The real advantage of undulating blades !

[Vincent Le Chevalier]

Hello Roy,

You suggest that the maximum amount of energy consumed by a person during sword handling could be up to 10,000 watts or 13.4 horsepower.

That might have been overstated indeed
I was talking about peak power though, not something you sustain permanently. That same wikipedia page lists 2kW as the approximate short-time power output of sprinting professional cyclists. The drag power I've computed is also for the worst case, at the peak of the drag, if you're trying to hit full-speed with the flat. Ordinarily the sword has its edge aligned even when doing great circles, it's only during the slower phases that redirections occur. As you know drag is very highly dependent on speed, so I guess that's why I don't experience much stall when handling my sword: in fast phases the edge is always aligned (at least I try ).

But you're welcome to try in practice anyway. I won't do it because so far I'm not convinced it matters.

Andrew,

if the aerodynamics of the blade actually did provide significantly less drag in air, then I'm just guessing that maybe there would be less drag when travelling through flesh

Flesh is very different from air. You don't get vortices in flesh; The specialists working on these particular wing profile say they work because of vortices...

I reiterate my question: what's wrong with just looking cool? Do we need a practical reason for everything? If the blade works at least as well as a straight one, and looks more impressive, why not use it?

Regards,

[Sal Bertucci]

Coolness is cool! But Coolness AND function is even COOLER! I wonder if we have a wind tunnel here.

[Stacy Clifford]

Interesting discussion here so far, but the kind where we could throw numbers and citations at each other all day and not convince anybody of anything. This is clearly a very testable hypothesis and it would be very interesting to see someone try it; I think that's the only way this type of argument is going to be resolved. Now if we could just get Albion to donate a couple of zweihanders to science...

[Sal Bertucci]

We just need to get a grant!

[Steven Ott]

Which begs the question-Are there any top of the line, historically accurate swords available on the market?

[Sal Bertucci]

lutel has a few

[Jonathan Newhall]

Well, I have access to a wind tunnel at school, though it's meant for models of things a bit smaller than swords (I suppose I could test a section of each type of blade?) If they'd let me anywhere near the thing with a hunk of sword, at any rate

[LafayetteCCurtis]

What's with this obsession over angles of attack, really? I thought with proper edge alignment a sword's aerodynamic angle of attack should be virtually zero!

[Roy Robinson Stewart]

Firstly it is not an obsession, it's an interest in the subject. Obsession is an ugly thing to be accused of. I am merely very interested.

I must also add that it is my job as a designer to investigate these phenomenon, it's not just a hobby.

Secondly, we read that these large two handed sword were used at times to defend against many ( being designed to do so ) and were used in wide sweeping circular motions. Such motion must inevitably include curved cuts, turns, and other arcs rather than just absolutely straight cuts. Turning a blade in mid air means that the blade is necessarilypresented at an angle of attack to the air flow. . . . it's not possible to turn a blade without doing so.

Now, the chord ratio of these blades ( as wings ) is very low, typically in the range of 3% to 6%. These low chord ratios mean that the blade will stall at very low angles of attack. Stalling is not ideal as it increases drag, slowing the blade and using more muscular energy. Stalling also drastically reduces lift.

The effect of drastically reduced lift due to a stall is that the blade will not 'steer' its way through a turn. If the blade does not stall the lift which it produces will tend to make it travel in the direction in which the edge is presented. If it stalls it will tend to continue on its path without turning properly flat first rather than edge first.. . . this tendency will have to be overcome by the swordsman using more muscular effort.

For wide sweeping arcs including changes in blade tip altitude and turns of various radii, the action of the swordsman in keeping the blade aligned to the airflow as much as possible will have the effect of making the blade follow the path in which it is directed better. It's a win/win situation as the edge direction tends to align the airflow and make the blade ( or wing )turn as directed.

That's unless the blade stalls, and just slews sideways while slowing down .

It is not possible to deny the fact that the kind of wide bladed swords we are talking about have significant aerodynamic properties at the speeds they can attain, or that they stall at very low angles of attack. Swords are not exempt from the laws of physics as we all know.

