Maybe in another universe, but not in this one.

So all else being equal, it is the crossbow with the longer draw that can shoot a quarrel at higher velocity. The easiest way to get higher velocity is to shoot a lighter quarrel. Shortening the draw length is just counterproductive.

European crossbows could have been made with long power strokes, even before those complex triggers, simply by extending the trigger downwards or forwards, instead of backwards along the butt of the stock. But going for more energy by increasing the draw weight instead of power stroke does have advantages. It should give somewhat more bolt speed for the same stored energy, and allows a more compact and lighter crossbow. The disadvantage is that you need a spanning mechanism. The Chinese-style crossbow has the disadvantage of weight and size, but has the advantage of not needing mechanical spanning at energies where European crossbows do need mechanical spanning.

http://myarmoury.com/talk/viewtopic....r=asc&start=20

As he's a physicist, I trust his opinion, even if it's just an internet posting. Note that he talks about the same energy, not the same weight. As we've discussed before, the Europeans at some era used long-stroke crossbows. It is, of course, weird that they transitioned to the less powerful short-stroke variants, especially since long-stroke is much more effective against heavy armor, but as mentioned elsewhere, long-stroke leg-drawn crossbows are difficult to draw, especially at energies sufficient to penetrate heavy armor. The rest of his post is an insightful mention of how pre-modern military technology does not necessarily move in a linear fashion; for instance, Alexander's Macedonian Phalanx was a highly flexible unit utilizing medium spears. With the Diadochi warring among themselves, the sarissa became absurdly extended, an optimization against other phalanxes, to the point where the resulting phalanxes were overburdened and highly inflexible, allowing the Romans to hack apart what was once an undefeatable military formation.

Regarding the Song dynasty Shenbi Nu, you are correct. Part of the confusion lies in that it uses a steel stirrup, and was supposedly one of the first steel-stirruped crossbows.

As to the Pilum, however; I disagree regarding energies. Take a look at this thraed and its sources:

For example of how non-Olympic experienced throwers throw, see Sir Baldwin Spencer's Native Tribes of the Northern Territory of Australia. Spencer wrote that men in community on Melville Island managed to throw a ten-foot, four-pound spear 104-143 feet (31-43.6 meters). So the worst thrower in this test, throwing by hand, did as well with a much heavier projectile as the folks with the ankyle.

However, the Melville Island throwers had a running start of up to twenty feet, while the ankyle users could only take one step forward. Come to think of it, that could easily account for much of the difference right there.

Looking at it some more, I think the high-speed camera failed to accurately record the throw velocity. According to this calculator, a projectile released at 5.4 m/s at a 45-degree angle would attain a range of less than 3 m in a vacuum. You need about 17.5 m/s to reach 31 m - and air resistance would increase that.

As an aside, Spencer's numbers support the notion that at least heavy spears/javelin could penetrate armor. Even the shortest throw probably had over 300 J of kinetic energy initially. This stands consistent with Vegetius's claim and has long made me wonder why thrown javelins or spears mostly fell out of use in the sixteenth century.

http://myarmoury.com/talk/viewtopic....&view=previous

Calculate the Australian figures together and you get roughly a 500-600J range. However, the important thing to note about pilum compared to crossbows is that the short trajectory of the projectile means that it bleeds off energy quickly, meaning that impact energies could be much less, and that the total range achieved is minuscule compared to the crossbow.

[HackneyedScribe]

The energy he means here is the energy stored in the crossbow (powerstroke*draw weight/2) as opposed to the energy of the quarrel itself. The only reason I can think of that a medieval crossbow can achieve higher velocity using the same quarrel despite having the same energy is because the quarrel suffers less friction from the shorter groove. But this is a very minor variable compared to powerstroke and draw weight. There are other minor variables such as the length of the arrow or the weight of the string, or the shape of the arrowhead, or the reflex of the prod or the weight of the prod (actually the last two are pretty important) that I have left out because powerstroke and draw weight affects quarrel energy on a greater scale. These variables I left out either favors a higher velocity for the Han crossbow or they don't, I assume they roughly even themselves out.

If Timo is a phycisit then by all means let us hear the basis of his claims instead of just taking what he said and exaggerating it. Btw, a medieval European crossbow of the same stored energy as that of a han crossbow would not be lighter, it would be heavier as the short draw length means a heavier prod given the same draw weight. Timo probably came to his conclusion thinking that given two bows of the same draw weight, the shorter bow can be lighter in mass. This is correct to an extent, but the conclusion is made under the assumption that both bows have the same draw length, which is not applicable to a comparison between medieval and ancient chinese crossbows. A medieval crossbow's full draw weight must be obtained when the string is pulled back about half a dozen inches, so the prod needs a lot of mass to achieve that. A han crossbow have about thrice that length for its draw weight to be reached. So given the same draw weight between that of a medieval and han crossbow, the han crossbow's prod need not be as stiff, which means less mass.

