directional figure 8 vs. butterfly

I see that the AMGA SPI manual is discussing the directional figure 8 rather than the alpine butterfly.

As far as I can tell the directional figure 8 is an inferior knot to the alpine butterfly mainly because it is unidirectional and will invert/roll if loaded on the wrong side whereas the alpine butterfly is a bidirectional knot. The alpine butterfly is also easier to untie after loaded.

So what is the appeal of the directional figure 8 over the alpine butterfly? Familarity/similarity with the figure 8? Is the directional figure 8 supperior in some way?

Interesting Mountaineering Freedom of the hills does not even mention the directional figure 8.

The directional figure of eight is a quick way of rigging a fixed line from 2 anchor points that are a long way from each other, e.g. trees. This is because it is quicker to adjust and tying a butterfly to make a 5m loop is a pain . However, as you say it is unstable. In this application a simple overhand makes more sense, and as the force is pulling across the knot it won't over tighten.

What are they suggesting it shown be used for? A handle?

Pat,

I think the Directional 8, or "In-Line 8" is a good option when you know which direction the knot will be loaded and there will be a load applied to the back strand. In this case it may just be a cleaner looking option than the Butterfly. I like David's application of the knot, and will try it out next time I'm in that scenario, Maybe even an In-Line 8 on a bight? The only time I really use it is in top managed sites with one rope. Fixing the middle, dropping one side as a rap line, and belaying from an In-Line 8 on the other, with myself tethered to it's back strand.

Seth Pettit wrote:Pat, I think the Directional 8, or "In-Line 8" is a good option when you know which direction the knot will be loaded and there will be a load applied to the back strand. In this case it may just be a cleaner looking option than the Butterfly. I like David's application of the knot, and will try it out next time I'm in that scenario, Maybe even an In-Line 8 on a bight? The only time I really use it is in top managed sites with one rope. Fixing the middle, dropping one side as a rap line, and belaying from an In-Line 8 on the other, with myself tethered to it's back strand.

+1

I use the in-line/directional 8 over the alpine butterfly because I find the 8 easier to untie.

animatedknots.com/fig8loopd…

If it's for setting up top ropes or a belay I sometimes use a double figure 8 (bunny ears). You can adjust either loop to the length required. Really useful knot.

Butterfly is a great knot to know in multiple circumstances from mountaineering to tock to canyoneering.

Learn it!

I have learned it. I just have it in an arsenal of many useful knots, and I'll use the one that's most appropriate?

Here is a link to a directional figure 8 (also known as the inline figure 8) animatedknots.com/fig8direc…

It is not the the samething as the double figure 8 which seems perfectly useful.

I don't see how the directional figure 8 can be easier to untie than an alpine butterfly? The alpine butterfly never really gets tight. For your reference animatedknots.com/alpinebut…

The AMGA SPI manual is suggesting that directional figure 8 can be used in place of a clove hitch when connecting components of an anchor together. I guess that it might be much easier than the alpine butterfly to move along the rope to get the right tension. It would also give a better sense of security than a clove hitch that has loosened or was never pulled tight.

The only time I have seen a directional figure 8 in use was when someone used it to tie into the middle of the rope so two people could climb on the same line, the common use for the alpine butterfly.

Thanks for the comments.
Pat

climber pat wrote: I don't see how the directional figure 8 can be easier to untie than an alpine butterfly? The alpine butterfly never really gets tight. For your reference animatedknots.com/alpinebut… Pat

"Animated knots by Grog" may claim that it "remains relatively easy to untie."

IMHE I've seen the opposite.

I'd recommend you try rappelling off a strand with these knots in them. You can decide which you think is easier.

Hey! I got a +1, thanks Avi. In re-reading my post I realized a mistake and I'll correct it before I'm called out.
The Directional Figure 8 by it's very nature is on a bight. When I said "maybe an In-Line 8 on a bight?", I meant that after I fixed the middle of the rope to the furthest anchor point I would tie one big Directional 8 on both strands together to add an anchor component and maintain the secure feeling of two strands of rope all the way to the master point,... where I might use it again facing the opposite direction!

