Just ran across this article about the use of multiple bows on certain types of Chinese crossbows where the bows are used to increase power to a single arrow ( Not 3 bows to fire multiple arrows, that would be something different ).
http://www.chinahistoryforum.com/index.php?sh...&st=30
http://en.wikipedia.org/wiki/Crossbow
A little search with Google gave some results but not as much information I am curious about like " WHY " and what would be the advantages.
1) More power ?
2) Same power but less stress on the bows?
3) Would this mean a longer power stroke or an effect similar to a modern pulley compound bow for greater efficiency.
History of use would be nice but maybe some of our members good with math and physics might be able to give us an opinion about performance advantages to these kinds of bows?
Oh, first became aware of these crossbows from a book I just bought:
FIGHTING TECHNIQUES OF THE ORIENTAL WORLD, AD 1200 - 1860, © Amber Books Ltd 2008,
ISBN-13: 978-0-312-38696-2
ISBN-10: 0-312-38696-6
Page 172 Text and illustration, SIEGE WARFARE.
I suspect a combination of #1 and #2 would be the most accurate guess, since the Chinese didn't seem to have developed steel prods and the kind of power needed for the strongest siege crossbows might well have been in excess of the mechanical capabilities of a laminated or composite prod. Multiple laminated/composite prods connected by a system of auxiliary cables could have been the most practical answer to the solution. Unfortunately, I don't know whether there are any pulleys in the system or not; if there are, then it might have #3's compound-bow effect as well.
| Lafayette C Curtis wrote: |
| I suspect a combination of #1 and #2 would be the most accurate guess, since the Chinese didn't seem to have developed steel prods and the kind of power needed for the strongest siege crossbows might well have been in excess of the mechanical capabilities of a laminated or composite prod. Multiple laminated/composite prods connected by a system of auxiliary cables could have been the most practical answer to the solution. Unfortunately, I don't know whether there are any pulleys in the system or not; if there are, then it might have #3's compound-bow effect as well. |
Maybe not a pulley system per say but I was thinking of a certain amount of a leverage effect as a 12" ( Arbitrary number ) of draw spread over 3 bow staves might mean that each stave's 4" of draw would end up adding together ? Not sure of the physics or the geometry of the thing ? ( Well leverage is " geometry " after all ).
The fact that they didn't have steel prods is certainly one reason for using multiple prods/bows to not overstress each single prod but end up with the power equivalent of a much stronger single prod.
As a design idea, but not a historical one, I wonder what European crossbow makers might have made using 3 very powerful steel prods?
Oh, again if my " theory " that the draw length would be a multiple of what a single prod crossbow would be ??? I wonder if this means that one could use much longer bolts and take advantage of the efficiency of very long draw lengths ?
Very powerful crossbows ( 500 pounds or more ) end up being only slightly more powerful than a 150 pound longbow due to the short draw length because of inefficiency of the system, but compensate by using " brute force " i.e. much less efficient in using the stored energy but having much more stored energy that they end up more powerful at the target end.
( NOTE: The above based on reading the other crossbow related Topic posts here on " myArmoury " and not my personal knowledge of the physics of crossbows: My best guesses about these crossbows. ;) :D )
San Gong chuang nu. Also known as Ba Niu Nu or eight ox crossbow. The arrow is like a Javelin, is used in siege battle, in the right position it could fire and nail into the defense wall, so the soldiers can use it to get up the wall. Developed during
968A.D-975 A.D North Song. The other name for this weapon is One spear and three sword.
http://a0.att.hudong.com/07/24/01300000247159...3070_s.jpg
968A.D-975 A.D North Song. The other name for this weapon is One spear and three sword.
http://a0.att.hudong.com/07/24/01300000247159...3070_s.jpg
| Li Jin wrote: |
| San Gong chuang nu. Also known as Ba Niu Nu or eight ox crossbow. The arrow is like a Javelin, is used in siege battle, in the right position it could fire and nail into the defense wall, so the soldiers can use it to get up the wall. Developed during
968A.D-975 A.D North Song. The other name for this weapon is One spear and three sword. http://a0.att.hudong.com/07/24/01300000247159...3070_s.jpg |
Thanks for the reply. :D :cool: With a spear sized bolt we are talking a siege weapon and if it could bury itself into a stone wall the power is not in doubt and very impressive.