As to the Pilum, however; I disagree regarding energies. Take a look at this thraed and its sources:


For example of how non-Olympic experienced throwers throw, see Sir Baldwin Spencer's Native Tribes of the Northern Territory of Australia. Spencer wrote that men in community on Melville Island managed to throw a ten-foot, four-pound spear 104-143 feet (31-43.6 meters). So the worst thrower in this test, throwing by hand, did as well with a much heavier projectile as the folks with the ankyle.

However, the Melville Island throwers had a running start of up to twenty feet, while the ankyle users could only take one step forward. Come to think of it, that could easily account for much of the difference right there.

Looking at it some more, I think the high-speed camera failed to accurately record the throw velocity. According to this calculator, a projectile released at 5.4 m/s at a 45-degree angle would attain a range of less than 3 m in a vacuum. You need about 17.5 m/s to reach 31 m - and air resistance would increase that.

As an aside, Spencer's numbers support the notion that at least heavy spears/javelin could penetrate armor. Even the shortest throw probably had over 300 J of kinetic energy initially. This stands consistent with Vegetius's claim and has long made me wonder why thrown javelins or spears mostly fell out of use in the sixteenth century.


http://myarmoury.com/talk/viewtopic....&view=previous

Calculate the Australian figures together and you get roughly a 500-600J range. However, the important thing to note about pilum compared to crossbows is that the short trajectory of the projectile means that it bleeds off energy quickly, meaning that impact energies could be much less, and that the total range achieved is minuscule compared to the crossbow.

I don't know how you calculated 500-600 J from a throw that only went 143 feet. The calculation for velocity is range= (velocity^2)(sin2theta)/gravity, which when plugged in we get about 20m/s for the highest velocity. This gives about 340 joules, not 600 joules. All the throws ranged about 260-340 joules. Of course, the equation was assuming that it was thrown in a vacuum, but with such a heavy projectile the effect is minimal. Plus, these guys had a 20 feet running start and are not encumbered by a scutum, not to mention precision aiming was not an issue. The Roman army didn't get to do any of that.

[Inst]

You're not understanding me. A long powerstroke crossbow is more efficient than a short powerstroke crossbow because it uses more time to transfer its energy to the projectile. A short powerstroke crossbow, on the other hand, transfers its energy in less time, and is thus more inefficient. Yet by snapping quickly, a short powerstroke crossbow can achieve higher speeds than its long-stroke counterparts. It may be less capable of efficiently transferring this speed, but it can still obtain higher speeds.

Hence a long powerstroke crossbow would have a higher optimum quarrel weight than a short powerstroke crossbow; the total energy of the long powerstroke crossbow would be higher, but the short powerstroke crossbow would be able to launch a faster, if less energetic, projectile.

====

About the pilum, I do admit I made a mistake. I forgot that KE = .5mv^2, not mv^2.

Still, interestingly enough, heavy pilums and heavy projectiles actually have an advantage over lighter pilums. When you're throwing a javelin, about 25% of the initial velocity comes from the speed of the runner, not the force with which the projectile is thrown. This means that while heavier pilums will necessarily be slower than lighter pilums, the total energy can be greater.

As a corollary, consider that Western skirmishing cavalry used javelins, not bows. A galloping horse can reach 40 km/h, imparting a much greater energy to heavy javelins.

Of course I do mention the drawbacks of javelins compared to bows; javelins can achieve higher energies than many simple bows, but that's with a high-mass projectile with limited range.

[Condottiere 40K]

I would have also thought that a shorter stroke would impact on accuracy.

[HackneyedScribe]

You're not understanding me. A long powerstroke crossbow is more efficient than a short powerstroke crossbow because it uses more time to transfer its energy to the projectile. A short powerstroke crossbow, on the other hand, transfers its energy in less time, and is thus more inefficient. Yet by snapping quickly, a short powerstroke crossbow can achieve higher speeds than its long-stroke counterparts. It may be less capable of efficiently transferring this speed, but it can still obtain higher speeds.

I'm understanding you perfectly, and what you are saying is not backed up by the laws of physics. If you think it is, then provide the physics equation which prove what you say is true, like I have done, or at least a quote from SOME source which backs up what you say.

As said before, given two projectiles of the same weight, the faster projectile has more energy because energy = mass*velocity*velocity. If the long power-stroke crossbow is shooting a projectile with more energy, and the projectile used is the same, then it must be shooting the projectile at a faster velocity. To say otherwise is to deny the laws of physicist. So no, a shorter powerstroke does not help in propelling a shorter arrow. "Snapping quickly" is not a characteristic of short draw bows. The velocity of the string is not affected by a short draw, the string only travels less distance due to the short draw. So a short draw only means there is less time for the arrow to accelerate, ergo less velocity for the arrow. I have given my equation, please give yours to back up what you say.

About the pilum, I do admit I made a mistake. I forgot that KE = .5mv^2, not mv^2.

