What is the top speed of a fencing weapon?

[Danger]

On the other hand, human experiences lie. It's one thing to think you've really done something, and another to take measurements to see if it really happened that way.

I have to agree with DaveC. There's a reason that professional fencers use biometric studies to improve their "game"... humans are just not built to accurately assess the speed of a thin bit of metal in the midst of an active sport. Eyewitness is not that useful in any circumstance when it comes to the details.

Which brings me back to my original point that instrumentation on or near the blade should be used to settle the matter. When I said "theory vs. practice", I meant that talking it out won't solve anything. Likewise, my suggestion that fencers have better idea of what happens than theoreticians wasn't meant to imply that they have definitive answers—merely that they know more through first-hand experience than does someone who has never held a sword. After all, we could talk about karate all day, but in the end I'll take the word of a black-belt over that of a kinesiologist whose only experience came from studying stick-men fighting on a computer monitor.

 

[DaveC426913]

After all, we could talk about karate all day, but in the end I'll take the word of a black-belt over that of a kinesiologist whose only experience came from studying stick-men fighting on a computer monitor.

I refer you back to the long-standing Martial Arts https://www.physicsforums.com/showthread.php?t=201409" of PF yore. Martial artists had it all wrong, physicists won that one.

 

[Danger]

I refer you back to the long-standing Martial Arts https://www.physicsforums.com/showthread.php?t=201409" of PF yore. Martial artists had it all wrong, physicists won that one.

Okay... I read the first page of that, and that was enough. Seems like a silly argument in the first place. I was always taught to aim for the back of the guy's head so my hand would be at maximum acceleration upon contact. Same idea as trying to put my cue into the rack on a pool break. (Ir)regardless, I concede your point in this matter. Don't get used to it, though.

 

[mugaliens]

The issue here is actually the speed of a fencing weapon. Can we save the gun-rights discussion for the politics forum?

Absolutely, Gokul, and no offense intended. :)

I think that this is coming down to theory vs. practice. Those like you who have practical experience are far better qualified to expound upon the issue than is someone examining it on a computer or (more my speed) on paper. It's one thing to prove that something can be done, and quite another to actually do it.

Multiple-angle strobe photography should be more than enough to verify or denounce claims with respect to tip speed. I've only twice witnessed fencing matches, but I never heard a crack. Just some stacatto clashes of steel and some high-speed swishes.

So, I just took a few moments and a 6' fiberglass bicycle flag (without the flag) I use for outdoor sports downstairs into the parking lot and gave it a few good swings.

I'm fairly strong, and have no trouble throwing my 100 lb son overhead for an hour in the pool, or connecting with 90 mph fastballs at the batting cage (though they're not much fun - 60 mph is more to my liking). Even with two hands, and all the force I could muster, still, nothing. Just swish, swish. I can also ring the bell 9 times out of ten at the amusement parks, so I do have both some pretty good upper body strength as well as enough practice splitting wood at my uncle's place to know how to use it. At least for splitting wood and hitting baseballs... (rolls eyes)

Back to physics...

Mathematically, a 6' pole swung in a circle comes to about 38' to 40', and with everything I can muster, I can't do it faster than about 1/4 of a second, which gives us a tip speed of, at best, 160 fps, or 110 mph.

That is nowhere close to 760 mph.

Part of the problem is the fact that a cylinder is horribly non-aerodynamic when compared to a thinner blade. Or for that matter, even a thicker, but more aerodynmic blade.

This negates the tapered cylinder of the foil, as well as well as the epee, which v-shaped. A sabre, on the other hand, still maintains an edge.

The question is whether that "edge" is enough, aerodynamically, in order to allow it to be swung fast enough for the tip to break the sound barrier?

In a straight swing, I just don't think there's any way to get anywhere close to mach. From 110 mph to 760 takes forty-seven times the power. Add mach drag rise effects and it's closer to 60 times the power.

But a straight swing isn't all that's out there.

The arm itself is somewhat shaped like a whip, thick at the shoulder and slender at the wrist, and segmented at several places, beginning, actually, in one's toes, and extending through the ankles, knees... Oh, you get the idea.

If the blade itself tapers and is flexible at the tip (which a saber is not), it's merely an extension of this effect. Swung in the right manner, particularly with a massive and powerful arm to initiate the initial momentum of the whip action, and the arm and the sword can impart a serious momentum to the tip, which, as you know, if light enough, might get close to or even break the barrier.

