Author Topic: Double Dragon Loop trumps the Bowline Family?  (Read 11748 times)

Festy

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Re: Double Dragon Loop trumps the Bowline Family?
« Reply #30 on: June 22, 2014, 10:10:36 AM »
1. The DD can be easily verified visually as being tied correctly.
There are some mistakes that can be made in tying that yields very convincing impostor knots.  Whether they have any especially problematic weaknesses is a topic of investigation.

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4. Resistance to side loading (as far as I can ascertain with just muscle power).
I'm not too sure what you mean by "side loading".  Can you clarify?

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5. Pulling hard on any combination of legs will not capsize or upset the knot (as far as I can ascertain with just muscle power).
As you note, muscle power isn't all that great, but I was able to fully capsize the Double Dragon Loop in 3/16" diameter nylon rope without much trouble by pulling the legs in opposite directions.  In some 5/16" diameter nylon rope, I was able to partially capsize the knot by pulling the legs in opposite directions such that upon normal loading, the knot was unable to return to it's usual shape.  All this was done with mere hand strength.

Thanks for that, Roo...............that throws it into the 'well maybe not then' category  :D


In paracord I wasn't able to capsize it like you did, but I'm no Mr Universe  ;D (by sideloading I meant pulling apart the loop legs when the knot is dressed)

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Festy

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Re: Double Dragon Loop trumps the Bowline Family?
« Reply #31 on: June 22, 2014, 10:12:16 AM »
I have never used the Double Dragon in mission critical applications (where a human life is at stake). So I have no empirical evidence base from which to comment. Be that as it may, I can confirm that it is definitely not in widespread use in the climbing, caving and vertical rescue community. But that by itself is not evidence to discredit the DD knot.

I will look into this in detail and get back to this site and comment soon...

Mark Gommers

Thanks, I look forward to that

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agent_smith

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Re: Double Dragon Loop trumps the Bowline Family?
« Reply #32 on: June 22, 2014, 01:02:23 PM »
I have conducted some very quick and dirty (and unscientific) tests on the Double Dragon.

Cyclic loading (which some call 'slack shaking' on this site) will compromise the core (nub) of this structure relatively quickly - unless - it is drawn up and vigorously cinched tight.

In direct comparison, the [Yosemite] Bowline did not require such strict attention to cinch down and compress the core (nub) - it was more resistant to cyclic loading.

This 'testing' was carried out with 8.0mm diameter Sterling USA cord (human rated 17.5kN high strength - my favourite brand of cordage).

Obviously, a lot more testing needs to be done!

Mark