# Crossbow vs Gun what if question
**URL:** https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235
**Category:** Great Debates
**Created:** [August 28, 2007, 4:05pm UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235 "2007-08-28T16:05:47Z")
**Posts on this page:** 13
**Page:** 2
### Author:  [@XT](https://boards.straightdope.com/u/XT)
#### Post date: [August 29, 2007, 10:58pm UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/21 "2007-08-29T22:58:54Z")
Excellent post matt! Exactly what I was looking for in this thread.
[QUOTE=matt]
I’m not so certain that it IS possible by modifying the drawing mechanism. You’re limited by conservation of energy. Heavy crossbows used a gear-and-ratchet bar mechanism (cranequin) or windlass to draw them back. To make these operate faster, you’d have to reduce the mechanical advantage they give, so the operator needs greater strength. The only way you can get “something for nothing” from this end is if the cranequin or windlass are very inefficient and waste a lot of the operator’s muscle power. By removing such inefficiences, you could up the cranking speed without requiring greater strength. I have no data regarding this.
[/QUOTE]
Maybe I’m missing something here. I’ve used a ratchet system to lift a car rapidly using just muscle power…and a car weighs significantly more than even the 750lb draw you mentioned (I’m also not exactly Arnold here with massive thews of steel). Granted, most of the rapid systems I’ve seen are hydrolic…but it should be possible to do the same thing with a series of differential gears, perhaps with some pulleys as well. No? Using a modern understanding of how mechanical advantage works, surely its possible to get 750lbs of draw by someone who can do 125lbs…thats less than 7 to 1 which doesn’t seem unreasonable to me.
-XT
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### Author:  [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)
#### Post date: [August 29, 2007, 11:10pm UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/22 "2007-08-29T23:10:25Z")
According to Michael Bellesiles’ controversial book [_Arming America,_](http://en.wikipedia.org/wiki/Arming_America) the great range and penetrating power of the longbow (not the crossbow) did, in fact, relegate personal firearms to a marginal role, until somebody invented a fairly simple and reliable muzzle-loading flintlock musket (the earlier arquebuses having been more complex and more difficult to handle in a combat situation).
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### Author:  [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)
#### Post date: [August 29, 2007, 11:45pm UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/23 "2007-08-29T23:45:13Z")
[QUOTE=xtisme]
Maybe I’m missing something here. I’ve used a ratchet system to lift a car rapidly using just muscle power…and a car weighs significantly more than even the 750lb draw you mentioned (I’m also not exactly Arnold here with massive thews of steel). Granted, most of the rapid systems I’ve seen are hydrolic…but it should be possible to do the same thing with a series of differential gears, perhaps with some pulleys as well. No? Using a modern understanding of how mechanical advantage works, surely its possible to get 750lbs of draw by someone who can do 125lbs…thats less than 7 to 1 which doesn’t seem unreasonable to me.
-XT
[/QUOTE]
Here’s the thing: as you increase mechanical advantage, you also increase the input movement length. Take two hydraulic jacks, a one ton jack and a ten ton jack. For the same amount of work I do pumping the handle, the ten ton jack will only move 1/10 as far as the one ton jack. A hydraulic jack (or any other mechanical advantage device) doesn’t _amplify_ your physical effort; it merely _concentrates_ it.
If you increase the mechanical advantage on your crossbow crank by a factor of three, you now need to move the crank three times as far to pull the string back the same distance. The only way to increase the mechanical advantage of a crank without increasing the number of turns it has to make would be to increase the length of the crank arm itself, thereby providing greater leverage, but I would imagine that longer crank arms on a crossbow very rapidly become impracticable.
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### Author:  [@ralph124c](https://boards.straightdope.com/u/ralph124c)
#### Post date: [August 30, 2007, 12:12am UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/24 "2007-08-30T00:12:00Z")
In the accounts of medieval battles, most crossbowmen seemed to be mercenary soldiers (Genoese, Swiss, Florentines). Being hired, most would probably not have fought with such elan as the English longbowmen. In an account of the Battle of Crecy, these hired crossbowmwn actually sized up the situation and left the battle early. I suspect that the crossbow was a good weapon for siege warfare, but not so good in open battle (a longbowman could get of several arrows while the hapless crossbowman was winding his crank. In any event the crossbow disappeared very rapidly, once the musket was developed.
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### Author:  [@RickJay](https://boards.straightdope.com/u/RickJay)
#### Post date: [August 30, 2007, 12:31am UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/25 "2007-08-30T00:31:37Z")
[QUOTE=xtisme]
Certainly…probably why we develop machines to give us mechanical advantage, ehe? Otherwise why use a bow at all when you could just throw a stick at your opponent. I’ve seen modern heavy crossbows that use muscle power to cock…and can be cocked rapidly. Granted they are using modern materials. However, I’m relatively certainly that, even using period methods, a winding mechanism could be made to enable a heavy crossbow (with all the power that implies) to be cocked relatively rapidly. Whether such a beast was feasible to make in quantity given the technology of the time is another question.
