Crossbow vs Gun what if question

Great Debates
1

I was recently re-reading Robert Jordan’s Wheel of Time series (in the vain hope that by re-reading the series it will somehow mystically spark the author to actually get moving on writing the next book…hope springs eternal). In the latest book, Knife of Dreams, one of the main characters is describing a new crossbow crank that has revolutionized warfare by allowing the soldier to spin a crank 3 times and fully cock the crossbow. This allows a rate of fire unheard of before…something on the order of 6-7 shots per minute according to the story. Probably unreasonable…but I could see how such a crank might get you 5 shots per minute…better than anything before the cap lock rifle I think.

I can see how you COULD make such a crank…though I’m unsure if such a thing WOULD have been made in sufficient numbers using pre-gunpowder technology. For debate though, lets assume that there is a way it could be done before gunpowder firearms came widely into use in Europe.

Assuming you could get 5-6 shots off of a heavy crossbow per minute would personal gunpowder firearms have ever even been developed? I would think the advantages of a rapid firing crossbow would have relegated gunpowder firearms to obscurity and stifled their development…at least until someone figured out how to rifle the barrels and maybe breach loading to get similar rates of fire.

-XT

2

The Chu-ko-nu:

. Gunpowder still has the advantage of range, and of course cannon are much more useful against fortifications than crossbows, regardless of the rate of fire.

3

Trouble with that is, spinning the crank just 3 times to cock the bow makes it twice as hard to crank as one that requires 6 spins. Or ten times as hard to crank as one that requires 30 spins.

The cranking mechanism for a crossbow will be designed to accomodate the difference between the strength of the bow and the strength of its operator. To crank faster, you need a weaker bow or a stronger operator. The Hulk could just heave the string back without a crank and get a hell of a rate of fire, but there’s no magic mechanism to allow an ordinary person to do this.

One way or another, you’re turning muscle power into projectile energy. There’s a limit to the work rate a human can provide. Fire more often, less energy per projectile.

4

I doubt it.

First of all, even the most powerful crossbow wouldn’t have the armor piercing ability of a basic arquebus.

Second of all, even if gunpowder small arms weren’t invented, the development heavy weaponry - cannons, mortars etc. - would go on unabated. Eventually, someone would have invented the percussion cap and the brass casing, and 20 minutes later would have had the idea to make a very very small version of the cannon for personal use.

Third of all, Robert Jordan is full of shit.

5

I believe that crossbows such as you describe were available and surpassed early firearms in rate of fire and effective range. They used a variety of ratchet, windlass and lever systems. This wasn’t enough to keep them in use, however. Crossbows are complicated mechanical devices, with many moving parts (things to break) and are expensive to manufacture and maintain. Early guns by contrast were little more than a bored out metal tube with a touch-hole and a wood stock. Other than a slightly higher rate of fire, why would you choose the more expensive and fragile option when you’re passing out weapons to the tercios, even if it were feasible? Until Gustavus Adolphus the bulk of the work was ususally done by pikemen anyways. :>

6

Another aspect may be the psychological effect of gunpowder weapons. The tremendous bang of a line of early firearms would have a significantly more damaging effect on the morale on the receiving troops than the twang of similar crossbows.
The goal of warfare from time immemorial has never really been to kill all the opposing troops (a few Cannaes excepted), but to make the enemy run.

7

Rogbert Jordan definitely does not know his stuff. Such a weapon as he decribes would be all but useless, as it would neccessarily have very low force; the full cocked state of the crossbow would be weak. This means it would have low range, accuracy, and penetrating power in battle, and still be more unwieldy, expensive, and difficult to use than bows. What possible use could there be for such a weapon?

In real life, crossbows were generally used to soften up a target pretty much like bows were. Until fairly late in their development (they date well back before BC, IIRC), they were rarely used on the battlefield. By the Middle Ages, they had a lower rate of fire than bows from other regions of the world*, but had considerable force and good range.

They had a particular use in seige warfare, since it didn’t take much to makea very large and powerful crossbow. Hence, you could make one with the same technology which was a small man-portable seige weapon, capable of a three thousand pound draw! It took a while to re-cock, but in a seige a few minutes more or less won’t matter.

*The advantage was that the recurved wood/bone/animal glue bows used elsewhere in the world tended to fall apart in Europe. Too many cold, damp mornings. The bows just got soggy and flew to peices. You could use them for a battle, maybe, but on real campaign they were useless. A crossbow could be unlimbered and used as soon as the mechanism was dry. A lack of just that caused severe problems at Poiters for the Genoese mercenaries in the service of the French.

8

Crossbows are a deadend technology. Ultimately, you’re dependent on muscle power. Guns are based on chemical energy which gave them a lot more room to develop in. This was obvious right from the beginning of gunpowder technology so weapons designers realized that even if contemporary guns weren’t better than crossbows, an investment in improving gun designs was better than an investment in improving crossbow designs.

9

Which brings us to a much more important point: ditch that Robert Jordan crap, and go pick up a copy of Eric Flint’s 1632.

10

Guns also possess a psychological factor not present with crossbows… they’re noisy and generate smoke and flame- if you employ them against an army composed of conscripts who are unfamiliar with them (especially in the late middle ages or early Renaissance), and you’re going to have an extremely effective physical and psychological ranged weapon.