Still, interestingly enough, heavy pilums and heavy projectiles actually have an advantage over lighter pilums. When you're throwing a javelin, about 25% of the initial velocity comes from the speed of the runner, not the force with which the projectile is thrown. This means that while heavier pilums will necessarily be slower than lighter pilums, the total energy can be greater.

As a corollary, consider that Western skirmishing cavalry used javelins, not bows. A galloping horse can reach 40 km/h, imparting a much greater energy to heavy javelins.

Of course I do mention the drawbacks of javelins compared to bows; javelins can achieve higher energies than many simple bows, but that's with a high-mass projectile with limited range.

Despite what people say on the internet, 4 lbs (1.8 kg) is already around the upper end weight of a pilum (Pilums go from 1-2 kg). So the javelin we calculated attained around the max joules that a pilum could attain, but ONLY IF the legionnaire has a running start of 6 meters, doesn't care much about accuracy, and ditched his scutum, each of which was an unlikely scenario. This is not to mention I have my doubts about your source as the earliest Olympic javelin gold medalists only achieved 60 meters with a .8 kg javelin, whereas your source says that 1 man out of the 9 could achieve 43 meters with a 1.8 kg javelin. The numbers don't match, especially when Olympic javelin throwers had a 20 meter run-up as opposed to the 6 meter run-up of Australian aboriginees, and it's harder to be mistaken for the former where the whole world is watching, as opposed to the latter. This source showed 0.45 kg javelins being thrown about 35-50m with a running start: https://www.academia.edu/2631534/Rec...Javelin_Thrown

The source matches well with what was expected from Olympic results. Yours do not.

You also keep talking as if you thought legionnaires had a significant running start when throwing their pilum. Most don't think this happened under normal circumstances, I don't know why you keep thinking they did. Is this because it's a total war forum? Lol.

[Inst]

You're wrong about the physics. Consider a Mongol-Turkic vs a Manchurian bow. The Manchurian bow can maintain higher energies and draw weights, yet it cannot reach the same velocities or distances as a Mongol-Turkic bow. The reason is that the Manchurian bow has heavy siyahs, which cannot reach the same speeds as the Mongol equivalent. A bow cannot project its projectile faster its own string.

Applied to the short vs long-stroke crossbow debate, a short-stroke high-weight crossbow should be able to achieve higher velocities than a long-stroke low-weight crossbow, even if the total stored energies are the same. The long-stroke crossbow should be more efficient, but it cannot propel its projectiles faster than the speed of its bow. Hence, with a heavy projectile, as we know the Qin and Han used, the long-stroke can achieve higher energies and better penetration than a short-stroke, yet it can be outranged by the short-stroke using a lighter projectile. With the same light projectile, the Han projectile would be limited by bow-speed, instead of energy transferrence efficiency or its total energy.

===

Another way to put it is as follows. I showed a picture of a Qin-Han crossbow to an engineer friend, and he mentioned it couldn't possibly be good for the bow, or that the bow would snap. Now, if we were to draw a European crossbow to the same draw length, that would definitely happen, not because the European bow was worse-made (it probably was, due to lacking advanced horn-sinew-organic-glue laminates), but because it was designed for high stiffness. A comparable Qin-Han crossbow would be able to store an identical amount of power, but at a lower tensile strength and a higher draw length.

You do argue successfully that a European prod would require more mass and weight than a Qin-Han crossbow, but a Qin-Han crossbow would occupy more volume (not in terms of material, but overall dimensions). Perhaps the total weight of both European crossbows and Qin-Han crossbows is about the same, with the European crossbow compressing the mass of the Qin-Han crossbow into a more dimensionally-compact space. Hence, there would be no trade-offs in total energy/mass.

===

Let me get my bias clear. I think the Qin-Han crossbow represents the pinnacle of crossbow engineering before modern times; the complex bronze triggerwork, as well as the enormous energies deployable, prove it. It was a game-changing weapon that controlled the development of Chinese civilization. Yet, we know that later crossbows were less capable, and a Qin-Han crossbow should have been able to defeat or at least penetrate the Iron Pagodas of the later Jurchens, with two layers of lamellar. The Song, however, struggled with Jin heavy cavalry, and their own intellectuals were aware that at least their trigger design was not comparable to the Qin-Han triggers from antiquity. The decline must have happened during the Age of Fragmentation between the Eastern Han and the Sui dynasty.

[HackneyedScribe]

You're wrong about the physics. Consider a Mongol-Turkic vs a Manchurian bow. The Manchurian bow can maintain higher energies and draw weights, yet it cannot reach the same velocities or distances as a Mongol-Turkic bow. The reason is that the Manchurian bow has heavy siyahs, which cannot reach the same speeds as the Mongol equivalent. A bow cannot project its projectile faster its own string.

