Double Fisherman's Knot

[Dru]

quote:

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Originally posted by crazyjz:

David Parker:

As you all know, I am one hill-billy juke mother fucker, and I have broke more old climbing ropes with trucks, cats, and tractors than I can count. They typically break either at one side of the knot, or at the hitch, shacle, or clevis. One time we were tryng to yard an old alder down with four parallel rope tied to D4, and they all broke essentially simulateously, with a report that sounded like a bomb.

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I have never broken a rope with a cat, when I try they just meow and bat at it. even promising some catnip tokes won't get them that motivated.

 

[none_dup1]

Hi folks,

Here is a nice site I found recently that has break tests data for lots of different climbing ropes and gear. (Using a Humvee winch and a tank - yes, a tank - to break gear. THAT sounds like a fun way to spend a Saturday!)

Check it out:

http://www.xmission.com/~tmoyer/testing/pull_tests_11_98.html

[haireball]

Kirk Mauthner, Rigging For Rescue, P.O. Box 399, Invermere, B.C. Canada - This guy does a great deal of pull and drop testing and is fairly generous with his results (publishing much of his material in SAR trade journals)

tests by a German lab associated with Edelrid (ropes) back in the early seventies found that ropes joined with a double-fishermans knot and then pulled-to-failure failed at a point OTHER THAN THE KNOT often enough that they felt it necessary to publish their surprising results, and begin trying to account for why this should be so. I never did see an authoritative resolution published.

I, too, have had the frightening experience of having a water-knot fail under the load of a rappel, (1972)and have since been suspicious of this knot's value for joining slick-finish tapes and ropes.

My personal preference to join two ropes for rappel-rigging is to tie a square-knot with long tails, and finish the tails as a double fishermans. The result is a square-knot "inside" a double fishermans knot. Yes, its bulky, but it retains the security of the DF while remaining easy to untie even if it gets overloaded. I've been using this method since the early 70's, and enough of my partners use it that I'm surprised that it apparently isn't widely practiced (at least, not among posters on this site...) I've tried the EDK, but have not become enamoured of it... I don't seem to get that many rappel-rigs stuck, so its major advantage doesn't exist for me...

[This message has been edited by haireball (edited 10-22-2001).]

[This message has been edited by haireball (edited 10-22-2001).]

[Bronco]

From Freedom of the Hills:

Rope Without Knot: 100%

Double Fisherman's: 65-70%

Bowline: 70-75%

Water Knot: 60-70%

Figure 8: 75-80%

Clove Hitch: 60-65%

Fisherman's: 60-65%

Overhand: 60-65%

I think these are all good knots to know and most have certian scenarios that work better than others. I usually pull a water knot tight with my teeth for rap anchors, but, you guys are freaking me out with your stories though.

Obviously you should also know a prussik knot and a munter hitch, but, what other knots should aspiring alpinists know?

[none_dup1]

My 2 bits -

I think climbers need to be versatile. Try to learn different techniques to accomodate different situations. Examples . . .

1) Rapping fast, multiple pitches, with lots of cracks and places for rope to maybe get hung up: EDK all he way.

2) Rapping slabs or snow with minimal danger of rope getting hung up: EDK or square knot finished with double fisherman's.

3) Setting a rap station for beginners to practice on all day, with many people using the same rope: triple fishermans with a "channel lock plier" finish!