Tie 2 ropes together| Rethreaded figure 8 vs Abnormal figure 8

Eric Frei

Often the need arises to join ropes together. This thread is focused on the tying of two ropes together the same size/type for life support.

The rock climbing, caving, adventure and rescue people know of the perils in tying the wrong knot when joining ropes for life support. There's also a lot of data and testing and I found a site where there's some great well explained results.

This site's PDF's toward the bottom are well worth a look. They are factual tests, and a range of knots used and ropes also including aged ropes to see strength loss. I have also loaded them here, view in order!

Bushwalkers Wilderness Rescue Squad - Research

When joining two same type of ropes together there's talk of using a figure 8 knot. However there's 2 ways of tying it, rethreaded or abnormal.

Here's pics of the two, AVOID THE ABNORMAL METHOD LIKE THE PLAGUE!

Attached Thumbnails

 

Attached Files

	1 main paper.pdf (983.5 KB, 166 views)
	2 Annex A 1-2.pdf (12.9 KB, 88 views)
	3 Annex B 1-2.pdf (16.8 KB, 47 views)
	4 Annex A-B 3-7.pdf (285.7 KB, 38 views)
	5 Annex B 8.pdf (5.3 KB, 42 views)
	6 Annex B-9.pdf (64.2 KB, 38 views)
	7 Annex D1-11.pdf (19.2 KB, 41 views)
	8 Annex E1-8.pdf (17.7 KB, 43 views)

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playfordtree

How many of us trust our lives to just the double fishermans knot and nothing else?

Looks like you could raise the Titanic with that knot.

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quercus

That's true, Playford... But the double fishermans knot is allmost impossible to untie when used in a dynamic rock climbing line whom has been under serious tension. The figure 8 is IMO better for dynamic lines. I don't even use the single figure of 8 loop anymore on a dnamic line. I use the double looped figure of 8 for that.

newguy18

Define or better yet post a pic of a single figure eight loop.

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Fairfield

How about the Zepplin Bend? I have started using that to take the place of the 8 and the double fisherman. Main reason is I hated how tight the frigen thing got on ya. Oh ya and I hate putting sticks in the knot!! So now I use the zepplin, pull and pull and pull on it and have problems getting it untied . If you want I have video of me putting it under a 3:1 test with me pulling on it ( I am 150lbs ) I can post for ya, let me know.

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Eric Frei

Where you been you BAMF!?

Yeah I use the Zepplin too however this thread was to point out the danger in the figure 8

Most people I know tie it the wrong way (abnormal) and roll out can happen.

Figure 8 is the strongest of all though. I know there's also the sheet bend however can you find numbers? the Zepplin never seems to have test info anywhere.

I have used the figure 8 to join ropes when pulling with a truck. Tied it close to the end of the rope, I call it a sacrificial knot, means if she doesn't come undone I cut it off and only lose the last little bit of rope. I do that because of the superior strength.

Sheetbend will go down to 50% rope strength and Zepplin I think is 65% where figure 8 is 80%, when you got a truck and leaning tree everything matters.

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Fairfield

HaHa, ya you got that right! rather cut the knot at the end of the day then have to rebuild a roof

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newguy18

Sure i'd like to see the video.I use a figure eight as the termination on my climb line[except for when i tail tie in which case i use a bowline].I'm always open to learning new knots.

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Fairfield

sorry for getting off topic boys. Here you go NewGuy.
zepplin bend on Yahoo! Video

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newguy18

Definatly need to remember that one.Thanks alot.

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bigshea13

myself, i use two running bowlines. strength is not sacrificed, its always able to be undone, and everyone knows how to tie it...even the ground guys.

Eric Frei

I'd argue that, got a pic? I think the bend ratio where the two ropes meet would be a servere weak point, much weaker than a rethreaded 8 anyway. Bowline are generally around 65% strength for termination use. Figure 8's in comparison 80%.

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newguy18

I also heard that where a running bowline bites it weakens the rope even more so than a regular bowline.Maybe someone can confirm?

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Eric Frei

Yep, drops down as low as 50%

But we need to confirm how he's using it coz like we have seen here there's more than one way to tie a knot of the same name.

With a sheet bend for instance you can take wraps before the tail goes through.

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newguy18

I usually hook on to hitch balls with a cats paw with a stopper knot in the free end for most of my pulling,simple to untie and fairly strong.

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Eric Frei

Well, I aint gonna bother asking for a pic of it if your taking it.

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newguy18

You might know it as a midline clove hitch.figure that with a figure eight in the tail.

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Eric Frei

There's another way to tie it, I tie it like shown here.

Zeppelin Bend : Knot Tying Tutorial | ExpertVillage Videos

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fatdog

Thanks for the video,looks like a good knot. I'm going to give it a try. Like they say it's always good to find new knots that work and easy to get undone afterwards. Thanks Fatdog