http://www.youtube.com/watch?v=3QWyMmZZBmM

this noob (me) was watching a video on you tube of some climbers on liberty ridge. it has some awesome shots on the mountain but.. i have some questions....

in the video you can see some of the anchors they built. it clearly shows three anchors close enough to evaluate. the first one is at frame 6:39. i think its obvious that aint bomber the next one is at 8:40.. im not sure about that one???? is it two slings or just one? then the third ever so equalized is at 9:11. looks like decent bodyweight placement but is it safe?? help me figure out the second and third anchors. thanks

anytime i come across a shot of an anchor in a photograph or video i have to stop and evaluate it. does anyone else do this?

The first one is an "American death triangle". Equalized but not redundant. If the sling breaks the whole anchor is shot. If one screw blows, the other is shock-loaded.
The one at 8:40 is a bit better. Two redundant systems and looks pretty well equalized.

stormflap wrote:http://www.youtube.com/watch?v=3QWyMmZZBmM

this noob (me) was watching a video on you tube of some climbers on liberty ridge. it has some awesome shots on the mountain but.. i have some questions....

in the video you can see some of the anchors they built. it clearly shows three anchors close enough to evaluate. the first one is at frame 6:39. i think its obvious that aint bomber the next one is at 8:40.. im not sure about that one???? is it two slings or just one? then the third ever so equalized is at 9:11. looks like decent bodyweight placement but is it safe?? help me figure out the second and third anchors. thanks

anytime i come across a shot of an anchor in a photograph or video i have to stop and evaluate it. does anyone else do this?

Some gnarly looking anchors! Time to get anal...

6:39 anchor - placed pieces are too wide for my liking (I'd prefer to see one above the other), hard to tell if they tried to scrape off the top, crappy layer of ice before putting in the screws, loaded carabiner should be locking, loaded carabiner's gate should be facing UP, anchor isn't non-extending...hope they aren't putting any serious weight on that! ?

8:40 anchor - Better, I would prefer to use a single runner or cordlette, tough to see if loaded carabiner(s?) are locking or not. Probably would use a munter hitch off the anchor, too.

9:11 anchor - Even Better, assuming there is a locking carabiner below that overhand(?) knot. I would make sure the direction of pull is more down than out when using that ice axe as a piece.


Simple, Effective, Rdundant, Equalize, Non-Extending.

Thoughts?

639 - death triangle - better would have been V with sliding x - loaded biner needs face up and locker

840 - looks like two separate runners each attached to a non locking opposed biner - looks good to me

911 - not sure, i think it looks OK

yea i dont understand how someone could mess up an anchor so bad. the weather in the video looked pretty wild too.

All 3 climbers are SP members, I do believe. Liberty Ridge is an amazing route.

Agree with the others as far as the anchors go, not sure what is up with the Amer. Death Triangle rig in the 1st belay. Experienced climbers getting lazy Otherwise the rest seem OK. After 30 years of climbing, I've resigned myself to the thinking that SERENE=FANTASY for setting anchors.

Also spending a second night on route? Weather can change up there so quickly. We just bivyed at Thumb (their first site) and then pushed up, over, and down the next day. The day before we reached the ridge, 2 climbers perished mid-way up due to iffy weather (they decided to cook inside their tent and died of CO poisoning-one of the climbers was a M.D. no less.)

There are multiple instances of the American Death Triangle in the video. Another on two screws.

I believe these guys know that's a bad idea, so why? When you've carried a bunch of single length runners up there, you grab one, clip it to the protection, and realize it's no where near long enough the make a sliding x. It's a pain in the ass to get another one from over your shoulder or wherever.

Much better to carry several double length runners on routes like this instead of several single length ones.

brandon wrote:There are multiple instances of the American Death Triangle in the video. Another on two screws.

I believe these guys know that's a bad idea, so why? When you've carried a bunch of single length runners up there, you grab one, clip it to the protection, and realize it's no where near long enough the make a sliding x. It's a pain in the ass to get another one from over your shoulder or wherever.

Much better to carry several double length runners on routes like this instead of several single length ones.

thats exactly what i was thinking too. they just didnt have double length runners to make it work. i havent been in this situation accept when i was practicing anchors on a tree in my backyard. it was simple....at that point i knew i better have the right equipment with me when im out

It is worth noting that for fixed inextensible sling length and fixed distance between two pieces of pro:

1. You can build an American Death Triangle if and only if you can build a sliding X.

2. The forces on the anchors are always lower for the sliding X even if the angle at the power point is wider than in the ADT.

3. The force ratio varies between square root of two and three halves depending on the angle.

brenta wrote:It is worth noting that for fixed inextensible sling length and fixed distance between two pieces of pro:

1. You can build an American Death Triangle if and only if you can build a sliding X.

2. The forces on the anchors are always lower for the sliding X even if the angle at the power point is wider than in the ADT.

3. The force ratio varies between square root of two and three halves depending on the angle.

Everything makes sense, except for point #3? How are you getting sqrt(2) and 3/2?

For both configurations, the force on each anchor point approaches infinity as the bottom angle approaches 180 degrees.

Force ratios for ADT and sliding-X, at given bottom angle:
0 deg: .707 and .500
60 deg: 1.00 and .577
90 deg: 1.31 and .707
120 deg: 1.93 and 1.00
150 deg: 3.83 and 1.93
And then the numbers get even more ridiculous at higher angles.

You are looking at equal angles, I'm assuming the same sling, and therefore, in general, different angles. (I'm also assuming an isosceles triangle.) The idea is that I'm given two already placed anchors and a sling and I have to build either a sliding X or an ADT. How do they compare?

In my case both forces diverge, but their ratio doesn't.

Let r be b/l, where b is the base of the triangle and l is the length of the sling. The values of interest for r are between 0 and 1/2. The ratio of the two forces is then sqrt(2(1-r)(1+2r)). If r > 1/2, I can build neither sliding X nor ADT.

Also, (2) is not so obvious before you write the equations, but turns out to be true. In conclusion, there's very little reason to build an ADT, but it's not as deadly as it is often made out to be.

EDIT: In your case, the ratio is also bounded, but the bounds are square root of 2 and 2.