“Twisted” & “Reinforced Super Strength” Soft Shackles

[Seaworthy Lass]

Originally Posted by StuM

There is no girth hitch involved in that soft shackle. It's a stopper at one one end and a running eye (ABOK #1699) at the other end of a single line.

I couldn’t tell precisely from the image, but it seems the eye is formed by doubling line which is then covered exposing only the eye, which would in essence make it a girth hitch wouldn’t it?

[Brocky II]

Originally Posted by StuM

There is no girth hitch involved in that soft shackle. It's a stopper at one one end and a running eye (ABOK #1699) at the other end of a single line.

More like 1700, it is just a stopper and loop, but the end of the loop is formed into a girth hitch to replace the usual noose. Most of the length of the Gin is covered in a tubular webbing, but two sections of rope go to the stopper. The hastily made rope example above is what is basically going on with more safety features added to the Gin SS.
Loading the shackle would tighten the girth hitch making it harder to be forced over the stopper, and I’m guessing it would be stronger than the noose and doesn’t require something as robust as the Buttonhole or Diamond. They only use an overhand that’s complicated for some reason before burying the tails.

[Seaworthy Lass]

Originally Posted by Breaking Waves

Lass,

It's too bad you did not get to know and work with Brion. You and he would have gotten along famously. He was interested in design ideas - less personally interested in the quantitative/testing side of things. But he did appreciate when we worked together how a testing/breaking feedback loop allowed him to make more targeted design improvements faster.

His death is a great loss. I corresponded with him several times via email after receiving The Complete Rigger’s Apprentice as a gift from a friend, but never met him. Apart from the breadth of his knowledge and his expertise, Brion’s book showed a huge love for all things related to rope work.

I would have loved the opportunity to bounce some ideas around. Apart from the pleasure of doing this, even whacky notions occasionally spark something that can turn out to be useful.

I, too, have found your load testing data to be invaluable. Advances can be made at a dramatically faster pace with this information.

[StuM]

Originally Posted by Brocky II

More like 1700, it is just a stopper and loop, but the end of the loop is formed into a girth hitch to replace the usual noose. Most of the length of the Gin is covered in a tubular webbing, but two sections of rope go to the stopper. The hastily made rope example above is what is basically going on with more safety features added to the Gin SS.
Loading the shackle would tighten the girth hitch making it harder to be forced over the stopper, and I’m guessing it would be stronger than the noose and doesn’t require something as robust as the Buttonhole or Diamond. They only use an overhand that’s complicated for some reason before burying the tails.

Ah yes, I see. I didn't realise that it was a covered loop, it wasn't at all clear from the images

[Breaking Waves]

btw . . . I was just trawling thru some of my old test data looking for two sets of results, and it looks like had I had some trouble with both getting what I considered accurate and repeatable enough data.

I was looking for bury lengths for the button soft shackles, and I see that I concluded that 16 diameters was certainly good, and that 10 diameters might be good but (because of tapering variation) I had trouble getting it all apples to apples repeatable at 10 and 8 diameters. 16 diameters seems a workable solution so I just did not work very hard trying to get the procedure more repeatable down at the short bury lengths.

And for the (typical line diameter) 'insert in the eye' reinforced shackles (which were all made by Brion) - the ones I tested were above the strength I felt comfortable breaking on my rig - I was bending both high tensile bolts holding it together and pulling shackles. I had a way to double the strength of the puller (with a tackle) but it created additional significant variability in my results. I could make some 'educated guesses based on some quite small diameter samples (which I made) I did break, but at the time I thought it sufficient just to say 'yea they are meaningful stronger'.

[s/v Jedi]

It’s so dead simple to insert a tapered length of 1/8” or 3/32” Dyneema into the loop.... what could be a negative for doing so?

[Breaking Waves]

Originally Posted by s/v Jedi

It’s so dead simple to insert a tapered length of 1/8” or 3/32” Dyneema into the loop.... what could be a negative for doing so?

It made the loop a bit stiffer/harder to work . . and it bulks up the loop size so that it may no longer fit thru chain links it used to fit. . . . and it means 'strength' is growing faster than chafe/wear resistance (which might or might not cause a problem)

Those may only be problems in certain applications. And if they are not issues, no problem (so long as the insert is correctly tapered at both ends, which I'm sure you and lass would do).

The feeling when we previously explored this was just going with a bigger line size if you wanted more strength (which also then gives you more wear and chafe and uv resistance). I guess I am sort of in that camp because I have not used the insert approach myself. But there is nothing at all wrong with the concept per say.

[s/v Jedi]

Playing with this, trying to make it simpler by braiding the whole thing and tying a stopper knot in the braided end. Best I found is an unfinished buntline hitch, leaving out the last step. This is a knot that comes together in the braided rope really nice, which is fast and eliminates the marking of unbraided part for a knot etc.

This thing feels like something I know but can’t put my finger on it now... isn’t there something similar made with twisted wire?

[Seaworthy Lass]

Originally Posted by Breaking Waves

btw . . . I was just trawling thru some of my old test data looking for two sets of results, and it looks like had I had some trouble with both getting what I considered accurate and repeatable enough data.

I was looking for bury lengths for the button soft shackles, and I see that I concluded that 16 diameters was certainly good, and that 10 diameters might be good but (because of tapering variation) I had trouble getting it all apples to apples repeatable at 10 and 8 diameters. 16 diameters seems a workable solution so I just did not work very hard trying to get the procedure more repeatable down at the short bury lengths.

