Climbing Physics Puzzler

[strandman]

the snow and wind are doing a good job right now

[SA]

This may sound blunt, but I've never pondered too much on all this emphasis in anchor building, (equalizing).

It must be a very small percentage of climbers in one year who have had anchors fail. I've never had an anchor fail, nor have I ever known anyone personally who has had their anchor pull.

Have I ever taken long leader falls, or caught any? Sure have, but never an anchor fail.

Ya, I know --I'm gonna die.

[DLottmann]

I agree with you SA, an over emphasis on anchor building skills exists considering that a very small percentage of climbing accidents in the last 50 years can be attributed to anchor failure (according to 50 years of ANAM data collection).

I think that since anchor building can lend itself to engineering debates is probably the root of this over "engineering".

The bottom line is if individual gear placements are solid it doesn't really matter how they are all connected together.

The vast majority of climbing accidents are;

1) Rappelling errors

2) Belaying/Lowering errors

3) Lead climbing errors (not enough pro to keep keep from decking)

Of the 50 years of published accidents the only "anchor failures" I can recall are single point anchors while rappelling...

[sneoh]

The vast majority of climbing accidents are;
1) Rappelling errors
2) Belaying/Lowering errors

+1 ... Far and away the most common causes, at least in recent memory.

[Pete Jackson]

Of the 50 years of published accidents the only "anchor failures" I can recall are single point anchors while rappelling...

Jolt's anchor failed this year. Fortunately nobody was attached to it at the time. 

For those still wondering about the math: The legs of the cordalette are 1, 2, and 3 times the length of the shortest loop. In a straight up-and-down anchor, leg 2 takes half the force of leg 1, and leg 3 take one-third the force of leg 1. So it's an algebra exercise to figure out the percentages.

Since reading Long's new edition, I've tried out a custom-tied quad as a top anchor instead of the typical two-draw Rumney anchor. I actually really like it.   

[sneoh]

Since reading Long's new edition, I've tried out a custom-tied quad as a top anchor instead of the typical two-draw Rumney anchor. I actually really like it.   

Diagram?  Sketch?  Illustrations?

[JakeDatc]

Since reading Long's new edition, I've tried out a custom-tied quad as a top anchor instead of the typical two-draw Rumney anchor. I actually really like it.   

Diagram?  Sketch?  Illustrations?

you mean you weren't on RC.com  for the great anchor thread of '09 (ish) ?    talk about engineer geeks galore..  guys came up with every variation of  Quad, equalette,  auto-equalizing thing they could think of. 

quad


equalette  (might be what Pete would use)


Equalette with cord

[eyebolter]

This may sound blunt, but I've never pondered too much on all this emphasis in anchor building, (equalizing).

It must be a very small percentage of climbers in one year who have had anchors fail. I've never had an anchor fail, nor have I ever known anyone personally who has had their anchor pull.

Have I ever taken long leader falls, or caught any? Sure have, but never an anchor fail.

Ya, I know --I'm gonna die.

Absolutely agree.   

The same textbook thinking makes people place cams almost all the way open "because they are stronger than with the cams fully retracted."  I guess they teach that in clinics, and it may well be true.

However, I have never seen a cam fail because the cams were fully retracted.  Maybe they technically are less strong, but they are still plenty strong enough.  On the other hand, I have seen tipped-out cams fail because of loose flakes in the crack, or because of walking in and opening up completely.   

[pappy]

This may sound blunt, but I've never pondered too much on all this emphasis in anchor building, (equalizing).

It must be a very small percentage of climbers in one year who have had anchors fail. I've never had an anchor fail, nor have I ever known anyone personally who has had their anchor pull.

Have I ever taken long leader falls, or caught any? Sure have, but never an anchor fail.

Ya, I know --I'm gonna die.

