Whats this Knot

[moray]

C and D look like very secure knots, but neither can be tied in the bight and both look like they would be very hard to untie after load.

When the weather improves in a couple of days I intend to do a break test on B. It will probably be similar in strength to A, but I hope it crawls a lot less under load. Crawling, per se, doesn't indicate a knot is weak--the strongest loop I have tested to date is the dbl fisherman's, and it crawled far more than weaker knots like the bowline or alpine butterfly. (The crawling came from the coils tightening up, not the tail creeping in). My problem with crawling is my uninformed guess that crawling in a tight knot damages the rope. Whether or not there is anything to this, it will be interesting to see if B performs differently from A.

 

[TheTreeSpyder]

i think C with the more Round turn around the Standing could give better strength, and easier untie (stabler drawing up too?). Probably better if not tucked quite so soon, and completed that last Turn to exit next to Standing like a proper Square finish?

 

[SINGLE-JACK]

ABOK 1116, THE FIGURE-EIGHT NOOSE

 

[davej]

None of these, except scaffold (dbl fisherman's loop), can be tied in the bight. I wanted an easy-to-tie loop I could tie midline that would be easy to untie after a significant load. The scaffold is easy to tie midline, but it isn't so easy to untie.

Oh well, for a midline slip knot I think this one is just fine and is very quick to tie. The butterfly would be slower to tie. Another option might be the "single bowline on the bight" ABOK 1058.

 

[derwoodii]

This is a scan of a test report running 8 vs. running 8.
The rope was double braid 12mm poly rated to 3400kgf.
One knot popped at 28 Kn. I hope the numbers are a help my testing was not good on control and technique. Wish to do more.

Watching the ropes & knots tension up in slow mo though the plexiglass was fun n scary with sounds smells and forces building up just under your nose till,,,,,, Bang!

A couple of times you got a double pop when the rope heart or core let go 1st add bit more then pop the knot.

 

[moray]

This is a scan of a test report running 8 vs. running 8.
The rope was double braid 12mm poly rated to 3400kgf.
One knot popped at 28 Kn. I hope the numbers are a help my testing was not good on control and technique. Wish to do more.

Watching the ropes & knots tension up in slow mo though the plexiglass was fun n scary with sounds smells and forces building up just under your nose till,,,,,, Bang

Nice chart, derwoodii. Your knot broke at about 84% of nominal rope strength, very close to my result of about 82%.

It is a treat to watch a knot tested to failure. It is a whole realm most of us never get to see, and it leaves me appreciating knots and ropes more than before. It is also a vivid warning to keep the stress on your ropes and knots far below the breaking point.

 

[moray]

The weather improved and I had a chance to test version B of the figure 8 noose. I tied identical knots at each end of a short length of Yale Blaze. After hand tightening each knot to remove the slop in the figure 8, I tensioned the rig. The knots writhed and crawled as slack was removed everywhere, but the tail stayed put and did not appear to crawl into the knot. This was very different from derwoodii's version A of the knot, which ate a lot of the tail.

But B was a disappointment. It broke at only 4036 lbs. (compared to 4592), and it was completely impossible to untie the surviving knot. Since it is also significantly harder to tie, and harder to verify for correctness, I would have to say version A wins hands down.

While I had my rig set up I finished testing the last pair of aluminum rings I had on hand. I had 10 or 12 altogether, and each ring was individually subjected to 1200 lbs. tension in one direction only. None showed any sign of distress. This doesn't prove they are good, but it is a confidence booster.

When I first started testing the rings, it seemed like a good idea to test the whole false crotch thereby verifying two rings and the connecting rope all at one go. Most of mine were made with Samson Treemaster 3-strand rope. As soon as tension was applied, the rope started to unwind. Since the piston in my testing rig is free to rotate in the cylinder, the rope was free to unwind as much as it wanted. A 3-foot piece of rope made 2 or 3 full revolutions by the time I reached 500 lbs., so I stopped the test and resorted to testing the rings individually (I also cut the rings out of that particular FC). I think I will stop using 3-strand for this application.

 

[TheTreeSpyder]

"Now, i think in theory, it could be better for especially narrow stuff if the fig.8 came around the Standing with both parts/ loops of the fig8 (or even better as a Stevedore at this point) like for hunting snares for small game."

i think C would give greatest strength retension; maybe even waiting for last tuck 1 more half time around to exit next to Standing like in properly finishing of Square (or "Simple Simon"/Crossed Round Turn(8) version of the SheetBend); as system will compress up anyway to look just about like (uncrossed) Round Turn (as applied to this Noose). Particularly maid for slipped into the bight (as well as 'strength')?

Perhaps another inter-arresting diversion would be a test on Single, Double(Scaffold), Triple, maybe even 'Quad' etc. Nooses. Like to see, where the line of diminishing marginal 'returns' was for strength(starting from single up). And how that strength can be effected by Round Turn on mount/bolt/eye first, before Noose / shrinking eye formed.

i guess in the bumper tie, i was meaning like some version of Tensionless Hitch (to another anchor); whereby "strength" was ruled by the size of the mount(how it deforms Standing), rather than how eye deforms/leverages Standing etc. (even more).

