Cutting a Jo

[pcnorton]

I'm trying to find a reference to a cutting a Jo with a sword espirement. I think it was Draeger, does anyone have any leads. I can't remember where I read it/saw it.

Paul

[Meik Skoss]

Espirement? Wazzat?

Draeger did mention that the white oak used in Japanese buki is pretty tough and not easy to cut through, but I don't believe that he referred to any research about testing its intrinsic toughness. The word used to describe that, if I recall correctly, is sectility, it's a measure of how much resistance a material has to breaking. Or was that its resistance to being cut? If you're truly interested, you can look it up in an engineering table.

Hope this helps.

[Jack B]

An acquaintance of mine performed the admittedly foolhardy experiment of having a student cut full strength with a bokken at his jo, while he held it overhead a la Sakan. The student was also shodan in Iaido, and both weapons were white oak. The bokken shattered.

An engineer student of mine heard about this and spent 10 minutes explaining the mechanical superiority of the jo in that position, and how it would be expected that the bokken would shatter. I have heard of a jo shattering when someone used it as a bokken (it's what he had in his hand at the time) in a full-force strike against a dobarai block. Once again, the jo was braced at two points and had a structural advantage.

I do know someone who took a white oak jo, leaned it diagonally against a wall, and brought his near 300 lbs weight onto it to break it. He just wanted to see what it would take. This was a $20 cheapie, standard SMR measure.

[pcnorton]

I meant expirement.:rolleyes:

What I remember is that a jo was going against a sword and wasn't being cut, the only way they (I thought it was Draeger) got to cut through was with a jo being held in a vise.

ANy way, I just saw a little movie were a L6 Howard Clark katana cut through a red oak jo. Although the jo was striking at the edge as the edge was striking at the jo.

I also thought I saw some vids of draeger doing jo on the net someplace.

I snapped a dymondwoood (laminate) jo in half once. Yokomen into two 2X4's nailed together, the jo blew apart. 2X4's just stood there taunting me and my destroyed jo.:D


Paul

[Daishi]

What kind of damage did the two 2x4's take? Spruce is extremely soft and would much rather dent or bend than snap. Orientation is very important too. But really, I am not suprised your very dense, very hard jo snapped when smashed against some very soft, very pliable wood in a much larger mass, wasplaced in a paralled grain to your jo. Physics seem to answer this one, (although I will be the first to admit physics has not yet fully explained every thing I have seen).


Dale Heisler

[pcnorton]

The 2X4 had a big dent. Yes Physics did have something to do with it, I hit the 2X4 with the middle of the jo instead of the tip. The jo tried to flex and exploded since it couldn't.


Paul

[fogarty]

I recall seeing a picture of a jo that had been used against a live blade. It wasn't Draeger's; it was some Japanese teacher's. What occurred to me most upon seeing the photograph was that I really wouldn't want to slide my hands along it in, say, honte or gyakute uchi.

My two yen,

ƒtƒHƒK?[ƒeƒBãÄ

[Hattori]

from a Japanese book. Jo after practice against live blade.

[fogarty]

That's the one. Yasuno-sensei copied it for me, but that's with all my stuff back in Canada. In case you're wondering, the caption says:

?^Œ•‚É‚æ‚é?˜‚¦•¨?Ø‚è‚Å‚ÍŠÈ’P‚É?Ø’f‚³‚ê‚é?ñ‚à?A“®‚«‚Ì’†‚Å?n‚ðŽó‚¯‚镪‚É‚Í?A?Ø’f‚³‚ê‚È‚©‚Á‚½?BŽÊ?^‚Í?n ‚ðŽó‚¯‚½??

Shinken ni yoru suemono kiri de (w)ha kantan ni setsudan sareru jo(u) mo, ugoki no naka de ha (w)o ukeru bun ni (w)ha, setsudan sarenakatta. Shashin (w)ha ha (w)o uketa kizu

Even with walking sticks being easily severed by (fixed) test-cutting with a live blade, where they have received the blade while in motion, they were not severed. The photographs show cut marks received by a blade

Someone might get a closer translation, but that's probably got the jist of it.

ƒtƒHƒK?[ƒeƒBãÄ

[Nathan Scott]

FWIW, I've cut Japanese white oak jo, six foot bo, white oak bokken, and the thick waxwood sticks we use for pre-arranged sparring with my shinken.