[/QUOTE]
Now, though, you’re starting to get not only into complexity, but also weight and dimensionality issues. Machines can get you the most out of yoiur muscles, but the upper limit is still reached far, far below what a relatively primitive chemically powered device can do. And there’s a limit as to what gears can do for you unless you start getting into some pretty large and/or heavy gears, and there’s a limit to the tension that a machine of a given structural strength can take. You don’t want your soldiers carrying frickin’ bicycles around.
Machinery’s great but the conversion from muscle-powered to chemical-powered devices is invariably a huge, huge revolution in warfare, whether it’s the propelling of projectiles or the movement of soldiers and material.
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### Author:  [@MrDibble](https://boards.straightdope.com/u/MrDibble)
#### Post date: [August 30, 2007, 6:46am UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/26 "2007-08-30T06:46:34Z")
[QUOTE=Malodorous]
The weapon in **athelas** ’s link actually has the flaw **Smiling** is talking about, its underpowered compared to slower firing crossbows (and firearms, presumably).
[/QUOTE]
…and yet they were \*still using them \*at the end of the 19th C. So clearly it had some utility for them, even when they also had composite bows, foot bows, firearms, flamethrowers… **bandit** said he couldn’t see what possible use such a weapon could have. Maybe the high rate of fire is all it takes to make it useful _in certain situations_.
[QUOTE=chowder]
Then they came up with gunpowder
[/QUOTE]
This is a woosh, right?
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### Author:  [@matt](https://boards.straightdope.com/u/matt)
#### Post date: [August 30, 2007, 8:38am UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/27 "2007-08-30T08:38:06Z")
[QUOTE=xtisme]
Using a modern understanding of how mechanical advantage works, surely its possible to get 750lbs of draw by someone who can do 125lbs…thats less than 7 to 1 which doesn’t seem unreasonable to me.
-XT
[/QUOTE]
Perfectly correct. It’s just that your 7 to 1 mechanical advantage also means you have to move the cranking device through 7 times the distance of the straight pull. Another factor here is how you use a crank or windlass, compared with a straight pull. Compare the two images near the top of [this page](http://www.arcobosque.com/ballesta.htm). It’s quite a different way of using your arms! The sorts of mechanical advantages I’ve been reading about are between 40-1 and 100-1 for a cranequin, depending on the gearing. Whether you actually need such high mechanical advantages to crank, I’ve no idea without actually trying the things.
My ballpark guesstimate is that a 3-turn crank gives a roughly 19-1 advantage (I assumed crank arm is twice the draw length) which on simple considerations should be more than enough, but is nowhere near the advantage of historic cranequins. Truth is, unless we build the things and play with them, we’re just not going to be able to know how easy or hard they were to use. I can’t even find out how many cranks the historic cranks take to draw a bow, youtube and google video have let me down…
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### Author:  [@matt](https://boards.straightdope.com/u/matt)
#### Post date: [August 30, 2007, 8:50am UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/28 "2007-08-30T08:50:13Z")
And now I find a link that cites a Scientific American article:
[http://www.fofweb.com/Subscription/Science/Helicon.asp?SID=2&iPin=ffests0227](http://www.fofweb.com/Subscription/Science/Helicon.asp?SID=2&iPin=ffests0227)
“the windlass, was introduced in the 14th century. This used pulleys, attached at the butt end of the stock to a winding device that, when hooked onto the bowstring and wound, drew it to the trigger. The windlass could draw the string in only 12 seconds, even though it had a pull of 545 kilograms (1,200 lb).”
“The cranequin required very little strength to draw the crossbow string, but it was slower than the windlass, requiring 35 seconds for loading.”
So it looks like the cranequin was like a scissors-type car jack, not requiring much force but taking a lot of winding.
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### Author:  [@Scumpup](https://boards.straightdope.com/u/Scumpup)
#### Post date: [August 30, 2007, 1:04pm UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/29 "2007-08-30T13:04:20Z")
[QUOTE=BrainGlutton]
According to Michael Bellesiles’ controversial book [_Arming America,_](http://en.wikipedia.org/wiki/Arming_America) the great range and penetrating power of the longbow (not the crossbow) did, in fact, relegate personal firearms to a marginal role, until somebody invented a fairly simple and reliable muzzle-loading flintlock musket (the earlier arquebuses having been more complex and more difficult to handle in a combat situation).
[/QUOTE]
Not quite. The matchlock musket was a very successful weapon for a very long time. While it isn’t particularly suited to use a personal defense weapon or hunting weapon, due to the smoldering match which ignites the powder charge, matchlocks worked reasonably well as military weapons. The matchlock musket could be fired more quickly than a crowwbow that required a cocking mechanism, too. Wikipedia has a decent article about [matchlocks](http://en.wikipedia.org/wiki/Matchlock).