I could also see these used on board of ships or on large warwagons as field artillery. ( In theory at least, but I don't know if these were use this way also ? ).
Actually, Sir you are correct. This weapon is base built on a wagon, or as a wagon. Usually the word Chuang means Bed, and Nu means crossbow, so chuang nu means Crossbow on a bed, so meaning is carried by a wagon. operated by five to seven people. The earliest model were developed in east Han, made from bronze. The creator named Chen Qiu said: Bow made from great wood, Feather spear as arrow, Fired by device, farther then a thousand steps, which delivers power. This weapon could actually fire about ten arrows at the same time, Sounds like Katyusha rockets.
About the weapon, the Ba Niu Nu, is huge, and it has to be operated by alot people, book says nearly hundred but I'm not sure. The ones above is the older model.
About the weapon, the Ba Niu Nu, is huge, and it has to be operated by alot people, book says nearly hundred but I'm not sure. The ones above is the older model.
Hi jean
Discovery channel had a bit on it in their anciant discoveries series plus a reconstruction of one they were used for siege work both to defend and attack. Range about 1000 yards was quoted bow limbs were massive all linked together via one cord. I am also positive that the Ospray series include one one oriental siege warfare and have an illistration of the weapon.
Discovery channel had a bit on it in their anciant discoveries series plus a reconstruction of one they were used for siege work both to defend and attack. Range about 1000 yards was quoted bow limbs were massive all linked together via one cord. I am also positive that the Ospray series include one one oriental siege warfare and have an illistration of the weapon.
| Robin Palmer wrote: |
| Hi jean
Discovery channel had a bit on it in their anciant discoveries series plus a reconstruction of one they were used for siege work both to defend and attack. Range about 1000 yards was quoted bow limbs were massive all linked together via one cord. I am also positive that the Ospray series include one one oriental siege warfare and have an illistration of the weapon. |
Thanks, will look into the book as I think it's available from KoA and might include it with some other order.
1000 yard range is impressive and I wonder at what velocity the missile leaves the crossbow ? ( one could say muzzle velocity but technically there isn't a muzzle. ;) :lol: ).
My best guess would be at least 200 ft/sec. but 300 ft/sec might be possible as modern composite pulley crossbows get close to these velocities.
I would still be curious to read what someone really good with the physics of the thing might be able to guess at power and leverage advantages if any of using 3 interacting bows and the possibly longer effective draw.
Hi jean
On the matter of ballistics you might want to consider the effect of kinetic enegy the missile were not exactly small or light so while initial velocity may not have been huge it carried a lot of enegy.
On the matter of ballistics you might want to consider the effect of kinetic enegy the missile were not exactly small or light so while initial velocity may not have been huge it carried a lot of enegy.
| Robin Palmer wrote: |
| Hi jean
On the matter of ballistics you might want to consider the effect of kinetic energy the missile were not exactly small or light so while initial velocity may not have been huge it carried a lot of energy. |
Yes momentum. ;) :cool: I think with mechanical throwing engines 200 to 300 ft/sec is probably the maximum one can expect from any reasonable machine as the speed one can get the bow string to move is not going to go up much more as the return speed of the limbs are limited by the elastic properties of the material used in a composite or steel prod.
But if one increases the strength of the machine it can throw a heavier projectile at close to the same speed as a lighter projectiles because of the extra draw weight.
Even at a more modest 150 ft/sec is going to be powerful if it can get a very heavy missile with lots of mass.
Just wanted to add that the idea of a multiple-limb bow isn't unique to China--there's also the Penobscot bow, or at least a modern reproduction of it:
http://www.woodlandarchery.com/prod12.htm
And I noticed an interesting question:
Probably it wouldn't have been worth that much since, by the time the Europeans could make bows with steel prods, trebuchets and gunpowder artillery had far exceeded the potential power that a crossbow-like device could deliver. The same might have happened in China, especially after the Mongols brought back counterweight trebuchets from the West (bringing things full circle from the time trebuchets were introduced to Europe and the Middle East from China through either Persia or Central Asia); the multiple-prod crossbow seems to have been an evolutionary dead-end that did not lead to notable further developments.