Blade undulations are able to increase the stall angle by 30 to 40%, that is a very significant improvement. The decrease in drag and the increase in lift are also helpful.

.

[Steven Ott]

For some reason people dont want to acknowledge that maybe our forefathers new more about swords than we do! I applaud your efforts to learn more about these fascinating weapons. Maybe people don't like them because there were a specialty weapon designed for stronger, larger men. Or maybe it's because there are no high-end versions available. Or maybe it's because they border on the realm of "fantasy" swords. But if those who used them in battle had so much adoration for them-their had to be a reason.
Crafting a well-made sword would have to be incredibly difficult. It may be had to do accurate research.

[Roy Robinson Stewart]

Thankyou Steven

It's a tad off topic but I'm wondering what size of person would have wielded the two handers, in height and weight, just in case of accidental custom orders for flame bladed two handers.

.

[Stacy Clifford]

It's a tad off topic but I'm wondering what size of person would have wielded the two handers, in height and weight

Probably some smaller guys than you might think. Kyle Cook here in Houston is about the same size as me (5' 6", 150 lbs.) and he loves his big zweihander and handles it well. I've never had any trouble handling one either. Bigger guys may have an easier time swinging it in a longsword-like manner, but any fit foot soldier of average size should have been able to handle one competently as it was meant to be used (more like a polearm).

[Roy Robinson Stewart]

Hi Stacy,

That's interesting thankyou for your reply.

It's clearly stated in the historical records that the two handers were used in continuous circular cutting motions, and that they had an advantage over thrusting weapons when dealing with many opponents.

For that reason I'm wary of seeing them as polearms if that means that they are used mainly for thrusting and for cutting only with a very wide grip and the shorter cuts used with such grips.

Controlling a 360 degree space with a pole arm using a continuous cutting action is not ideal due to the high air resistance involved. . . it's far too slow in my opinion. A two handed cutting sword doesn't have this problem, which is no doubt why they were made at what must have been great expense.

So I'm assuming that you are thinking of the two hander as used as it probably was in a judicial duel context, rather than in the 'one against many' 360 degree context which is the basis for the aerodynamic analysis I've been doing.

Please excuse me if I've misninterpreted your intention.

.

[Greg Coffman]

On use of the two-hander, seems like there are two general ideas on how to use it. One is to hold off large spaces against many foes with continuous circle cuts. That method is certainly represented in period accounts. The other is to use it more online, like other polearms. Achille Marozzo's guards seem like they are tailored for this second method.

But really, it seems to me like the sword could and would be used both ways according to situation. On the battlefield, sometimes you have to work in close packs with fellow soldiers where the wide cuts wouldn't work. And at other times if a gap opens up in your formation the wide cuts would work quite well to stop up the gap until other polearms could fill the hole. Thus, you fight according to the situation, just like with any weapon.

As far as cutting in large circles with either the dopplehander or another polearm, I think the mass distribution has quite a bit more to do with ease of use than wind resistance which I think is wholly negligible. A dopplehander, like other swords, has the center of balance closer to the hands, and the hands are closer together. This allows the user to more quickly change the direction of the cut, even when using continuous cutting motions. You don't just stand and cut the same circle over and over. A polearm on the other hand has a center of balance past the middle of the staff and out towards the head, and your hands are necessarily further apart while cutting. This makes it quite a bit more difficult to make continuous cuts and to control them.

[Stacy Clifford]

I agree with Greg that it can and should be used both ways according to the needs of the situation. As I said, bigger men might have an easier time controlling the wide cutting arcs, but that doesn't mean someone of my size can't do the same with sufficient practice and exercise. Look at the range of weights on this page:

http://www.thearma.org/essays/2HGS.html

The heaviest swords were certainly for big men, but there are also some that weigh less than the Lutel longsword blunt I practice with now, which is almost 4 lbs. I probably wouldn't mess with anything much over 6 lbs., but there are a lot of zweihanders in that range. It's worth remembering just how much variation there was within a single weapon "type" despite the cookie-cutter pictures we get in our heads sometimes.