Good morning,

I'm writing a research paper about the physics of swords. And I got to the point where I need some information for examples. So maybe yall can help me. I need the maximum velocity of a one-handed sword which is held above the head and then smashed down to an opponent's head. I know that that is difficult to measure. If anyone knows anything about the velocity or the impact of swords at all, please feel free to contact me.

Thanks for helping.

Here is something on sword dynamics, I do not recall if there is specific velocities mentioned.
I have somewhere read of 50+ miles/hour

http://www.thearma.org/spotlight/GTA/motions_and_impacts.htm

50 mph is in the right range I think. . in studies of major league baseball players 45-60 mph are typical for bat swing speeds, for cricket players less so. different motion admittedly but if you need a ballpark (pun intended :D ) number there you go

Thanks. I'll go with that.

Hello,

One thing to bear in mind is that a baseball (or cricket) bat is not balanced in the same way as a sword, and therefore that a sword might be able to achieve greater tip speed...

I think a good way to include that difference is to consider kinetic energy instead of speed, and eventually use it to deduce the speed if you need it, depending on the motion and mass distribution of the sword (which you'll need anyway if you want to make impact calculations).

This article gives a figure for the kinetic energy of a bat hitting something: 515 kg m^2/s^2. Assuming the same energy and rotation about the pommel at the moment of impact, with the dynamic properties of the Brescia Spadona, I arrive at a tip speed of 50 m/s, which is about 110mph... Quite a bit more than what a baseball bat with more weight near the tip can achieve with the same energy.

Will your article be publicly available at some point? I'd be interested :)

Regards,

Tip speed of a sword is irrelevant unless that is the place that makes contact. Measurements should be taken at the point of impact.

Consider:
1. It takes very little to cut flesh - far less than the maximum velocity that can be achieved.
2. No human can swing a sword fast enough to reliably cut through armour.
So how is maximum sword velocity relevant?

His original post implies that he is interested in cutting heads. If so then my original comment stands. You don't need maximum velocity to determine whether a sword can kill someone without a helmet. If there IS a helmet then maximum velocity is still irrelevant since it is very unlikely that you could cut through it. The only interesting aspect is how much blunt trauma is imparted through the helmet.

I've read that it is possible to split a helmet and a head. It always depends on the period. When the French took over Europe the helmets were made out of brass and the soldiers had only little protection at all, because firearms would get through the heavy protection anyway. And so a cavalier could hit a soldier and maybe both would split.

My point of asking was because I wanted to calculate the kinetic energy. When a sword hits a target all the kinetic energy will perform work, which pretty much is the damage. I was just trying to get a picture of how dangerous sword cuts can be. Well after all it isn't accurate at all, because there are too many aspects that are involved in a cut. Starting with the body type, the sword itself (the balance, main purpose...), how profecional the sword can be led through the cut etc.

Quote:

Will your article be publicly available at some point? I'd be interested Happy

I can send it to you once I'm done with it, but it's going to be in German. So that might be a little problem.

Ah. Well there definitely are eyewitness reports of swords cleaving through 19th century brass helmets. Just keep in mind that it doesn't have much relevance to medieval armour.

Not sure I am going to phrase this corectly, so forgive me if it comes out garbled. Presumably KE would also be a factor in situations where two parts of the body are made to move out of unison with each other. I am thinking of a hit downwards at an angle at a helmeted head where the helmet is not cut through and there isn't enouigh impact transfered to damage the skull, but where the head is "cranked" sideways in such a way as to injure the muscles of the neck. I imagine a lateral blow to the "snout" of a pigfaced bascinet could couse the head to twist in such a way as to "rattle" the dude inside. This is all uninformed theorising (or rather, talking bollocks).

I had a friend of mine measure the speed of his swing with a chronograph. He was hitting between 160 and 180 mph after we converted from feet per second. I am planning on getting a chronograph soon myself. We tried to also figure out the Energy but it is difficult because you can only guess the mass. It might be around a pound near the tip of a Type X but much less for a Type XV.

The blades speed is slower near the forte... but the physics change considerably because when I strike with the forte, I punch the sword out. In essence I am putting more mass into a forte-punch to make up for the lesser velocity.


Interestingly enough, the measure that my friend took came close to a calculated computation I had made based on how fast I throw a baseball. I throw a baseball at about 30-35 mph. Adjusted for rotational acceleration it comes out to about 160 mph for a 30 inch blade. Of course this is a very rough computation but it game me a ballpark figure.