Applied to the short vs long-stroke crossbow debate, a short-stroke high-weight crossbow should be able to achieve higher velocities than a long-stroke low-weight crossbow, even if the total stored energies are the same. The long-stroke crossbow should be more efficient, but it cannot propel its projectiles faster than the speed of its bow. Hence, with a heavy projectile, as we know the Qin and Han used, the long-stroke can achieve higher energies and better penetration than a short-stroke, yet it can be outranged by the short-stroke using a lighter projectile. With the same light projectile, the Han projectile would be limited by bow-speed, instead of energy transferrence efficiency or its total energy.

Heavy siyahs are not the same as draw length. They are completely different concepts. Neither ancient Chinese nor Medieval crossbows have heavy siyahs, so the point is moot. You are now just repeating everything you've said while ignoring what was addressed to you. Do you have sources or equations back up your claim that shorter draws are better at shooting light arrows at higher velocity? I provided my equations, I will continue by providing a source.

From "The Practical Guide to Man-Powered Bullets":
Final velocity is entirely dependent on acceleration, a bow accelerates a missile from a standstill, and the longer the time it has to accelerate, the faster will the final velocity be. This is really rather important as it has implications on draw length..... increasing the draw length increases the time available to accelerate our bullet, and the general is that this will have a great effect on increasing its launch velocity -pg 84-85

Also keep in mind that the ancient Chinese crossbows did use lighter quarrels. The Records of Wu and Yue stated that for each stone of draw weight, quarrel weight should increase by one liang (one liang being about 15.625 grams). So given no base weight, crossbows of 1-3 stone would be using quarrels lighter than Medieval quarrels. With their trigger mechanism, they could easily shorten stock length to attain shorter draw length if they so wanted. So if shorter quarrels can shoot lighter quarrels at faster velocity, then why didn't the Han 1-3 stone crossbow function like pistol crossbows? It would be incredibly easy for them to do.

Another way to put it is as follows. I showed a picture of a Qin-Han crossbow to an engineer friend, and he mentioned it couldn't possibly be good for the bow, or that the bow would snap.

No, it won't. The Chinese prod is longer, so it prevents snapping at a typical draw length of 24 inches. A Medieval prod would snap at that draw length due to the short length of its arms. Enough with your vague generalities in which you expect others to take your word for it. There are plenty of shorter bows with even higher draw length. In what way do you think you are more convincing here? Your engineer friend either don't know much about the subject, or you showed him an inaccurate picture.

Short Korean bow being drawn to the ear:

You do argue successfully that a European prod would require more mass and weight than a Qin-Han crossbow, but a Qin-Han crossbow would occupy more volume (not in terms of material, but overall dimensions). Perhaps the total weight of both European crossbows and Qin-Han crossbows is about the same, with the European crossbow compressing the mass of the Qin-Han crossbow into a more dimensionally-compact space. Hence, there would be no trade-offs in total energy/mass.

Volume is not weight. Mass is weight. A shorter bow may require less mass to be the same draw weight as a longer bow, but a European Medieval prod of about 100 lbs draw weight would have the mass equivalent of a bow of ~300 lbs draw weight, assuming a linear draw force curve. Why? Because it needs to reach its draw weight with only 1/3 the powerstroke of a bow, so we multiply 100 lbs draw weight by 3 to get 300 lbs. A short bow of 300 lbs is heavier than a long bow of 100 lbs. There is nothing to argue about here. Plus, given the same energy (energy being powerstroke*draw weight/2 in this case), a Han crossbow prod needs 1/3 of the draw weight as that of a Medieval prod to attain the same energy. So we multiply the Medieval prod again by 3. A Medieval prod with the same energy as that of a Han crossbow of 100 lbs draw weight would essentially be comparing a 900 lb short crossbow prod with that of a 100 lb long crossbow prod. This is not accounting for the factor that steel prods require more mass in order to have the same draw weight as that of a composite bow. Now both Medieval crossbow makers and the Han crossbow makers might intentionally make their crossbows heavier to reduce kick-back, but in terms of potential, the Han crossbow is lighter by a significant amount.

Yet, we know that later crossbows were less capable, and a Qin-Han crossbow should have been able to defeat or at least penetrate the Iron Pagodas of the later Jurchens, with two layers of lamellar.

The typical Han crossbow shot somewhere in between 200-300 joules, which would be stopped by iron plate of 3 mm, but hardly any armor back then had that type of thickness. At least in the West, plate armor of 3 mm or over were a rarity until the rise of gunpowder weapons. I do not know about the thickness of lamellar scales in the East, but a suit of lamellar tends to overlap. Assuming Jurchen lamellar had around the same thickness as metal scales in the West, one suit of lamellar probably wouldn't be enough to stop a Han crossbow. If the Medieval Iron Pagodas of did indeed wear two suits of lamellar one under the other, then chances are the Iron Pagodas would be immune from penetration to crossbow shots, albeit they still might receive an uncomfortable "thump" when hit.

From "Knight and the Blast Furnace":



Chinese crossbows truly declined during the mid-late Ming era (~Reinassance onwards), when their draw length decreased by about thrice, and their prod quality also decreased significantly.