http://www.woodlandarchery.com/prod12.htm
And I noticed an interesting question:
| Quote: |
| As a design idea, but not a historical one, I wonder what European crossbow makers might have made using 3 very powerful steel prods? |
Probably it wouldn't have been worth that much since, by the time the Europeans could make bows with steel prods, trebuchets and gunpowder artillery had far exceeded the potential power that a crossbow-like device could deliver. The same might have happened in China, especially after the Mongols brought back counterweight trebuchets from the West (bringing things full circle from the time trebuchets were introduced to Europe and the Middle East from China through either Persia or Central Asia); the multiple-prod crossbow seems to have been an evolutionary dead-end that did not lead to notable further developments.
Hi jean.
I am no expert but as I understand it the long bow style of limb tends to be suited better to shooting heavy missile while the faster limb action of the recurve suits lighter higher velocity arrows. The illustrations I have seen of the triple bow show long thick self bows which would be ideal for shooting heavy missiles. The longer slower shove would be ideal for launching the heavy missiles.
yours Bob plamer
I am no expert but as I understand it the long bow style of limb tends to be suited better to shooting heavy missile while the faster limb action of the recurve suits lighter higher velocity arrows. The illustrations I have seen of the triple bow show long thick self bows which would be ideal for shooting heavy missiles. The longer slower shove would be ideal for launching the heavy missiles.
yours Bob plamer
| Robin Palmer wrote: |
| I am no expert but as I understand it the long bow style of limb tends to be suited better to shooting heavy missile while the faster limb action of the recurve suits lighter higher velocity arrows. |
Only if the recurved bow is short and light (in terms of physical weight, not draw weight)! Remember that "recurve" does not equal "composite," that a static recurve is different from a working recurve (both of which are found in Chinese bows), and that composite bows aren't always the short flight bows that they are often represented by in popular culture.
I realize that this topic is quite old but I'm new to the forum and just now discovered it.
I'm building a reproduction engine of this style and can confirm the OP's hypothesis that such a configuration results in a much longer draw. Further, builder heavier and heavier bows is not as productive as building more bows. My bows are made of stacked layers of bamboo and hardwood, lashed with jute cordage. Here's a picture in it's initial configuration. I've since rebuilt the bows with hardwood siyahs to improve performance. Also, the temporary trigger shown has been replaced with a period replica.
[ Linked Image ]
I'm building a reproduction engine of this style and can confirm the OP's hypothesis that such a configuration results in a much longer draw. Further, builder heavier and heavier bows is not as productive as building more bows. My bows are made of stacked layers of bamboo and hardwood, lashed with jute cordage. Here's a picture in it's initial configuration. I've since rebuilt the bows with hardwood siyahs to improve performance. Also, the temporary trigger shown has been replaced with a period replica.
[ Linked Image ]
| Steven Gardner wrote: |
| I realize that this topic is quite old but I'm new to the forum and just now discovered it.
I'm building a reproduction engine of this style and can confirm the OP's hypothesis that such a configuration results in a much longer draw. Further, builder heavier and heavier bows is not as productive as building more bows. My bows are made of stacked layers of bamboo and hardwood, lashed with jute cordage. Here's a picture in it's initial configuration. I've since rebuilt the bows with hardwood siyahs to improve performance. Also, the temporary trigger shown has been replaced with a period replica. |
Actually there is no time limit on replying to old posts if one has new and interesting information: It's just the nature of the Forums for old posts to move on to being on page 62 or page 105 etc ..... they are still there that the right search words can bring them back to anyone curious about something or other. :D :cool:
I would sure be interested to know what the draw weight ends up being relative to the speed of the arrow or bolt compared to a similar draw weight of a single prod European crossbow with a limited 6" to 8" draw length, 8" draw length being somewhat optimistic.
Without some measuring instruments to measure velocity of the arrow/bolts leaving this crossbow I guess we would have to go by general impression eye balling each projectile from each type of crossbow.
