Quote:
Originally Posted by Brion Toss
Hello again,
Strength vs. security. Bury length vs Diamond weakness. Ring Hitched vs. plain eye. Steadily increasing loads vs what happens in the World. All these factors and more are what went into the establishment of splicing protocols. Sorting them all out and accounting for them in a test can be tricky. Taking another look at the second configuration in your previous post, it appears that bury length is not the primary determinant of strength. By making an eye at the fixed end instead of a Diamond Knot, you open up some interesting possibilities. the Brummel at the point where the bury for the small eye exits contributes to the strength of that end.
A locked Brummel where the Ring Hitch ends go together, or maybe even a multiple version, would provide significant strength to the other end, perhaps to the point where the bury is simply there to dispose of the ends, not to provide strength or security. And the Ring Hitch takes further load off that Brummel. Did you lock-Brummel the Ring Hitch loop? It appears that this structure is stronger than the conventional soft shackle, as that broke first. Had you "set" the Diamond in that before the test?
Fair leads,
Brion Toss
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Hi Brion,
Thanks for the reply. I will try and answer your questions regarding what I did.
I made versions both with a brummel in the ring and with just the bury and lock stitch. The brummel was difficult as the only way I could figure out how to tie it was with the un-breaid cross over and re-braid I think you reference as from Book 5. In previous tests, I have tested the lock stitch and brummel versions of eye splices and find them both stronger than the line with actually more stability from the lock stitch so that is my preference and what I tested. That said, if there is a way to make a brummel in a loop without the re-braid I would like to know how to make it.
In terms of the diamond knot stopper loop, I lock the diamond knot by putting the tails in a vice and pulling on the loop with a lever so there is a large force. After it is locked, it is hard like a marble.
I think the strength of this shackle should be half the strength of a normal soft shackle as the diamond knot has twice the load that it has in the normal soft shackle. This can be addressed some by using the next size up line to make the stopper loop.
My concern now with this shackle is the constriction force on the sheet eye splices. The Ring Hitch really clamps down hard on the line and I am afraid it would tend to cut them under load. My thought is that it is the action of the ring hitch that gives the shackle its strength with the short bury but it comes with a price. I would love to hear your thoughts on this aspect of the shackle.
My concern as led me to work on variation #4, a double soft shackle and will post when that is tested although I need to deal with the broken hydraulic jack.
Allen