[Inst]

Whereas you are, like on Historum, just repeating the same old facts over and over again. It's not nice; I have a particular distaste for Han nationalists because the history of nationalism is either violence towards one's own, or violence towards others.

The point you need to accept, though, is that an extremely powerful bow or crossbow cannot propel any projectile faster than its limb speed. A large object hitting a small object might be able to impart significantly more velocity than that of the large object, but not more momentum. A bow, on the other hand, is a launching device, and it cannot impart its stored energy beyond the launch cycle of the weapon, as the bow limbs themselves will absorb any excess energy.

Regarding my engineer friend, you're showing a lack of reading comprehension, although I have worded things ambiguously. The point here is not that a Qin-Han crossbow would snap, but that the difference in capability shows the difference in design between Qin-Han crossbows and their Western counterparts. The Western crossbow is built for high stiffness and high tensile strength; an instructive example of German crossbows shows that the prod is absurdly thick and vertical, compared to the more bow-light profile of Qin-Han crossbows. Such an enormous stiffness could not be drawn to the same length as a Qin-Han counterpart. Yet both the German crossbow and the Qin-Han crossbow could store comparable amounts of energy; one working through stiffness and draw weight, the other through powerstroke.

Here is where you misunderstand me when I talk about mass and volume, or more rightly, dimensions. A stiff, heavily reinforced crossbow resembles nothing so much as a Chinese triple-bow arcuballista, where multiple bows are used to propel the string and projectile. However, unlike the Chinese version, these bows are stacked on top of each other and thus interconnected, forming a single plank that functions as a prod. While dimensionally more compact than its Chinese counterpart, such a weapon has a similar total mass, because the wood mass of the smaller crossbow is distributed into the large dimensions, or volume, of the Chinese crossbow.

Practically speaking, the Qin-Han crossbow is more efficient, of course, due to its high powerstroke/low power construction. Yet what I'm trying to argue here is that the German plank-type crossbow prods had their own advantages, in terms of being able to rapidly flex and achieve a higher maximum limb speed.

As an example of a reproduction of a medieval plank-style crossbow, look at this:

http://paleoplanet69529.yuku.com/top...ieval-crossbow


Now, as to whether the decline in the Chinese crossbow had occurred by the Ming or the Song, I can show you clear evidence that at least some degeneration had occurred by the Song dynasty. Here's regarding the loss of the sighting blade technology:

http://historum.com/asian-history/90...-levels-2.html
Read the section on the sight gradation, a few pages after the link:

https://books.google.com/books?id=wY...0sight&f=false

So obviously crossbow technology was already being lost since the Han Dynasty.

====

As to being able to prove through physics that the heavy crossbow (which is what it should be called) would have been unable to shoot high-velocity arrows, the best argument would rather be the power-weight ratio of the prod, because it wouldn't rely on rare measurements of crossbow limb speed. I can't seem to find literature showing the exact prod weights of Han or Song dynasty crossbows, which may have been long-strokes, but we can do a proxy by comparing a European crossbow shooting in the 150 joules range to a European longbow shooting in the 150 joules range. The crossbow might be shooting a lighter bolt or quarrel, but both presumably use optimized ammunition.

It's getting very late, and I won't be back until I've dragged out the relevant statistics or at least something that can argue the matter more effectively.

[HackneyedScribe]

Whereas you are, like on Historum, just repeating the same old facts over and over again. It's not nice; I have a particular distaste for Han nationalists because the history of nationalism is either violence towards one's own, or violence towards others.

Which facts have I repeated? Please quote the "fact" that I supposedly repeated with the post number and my original statement which it was repeated from. And please tell me how you addressed it in the first place, if you haven't addressed it then you shouldn't complain if the counter-argument were repeated back to you. On the other hand, you keep repeating that short draw length is superior at shooting a lighter quarrel, but when I ask for sources I get nothing

As for Han nationalism, I merely disagreed with you on matters of Han crossbow velocity, if you are going to bring in accusations of ethnic nationalism over something as little as this, then you are just over-sensitive. In other threads I was willing to admit Ming crossbows were inferior to Medieval European crossbows, you did not go pages and pages arguing against me on that. Yet on Han crossbows you did, even though I provided way more sources to prove my point here. If you want me to appear less of a Han nationalist, then maybe you should disagree for pages and pages when I said Ming crossbows were inferior. The Ming were a Han Chinese dynasty, were they not? So don't look at me, look in the mirror.

The point you need to accept, though, is that an extremely powerful bow or crossbow cannot propel any projectile faster than its limb speed. A large object hitting a small object might be able to impart significantly more velocity than that of the large object, but not more momentum. A bow, on the other hand, is a launching device, and it cannot impart its stored energy beyond the launch cycle of the weapon, as the bow limbs themselves will absorb any excess energy.

