Author Topic: Zigzagging Questions (Zigzag Turns)  (Read 8558 times)

Andy

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Zigzagging Questions (Zigzag Turns)
« on: October 14, 2009, 06:20:04 PM »

Hello everyone,

I am trying to get my head around a basic tying technique, and I seem to be drawing a blank: I can't find where in my books it is discussed, what it's called etc.
Can you please enlighten me ? :)
The principle I am talking about is what I would call "zigzagging", or "zigzag turns", or "using zigzags to add tension", but I am not sure what is the right name.

This principle is used all the time in the bush and by a lot of people to tighten a rope's grip. For instance, in lashing, I use it to make frapping turns even tighter, and also sometimes to tighten the regular gripping turns. And I've seen a lot of people use zigzagging in different ways to add tension. Basically what I am talking about is passing a bight around an object, and pulling the working end through that bight to constrict the object.
Here are a few pictures. The first two show a single zigzag being set-up and tightened. The third shows a double zig-zag, adding even more tension. The fourth shows a simple way (one of many) that a zigzag can be stopped to complete a hitch.


 
 


Some features of "zig-zagging" I've noticed:
1. There is some pulley action in zigzagging, as in the truckie's hitch;
2. You can put one zigzag after another, as in the third picture;
3. You can zigzag at various stages of knot-tying, e.g., when you start a binding, in the middle of a lashing, or after a clove hitch to make sure it doesn't slip.
4. If your rope is weak, zigzag turns can add so much tension that the rope will break.

What I'd like to know:
1. Is there a common knotting name for this practice? (As there is a name for bights, bends, frapping, turns etc) If not, how about a "zigzag turn"?
2. I don't find "zigzag turns" discussed in knot books, am I being blind? Do I not have the right books?
3. Do you know simple hitches (like the ones shown in the pictures) using the principle, and what are their names?
4. If the principle is not widely discussed in the knotting literature, why not? Is it bad? Is it because it can break ropes?
5. What other thoughts do you have about zigzag turns?

The closest illustration of the principle that I can find is in Ashley 1195, the zigzag knot. And that knot is not even used for constricting. In Ashley, I find other mentions of zigzags, but they don't really describe the strong zigzag tensioning I am talking about: #3610 (zigzag hitching), #213 (jumper hitch), #751 (zigzag lanyard knot), #2506 (zigzag bars).

I'm really puzzled about this and feel a bit silly for asking these "basic questions", but I know that this is THE place to learn---you guys know so much about knots, I can't wait to learn from your replies.

Wishing you all a gorgeous day,

Andy

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roo

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Re: Zigzagging Questions (Zigzag Turns)
« Reply #1 on: October 14, 2009, 07:39:55 PM »
I think you may be trying to over-analyze this.  Rope or cord changing direction to simulate a pulley system is commonly employed for tightening operations, from shoe lacings to a Versatackle (though the changes in direction aren't spread out):

http://notableknotindex.webs.com/Versatackle.html

Hitches do often have changes of direction in rope, but they don't need to actually tighten anything, per se.  The role of hitches is just to anchor a rope to an object, not squeeze the object, necessarily.  Binders or binding knots are more likely to use pulley simulation to actually apply force.  The reason they often don't apply many changes in direction is for simplicity, and the diminishishing return of force as friction builds up.

http://notableknotindex.webs.com/butcherknots.html

On friction:
http://notableknotindex.webs.com/friction.html
« Last Edit: June 30, 2010, 08:05:06 PM by roo »
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squarerigger

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Re: Zigzagging Questions (Zigzag Turns)
« Reply #2 on: October 15, 2009, 06:04:17 AM »
Try looking up "Catharpings" or "Catharpins" in a nautical dictionary for a view of what you have described as a zig-zag.  They are lines used to tension the futtock shroud ends under the mizzen-tops, main-tops and fore-tops of square-rigged ships - tells you something of how old the technology is!  The Diamond Hitch used in mule-packing is similar and uses the same technique. ;D

SR

Andy

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Re: Zigzagging Questions (Zigzag Turns)
« Reply #3 on: October 15, 2009, 04:34:48 PM »
Hi Roo, Hi Squarerigger,

Thank you for your thoughtful replies.

SR:
I looked up cat-harpings on Wikipedia and other online sources. That's a fun new word for me! I haven't found any illustrations so far, and the definitions do not all agree, so would you be able to provide one additional detail: Does the zigzagging rope of catharpins come back and grab itself as in the second picture, or does it zigzag in a different way? [Added an hour later: found catharpins in Ashley 3277 but the question stands.]

Thank you also for mentioning the diamond hitch. I had never looked at it up close. What a cool tensioning knot. I can see the pulley action and zigzagging effect (far more elaborate than what I was thinking about when I asked the question).

Roo:
Thank you for pointing to the packer's knot. I like your description ("change of direction"). I can see how in a sense that's the principle I was asking about, except more secure: instead of grabbing a bight, the rope goes through a figure-8. On the other hand, because both ends of the rope are used, maybe I'd put this in the family of nooses that are obtained by running the working end through a loop, as in a running bowline.

Quote
I think you may be trying to over-analyze this.
Maybe so? On the other hand, what makes us decide that one concept (e.g., "frapping turn", "half hitch") should be named and discussed, but not another? I guess it depends on whether the concept is useful as an object in the mind. For me this idea of zigzag turn is an object in my mind because I encounter it all the time when making structures with tarps, etc. That's why I was curious to know if is part of the knot language, and, if so, what is said and thought about it---uses, limits, pros, cons, etc.

You are right about the gripping action of shoe-lacing. I guess what I like about zigzags is that they give you this same gripping action, but in the bight---you don't need both ends of a rope (as you do when lacing shoes): one end of the rope may be on another spar, but at anytime you can apply tension with this little "zigzag turn" trick.

You mentioned a tackle system. I too love pulley systems with rope. So great for lifting a full solar shower bag up to a high branch.

Thanks again to you both for sharing your knowledge and insights.

Wishing you all a gorgeous day,


Andy
« Last Edit: October 15, 2009, 06:37:35 PM by Andy Asan »
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Dan_Lehman

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Re: Zigzagging Questions (Zigzag Turns)
« Reply #4 on: October 16, 2009, 06:07:41 PM »
Hmmmm, this "zig-zag" looks not too much different than a
drunken half-hitching or marling.  And the supposed pulley
advantage seems, as is often the case, dubious:  you pull
with 2:1 nominally but impart that force to the two legs
of the bight pulled upon -- begging the question How is
that better than just hauling on the wrap?  (Esp. after
considering all the force lost to friction.)

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bj

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Re: Zigzagging Questions (Zigzag Turns)
« Reply #5 on: July 23, 2016, 08:08:30 PM »
For history:
The basic idea is called a Crossing Hitch (Ashley #206, p. 40; #1818 p. 306)
which the same form as a Munter Hitch.
Also see the Zigzag Hitch (Ashley #1195, p. 217) and a Tugboat (Lighterman's) Hitch.

Olegan67

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Re: Zigzagging Questions (Zigzag Turns)
« Reply #6 on: July 24, 2016, 12:12:15 PM »
For history:
The basic idea is called a Crossing Hitch (Ashley #206, p. 40; #1818 p. 306)
which the same form as a Munter Hitch.
Also see the Zigzag Hitch (Ashley #1195, p. 217) and a Tugboat (Lighterman's) Hitch.