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### Author:  [@smiling\_bandit](https://boards.straightdope.com/u/smiling_bandit)
#### Post date: [August 30, 2007, 3:19pm UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/30 "2007-08-30T15:19:57Z")
[QUOTE=MrDibble]
…and yet they were \*still using them \*at the end of the 19th C. So clearly it had some utility for them, even when they also had composite bows, foot bows, firearms, flamethrowers… **bandit** said he couldn’t see what possible use such a weapon could have. Maybe the high rate of fire is all it takes to make it useful _in certain situations_.
[/QUOTE]
Alright, I should have been more specific. On a battlefield, these things were not as useful, and the Chinese did not use them on the battlefield very much. They did use them for guarding, and were popular on the Great Wall. You could send out a nice volume of fire. But volumes of ineffective fire wasn’t that useful unless the enemy tried human wave tactics. Anyone with seige weapons could easily defeat a city defended by Chu-Ko-Nu.
On the other hand, note that the Chinese didn’t use them all that much on the batllefield, and that virtually none of their enemies wore serious armor. In addition, they’re not known as particularly great weapons, and no accounts of Chinese wars or battles I’ve read give so much as a mention of them, whereas they sometimes go into considerable detail about force composition, training, and armament. The best late Chinese generals, even against light forces (where you’d expect the things to be most useful), used wholly different weapons.
[This](http://www.arco-iris.com/George/chu-ko-nu.htm) site has the sole description of the things being used in battle I’ve ever heard of.
> [@](#):
>
> The chu-ko-nu is of quite ancient origin, there being reason to believe that its lineage dates back to, at least, about 250 BC. The earlier lien nu version reportedly was used in 210 BC by the first Ch’in emperor for shark shooting (1). During the 1st century BC, the retreat of 5,000 Chinese troops before a much greater force of Hsiung Nu (Hun) cavalry was successfully covered by 1,000 crossbowmen, who are said to have shot 500,000 bolts in a day (1). This is quite a feat which, if reported accurately, indicates that the chu-ko-nu may well have been part of the armamentarium of these crossbowmen. There is no doubt whatever that the chu-ko-nu was used as late as the Boxer Rebellion. The writer clearly recalls a published photo of a ravaged Peking fort, showing an abandoned chu-ko-nu, at the top of a battlement, its muzzle thrust upward and its bow in full profile, vividly silhouetted against the bright featureless sky!
However, there’s rather some doubt as to whether or not this story is likely. It’s highly implausible that a force of 1000 crossbowman could even get their hands on that many bolts. Likewise, if they had to fire that many, the enemy either had about a million men or were not particularly hurt by it. And given that the Chinese eventually had to bribe the Huns, it aparently wasn’t a devastating weapon.
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### Author:  [@Lumpy](https://boards.straightdope.com/u/Lumpy)
#### Post date: [August 30, 2007, 6:05pm UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/31 "2007-08-30T18:05:59Z")
One innovation used in crossbows was a mechanism that varied the force of the bow through the range of it’s draw. It was referred to as “the Virgin”, since “it offered little resistance when slack and much resistance when taut”. 😃
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### Author:  [@XT](https://boards.straightdope.com/u/XT)
#### Post date: [August 30, 2007, 9:22pm UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/32 "2007-08-30T21:22:59Z")
[QUOTE=matt]
My ballpark guesstimate is that a 3-turn crank gives a roughly 19-1 advantage (I assumed crank arm is twice the draw length) which on simple considerations should be more than enough, but is nowhere near the advantage of historic cranequins. Truth is, unless we build the things and play with them, we’re just not going to be able to know how easy or hard they were to use. I can’t even find out how many cranks the historic cranks take to draw a bow, youtube and google video have let me down…
[/QUOTE]
I still appreciate your and others posts in this thread. Its given me a lot to chew on here. I’ve always wondered why anyone bothered with gunpowder in the early days when it seemed you could get more battle field effect from the more convention weapons of the day (long bow and cross bow). I understood why the long bow was eventually eclipsed…it took a lot of training and practice to make an effective long bowman (or horsebowman). Years in fact. While training some mope to stand in a line and fire even the early matchlock weapons was really just a matter of a few weeks training to load and fire…and the much harder training to get them to actually stand there and do it when under fire. But I always wondered about the crossbow. It doesn’t take much training to teach someone to load and fire, and if you used it in the same kind of line formation and if you could get it to reload relatively rapidly…well, a lot of what ifs there, no doubt.
I guess I have my answer though.
-XT
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### Author:  [@chowder](https://boards.straightdope.com/u/chowder)
#### Post date: [August 31, 2007, 9:48am UTC](https://boards.straightdope.com/t/crossbow-vs-gun-what-if-question/417235/33 "2007-08-31T09:48:02Z")
[QUOTE=MrDibble]
…and yet they were \*still using them \*at the end of the 19th C. So clearly it had some utility for them, even when they also had composite bows, foot bows, firearms, flamethrowers… **bandit** said he couldn’t see what possible use such a weapon could have. Maybe the high rate of fire is all it takes to make it useful _in certain situations_.
This is a woosh, right?
[/QUOTE]
😃
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