This is what you do all the time, you bring in a variable and just assume that the variable supports what you say. Yes, a bow is limited by limb speed, but that does not mean shorter draw lengths automatically have better limb speed. You need to prove that, but so far you haven't done anything to do that. As I said before, just because the string travels a shorter distance does not mean the string is going faster. And just because a string is going faster does not mean a Medieval quarrel won't slow it down significantly. You just assume these variables back up what you say but you did NOTHING to prove it. On what basis do you assume Medieval crossbows have faster dry fire speed? Where is your source?

My source shows it's not so simple:

In flight shooting where dry-fire speed is most important, a short bow with a very long draw is a much better choice, as it recoils faster.....

In medieval-style heavy crossbows the F/D curve is not nearly as relevant as in handbows because the final draw length is not a big issue due to mechanical cocking and release. Also, as a bow is made thicker (=more powerful), it's not generally made longer in proportion. This means that it's draw length has to be reduced or the bow will break. So, the shorter the crossbow's draw length gets, the flatter it's F/D curve will be, meaning it's energy storage characteristics approach the optimum. However, this comes at the cost of reducing the increase of dry-fire speed as discussed above. This phenomenom explains why even the very heavy steel crossbows of the medieval times had relatively limited maximum range, around 400 yards, regardless of their very high draw weight and energy storage (e.g. Payne-Gallway 1990: 21)

-http://crossbow.wikia.com/wiki/Bow_design

Medieval prods may be short, but it has very little draw length. Draw length helps dry fire speed, it doesn't hamper it. The only thing helping to increase the high dry fire speed of Medieval prods was its short length, but its high mass and short draw length does not help but hamper dry fire speed.

What I can give is that short bows do not have better limb speed. I show my source:

Bowyer's Bible said: It's easier to swing a two-foot long club than a three-foot long club. It's easier for a bow to swing a two-foot long limb than athree-foot long limb. Given two bows of equal draw weight and draw length, one four-feet long, the other six-feet long, you'd expect the shorter bow to cast the faster arrow. But once again, reason alone has fallen short.
Short bows shoot same-weight arrows slower because short limbs stack badly, storing less energy. The following bows each have about 1-1/2'' string follow, and draw 50 lb at 28''. Each is well tillered and crafted, and represents best-likely performance for its length and set. Each was chronographed shooting a 500 grain arrow.
These results are an approximation. Tens of bows of each length would need testing for complete dependability. But it's unlikely these figures would shift substantially either way.
For different length bows to assume equal sets, longer bows must be narrow-er and thicker, shorter bows wider and thinner. Strong and elastic woods, of course, are made narrower than weaker woods..... [stats show that 66'-67'' length hickory and maple bows outperform bows of 48''. 66' and 67'' bows shot arrows of 23 oz at 153 fps, whereas the 48'' hickory bow only shot an arrow of 17 oz at 135 fps.] - pg 69

Regarding my engineer friend, you're showing a lack of reading comprehension, although I have worded things ambiguously. The point here is not that a Qin-Han crossbow would snap, but that the difference in capability shows the difference in design between Qin-Han crossbows and their Western counterparts. The Western crossbow is built for high stiffness and high tensile strength; an instructive example of German crossbows shows that the prod is absurdly thick and vertical, compared to the more bow-light profile of Qin-Han crossbows. Such an enormous stiffness could not be drawn to the same length as a Qin-Han counterpart. Yet both the German crossbow and the Qin-Han crossbow could store comparable amounts of energy; one working through stiffness and draw weight, the other through powerstroke.

You said, and I quote: "I showed a picture of a Qin-Han crossbow to an engineer friend, and he mentioned it couldn't possibly be good for the bow, or that the bow would snap." That's the part I disagreed with, considering there were shorter bows with longer draws. If you meant that your "engineering friend" did NOT say that the bow would snap or that the draw wouldn't be good for the bow, then why did you say "he mentioned it couldn't possibly be good for the bow, or that the bow would snap". How am I lacking reading comprehension here? What part did you think I was disagreeing with? All the rest you said about one working through stiffness and the other working through powerstroke is not something I disagreed with.

Here is where you misunderstand me when I talk about mass and volume, or more rightly, dimensions. A stiff, heavily reinforced crossbow resembles nothing so much as a Chinese triple-bow arcuballista, where multiple bows are used to propel the string and projectile. However, unlike the Chinese version, these bows are stacked on top of each other and thus interconnected, forming a single plank that functions as a prod. While dimensionally more compact than its Chinese counterpart, such a weapon has a similar total mass, because the wood mass of the smaller crossbow is distributed into the large dimensions, or volume, of the Chinese crossbow.

We weren't talking about triple-bow arcuballistas. I am talking about Han handheld crossbows, which are single prod crossbows. You're just changing the subject and justifying it by saying I "misunderstood" you.

Practically speaking, the Qin-Han crossbow is more efficient, of course, due to its high powerstroke/low power construction. Yet what I'm trying to argue here is that the German plank-type crossbow prods had their own advantages, in terms of being able to rapidly flex and achieve a higher maximum limb speed.

