Loop Shackles/Connectors aka The Nacrabiner

[UCMWINGS]

how would you attach the bead?you could larkshead it onto a continuous loop.you could biuld the bead into a continuous loop....there is possibilities. if i had some large beads i would tie...

Maybe take both ends through the bead then back around the bead, through the cord then bury.

[Schneiderlein]

Very good question. It would definitely hold...how much weight is the big question. Sounds like a good project for Schneiderlein if he can get some more time on the machine.

These would be much easier to make, and probably easier to use.

I made one with the larkshead. Definitely easier to make, but not by much. I think it is more difficult to use and has to be made longer than the spliced version. Will probably add 0.5g Biggest advantage I see is that you can make them in the field without a splicing needle. If there is interest and people want to use them this way, I'd be happy to test one like that next time I go to the place, which will likely not be before May.

[Albert Skye]

What would be the effect of not creating an adjustable loop with a bury or a passthrough and making the loop by larksheading the end opposite the diamond knot around the line before the knot.

Good call. Kite surfers use that method for attaching control lines to the "pigtails" of the kite (short loops with a series of overhand stopper knots providing several positions for some adjustment of pitch).

It may not seem as elegant as the pass-through loop but I think it should actually be stronger and more secure. Don't take my word for it though. Test!

[lonetracker]

Maybe take both ends through the bead then back around the bead, through the cord then bury.

i can picture it.it would work i think.could use a seperate bead as a stopper.
also could double as jewelry then

What would be the effect of not creating an adjustable loop with a bury or a passthrough and making the loop by larksheading the end opposite the diamond knot around the line before the knot.

good idea


i like the flurry of ideas.brainstorming is fun.
i am allmost out of amsteel,have more then enough of these tied.no two are alike though

[Just Jeff]

That's b/c HF is a forum of innovators...

[Schneiderlein]

It may not seem as elegant as the pass-through loop but I think it should actually be stronger and more secure. Don't take my word for it though. Test!

I think they may be more secure as far as the knot slipping through, but I have a hard time believing they will be stronger. After playing with this method for a while, I see a potential for these to have significantly lower strength. The spliced loop allows both legs of the loop to be loaded, even if the legs are very unbalanced. The larkshead method, in my opinion, has the potential to only load one leg of the loop. After tying a larkshead knot that left the two legs unbalanced, I was unable to get both legs loaded using my body weight. I think these could easily fail at less than half the load of the "classic nacrabiner". Given the added inconvenience of undoing the larkshead (which takes a while after you loaded it), I see the only advantage of this method that you can make them quickly and without splicing tools. But Amsteel is so easy to splice, you can make a real nacrabiner with nothing but a ball point pen, or you can make a splicing tool from a piece of paper, or any number of other objects you are likely to have with you.

Until somebody tests these for strength, I would recommend to stick with one of the proven methods, which showed a breaking load of 87.5% of the rope strength.

[Albert Skye]

The spliced loop allows both legs of the loop to be loaded, even if the legs are very unbalanced. The larkshead method, in my opinion, has the potential to only load one leg of the loop.

Another good call. I'm curious to see test results though (for both unbalanced and balanced girth hitches).

Generally, I think these shackles ought be built of thick stuff anyway (hence, much stronger than necessary), to mitigate abrasion and distribute forces.

[WarmSoda]

I finally found some use for my suspension rope that came with my Hennessy. The narcabiners are big, but they work well. Obviously I'm not using a splice. Thanks everyone for the inspiration.

[p moore]

Just a tip for you guys. Tie up a few extra of these and use them for zipper pulls. That way they are always handy for other uese. I have made these out of paracord, but will be making up my Nacrabiners tonight.

Good job Nacra!

Paul

[Hayden]

I did not mention this, but I also tested a UCR, and that test did not ease my worries. The UCR was 7/64" Amsteel blue with a 12" bury. Without tension on the free end, the UCR kept slipping around 200 lbf, right around the load you might get in a hammock suspension, depending on weight of the occupant and the angle. By putting minimal force on the free end, I could easily load the UCR to 1,000 lbf, but when I let go of the free end, it immediately slipped. I think without a way to ensure there is some small load maintained on the free end, it is not a question of if, but when a UCR will let you down. I think I will stick with the WS and get some Dynaglide for weight savings instead of using a UCR.

Hi Schneiderlein, I am curious just how much force you think would be required on the tail end of the UCR in order to keep it from slipping? Would using a line lok to tension the tail to the tensioned side of the loop be sufficient to hold? This would allow one to use less amsteel for suspension lines, instead of needing double the length for a whoopie sling. I realise this is slightly off topic, but you mentioned it here...