Absolutely. Although I do remember an incident where two guys were killed at Tahquitz back in the '90s(?) I think. When they found them one of the guys was still tied into three cams. They figured that they were near the top and the leader had probably run it way out on the low angle slabs and fell directly on the belay. Don't remember the analysis of how the belayer was attached to the cams or if there even was one, bitd about we cared about was getting two good pieces.
The internet also fosters this kind of over thought engineering. The interminable effing discussions of whether this piece is good to 9kN while that was good to 10kN so it's better, blah, blah, blah. One buddy of mine who was a gear head was berating me for using 'inadequate' gear (like I never heard that before) and I just said, 'if you don't fall, it don't matter.'

[kenreville]

The belayer gets 99% of the force because the idiot leader didn't have a piece clipped..the cordalette fails and all the gear remains as booty

As usual, Strand is the only one that got it right.

I had a cordalette once, one of my buddies gave it to me as a birthday present. First time out I lost it. It wasn't intentional, really, just Freud in action, but climbers should not carry extraneous pieces of gear.

+++++1

From strand getting it right to phuk the cordellet. Or whatever the hell you wanna call the UNNECESSARY crapola one chooses to carry.

[lucky luke]

This may sound blunt, but I've never pondered too much on all this emphasis in anchor building, (equalizing).

It must be a very small percentage of climbers in one year who have had anchors fail. I've never had an anchor fail, nor have I ever known anyone personally who has had their anchor pull.

Have I ever taken long leader falls, or caught any? Sure have, but never an anchor fail.

Ya, I know --I'm gonna die.

Absolutely. Although I do remember an incident where two guys were killed at Tahquitz back in the '90s(?) I think. When they found them one of the guys was still tied into three cams.

In 2012, we had 17 rapel anchor incident and on those 3 was for inadequate anchor. zipper effect enter also in rope management. I open accident in north America 2013 and it was an accident with inadequate. Jeff wrote, in an other traid,: the modern concern with static materials to tie in to a belay has come about from studying some accidents where someone clipped into an anchor, climbed above it to place another piece, fell off, and either the sling broke, or a carabiner broke, causing a much longer and injurious fall ( in at least one case, fatal).

As you both papy and sa learned to climb with piton. You learned with the trad mentality and have the chance that crag talk was about those element of safety that I took from mountaineering freedom of the hill fifth edition Any thing that can save your life was discuss seriously,  not ignore or disguise as no important. In the beginning of accident in... they gave a little history of fundamentals to save your life that didn't present a quarter of the knowledge to be safe in a cliff.

an accident is like a storm...if you don't see the first sign of it (negligence here) you got caught in it. 

[Pete Jackson]

quad

I use the first one: but not as often as I'd like to. I rigged an anchor with one of these once, and the old-school dude I was climbing with looked at me like I had lobsters coming out of my ears. Which was amusing, since most people consider this guy a little nuts.

So usually I don't rock the boat with fancy newfangled knots and rigging, though I think some of the newer techniques have some merit.

One thing I never do when setting an anchor is math. But, I definitely like thinking about the physics from the comfort of my office chair!

[strandman]

I'll bite- in photo #2, the two slings equalized,  why are they knotted in the middle ??  I would think that when the climber swings to one side or the other that a bit of sliding would help even things out ?
Of course I have had a problem with side by side anchors forever..slightly off set in the vertical mode is much better from a swinging/strength mode....of course if the gear is bomber..........

The only anchors i have ever seen "fail" were fixed bolts/pins and that  was a partial.... pushing pins back in on some sandstone while your partner raps  (really)  and a FOUR bolt belay on El Cap that ripped and killed 2 people (incorrect rigging and side loading)

No wonder I left physics in school

[JakeDatc]

The knots prevent the whole thing from becoming nothing if one strand gets cut  and reduces extension if one piece blows.     

i tend to use sliding x's a lot with one of the pieces clove hitched. unless the pieces are far apart, which they sometimes are at the gunks.. then i use my giant dyneema sling-olette thing that gives me a lot of choices    or i throw it around the biggest tree and call it good. 

[DLottmann]

Why Clovehitch one piece when using the sliding x?