Then prove it instead of just claiming it. I have already given sources that shows longbows of the same draw weight and draw length shooting a 30 gram arrow (lower weight than medieval crossbow quarrels), and the outcome is that shorter length bows is not always better.

Now, as to whether the decline in the Chinese crossbow had occurred by the Ming or the Song, I can show you clear evidence that at least some degeneration had occurred by the Song dynasty. Here's regarding the loss of the sighting blade technology:

http://historum.com/asian-history/90...-levels-2.html
Read the section on the sight gradation, a few pages after the link:

https://books.google.com/books?id=wY...0sight&f=false

So obviously crossbow technology was already being lost since the Han Dynasty.

I thought it obviously I was speaking of decline in terms of energy transference efficiency. If you want to include other things, then take note that the crossbow stirrup was invented by the Song dynasty.

As to being able to prove through physics that the heavy crossbow (which is what it should be called) would have been unable to shoot high-velocity arrows, the best argument would rather be the power-weight ratio of the prod, because it wouldn't rely on rare measurements of crossbow limb speed. I can't seem to find literature showing the exact prod weights of Han or Song dynasty crossbows, which may have been long-strokes, but we can do a proxy by comparing a European crossbow shooting in the 150 joules range to a European longbow shooting in the 150 joules range. The crossbow might be shooting a lighter bolt or quarrel, but both presumably use optimized ammunition.

Hold your horses, who said heavy crossbows can't shoot high-velocity arrows? Which heavy crossbows and relative to which speed? Is this an attempt at strawman? I asked you to have equations/sources over your claim that short draw lengths were better at shooting light quarrels at higher velocity than that of long draw length prods. You have yet to prove that, and I have given sources to prove otherwise. Here is one more source:

From the Great Warbow, pg 409, a 150 lb longbow at 32 inch draw was shooting arrows of 53.6 grams at speeds of 64-70 m/s. Andreas bichler's crossbow of 617.3 lbs, and 9 inch draw length could only shoot a 41 gram quarrel at 61 m/s. It's shooting a lighter quarrel at a slower speed than that of the longbow. It certainly doesn't sound like short draw length contributes to shooting lighter quarrels at all.

[+Marius+]

As a corollary, consider that Western skirmishing cavalry used javelins, not bows

Not all of them though, not even close to a majority.

They usually used bows and crossbows.

but hardly any armor back then had that type of thickness. At least in the West, plate armor of 3 mm or over were a rarity until the rise of gunpowder weapons.

They do appear, they are just not the majority of the equipment.

Front plates of helmets did achieve over 4mm, but most of the armor was thinner than that.

Do take into account that the tests done by Williams's team are being argued as well, with the 50J for 1mm being seen as a result of them testing on a flat sheath of metal instead of a properly constructed plate section.

I do not know about the thickness of lamellar scales in the East, but a suit of lamellar tends to overlap.

Some lamellar scales do overlap in some constructions, but in others that is not the case.

Nevertheless, it would mean nothing to the crossbows you speak of.

If the Medieval Iron Pagodas of did indeed wear two suits of lamellar one under the other, then chances are the Iron Pagodas would be immune from penetration to crossbow shots

I disagree, not only is wearing two suits of lamellar one over the other a very, very unlikely sight, but even with the additional thickness, from the heavy Han crossbow, with your stats, would be far from immune.



I do have three questions though;

1) If those crossbows were so powerful, why isn't most of Euroasia speaking Chinese now, why did the Chinese simply not obliterate everything before them?

Because with such armament, with such mass production, they should not be able to lose any battle, against anyone, ever...yet they did.

We are talking 15th century breastplate piercing stuff here, in the hands of peoples who engaged people mostly dressed in rags.


2) Why was the trigger mechanism not a product of either trade or tech adoption by neighbor states/cultures?

3) Is the crossbow mentioned anywhere as a trading commodity?

European arquebus, artillery and musket designs were copied and developed by other cultures immediately, why did the same not happen in the East?


I will just finish this post by repeating my opinion that I accept the awesomeness of the design, just not the proposed draw weights.

There is something missing here, because if true, the Chinese armies would be able to obliterate everything in their path without any issue whatsoever, with their bodybuilder crossbowmen pulling 300-500 pound stressed strings with their bare hands.




The entire Earth would be a cakewalk for them with half a million of such crossbows.

[HackneyedScribe]

They do appear, they are just not the majority of the equipment.

Front plates of helmets did achieve over 4mm, but most of the armor was thinner than that.

I said that armor over 3mm was a rarity during Qin-Han times. If you respond by saying that such plate are not the majority, I don't know why you are making it sound like you are disagreeing with me. Anyway, if you say there were armor of 4mm in thickness during that time, I would like to see it.

