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Crazy Question

MasterBlaster

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I figured I'd throw this in this forum as well as any. If I were to braid three Black Widow (7400 lbs) Micro Bull Lines together, would that give me a braided bullrope with 22,200 lbs tensile strength?
 

lumberjack

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Nope, but you should be able to get near it, maybe 20-21k.

Bends in the rope reduce strength. 3 straight lengths would get you at/near/above 22.2k. Looser the braid the closer you'll get.
 

gf beranek

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Well, the math says so, Butch, but the ultimate straw in the equation I believe would be how it was braided and knotted to the work. Sure, on straight draw strength the rating would hold true.
 

MasterBlaster

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Just a regular flat three strand braid, like a pigtail.
 

gf beranek

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Same either way I'd think.

I pondered a similar question with the Zing-It(Spectra) throwline. Wondering if I could braid a bull line using multiple strands of it. There's not doubt that it could be done, but would it be practical? In a pinch situation where the need was it could work.

There's a lot of permutations possible.
 

lumberjack

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It depends on how tight the chevrons are braided. Tight as corn rows will be really weak, french braid would be stronger, and even looser would be stronger.
 
M

moray

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I think lumberjack has it exactly right. But even if a loose braid would get you close (it would), you have a much trickier problem trying to attach your "rope" to anything in such a way that you don't take one of the little ropes right out of the equation. With a very stiff rope like Black Widow, a small lack of symmetry in the attachment could mean one of the little ropes is slack even when the other two are under heavy load. The slack rope would not start to share the load until the other two have stretched enough to cover the slack. With much stretchier rope, the same exact scenario has a much better result. The two loaded ropes have to stretch the same distance to remove the slack, but much less force is required to stretch them. The inequality in load sharing would thus be much less. Whew!
 

lumberjack

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Raising doesn't generate much heat, and it would be well suited.

The rope I use for lifting is essentially thick black widow covered with poly. The poly is only there to protect the core.
 

Al Smith

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Well,I don't have a clue about braided line being an old three strand type of guy myself .

However on large steel chokers I've often seen braided ones I thing it is mostly for flexability . It's a lot easier to bend 4 -5 or so half inch lines than one 1 inch . Often also on a becky or endless /loop choker they often just wrap multiple passes of 1/4" cable around and around and press on one sleeve to hold the ends on that one cable together .
 

NickfromWI

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If the 3 ropes work together evenly, I think you might get considerably higher than 3x the ABS of the original rope.

Sounds like a fun (expensive) experiment.

love
nick
 

lumberjack

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How'd that be, Nick?

ABS is an average, if you take 3 strands working evenly how do you increase each ropes efficency greater than 1?

Seems to me that 3x BW lines working perfectly together would equal 3x the ABS. Given sufficent tests, the bell curve on the ABS of each 3 strand test would closely resemble the curve on the 1 strand's ABS since the 3 strands is nothing more than 3 of the single strands.
 
T

TheTreeSpyder

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Even if you could get all 3 lines to bear evenly, you would have some loss do to angle and frictions within the new rope itself. There would be a raise in strength, but then reciprocal loss to elasticity, of which the braid itself (and slip of frictions) could help with.
 
M

moray

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Even if you could get all 3 lines to bear evenly, you would have some loss do to angle...
This has got to be right! The 3 individual ropes, now twisted or braided around each other, are no longer oriented in the direction of the load, and can't be as strong as they would be if they were. Twisted and braided constructions have all sorts of advantages (good handling, mainly) but parallel strands will always be the strongest configuration.

The off-angle load is another version of the clothesline problem: hang ten pounds from the middle of a clothesline and you have two legs of the line supporting the ten pounds. But the tension in each leg is always more than 5 pounds as long as the two legs are not parallel.
 
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