So, I just returned from downstairs again, with my trusty fiberglass whip, only after thinking about it I've modified my grasp to both impart more momentum (rather than pure velocity). Put simply, I choked up a bit on the "bat," about a third, and was swinging it down like an axe as is more my custom.

Still no crack, but the swishes were of somewhat higher pitch, which means greater tip velocity.

I understand the physics of it, but when it comes to fencing, there must be some sort of move designed to impart maximum energy to the weapon, perhaps as a coup de grai (sp)?

Still, with any sort of rigidity to the blade at all, even with the foil, I don't see how it's remotely possible for the tip velocity to exceed , at best, 250 fps.

Meanwhile, I've shot arrows using a compound bow which have been clocked at just over 300 fps, which given the arrows used, would cause much more damage than a slash with any of the three weapons used in fencing.

So... Mach? I'm sorry, but I just flat don't see out it could be done with any sword blad of any type.

However, I did think of a new type of blade which would do the trick: One that was metallic, about 12' long and segmentedly tapered to make it look like a whip, provided it's linear and total mass was about the same as that of most whips...

But that would be a metallic whip, not a sword, by definition.

 

[nismaratwork]

Absolutely, Gokul, and no offense intended. :)



Multiple-angle strobe photography should be more than enough to verify or denounce claims with respect to tip speed. I've only twice witnessed fencing matches, but I never heard a crack. Just some stacatto clashes of steel and some high-speed swishes.

So, I just took a few moments and a 6' fiberglass bicycle flag (without the flag) I use for outdoor sports downstairs into the parking lot and gave it a few good swings.

I'm fairly strong, and have no trouble throwing my 100 lb son overhead for an hour in the pool, or connecting with 90 mph fastballs at the batting cage (though they're not much fun - 60 mph is more to my liking). Even with two hands, and all the force I could muster, still, nothing. Just swish, swish. I can also ring the bell 9 times out of ten at the amusement parks, so I do have both some pretty good upper body strength as well as enough practice splitting wood at my uncle's place to know how to use it. At least for splitting wood and hitting baseballs... (rolls eyes)

Back to physics...

Mathematically, a 6' pole swung in a circle comes to about 38' to 40', and with everything I can muster, I can't do it faster than about 1/4 of a second, which gives us a tip speed of, at best, 160 fps, or 110 mph.

That is nowhere close to 760 mph.

Part of the problem is the fact that a cylinder is horribly non-aerodynamic when compared to a thinner blade. Or for that matter, even a thicker, but more aerodynmic blade.

This negates the tapered cylinder of the foil, as well as well as the epee, which v-shaped. A sabre, on the other hand, still maintains an edge.

The question is whether that "edge" is enough, aerodynamically, in order to allow it to be swung fast enough for the tip to break the sound barrier?

In a straight swing, I just don't think there's any way to get anywhere close to mach. From 110 mph to 760 takes forty-seven times the power. Add mach drag rise effects and it's closer to 60 times the power.

But a straight swing isn't all that's out there.

The arm itself is somewhat shaped like a whip, thick at the shoulder and slender at the wrist, and segmented at several places, beginning, actually, in one's toes, and extending through the ankles, knees... Oh, you get the idea.

If the blade itself tapers and is flexible at the tip (which a saber is not), it's merely an extension of this effect. Swung in the right manner, particularly with a massive and powerful arm to initiate the initial momentum of the whip action, and the arm and the sword can impart a serious momentum to the tip, which, as you know, if light enough, might get close to or even break the barrier.

So, I just returned from downstairs again, with my trusty fiberglass whip, only after thinking about it I've modified my grasp to both impart more momentum (rather than pure velocity). Put simply, I choked up a bit on the "bat," about a third, and was swinging it down like an axe as is more my custom.

Still no crack, but the swishes were of somewhat higher pitch, which means greater tip velocity.

I understand the physics of it, but when it comes to fencing, there must be some sort of move designed to impart maximum energy to the weapon, perhaps as a coup de grai (sp)?

Still, with any sort of rigidity to the blade at all, even with the foil, I don't see how it's remotely possible for the tip velocity to exceed , at best, 250 fps.

Meanwhile, I've shot arrows using a compound bow which have been clocked at just over 300 fps, which given the arrows used, would cause much more damage than a slash with any of the three weapons used in fencing.