The purpose was R&D from the sword point of view though, so the objects being cut were not moving. My experience is that swords will cut about 3/4 of the way through a hard wood of this thickness before causing the wood to snap (from the wedge shape being forced through it). The part that is cut is as smooth as glass though. The cuts shown on the jo in the above picture appear to be caused from deflections on the side of the jo, rather than a hard block. That would make sense. I don't recommend hard blocks against a shinken! ;)

Regards,

[pcnorton]

Your Jo's weren't moving, probably in some sort of vise or were they free hanging?

I don't know of anyone that advocates a static block against anything with a jo,sword,arm, leg etc. etc.


Paul

[Nathan Scott]

Hello,

The articles I posted about cutting in my previous post were done in various ways. Some were held in a forward kamae by someone else, some were supported by some type of improvised stand, etc.

My purpose was not necessarily to replicate what might be possible if someone held a static block, but simply to see what the capability of the sword was. Obviously, I don't recommend cutting hard objects like this without proper instruction, as it can be quite dangerous.

As far as static blocks, I don't know about jo, but most arts I know allow for the possibility of a hard/static block. In sword, what is sometimes called "torii no kamae" (a two hand supported over head posture) can be used in this wasy if necessary. Even the Aikido style I study teaches hard blocks as kihon practice. Later, we divert or avoid strikes when possible, but retain the option of hard blocking if necessary.

If my last post stated the obvious, then I apologize for the redundancy.

Regards,

[fogarty]

I'm sorry, but I can't imagine a static block in an anal-retentive physics sense of the word "static". Blocking is an action, hence dynamic, so "static block" is an oxymoron. For that to happen, wouldn't the attacker have to attack the weapon and the defender not react? A "hard block" sounds like what I've heard called "meeting the force" as a stop. In the styles I've been acquainted with, this means you get out of the way, stopping the weapon. There was hearsay once about a fight involving machete-like knives where one blocked so hard, he cut through the other's knife, only to lose his hand when the severed blade flew into it. In jojutsu the way I remember the "torii no kamae" the sword handle is raised first, and the tip of the blade comes to meet it. In aikido, IIRC, the reverse case took place. The resultant "twist" would disturb the hasuji. Besides, you close the distance a little, so you aren't blocking the preferred cutting part.

I don't know if I had a point, or why I'm writing this. Cutting a fixed/static object (i.e. suemono) is different from cutting a mobile target, perhaps.

?Ï‚Ý‚Ü‚¹‚ñ?A

ƒtƒHƒK?[ƒeƒBãÄ

[Nathan Scott]

Cutting moving objects as opposed to fixed is different. Having done both, you find that there are certain angling and movment rules that must be adhered to, in addition to the other obvious elements (maintaining ma-ai, etc.).

Torii no kamae can be assumed any number of ways, and they are all correct if you follow the way that your art teaches. I'm not a scientist, so "static" may not be the perfect word to describe a "block". But what I'm referring to is something that is often taught to beginners as kihon renshu, or, what happens when your perfect plan for applying techniques fail and you have to CYA or get cut. In other words, you've tried your textbook technique and it didn't work (the opening wasn't adequate, you were succesfully faked out, your application of the technique was insufficient, your opponent avoided and counter cut [nuki-waza], etc.). Most people will block rather than allow themselves to be cut. Those that have free-sparring experience usually relate to this situation, though as you get better obviously, these "hard" blocks become far less necessary.

If your interested, I wrote some things about this in my FAQ (if you have suggestions for better terminology, I'd welcome them):

http://www.tsuki-kage.com/faq.html#3

Regards,

[Walker]

Geez you guys.

http://www.summerchild.com/L6test/3clips.avi

note last segment of two yahoos playing in the backyard.

No. It don’t prove nothing...

[Mekugi]

lessee...

Chinese red oak dowels....weak, stringy and I have snapped those in two by bending them slightly.
These guys don't have access to $150 dollar per shaku Japanese Red Oak, which is extremely dense and it is notorious for breaking and dulling carpenter chisels. I have seen that stuff fire treated and destroy power tools left and right. I wonder......

-Russ