Whats this Knot

[moray]

Results

The tails of the overhand knots never stopped crawling into the knots, but one of the knots won the race and came apart at 3934 lbs (The nominal strength of Blaze is 5600 lbs). The survivor was so tight I had to cut it off the shackle.

The tails of the running 8's did some crawling initially but then settled down. Finally one of the knots broke at 4592 lbs. The survivor, contrary to derwoodii's experience, was quite easy to take apart. Inspection of the survivor showed the sharp nip had produced a striking dent in the tail, reducing its diameter by almost half. There were broken surface fibers on the inner surface of the nip predicting where the failure would occur.

When a standard bowline was tested in this same fashion, it broke at 4406 lbs. A figure 8 on a bight, an overhand on a bight, and an alpine butterfly all peformed about like the bowline. Only the double fisherman's loop stood out from the others, breaking at 5144 lbs.

For a midline loop this knot seems like a good one: it is strong, it is extremely easy to tie, and it is easy to untie after being loaded to near its breaking point (in Blaze, at least).

 

[TheTreeSpyder]

Wow, thanx for the numbers; i was thinking of you when reading all this...

On the subject of truck pull hitches; might i be so bold as to suggest not deforming the Standing Part (any more than the usually small mounts do)with a bend from the eyes and just taking a Turn or 2(Round Turn ) on the primary contact/mount, then leading to a 'secondary', that is the actual hitch point. The 'primary' should be the larger, smoother diameter of the 2, that takes most of the force, and should thereby be most inline and/or structured to frame. The path to the secondary would be along tube/bumper inline, so less important if that point is inline with frame.

Ball Hitches are common, but have a few quirks. They usually are not inline with frame beam, but; are larger for a primary than a common tow hook. Also, the ball's tapering (from the orb of the ball on top, and from bottom on reinforced tapering mount models), can take a 'friendly hitch' and make it more deformed and also make it lock on by the taper allowing the forces to compress the knot 'mass' making release very difficult. A lot of times; i'd prefer a simple Slipped Half Hitch to get the line off easier from this small, tapered mount. Pulling the end of the slip can give a 2x potential at the right time to release; and a length of run to that point...

 

[blewgrass]

For a midline loop this knot seems like a good one: it is strong, it is extremely easy to tie, and it is easy to untie after being loaded to near its breaking point

This is the only time that I've used this knot, as a midline tie-in for a trucker's hitch. The forces on the knot are different when it is used this way though because rather than the tails hanging idly they become the rest of the rig and end up putting more stress on the knot.

I was hoping Moray would jump into this thread!

 

[outofmytree]

experiments can get people killed.

Yes that is always a possibility hence the need to test any new rig as exhaustively as possible prior to use. On that note thanks Moray. I love your work. Ditto for Treespyder.

I am always "tinkering" with my climbing and hauling gear looking for extra efficiency or safety or strength. At the same time, I am happy to steal anybody elses good ideas and use them too. Thats what this forum is all about IMO. Sharing what we know.

 

[pdqdl]

I seem to have missed something here.

Moray: When you tell us that you tied this as a mid-line knot, does that mean that you were loading BOTH legs that exit the knot, as well as the loop? If so, of course that will be a stable knot.

Unless I am mistaken, the original post was for use as an anchor hitch to a tree or falling log.

You might consider looking up my threads on the manharness knot. It is my favorite, having learned it in Boy Scouts almost 40 years ago. For use as a mid-line knot, it is vastly superior to this sliding figure 8. It unties easily, it ties very fast (once you learn it), and it does not choke down onto whatever is tied onto it. Strength...I have no idea. Probably just average.

 

[moray]

No, I was only loading one leg.

I did not know your pioneer knot--looks a lot like the butterfly, but simpler. Very easy to tie.

Spydie alluded to a very good point about these loop knots: the forces on the knot will tend to be greater for a fixed loop than a slip knot. In the latter case the first serious nip in the knot comes after the rope has passed around the anchor. Friction against the anchor eats up a lot of the rope's tension as load increases and reduces the load on the first nip of the knot. Adding another wrap around the anchor, if you can, is still better.

On the rare occasions when I need a knotted loop to hold a significant load I unfortunately have very few arrows in my quiver. Since I am not on the clock, my first aim is to be nice to my rope. This sliding 8 or running 8 seems like a pretty good choice for many situations.

 

[Rftreeman]

people keep trying to fix what ain't broke and someone's going to end up broke and I don't mean the money broke......

just my opinion...

 

[pdqdl]

For what it is worth, here is my final thoughts on this knot:

A figure-8 is a reliable and strong knot, but this application is a clear departure from previously reliable uses. It looks very reliable once set and loaded (as in Moray's wonderful closeup pics) but it also will be prone to falling apart when quite loose and tied with a short tail (as in sliding up a tree to secure a remote branch).

It is also completely untested while holding a large diameter log that may be falling or tumbling before it is loaded, so I decline to think that it may be a good knot for that application. Since there are other rigging knots/hitches that will serve this purpose very reliably, and just as easily, I cannot think of any good reason to use this knot, except familiarity and lack of knowledge for a better knot.

As always, great report & analysis Moray! I am pleased to see you take up the gauntlet for this new knot, even if I don't plan on using it.

 

[TheTreeSpyder]

Once again, this is just a simple Noose, with an extra twist in the Overhand Knot. Thus, instead of an Overhand to self to form shrinking eye/ noose; it presents and advancemeant of a fig.8 to self to form eye.

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.




Now, a perhaps interesting experimeant (slightly off topic) would be for a Running Bowline, that gave a Round Turn with it's eye around the Standing (to fortify this destabilized region more like a dbl. Noose/ Scaffold / Dbl.Fisherman's). Also, if that eye was longer even, to place the SheetBend of the Bowline around the log, and only the 2 legs of the eye taking brunt of impacts etc. on that side. Furthermore the trapping of the Bowline against the log, would keep it fairer; like a Square Knot is kept more surely by trapping against a parcel etc. that it wraps around (Square to be used as knot, not Hitch).

 

[Plasmech]

For 25 years I have used this. Unsure rope terms, call it a running hitch and non locking so good to secure limbs for lowering or say pulling over trunks. I hope to share and have peer reviewed as a simple quick easy knot for tree timber handling. I could whip the rope around a limb and tie the knot with one hand so it was high use when I was climbing for a living. Its never failed me and always easy to unlock even after heavy tension. I'll try to explain how its tied but pictures are always better. The only trick hard to show or explain is the turn/twist a loop that the line end passed though.
Why I ask? it was never shown to me, I just muffed it one day and it worked but not seen it else where.

Knot sure, but I know it's knot one I'll ever use

 

[davej]

The tails of the running 8's did some crawling initially but then settled down. Finally one of the knots broke at 4592 lbs. The survivor, contrary to derwoodii's experience, was quite easy to take apart.

Compared to running bowline, buntline, taut-line, scaffold?

There are many lesser known knots that could be considered if you want to wander off the known path. Consider the "sash weight" knot ABOK 199.

http://www.amazon.com/reader/038504...LQpbW7ccwZZQ==&query=buntline&page=315#reader

 

[treeclimber101]

what happens if it tightens up and you can't untied it? I will always use the bowline, been using it for 21 years and put some heavy loads on it and never had it once get to tight to untie.

The best all around knot there is ..

 

[derwoodii]

All-right what interesting day. I went to a rope manufacturer and they let me test the knot on a $70K machine.
Results again finds the "running 8" beat a bowline.
The testing was not strong on the science side, no lab coats or many multiple repeats of task. However the knot held up well and after all rope failures still unlocked easy.
10 mm 12 mm and 22mm poly double used and with one test put the running 8 up against its self till one end failed.

