New and improved double soft shackle

[Dan Lehman]

Originally Posted by allene

Dan,
I am not completely following what you are saying but let me respond to what I think you are getting at. Clearly this is not a fisherman's knot but half of one with another knot. I think you may be pointing out that the combination has a name but I am not completely sure what you are saying.

Yes, the "half" is a strangle --and one can attach "knot"/"binder" or "hitch" depending how much you want to advance some nomenclature : the knot is typically promoted for being tied around something to bind it (such as for whipping, where a multiple strangle can work quite well, in slick material!), but also tied around another strand as a securing of an end --lightly or heavily loaded (the "Barrel knot" is one name at used to denote a noose employing this).

A nice aspect of using "strangle" (which is a double overhand ) is that the modfiers "double", "triple", ... will match the visible "overwraps" that give it such security.
(Whereas, as I remarked, a "dbl.fish" has 1 overwrap, the triple, 2, and so on --mismatching.)
(So, for rockclimbers, who often use dbl./trpl., going with "Grapevine (bend)" which begins with strangle (single) components, one gets the nominal matching.)

As far as pre-tying and using a larkshead to attach the sheets, that was what my previous designs were. You can look up my older posts. Those designs had three shortcomings that this design solves. First is that they constrict the sheets which is a strength concern for the sheets. Second is that it is more difficult to attach than this design, although that is minor.

You seem to mistake what I'm recommending : simply have a single doubled-line structure in which you have at the fold-back point your "Brummel"ish small *eye*, and the two ends joined by the diamond knot or other stopper (Ashley's, e.g. ?) ; and so the use entails first loosening & separating the join of eye around stoppered end, and then reeving the eye through the clew and re-attaching it.
Which puts the nature of the connector the same as you have above --a twin line w/stopper being connected to the eye. At the clew end (well, this joint would be able to shift position, hitching to nothing), the twin line simply loops through it, knotless.

You have 2 twin-strands spanning the connection, with a turn around the clew and the sheets --no more/less compression than above (identical), and more material throughout than any of your designes (double the doubled strands).

But it turns out that this design is stronger by about 50%. With the larkshead the failure is at the larkshead and at a force about 2/3 the force that this design yields. With a smaller stopper loop, the failure would be at that end but with a larger size stopper, the failure moves to the larkshead.

But in your earlier design you have full load on the doubled line which forms the larkshead (oddly, in British climbing circles, this has become "larksfoot"!?), in contrast to having the doubled line essentially being stopper-connected to form a circle of twinned line --halving the load on any twin-lines part.


Now, I referred to my suggested structure as "loose", by which I mean that it isn't *hitched* in place; its only security is in the well-fit small eye choking the stoppered end, and I think that that's adequate (for loose jostling around ; certainly for full tension). If this is a concern, one can I think arrange for some more knotted structure to include a hitching of your connector to the sheets (this seems to be desired by you), and then one will again reeve the eye-end through the clew and bring it back to the sheets-end for ensnaring the stopper (which, e.g., could be positioned as the crossing arc of the larkshead --just to show an idea), perhaps preferably after doing some knotting or just turning through the sheets (thereby offloading some force before choking the stopper).

Working in such slick material as HMPE, though, takes some care in choosing a hitch (perhaps a *doubled* larkshead --i.e., where the "arcing" part is a full round turn, to try to give some frictional security-- ; sometimes called "bull hitch" (stronger than "cow")).
But, then, your systems --all-- seem to involve a pre-tied larkshead + stopper second piece of line on the clew, which I'd think is vulnerable to loosening and falling off! !?

As for constricting the sheets, I should think that their mere turning around the thinner twin strands of the HMPE connector would be as much damaging --maybe only showing on one spot vs more generally, but ... "weakest link", still. .:. minor difference, overall.

Cheers,
--dl*
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