So... Mach? I'm sorry, but I just flat don't see out it could be done with any sword blad of any type.

However, I did think of a new type of blade which would do the trick: One that was metallic, about 12' long and segmentedly tapered to make it look like a whip, provided it's linear and total mass was about the same as that of most whips...

But that would be a metallic whip, not a sword, by definition.

Generally speaking, the forward lunge is the maximum energy delivery mechanism, because you're putting the energy of your lunging body behind the blow. The thing is, fencing is really nothing at all like real sword-fighting, so there is no practical "killing" blow. With a slashing weapon such as a Kilij, Katana, or Saber, the main strikes are eightfold: vertical down and up, lateral across and back, and the 4 diagonals in between. A "Coup de grâce" (pronounced Koo day grahs) is traditionally delivered with the Main Gauche (a dagger), to the neck/spine, head, or heart. It was developed as a means to (relatively) humanely dispatch an opponent who was mortally wounded, but would not die quickly.

Finally, consider the difference (not superiority), between a piercing weapons such as a real rapier, a slashing weapon such as a Kilij, standard Longsword, or Katana, and a piercing projectile such as a hunting arrow. The former does it's damage when critical regions are struck, such as major blood vessels, the heart or throat. The second can sever limbs in a single blow, open the guts, or on other general way kill in one blow, and induce enormous shock and catastrophic blood loss. If you lip off an arm at the elbow, it's not as fancy as decapitation (which is certainly possible with such weapons), but the pain, and blood loss from the brachial artery and more is immensely effective.

Finally, the arrow, which has the benefits of the precision in a rapier, and in the case of a bladed head will cause a significant wound channel. However, a 300 fps bolt or arrow in the arm or thigh can be less than lethal... it is the range and aim which the bow affords making it so deadly. In terms of one shot, one kill, you can't beat cutting someone in half, but there is no weapon in the genealogy of European fencing which can do such a thing.

Hell, if you look at bullets, ignoring armor (as we are for the bladed weapons and bow), you don't want a super-fast round, but rather a Jacketed Hollow-Point round to mushroom and cause a large permanent cavity. Supersonic weapons are only useful if they are massive (tungsten rods from orbit), or meant to cause terror and pain, like a whip.

 

[mugaliens]

Generally speaking, the forward lunge is the maximum energy delivery mechanism, because you're putting the energy of your lunging body behind the blow. The thing is, fencing is really nothing at all like real sword-fighting, so there is no practical "killing" blow. With a slashing weapon such as a Kilij, Katana, or Saber, the main strikes are eightfold: vertical down and up, lateral across and back, and the 4 diagonals in between.

I checked with my friend across the hall, and he assured me of two things: 1) any competant swordsmap can usually deflect a straightforward "killing blow" 2) any competant swordsman can occasionally render a crosswise killing blow.

In short between expert swordsmen, it's usually a draw.

 

[nismaratwork]

I checked with my friend across the hall, and he assured me of two things: 1) any competant swordsmap can usually deflect a straightforward "killing blow" 2) any competant swordsman can occasionally render a crosswise killing blow.

In short between expert swordsmen, it's usually a draw.

It depends on the swords employed, the reach and athleticism of the swordsmen, and armor. In practice, history shows that there were great warriors such as Miyamoto Musashi, or William Wallace (to draw from radically different weapons and styles), who repeatedly bested opponents. Musashi tended to fight duels with a Katana (later in Iaido style, then with Bokken), and it seems he never lost. Wallace was a master with the Claymore, and he was fighting well armored foes who were not poorly trained.

I don't know what qualities make such a fighter, but in a duel or war, a draw is not an option. You simply rinse and repeat until you win, or die. In many ways, regardless of technique, this is the great difference between fencing, and fighting... the former deals in single "points", but the latter allows for so much more.

Anyway, to the point you were responding to, the lunge is interesting in that you cross a large distance in a very short period of time, and deliver a great amount of energy to the target. The downside is that you have to commit, and it leaves you open. If someone tries a crosswise slash with a Kilij, there is a similar opening, but the target is likely to attempt to dodge or block, then will need to recover. With a foil, saber, or epee, this is just not the case, as they are all light weapons. Fencing is a fun sport, but it really has nothing at all to do with combat, and the notion of a "killing blow" is just not applicable.