Multi drop single rope

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Re: Multi drop single rope

Postby PeterFJohnson » Jan 28, 2013 11:00 am

NZcaver wrote:Butterfly versus figure 8 bight, both loaded across legs of knot - the butterfly broke at 3152 lbf (14.0 kN).


Interesting. Do you have more information on this by any chance NZcaver? Most testing I have seen would indicate that the eight loaded in an atypical or flat orientation(i.e. loading both legs but not the loop) would cause it to capsize - often at body weight loads. It is interesting that you all were able to create a situation that this didn't occur. In any case, it seems to me that this(Loading of a figure eight across the legs a the rebelay fails) is the one of the least tested of all possibilities in this mental exercise.

Mike Hopley wrote:witness the recent French testing of the bowline-on-the-bight.


Is this research published anywhere? I would be interested to see it. Especially if it includes independent loading of each loop.
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Re: Multi drop single rope

Postby Mike Hopley » Jan 28, 2013 11:44 am

PeterFJohnson wrote:Is this research published anywhere? I would be interested to see it. Especially if it includes independent loading of each loop.


http://efs.ffspeleo.fr/techniques/noeuds

The method of failure was loading a single loop, which can cause the knot to slip disastrously. This has been discussed extensively on UK Caving.
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Re: Multi drop single rope

Postby NZcaver » Jan 28, 2013 3:39 pm

PeterFJohnson wrote:
NZcaver wrote:Butterfly versus figure 8 bight, both loaded across legs of knot - the butterfly broke at 3152 lbf (14.0 kN).


Interesting. Do you have more information on this by any chance NZcaver?

See the video I posted previously.
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