Tag Archives: Angle

The American Death Triangle Fairy

Apparently there is an American Death Triangle Fairy travelling around crags unwittingly doing a safety disservice for climbers. He was spotted by Nicole Castonguay at Smith Rock State Park back in October, although apparently (and unfortunately) she didn’t realize he was the American Death Triangle Fairy at the time. Here’s the story, from what I can gather from what Nicole told me:

Nicole decided to climb Chalk Wave with a pair of climbing students in Early October. Chalk wave is a sport route, meaning it has bolts (duh!) and a bolt rap anchor at the top (duh!). Bear with me, this will be important later.

Anyway, at the base of the route they encountered a couple who were just packing up to leave (SPOILER ALERT: One of these two people was the American Death Triangle Fairy!). As Nicole and her students set up, and the couple packed up, they engaged in some climbing small talk, you know, like you do. Anyway, one half of this couple, this unidentified guy whose name we may never know, informed Nicole that it was very difficult to pull your rope if you rappelled directly off of the bolts. So as a public service he’d constructed a rappel anchor with webbing, so people could rappel from a proper rappel ring, from which it is oh so much easier to retreive your rope. He added that Nicole and her students need not clean his webbing rappel anchor, that he always brought extra webbing with him for this purpose, and that in fact, he provided this kind public service frequently. My, what a kind, thoughtful person!

So they eventually said their goodbyes and Nicole lead up the route to the anchor, where she encountered this:

Classic American Death Triangle, Double Looped for Fake Redundancy.

Classic American Death Triangle, Double Looped for Fake Redundancy.

Oh yes. That’s right. Classic American Death Triangle! This is the gift that nameless couple guy leaves “frequently”! And this is why I have dubbed nameless couple guy The American Death Triangle Fairy. Is his philanthropy limited to Oregon? The Pacific Northwest? Does he provide this service internationally? We may never know. When I asked Nicole if she had an opportunity to tell this guy that his public service was Jive-Ass (in kinder, more diplomatic terms), she sadly told me, “He was long gone by the time I discovered his handiwork.” Dang!

As Nicole herself pointed out, notice that this is not only a classic American Death Triangle, but it’s double threaded from the same piece of webbing. Presumably the double wrap is for added strength and redundancy. But there are no limiter knots tied anywhere. It’s just one continuous loop of webbing. So the entire system is a single point of failure.

So what’s the big deal with the American Death Triangle? Well it’s an anchor so jive-ass that it has its own Wikipedia entry. If you’re not familiar, take a look, but in summary, the American Death Triangle creates unnecessary magnification of force on the two anchor points. It’s also not redundant in any way. Any bit of the webbing fails, and the whole works fails.

And okay, fine, these are bolts, which are pretty bomber, and we’re only talking about rappelling, which doesn’t generate a lot of force. And in that sense, this American Death Triangle isn’t likely to fail if you rappel off of it. But that doesn’t make it okay. It certainly isn’t EARNEST or SERENE. And most importantly, this certainly isn’t a very good public service.

In conclusion, I’d like to put out an APB (All Points Bulletin) to the climbing community. Be on the look out for The American Death Triangle Fairy: a man who leaves American Death Triangle rappel anchors with a fake redundancy extra loop on sport routes, last seen in Central Oregon, and considered dangerous (to himself and others). Find this man, educate him, and make him to stop leaving Jive-Ass anchors around.

Location: Smith Rock State Park, Oregon, USA

A is for Angle

Anchor angle is too wide

The angle is far too wide.

As you likely already know, the ‘A’ in the rock climbing anchor building mnemonic acronym ‘EARNEST’ is for “Angle”. The angle between the legs of your anchor shouldn’t be too wide, right? Certainly less than 90°, and ideally less than 45°. The angle formed by the outer legs of the anchor in the photo above are too wide. This is a bolted three point anchor, so it’s not likely to fail. But it’s odd that the bolt on the right is so far off from the two on the left. I mean who bolts a route to make this scenario likely? This anchor could be improved simply by using longer cord and extending the power point closer to the edge of the cliff. The further away the power point is from the bolts, the smaller the angle becomes.

Location: Unknown.

Why does the angle matter? Intuitively, it makes sense that regardless of the angle created in constructing a two point climbing anchor, each of the two anchor points will carry half (50%) of the load. But this isn’t true. The wider the angle, the greater the load each anchor point has to bear.

Take a look at this graphic from the AMGA Manual. You have to create a narrow 20° angle between the anchor points to have them each bear 50% of the load. At 45° the weight distribution only increases to 54%, at 80° it’s 70%, and by 120° each anchor point is bearing 100% of the load! If you really want to geek out on the physics involved, check out this trigonomic analysis of tension in climbing anchors.

Climbing anchors angle

Relative weight distribution on a climbing anchor determined by angle