And for the (typical line diameter) 'insert in the eye' reinforced shackles (which were all made by Brion) - the ones I tested were above the strength I felt comfortable breaking on my rig - I was bending both high tensile bolts holding it together and pulling shackles. I had a way to double the strength of the puller (with a tackle) but it created additional significant variability in my results. I could make some 'educated guesses based on some quite small diameter samples (which I made) I did break, but at the time I thought it sufficient just to say 'yea they are meaningful stronger'.

Thanks for the info. Was 16 x diameter were the longest inserts tried? My 40 x diameter (20 of which was taper) was clearly overkill then. Did you note where the shackle actually broke when the eye was reinforced? Was it the base of the stopper?

I know that it takes a phenomenal amount of time making and testing sufficient numbers of samples to achieve a statistically significant result when comparing numerous variables (in this case length of insert, diameter of insert & type of taper). “Meaningfully stronger” will have to suffice .

Originally Posted by Breaking Waves

It made the loop a bit stiffer/harder to work . . and it bulks up the loop size so that it may no longer fit thru chain links it used to fit. . . . and it means 'strength' is growing faster than chafe/wear resistance (which might or might not cause a problem)

Those may only be problems in certain applications. And if they are not issues, no problem (so long as the insert is correctly tapered at both ends, which I'm sure you and lass would do).

The feeling when we previously explored this was just going with a bigger line size if you wanted more strength (which also then gives you more wear and chafe and uv resistance). I guess I am sort of in that camp because I have not used the insert approach myself. But there is nothing at all wrong with the concept per say.

I remember when I first started making “high strength” soft shackles with the Brion Toss Button, there was a huge amount of resistance. Almost universally the comment was “why bother, just bump up line diameter to increase strength and UV and chafe resistance”. All valid points, but handling and cost per strength are considerations too. Also just the satisfaction of making something better .

I found the stiffness of the reinforced eye made the eye feel satisfyingly good. It look less than a second to overcome the added friction and close it and when it closed it felt solid and secure. Also it was easier to open as the stiffer portion could be pushed more easily. I liked the feel of it very much, irrespective of whether or not strength increased.

[Seaworthy Lass]

Originally Posted by s/v Jedi

Playing with this, trying to make it simpler by braiding the whole thing and tying a stopper knot in the braided end. Best I found is an unfinished buntline hitch, leaving out the last step. This is a knot that comes together in the braided rope really nice, which is fast and eliminates the marking of unbraided part for a knot etc.

Neat idea!
I had a go using the best “easy” stopper I found when I was playing before: the Ashley stopper. It has a lovely wide base and is quick to tie. I think Stu M uses this as his preferred stopper generally, so I knew it must have merit .

You are right, it is quicker not taping anything (I just made sure I did not let go of the ends while I was tying it, otherwise they unravelled). The knot needed much less dressing than tying it with loose ends as well. As an added bonus, the swirls in the knot were very attractive.

If making it in lightweight paracord for hanging things inside I think an Ashley stopper with your idea of tying it with the twisted portion is the best option so far:

[Seaworthy Lass]

Originally Posted by s/v Jedi

This thing feels like something I know but can’t put my finger on it now... isn’t there something similar made with twisted wire?

Your image reminds me of barbed wire. I climbed over and under lots of country fences as a kid and still bear scars .

[Brocky II]

For the reinforced eyes it seems like the buries should be the more than half of the usual amount for an eye splice. Wouldn’t there be a full load for both “halves” of the eye and their respective tail. They would only share the load if they are anchored to the cord, they may slip before the finger trap action could hold them.
Next, say the eye buries do hold, the eye is now a like a class one double braid where cover and core are approximately the same break strength. Are they going to be able to be balanced to work together to break at around the same time?
And lastly, the increase in diameter from the insert would weaken the outer “cover” because of the expansion, wonder how much added break strength there would be.

[Breaking Waves]

Originally Posted by Brocky II

wonder how much added break strength there would be.

I believe I am the only one* to have broken a bunch of these with a load cell attached.

I can tell you they ARE meaningful stronger.

I am somewhat reluctant to quote a specific number because there are a ton of factors (just for example like how thick the insert is) and also my sample sizes for any specific design variation were not very large to give a tight estimate. But just to give a rough idea - the gain vs the regular stronger button design is about half the gain from diamond to the stronger button.


*Note: NER also broke a box of them, but they somehow screwed it up and got super weird results that Brion and I agreed should just be discarded. Brion was going to send them a second box to do properly but never got around to it.

[Seaworthy Lass]

Originally Posted by Breaking Waves

I believe I am the only one* to have broken a bunch of these with a load cell attached.

I can tell you they ARE meaningful stronger.

I am somewhat reluctant to quote a specific number because there are a ton of factors (just for example like how thick the insert is) and also my sample sizes for any specific design variation were not very large to give a tight estimate. But just to give a rough idea - the gain vs the regular stronger button design is about half the gain from diamond to the stronger button.

.......

That would give roughly about 270% of line strength, which is impressive. The modification is quick and easy to do.

Strength issues aside, from the small amount of handling I have done, I very much like the feel of these. The other user on board is suitably impressed as well. The eye just feels very snug and secure. We will try these over the next few months and see if these early impressions persist.

[s/v Jedi]

Originally Posted by Seaworthy Lass

That would give roughly about 270% of line strength, which is impressive. The modification is quick and easy to do.

Strength issues aside, from the small amount of handling I have done, I very much like the feel of these. The other user on board is suitably impressed as well. The eye just feels very snug and secure. We will try these over the next few months and see if these early impressions persist.

What size Dyneema did you use for shackle and for the insert? I often use 1/4” Amsteel Blue and am considering trying it with a 3/32” Dyneema insert...