Also, after all this discussion I have decided that "In-Line 8" is a less accurate description of this knot than "Directional 8" so I'm going to refer to it as the latter from now on. Thanks!

The directional 8 is my favorite knot for clipping my guide style belay device into while bringing up a follower

Jon Rhoderick wrote:The directional 8 is my favorite knot for clipping my guide style belay device into while bringing up a follower

It seems to me that the standard figure 8 would be a better knot for this application because you do not expect to load the line coming out of the directional figure 8.

Directional figure 8's are excellent in rescue situations. I find them vital in creating a (directional) fixed point on a rope when building a 3:1 or 4:1 hauling system.

They are quite expedient and much easier to adjust. IMO

The directional 8 or inline 8 has advantages in real rescue applications. As far as SPI terrain, I'll keep using a clove hitch. It's plenty strong, and it's not very hard to tie. The knot efficency of a butterfly knot is not as good as some other options.

Direction figure 8? Alpine butterfly? Why bother?

Does anybody have a real reason why an overhand on a bight isn't just fine? It is also "multi-directional" like many knots and is super easy to tie and untie. We use it joining ropes why not use it on the bight too.

Strength? Well I'm happy enough with my rope breaking at the knot 12kN vs 14kN. I'm really not fussed.

David Coley wrote:....tying a butterfly to make a 5m loop is a pain ....

Try it this way:

youtube.com/watch?v=_hTH-Lu…

I agree that if you want to hang your belay device on a loop of rope, the overhand is perfectly adequate. If you want a knot on bight you can load up big and/or for a long time and then untie easily, use a bowline on a bight, animatedknots.com/bowlinebi… . The DAV has found this is actually the best knot for tying in to the harness with (in which case it is often referred to as a "rethreaded bowline" and incorrectly described as a "double bowline"), so it is fully capable of performing when only one of the two strands exiting the knot is loaded. It is a fast to tie as an overhand. It isn't particularly easy to adjust up and down the line (although still easier than a butterfly), but is so easy to tie that you can pretty much get it right without adjustment, and no problem tying a big loop with it.

Gregger Man wrote: Try it this way: youtube.com/watch?v=_hTH-Lu…

Thanks! That was very neat.

patto wrote:Direction figure 8? Alpine butterfly? Why bother? Does anybody have a real reason why an overhand on a bight isn't just fine? It is also "multi-directional" like many knots and is super easy to tie and untie. We use it joining ropes why not use it on the bight too. Strength? Well I'm happy enough with my rope breaking at the knot 12kN vs 14kN. I'm really not fussed.

That isn't "multi-directional" in the sense that is being described in this thread. All of the knots being discussed have two strands coming from a knot, and a loop on the other side of the knot. People are proposing various ways to load those three pieces, with the two strands being pulled in different/opposite directions. Do this with a regular overhand bight, or a figure eight on a bight, and the knot tends to start "rolling inside out." Do this with a butterfly, or a directional figure 8 and the knot just cinches down nicely.

Tom Nyce wrote: That isn't "multi-directional" in the sense that is being described in this thread. All of the knots being discussed have two strands coming from a knot, and a loop on the other side of the knot. People are proposing various ways to load those three pieces, with the two strands being pulled in different/opposite directions. Do this with a regular overhand bight, or a figure eight on a bight, and the knot tends to start "rolling inside out." Do this with a butterfly, or a directional figure 8 and the knot just cinches down nicely.

This very succinctly expresses the reason to use the directional figure 8 or alpine butterfly. The alpine butterfly is stable if the loop is pulled against either strand; the directional figure 8 is stable if the loop is pulled against one strand but not the other. Both knots are stable if the two strands are pulled upon; the figure 8 and overhand are not.

Tom Nyce wrote:Do this with a regular overhand bight, or a figure eight on a bight, and the knot tends to start "rolling inside out."

Rolling? You better tell that to all those people using an overhand to tie two ropes together. AKA the EDK.

(An overhand on a bight being loaded on either end has the same knot topology as an EDK.)

climber pat wrote:Both knots are stable if the two strands are pulled upon; the figure 8 and overhand are not.

Please explain further the problems associated with the overhand and why we should worry about it on a bight but not when joining rappel ropes.