11

Robert Jordan has become a very tedious writer, but I wouldn’t hold his crossbow “invention” against him. He’s a fiction writer, for chissakes, and a fantasy one at that! The genre is filled with all sorts of contraptions and such that have no hope of obeying the laws of physics. Perhaps the magic that the Aes Sedai draw upon also infuse crossbow mechanics (think of it like power steering ;)).

12

It isn’t cold and soggy in Japan? In northern China?

13

The Chinese managed to get use out of just “such a weapon” for 2 millennia - did you *read *athelas’ link?

14

Then they came up with gunpowder :stuck_out_tongue:

15

The weapon in athelas’s link actually has the flaw Smiling is talking about, its underpowered compared to slower firing crossbows (and firearms, presumably).

16

You tube has a video that from the history channel of a repeating crossbow here.
Its about 1 min. in.
Underpowered doesn’t begin to describe it.

17

Yea, it drives the arrow (shaft? quarrel?) just like 4 inches into those hay bails at close range. Against an armored opponent, you’d just be pissing them off.

Neat video by the way, thanks.

18

The English longbow was made from wood with two different resistances to bending – if I recall, from a single piece of wood, but, cunningly, some of it was “heartwood” and the rest normal timber – thus mimicking (not consciously) the stronger performance of the wood, glue, and bone composite bows used in Asia, but without the dange of glue getting wet in the English climate.

In general, bows had several military advantages over crossbows.

They could fire faster, being easier to load and draw. They imparted more impulse to their projectile, giving greater accuracy. (Impulse in this case was a function of acceleration over time, time being draw length).

Their projectile (an arrow) was itself longer, allowing the stabilizing feathers to be placed farther from the arrow’s center of gravity, reducing destabilization or tumbling, especially at long range.

Beacause the bow is tall and narrow when in use, more bowmen can be packed into a given frontage of the line than crossbowmen.

Hence, from two equal lengths of front, bowmen would throw many more projectiles farther and more accurately and much more often than crossbowmen.

The longbow was considerably better than early firearms that replaced it.

But it required much more training, its armor-penetrating power was quickly surpassed by guns, and it lacked gunpowder’s ability to frighten unfamiliar troops (and perhaps also cavalry horses). Also, arrows take more wagon space than lead balls, when one is packing tens of thousands of them.

Still, a force of crack longbowmen would have been an asset even as late as the Revolutionary War, perhaps.

Sailboat

19

I thank everyone for their posts…very interesting. Even those who don’t like Robert Jordan (which seems to be the majority position around these parts).

What do you base this statement on? Unless I’m mistaken a heavy crossbow has the ability to penetrate period armor about the same as that of the early (or even later pre-rifled) arquebus. At about the same range. The primary problem with the cross-bow was that it was bulky, cumbersome and the rate of fire was far less than for the bow…and less than for even the early model firearms too IIRC.

Sure, depending on what gearing you are using…or what ever else you are using for mechanical advantage. My assumption was that there is a gearing mechanism out there that could move a heavy crossbow into firing position by cranking the device 3 times…but not requiring the user to have a hulk like build. I’m reasonably certain such a winding mechanism is possible…whether its feasible or not I couldn’t say.

For the debate I was basically just saying what if such a thing WERE possible. That a HEAVY CROSSBOW (not a light crossbow that other posters seem to be fixated on) were capable of being fired at a rate of 5-6 shots per minute.

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.
I can’t find it now (I’m at work and don’t have much time) but one poster in the thread mentioned the complexity of a crossbow (and of course the even more complex mechanism proposed to cock it so rapidly) as a potential problem. I admit, I hadn’t thought of that and this seems a very valid argument. Much more so that ‘Robert Jordan sucks’, in my own book anyway.

-XT

20

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.

That is different. According to this site, modern crossbows transfer much more of their stored elastic energy to the bolt, to the extent that a 150 lb draw modern crossbow can loose a bolt with higher velocity than a 740 lbs (ye gods!) draw medieval crossbow. Such a bow could certainly be cranked more rapidly, in fact by weakening the draw to 125lbs you could dispense with the crank and pull the thing by hand, giving 7-8 shots per minute.

Whether such a bow could be constructed with period technology is a good question. I suspect that much of the improvement is due to the compound string arrangement rather than materials technology. The trick is to put more of the bow’s energy into the bolt rather than leaving it in the juddering ends of prod after the bolt has departed.

So, assuming a powerful but low draw force, 3-turn crankable bow could be build with period technology, your OP becomes feasible! How would such a development have affected history? Not my field, but I suspect gunpowder weapons would initially have been limited to artillery. I’m not sure at what point a gunpowder firearm would have appeared a viable alternative to the advanced crossbow… after breech loading was developed? Cartridged ammo? In this scenario, there would be little impetus to develop the matchlock and flintlock firing mechanisms!

One advantage that primitive gunpowder has over advanced crossbows however, is that there’s no decent crossbow equivalent of the pistol in terms of bulk, or rather the lack of it. Perhaps pistols would have developed anyway as sidearms and short range weapons, locks and barrel making improving over time, and the musket then emerging from them.

Tangential, but I thought I’d share this link: