Soft Halyard or Line Shackle

[Anton B]

Oh, also, please tell me more about Watthew Otto's work.

Did he make something similar in function to what I am trying to do, only with locked brummels, or are you saying that he was testing locked burmmels in a similar manner?

Anton

PS Maybe Opening eye? Openable eye? Was that my third eye? Was it blind?

PPS I guess allene is just calling it a shackle, but that is what I was using as the name for a soft shackle, the whole assembly. Hm.

[allene]

I would encourage you to use either a brummel or stitch, not a whipping.

If I understand what you are doing, I do not think the multiple diamond knots will hurt the strength of the assembly. The weak point will be the joint at the diamond knot and the eye of the line shackle.

These things typically break at the knot. You should have a strength of about 1/2 line strength but if your setup is doubled as Brion says, then getting about line strength would be right. It should not break at the splice so that is a huge mystery. You should have close to line strength there. Perhaps I am not understanding the setup.

[Brion Toss]

Hello again,
First, a picture of Otto's adjustable sling. Kind of a reverse version of yours, with no adjustable eye needed. We don't have confirmed break numbers for this one, either. Your configuration shows promise, but your enthusiasm and creativity is somewhat offset, at the moment, by a lot of variables and approximations; we just can't get meaningful numbers based on the setup you show. For that matter, we can't even comprehend what that setup is. I urge you to make friends with someone who can do some formal breaks.
Fair leads,
Brion Toss

[allene]

I looked at the flicker pictures again and my guess is that you are pulling on line that goes around one of your pins and then breaks after the pin. My thought is that you are getting friction at that pin so not all the force on the line goes to the DUT. But I can't really know for sure because the setup is not clear from the pictures.

Allen

[Anton B]

I attached the one end in several different ways, only in order to get the length right, not having taken any care in the length of the connecting line. None of which affected how they broke.

They broke at the end of the bury in the spliced line for the most part. The eye and the knot breaking were anomalies.

I will re-do the test with more care, and better pictures and I hope I will confirm that the breaking point will consistently be the bury and not the knot, and not the eye, but we shall see.

I am pretty sure I have already proved that it will break at close to line strength, in the application the tension is probably less than 20% of breaking strength even at peak loads, I just wanted to make sure that there wouldn't be some freak situation at the diamond knot that would give me less than 50% strength.

What I am doing is exactly like Allen's Soft Halyard, only with more diamond knots. In 9 test pulls, it never broke at the diamond knot closest to the loop, only at the last knot, the one the eye was pulling on, and seemed to break at about 80% of line strength.

I'm pretty happy with that.

[Anton B]

Brion,

how does Otto's sling work? Do you hook the different openings onto something? Is he using the diamond knot like I am, like the Soft Halyard?

Also, I do not seem to be allowed to post attachments, thus the Flickr {ics. Is there a way to do it that I am missing?

Thanks,

Anton

[allene]

First, to insert an image, you click on the insert image icon and give a web address where the picture is. It has to be a web address ending in jpg so I don't think you can use a flicker image. Google plus images work if you open them in a new tab and then use that url.

The issue Brion and I have with your reported results is that they are so far from our experience. Roughly a soft shackle is about line strength. Well, it may be higher than that and probably is but not double. Since the load is shared with two sides of the loop, that means that the strength of each end is somewhat above 1/2 of line strength. But you are seeing something close to line strength and breaking the line to prove it. That would mean that the string of diamond knots that are beyond the knot under load are increasing the strength considerably. Possible and if true something we want to understand as it may have implications for making soft shackles stronger. So we want to see pictures of your setup to see if anything pops out. You may have discovered something significant.