Do take into account that the tests done by Williams's team are being argued as well, with the 50J for 1mm being seen as a result of them testing on a flat sheath of metal instead of a properly constructed plate section.

An arrow striking curved plate at the optimal angle for penetration is the same as striking flat plate at the optimal angle. Curved plate only increases the chance that an arrow would hit the armor at a greater angle, and Alan's test shows what those angles were.

Some lamellar scales do overlap in some constructions, but in others that is not the case.

well if you can find Chinese examples of iron lamellar that has no overlap, be sure to let me know.

Nevertheless, it would mean nothing to the crossbows you speak of.

overlap means you increase the amount of joules required for armor penetration, it's kind of important.

I disagree, not only is wearing two suits of lamellar one over the other a very, very unlikely sight,

unless more about jurchen equipment is known, you are stating an opinion.

but even with the additional thickness, from the heavy Han crossbow, with your stats, would be far from immune.

my stats showed that plate of 3mm could resist han crossbows even at point blank range. And it sounds like you believe the stats are too much in favor of the arrow. Why the flip-flop?

I do have three questions though;

1) If those crossbows were so powerful, why isn't most of Euroasia speaking Chinese now, why did the Chinese simply not obliterate everything before them?

just because you have a technological edge in one area of weaponry does not mean you have the capability, willpower, or logistics for world conquest. That doesn't even apply to a total war game, much less real life.

Because with such armament, with such mass production, they should not be able to lose any battle, against anyone, ever...yet they did.

There were times when troops with flintlocks managed to lose battles against people armed with spears and rawhide shields. There are countless factors to warfare, just because an army has one advantage in one variable does not mean victory is assured. The Han themselves mentioned other factors for warfare:

Now both the country and the tactics of the Xiongnu are different from those of the Chinese. Their lands are nothing but mountain-slopes with ways going up and down and winding through gorges in and out; in such regions our Chinese horses cannot compete with theirs. Along the tracks at the edges of precipices still they ride and shoot; our Chinese horse archers can hardly do the like. Rain and storm, exhaustion and fatigue, hunger and thirst, nothing do they fear; our Chinese soldiers can in these things hardly compare with them. These are the merits of the Xiongnu.
On the other hand, on plains light chariots can be used and cavalry charges made; in such conditions the Xiongnu are readily thrown into confusion. The strong crossbow (劲弩) and the ballista shooting javelins have a long range; something which the bows of the Xiongnu can in no way equal. The use of sharp weapons with long and short handles by disciplined companies of armoured soldiers in various combinations, including the drill of crossbowmen alternatively advancing [to shoot] and retiring [to load]; this is something that even the Xiongnu cannot face. The troops with crossbows ride forward and shoot off all their bolts in one direction; this is something which the leather armour and wooden shields of the Xiongnu cannot resist. Then the [Chinese horse-archers] dismount and fight forward on foot with sword and halberd; this is something that the Xiongnu do not know how to do. Such are the merits of the Chinese. -Chao Cuo

We are talking 15th century breastplate piercing stuff here, in the hands of peoples who engaged people mostly dressed in rags.

If they engaged mostly people dressed in rags (seriously?), then you answered your own question. High armor penetration is redundant against people dressed in rags.

2) Why was the trigger mechanism not a product of either trade or tech adoption by neighbor states/cultures?

there were plenty of inventions/practices that took more than a thousand years to transmit or weren't transmitted at all. Why should crossbows be an exception?

3) Is the crossbow mentioned anywhere as a trading commodity?

weapons were prohibited from being traded to those outside the empire in general.

European arquebus, artillery and musket designs were copied and developed by other cultures immediately, why did the same not happen in the East?

because Europeans traveled everywhere and imposed itself everywhere. Roman torsion weapons didn't make it to India or China either. Plus the arquebus and musket was a much more deadly weapon than the crossbow.

I will just finish this post by repeating my opinion that I accept the awesomeness of the design, just not the proposed draw weights.

There is something missing here, because if true, the Chinese armies would be able to obliterate everything in their path without any issue whatsoever, with their bodybuilder crossbowmen pulling 300-500 pound stressed strings with their bare hands.

I repeat, the draw weights of 300 lbs and over were being pulled not just by hands, but by the legs. Legs are magnitudes stronger than arms. Even today distance archers would draw with their legs using foot bows, and the longest shot made by Harry Drake was made with a foot bow (over a mile). This is a foot bow:

https://www.youtube.com/watch?v=pRWvY8PUPwk

The entire Earth would be a cakewalk for them with half a million of such crossbows.

that wasn't even true for civilizations armed with flintlock muskets. You are assuming that good ideas/technology must be transferred at a reasonable speed, but historically this simply isn't the case. Chinese blast furnace didn't transfer outside of China for a thousand years and had to be invented independently. Precision seeding wasn't transferred for even longer (despite its simplicity in practice). Chinese porcelain wasn't able to be reproduced until around the industrial revolution. I'm sure there are also plenty of examples for inventions outside of China as well.