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General => General Climbing => Topic started by: DLottmann on November 05, 2013, 07:37:44 pm

Title: Climbing Physics Puzzler
Post by: DLottmann on November 05, 2013, 07:37:44 pm
This one is right up your alley Champ!

You have a 3 piece anchor in a bomber vertical crack with the classic “pre-equalized” 7mm 6m cordelette (looped with a double fisherman though that is not too relevant).

Your lowest piece is a solid #1 BD Cam. 6 inches above that you have a .75 BD Cam, and your top piece is a bomber looking #7 nut.

You tied off the cordelette to form a master point with a figure eight on a bight. The “leg” to the #1 is 6 inches long, the “leg" to the .75 is 12 inches long, and the “leg" to the nut is 18 inches long. The angles between the arms are very minimal, less than 10 degrees from the outer arms.

The leader clips the master point before leaving the station, climbs up 5 feet, and falls. Let’s assume the fall is clean, the belay sucessfully arrests (though it is violent), and all the gear holds.

Which piece of protection withstood the most force, or did they all receive 1/3ish.
Title: Re: Climbing Physics Puzzler
Post by: Pete Jackson on November 05, 2013, 08:06:38 pm
This one is right up your alley Champ!

You have a 3 piece anchor in a bomber vertical crack with the classic “pre-equalized” 7mm 6m cordelette (looped with a double fisherman though that is not too relevant).

Your lowest piece is a solid #1 BD Cam. 6 inches above that you have a .75 BD Cam, and your top piece is a bomber looking #7 nut.

You tied off the cordelette to form a master point with a figure eight on a bight. The “leg” to the #1 is 6 inches long, the “leg" to the .75 is 12 inches long, and the “leg" to the nut is 18 inches long. The angles between the arms are very minimal, less than 10 degrees from the outer arms.

The leader clips the master point before leaving the station, climbs up 5 feet, and falls. Let’s assume the fall is clean, the belay sucessfully arrests (though it is violent), and all the gear holds.

Which piece of protection withstood the most force, or did they all receive 1/3ish.

The #1 cam takes 55% of the impact force, the ..75 takes 27%, and the nut takes 18% of the force. 

And I cannot wait to hear the arguments over this one.
Title: Re: Climbing Physics Puzzler
Post by: hobbsj on November 05, 2013, 08:23:16 pm
This one is right up your alley Champ!

You have a 3 piece anchor in a bomber vertical crack with the classic “pre-equalized” 7mm 6m cordelette (looped with a double fisherman though that is not too relevant).

Your lowest piece is a solid #1 BD Cam. 6 inches above that you have a .75 BD Cam, and your top piece is a bomber looking #7 nut.

You tied off the cordelette to form a master point with a figure eight on a bight. The “leg” to the #1 is 6 inches long, the “leg" to the .75 is 12 inches long, and the “leg" to the nut is 18 inches long. The angles between the arms are very minimal, less than 10 degrees from the outer arms.

The leader clips the master point before leaving the station, climbs up 5 feet, and falls. Let’s assume the fall is clean, the belay sucessfully arrests (though it is violent), and all the gear holds.

Which piece of protection withstood the most force, or did they all receive 1/3ish.

The #1 cam takes 55% of the impact force, the ..75 takes 27%, and the nut takes 18% of the force. 

And I cannot wait to hear the arguments over this one.

Care to explain?  Is it the the length of each leg?  Not seeing how you came up with those percentages.....May be the beer making my math skills fuzzy along with my vision.
Title: Re: Climbing Physics Puzzler
Post by: danf on November 05, 2013, 08:48:27 pm
The #1 cam takes 55% of the impact force, the ..75 takes 27%, and the nut takes 18% of the force. 

And I cannot wait to hear the arguments over this one.
I'm not sure how to compute that, but based on my understanding, that sounds right.  It's all pretty well explained in the second edition of John Long's anchor book.  Which is part of the reason why I keep a cordellette tied and ready for a sliding X anchor system, rather than the typical one described above.  One of these days, hopefully, my wife will be ready to swap leads with me and I can (to quote Strand) "just use the F'n rope". :)
Title: Re: Climbing Physics Puzzler
Post by: DLottmann on November 05, 2013, 08:49:40 pm
Pete got the gist of it. Let's let lucky like explain the why.
Title: Re: Climbing Physics Puzzler
Post by: strandman on November 05, 2013, 09:22:22 pm
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
Title: Re: Climbing Physics Puzzler
Post by: lucky luke on November 05, 2013, 11:04:04 pm
The leader clips the master point before leaving the station, climbs up 5 feet, and falls. Let’s assume the fall is clean, the belay sucessfully arrests (though it is violent), and all the gear holds.

It is a fall factor 2 directly on the anchor. What I want to protect as much as I can...it is my anchor. No anchor and I am death in that situation.
The question is how I can protect my anchor? The question of the force on the pro is not important because one way to rig the anchor is to do a clove hitch on the first cam, an other on the second and an other on the third. In that way, if the first didn't hold the fall, it will take a percentage of energy, if the second don't hold, it will take an other percent of energy and the third have some chance to hold (present in john long with piton).

How I can I protect my anchor is more than an interesting question. Some study show that when load, the harnest took a part of the energy.  The energy took by the harnest and rope running true the device can be as hight as 20 %. So, if you belay directly on your harnest, instead of risking your life by using the anchor as a first pro, you have 20% more chance that it will hold.

personally, I use a sliding x on the anchor and I back up the sling with my rope on a protection. If I don't think that one of my pro will hold more than 12KN, I will double it with an other. For example, if my second and third pro was no as safe as I want, I will use a sling between them to a master point and an other sling joining the master point to the other pro. I will use a back up differently.