I am very please to see much debate about this. I was anxious my goofy knot could be an embarrassment. Now I am anxious about any harm it could bring.
Its new and needs more evaluation. I hope to return to test machine with more time & get graphical data
Those who want to trial. 1st do no harm. 2nd if you want to test let AS know results & any hint of structure failure.
Thanks Moray your work & running 8 seems an apt name and Treespyder your clearly wise in ropes.

 

[Rftreeman]

I'd like to see a test on a large diameter log and shock load it.

When you say "bowline" are you referring o the running bowline or stationary.

 

[blewgrass]

running 8 seems an apt name

except that it's already called a figure eight slip knot. see section 4-25 here for a precedent.

edit: pdqdl- at the above link there is also a knot that looks alot like the manharness or pioneer knot that you have described in the past. They call it a wireman's knot and it's at section 4-16.

 

[Rftreeman]

except that it's already called a figure eight slip knot. see section 4-25 here for a precedent.

edit: pdqdl- at the above link there is also a knot that looks alot like the manharness or pioneer knot that you have described in the past. They call it a wireman's knot and it's at section 4-16.

opcorn:

 

[pdqdl]

....
edit: pdqdl- at the above link there is also a knot that looks alot like the manharness or pioneer knot that you have described in the past. They call it a wireman's knot and it's at section 4-16.

Nope. Not my knot! That looks like an apline butterfly, although they don't show a final picture, and the description is a bit difficult to follow.

 

[derwoodii]

Great work Bluey g you've solved my mystery knot.
For years I searched to find any look alike in knot books, no luck.
Unconvinced it was a goofy creation I put it out to AS which predictably gave it great feed back + & - and now a name,
knot quest over I can rest easy.
All who want to test or use (Primum non nocere) care please. Yes its simple, quick and easy to un-load but that could be a trap, one miss turn and you loose the lot. I think proven trade knots have built redundancy in design, a dropped turn can be survived.
My 25 years experience it never failed, but I truly never fully trusted it, found myself flipping that extra hitch in the tail when a load was live or die.

RFtree it was just the a bow line not a running one.

 

[TheTreeSpyder]

Bravo! and Thanks for a great link!

i've been thinking it would make an interesting slip; especially midline. Not like a slip knot as outlined (which i more call a noose) but rather in the 'slip'/ quick release sense.

Great info on testing to confirm Moray etc. i expect a Double Noose /Scaffold to do better; if just simple Turn around load, but not if a Round Turn around load. i think Running Bowline with a Round Turn around Standing would be similar (if no Round Turn around load preceding the more 'firming' greater line tension in eye constricting around Standing).

But, i also think have to be very careful in exact setups (which the testers probably due, but thinking about those in field). This could especially be true (for all the shrinking eye / nooses and Running Bowline, not the fixed eye Bowline that deforms standing by Half Hitch formed in Standing, not by eye bending Standing) for how intensely the eye leverages the single support of the Standing. If setup starts with eye cocked to the side and on loading is allowed to cinch up tighter; it is deforming the Standing more (to give higher leveraged multiplier x the tension needed to 'support' the load) etc.

 

[moray]

Compared to running bowline, buntline, taut-line, scaffold?

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.

There are many lesser known knots that could be considered if you want to wander off the known path. Consider the "sash weight" knot ABOK 199.

I looked this up and played with it for awhile. A nice knot. Even when looped over a carabiner it is easy to flip one of the wrapping coils over the other to get the dbl fisherman's loop. I think this one would be hard to untie after a big load.

While playing with derwoodii's knot, I created 3 more variations. In the original version (A, below), the tail emerges from one eye of the fig. 8 and both legs of the loop emerge from the other. The arrow in all the photos indicates the most heavily loaded nip in the knot.

In the first variation of the knot, B, things look very different. The tail and standing part emerge together from one of the eyes, and the other eye contains the other leg of the loop. I like the looks of this better than the original, A, but it is harder to tie. Because the tail and standing part emerge on the same side of the eye, it should be easy to loosen the knot after a load. And it can be tied in the bight like A. Interestingly, you can put a carabiner in the loop and freely convert A into B and vice versa without any access to the rope end!