Anyway, a video if possible, of an arrow/bolt being loosed from the crossbow would be interesting as well as hearing the " Thunk " of it hitting a target ..... comparative penetration in the same target material might also tell us something ?
| Robin Palmer wrote: |
| Hi jean
Discovery channel had a bit on it in their anciant discoveries series plus a reconstruction of one they were used for siege work both to defend and attack. Range about 1000 yards was quoted bow limbs were massive all linked together via one cord. I am also positive that the Ospray series include one one oriental siege warfare and have an illistration of the weapon. |
this is also where i saw this idea at first (actually i love the series ancient discoveries) although the range of 1000 yards seems - complicated. unless you have some kind of optics you can't see 1000 yards away too well. unless the idea was just hurl blots into a city or army from an extreme distance. and that's not to mention the role the atmosphere can play with the projectile at that distance. although getting a bolt to land 1000 yards away would surly tell someone to keep their distance.
i look at it and see much more of the idea that your building 'stack' of 'stacking power' in the limbs, but does having 3 bows at 50lb = a single bow of 150lbs? it would seem true, but why not just build it into one big limb?
it is very interesting.
I think it's the long draw that is critical. It allows more time to get a heavy bolt up to speed.
http://video.baomihua.com/11240671/15674075?ab01
11'12
17'44"
21’
162 meters（It is possible that the max range is more than 200 meters ）
1.8cm plywood at a range of 50m
drive in the brick wall at a range of 50m
and they are just 3 poor bamboo bows
if this farmer used ash, mulberry, teak or composite bow…
11'12
17'44"
21’
162 meters（It is possible that the max range is more than 200 meters ）
1.8cm plywood at a range of 50m
drive in the brick wall at a range of 50m
and they are just 3 poor bamboo bows
if this farmer used ash, mulberry, teak or composite bow…
| X Zhang wrote: |
|
162 meters（It is possible that the max range is more than 200 meters ） 1.8cm plywood at a range of 50m drive in the brick wall at a range of 50m and they are just 3 poor bamboo bows if this farmer used ash, mulberry, teak or composite bow… |
Thank you for the very interesting link, the video is very informative even if one, like me, doesn't understand the language.
The velocity of the arrows/bolts in the second version, that seems to be using better bows, seems very fast.
It's also is interesting that it looks like one could use 3 regular hand bows and put them into the the frame and use them after linking them together with a special bow string.
What is also amazing is that once set-up and after a ranging shot or two one has impressively small groupings of arrows and great accuracy: Useful, in a siege where one could aim a number of these to hit arrow slits and suppress return fire from these slits.
I imagine one could make bigger and more powerful versions that could shoot even larger and heavier projectiles: Not tree trunk sized, but something like 8 feet long with a 2" diameter shaft might be at the upper range of what could work in a siege.
Probably more useful to have lots of the more modest sized ones to give suppressive fire in a siege or as field artillery.
For knocking down walls trebuchet would be better.
Last edited by Jean Thibodeau on Mon 01 Jul, 2013 11:52 pm; edited 1 time in total
| Jean Thibodeau wrote: | ||
Thank you for the very interesting link, the video is very informative even if one, like me, doesn't understand the language. The velocity of the arrows/bolts in the second version, that seems to be using better bows, seems very fast. It's also is interesting that it looks like one could use 3 regular hand bows and put them into the the frame and use them after linking them together with a special bow string. What is also amazing is that once set-up and after a ranging shot or two one has impressively small groupings of arrows and great accuracy: Useful, in a siege where one could aim a number of these to hit arrow slits and suppress return fire from these slits. I imagine one could make bigger and more powerful versions that could shoot even larger and heavier projectiles: Not tree trunk sized, but something like 8 feet long with a 2" diameter shaft might be at the upper range of what could work in a siege. Probably more useful to have lots of the more modest sized ones to give suppressive fire in a siege or as filed artillery. For knocking down walls trebuchet would be better. |
er……yes, it would probably be designed for effective strength, more than destroying buildings or castles.
In the winter of 970~971BC, the army of Song Empire won the battle becouse they killed and routed lots of Nanhan kingdom's war elephant by this crossbow. And in the summer of 1259, Möngke Khan, the grandson of Genghis Khan, was killed by this crossbow also outside the 钓鱼城（fishing castle？ i don't know its English name）in the siege war.
So, i think this crossbow often works as the anti-tank gun or something like that.
BTW: According to the legend, as a siege weapons, this crossbow can shot huge bolts on the wall for soldiers climbing.
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