 

[pdqdl]

A lot of thought went into this thread, and every time I looked at the permutations of a figure-8, I kept seeing similarities to how a timber hitch is tied.

Having made that connection...how are any of these superior to a well tied timber hitch?

 

[TheTreeSpyder]

They are alike in that a Timber with a Round Turn around the Standing is better. A fig.8 style Timber is better than a 'simple' Half Hitch style Timber.

They are different in that a Timber relies on convex mount at the nip positions where the 'twirls' of the 'loose splice' press against the mount; noose doesn't depend on mount for nip. Also, can be easier to tie these nooses because you come around and don't double back/everything is on 'top'. A noose can seize up easier, but then is more secure too; and take less line, especially on a large mount.

 

[moray]

I had a dead limb to take out of my big poplar tree today, so I used derwoodii's knot, version A, for my SRT anchor. Not really a good test as the load on the knot is very very low. (And for those who are going to jump on me for using the carabiner that way, the load on it is very very low as well.) The next time I have to pull something with a vehicle I will give the knot a real test.

 

[pdqdl]

Did I catch that right? You are TESTING a knot's reliability by putting it on a SRT line?

Please don't do that anymore. I like your test reports too much to advise this kind of test. Use it for a rigging knot that holds a chunk of wood, not yourself.

 

[blewgrass]

Did I catch that right? You are TESTING a knot's reliability by putting it on a SRT line?

Please don't do that anymore. I like your test reports too much to advise this kind of test. Use it for a rigging knot that holds a chunk of wood, not yourself.

:agree2:

 

[moray]

Thanks for the concern, guys, but come on!

There was like a 50-foot tail on that knot. Anyone ever hear of a knot swallowing 50 feet of tail? When I tested the knot to 4500 lbs. it ate only 2 or 3 inches of tail.

Could it break? Not from anything I could do to it without a hydraulic cylinder. The bottom line is that the worst knot in the world with a 50-foot tail would be perfectly safe for an SRT anchor. Optimum, maybe not, but safe, yes.

But quite seriously, I am thinking of making this my standard SRT anchor knot. I had been using a fig. 8 on a bight or an alpine butterfly, but for the last dozen times I used a simple overhand on a bight. All of them with a long tail. This new noose is easier to untie than any of the above and about equal to the overhand in ease of tying. And I like the cinching action of the noose--it removes some slop from the system that doesn't need any slop. If I ever have to tie it with a short tail, I will of course stopper it.

What's not to like?

 

[pdqdl]

Silly me, I presumed that you were TESTING the knot by loading it with your own weight. What kind of test is it where the knot cannot come undone? Besides, you didn't mention the long tail before.

For an SRT anchor point, you should consider using something that can be used as a friction device to lower you out of the tree with.

I don't do SRT yet, but I do hang my DRT from a line, so the effect is the same. Wrap the anchor line around the tree a few times, maybe adding a marl or two, and then it won't matter what knot you use. Once, I never tied it at all, I just went around the tree 7 times. (using my children as groundmen while playing in a tree)

(I got that concept here at AS from D Mc. So far, I have liked it better than any other approach to getting into a tree.)

 

[moray]

Silly me, I presumed that you were TESTING the knot ...

Ah, now I see the problem. My bad. It was my careless use of the word testing, which I meant in the sense of "test drive," not "experimental test."

I would like, as you suggest, to put a Porty or some other device at the bottom so someone could lower me if needed, but the great bulk of the time I am working the tree alone and it would be pretty useless. I have lowered someone else on a few occasions just for the practice, which always strikes me as pretty cool.

 

[blewgrass]

the tail length was my biggest concern.

 

[pdqdl]

Ahhh...I begin to understand.

When you began referring to that slip-eight as a mid-line knot, I did not understand why you would refer to it as such, nor why you would be calling it that when the original use was for lowering logs. Since you seem to be using it as an anchor tie for your carabiner at the base of your SRT, I can see the need for testing it as a mid-line knot. Just out of curiosity, why do you have such a long tail on your SRT anchor, especially since you do not seem to be setting yourself up to be lowered from it?

Give that man-harness knot a try. It's even easier to untie than your slip-eight.

 

[moray]

...Just out of curiosity, why do you have such a long tail on your SRT anchor, especially since you do not seem to be setting yourself up to be lowered from it?

Sometimes I have my saw with me and I want to drop some limbs. If the rope I climb barely reaches the ground it is easy to pull it up to get it out of the way of falling wood. All the excess rope is on the other side of the tree where the anchor is. The excess is the long tail of my knot. The other reason is to spread out the wear on the rope by tying the anchor knot in many different places but only rarely at the end of the rope.

 

[pdqdl]

ABOK 1116, THE FIGURE-EIGHT NOOSE

Neat knot, but there is a slight problem: when the slip is pulled out, an overhand knot remains to be untied. Conversely, it is not practical to use this as a midline knot.