Falcon Guide's "The AMGA Single Pitch Manual"--Review

Managed to snag a copy of Falcon Guide's The AMGA Single Pitch Manual. Good read, really liked it.

Complete review on Elevation Outdoors: elevationoutdoors.com/blogs…

Get it through the AMGA website and it costs less than Amazon...free shipping, too!

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I can't figure out what they mean on page 74, when they say the double loop figure 8 isn't redundant if both loops are used at the same master point. Do you?

If it's the same knot I'm thinking of (fig.8 "bunny ears") it's because the two loops are actually a part of the same strand which doesn't bind in the knot. This is why it's fairly easy to re-equalize the knot. Unfortunately it also means that if you cut one strand both loops will pull through.

I just played with the knot in some cord and can see what you mean. I could force one loop through if I pulled a certain way on the other loop, but it was kind of unnatural. Don't some people use this knot to make a rope anchor with 2 bolts?

Hubert Cumberdale wrote:I just played with the knot in some cord and can see what you mean. I could force one loop through if I pulled a certain way on the other loop, but it was kind of unnatural. Don't some people use this knot to make a rope anchor with 2 bolts?

It's my go-to knot to connect to two bolts or bits of gear. As the post above says, it APPEARS not to be redundant. But in REALITY (it's been pull tested) if one loop fails it DOES NOT undo the other loop. Breakage occurs where the rope makes the first turn in the knot. You can try this yourself - set it up and load both loops as if they were on bolts. Then unclip one and pull as hard as you can on the rope. It won't pull through, it just tightens up the knot.

But I've found I'm wasting my time when I meet climbers, incl. some "book smart" experienced climbers, who won't use it because "it's not redundant". Kinda like the locking-biner-through-the-harness-tie-in-points instead of clipping to the belay loop. Or the outer-lobes-of-a-camming-unit-go-downward (in a horizontal crack) nonsense.

I guess I disagree with the authors on this point then, huh? But it's an author's prerogative to err on the side of caution I suppose.

Are we talking about the Super 8? I use it all the time as the master point. have have thought about it redundancy. time to test.

Thinking about the system as a whole. It seems the anchor is really the only redundant part of the system. Think about the belayer to the climber in a TR situation.

Despite the comments above, the 2-loop 8 is in fact not redundant, and generally not a good choice for an unattended master point such as in a slingshot top rope scenario. The potential failure mode is not the one Gunkiemike describes as being a non issue. The vulnerability lies in the final loop of rope that's passed over the entire knot and then cinched to adjust the two masterpoint loops (the "bunny ears"). If the strand that forms this loop is abraided / cut, both of the master point loops could certainly fail. This is an entirely plausible scenario, and the pull tests gunkiemike mentions above don't sound as though they address it. Could you provide a link to the test data Mike?

All that said, the 2-loop eight is a very useful knot when applied in the right places. An unattended TR masterpoint just isn't one of them. This is the take away from the manual on this topic. Clipping in to a 2-bolt anchor, where one has eyes on the knot and abrasion / cutting is unlikely and easily observed is on the other hand a great application.

Derek, what you describe is an extremely specific failure mode, one which I would consider insignificant in the grand scheme of things. While I look for the source of my testing statement, can you provide any instances where such a failure of the bunny ears 8 has occurred?

Another mitigating factor re. this knot is when it is tied in beefy (we use 10mm) static rope. While not taking anything away from the importance of SRENE/ERNEST anchors, it is commonly accepted that redundancy does not apply to certain elements in the system such as the ATC, the belay biner, and of course the climbing rope itself. Many folks seem to feel that a 10mm rope at the anchor falls in this doesn't-need-to-be-redundant category. I don't personally, but I see an awful lot of TR setups with a single loop of static rope at the powerpoint.

Adding - Here's one link to testing:
queenslandclimbing.yuku.com…

Gunkiemike wrote:Derek, what you describe is an extremely specific failure mode, one which I would consider insignificant in the grand scheme of things. While I look for the source of my testing statement, can you provide any instances where such a failure of the bunny ears 8 has occurred? Another mitigating factor re. this knot is when it is tied in beefy (we use 10mm) static rope. While not taking anything away from the importance of SRENE/ERNEST anchors, it is commonly accepted that redundancy does not apply to certain elements in the system such as the ATC, the belay biner, and of course the climbing rope itself. Many folks seem to feel that a 10mm rope at the anchor falls in this doesn't-need-to-be-redundant category. I don't personally, but I see an awful lot of TR setups with a single loop of static rope at the powerpoint. Adding - Here's one link to testing: queenslandclimbing.yuku.com…

Hi Mike,

No, I'm not aware of instances of this failure mode playing out in the field. That could be because so few people actually know and use the knot, or it could be because the real probability of it occurring is so low as to be insignificant as you suggest. We don't know, which should be reason enough to scrutinize the way in which we apply the knot.

My perspective (and what I teach in the SPI program) is that since the knot doesn't achieve the only aim folks generally present for using it in the first place (redundancy), there are equally simple alternatives that do (the BHK for example), that there is a demonstrably plausible failure mode, especially in smaller diameter, more abrasion / cut vulnerable materials, and that use of these very materials is both common and represents situations in which redundancy at the master point is most desirable, there is simply no defensible argument for using it over the alternatives in that application.

Note that all of my comments apply specifically to unattended master
points in top rope scenarios. There are many excellent applications for the 2-loop eight in other contexts, including the one you yourself offered. I do teach such appropriate applications in SPI courses.

Though I do tend to agree with the AMGA that the knot s not redundant and there could be a pull through if one of the strands were to be cut somehow. Now the likely hood of a 10 mm static line cutting through on a day of topropeing should not be on your mind when running a toprope site.

As a certifed amga spi guide you should be using bHK over a double, because that is what the certifying bodies say to do. Also in my experince it is way simpler and faster to equialize.

Now if you are out with your buddies and you want to tie a double 8 or drink beer while you climb or belay that's in you.

The point being is, that this is what the amga recommends and if you are to be certified by them you should be useing the methods they practice.

Maybe all of this is redundant with what Derek said, but it is my two cents on the topic.

Also, I think that they did a great job with the cover models. The guy in the blue is handsome!