As usual, what is important is that the anchor hold the fall. If one pro hold 100 % and the other 0 is not more important than if each pro old 33% of the fall. It is superficial rules and that kind of challenge doesn't help to safe life of people. I think that the new generation of climber have a lack of knowledge on safety.(not apply to every climber, some are very safe and have bad advice...)   
Title: Re: Climbing Physics Puzzler
Post by: DGoguen on November 06, 2013, 07:43:10 am
This one is right up your alley Champ!
Let's let lucky like explain the why.

Dave, you're starting threads looking for arguments at this point.
Around here they come by themselves willingly, don't rush it.  :)
Title: Re: Climbing Physics Puzzler
Post by: DLottmann on November 06, 2013, 10:04:35 am
I really wasn't trying to start any arguments... but was honestly curious if LL would answer the question simply or go off on a tangent. I won't declare what happened but for anyone (Hobbsj) who was interested in the answer...

Danf and Pete referred to it... the issue raised in Long's book is that cordelette material is somewhat dynamic. It stretches under load. Therefore it's reasonable to argue that any 3 point anchor tied off this way, the SHORTEST leg will see the most force when the master point is loaded. JL uses this as an argument for abandoning the ever popular cordelette method and adopting "Equallette's and Quads"... or as some would say, to have a reason to write a new book...

I do not subscribe to this rejection of the method, since most of the time if I use a cordelette I just try to not have one leg that is incredibly short, but if I do I make sure that that piece of gear is bomber, and as LL mentions, worry more about protecting the belay by getting a solid first piece soon after leaving the anchor.

There's a dozen different ways to build an anchor and 11 of them are totally fine, provided the individual placements are solid.

Personally my cord stays on the back of my harness 99% off the time... there are quicker ways of building solid anchors than using a 20 foot loop of cord IMO.

Title: Re: Climbing Physics Puzzler
Post by: lucky luke on November 06, 2013, 10:12:09 am
As usual, what is important is that the anchor hold the fall. If one pro hold 100 % and the other 0 is not more important than if each pro old 33% of the fall.

Title: Re: Climbing Physics Puzzler
Post by: DLottmann on November 06, 2013, 10:21:01 am
As usual, what is important is that the anchor hold the fall. If one pro hold 100 % and the other 0 is not more important than if each pro old 33% of the fall.

I love how you quote yourself.

And agreed.
Title: Re: Climbing Physics Puzzler
Post by: pappy on November 06, 2013, 10:25:51 am
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.
Title: Re: Climbing Physics Puzzler
Post by: JBro on November 06, 2013, 10:37:07 am
I really wasn't trying to start any arguments...


Come on man you live for this shiiite!


(http://24.media.tumblr.com/tumblr_m4eflpyBwO1qaspmko1_400.gif)
Title: Re: Climbing Physics Puzzler
Post by: steve weitzler on November 06, 2013, 01:03:28 pm
Strand falls and I rescue his wife. ;) ;) ;)
Title: Re: Climbing Physics Puzzler
Post by: sneoh on November 06, 2013, 02:26:33 pm
Watch out, Strand.  And lock yourselves in.  :)
Title: Re: Climbing Physics Puzzler
Post by: strandman on November 06, 2013, 05:09:11 pm
the snow and wind are doing a good job right now
Title: Re: Climbing Physics Puzzler
Post by: SA on November 06, 2013, 05:44:33 pm
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.

Title: Re: Climbing Physics Puzzler
Post by: DLottmann on November 06, 2013, 07:05:54 pm
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...
Title: Re: Climbing Physics Puzzler
Post by: sneoh on November 06, 2013, 07:38:51 pm
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.
Title: Re: Climbing Physics Puzzler
Post by: Pete Jackson on November 06, 2013, 07:46:50 pm
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.  ;D

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.   
Title: Re: Climbing Physics Puzzler
Post by: sneoh on November 06, 2013, 08:15:34 pm
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?
Title: Re: Climbing Physics Puzzler
Post by: JakeDatc on November 06, 2013, 08:45:23 pm
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
(http://www.mountainproject.com/images/92/1/107359201_medium_9ff536.jpg)

equalette  (might be what Pete would use)
(http://i255.photobucket.com/albums/hh131/daveebel92/321211_10150343346264661_503889660_7810850_1096085408_n.jpg)

Equalette with cord
(https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQ_mrP9VXsrE8T5XURz_TEsoIFo_gfWOwqprSFnsMPLpSJPeJjjTg)
Title: Re: Climbing Physics Puzzler
Post by: eyebolter on November 06, 2013, 08:50:03 pm
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.   
Title: Re: Climbing Physics Puzzler
Post by: pappy on November 06, 2013, 09:06:16 pm
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.'
Title: Re: Climbing Physics Puzzler
Post by: kenreville on November 06, 2013, 09:32:16 pm
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.
Title: Re: Climbing Physics Puzzler
Post by: lucky luke on November 06, 2013, 10:39:26 pm
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. 
Title: Re: Climbing Physics Puzzler
Post by: Pete Jackson on November 06, 2013, 11:18:42 pm
quad
(http://www.mountainproject.com/images/92/1/107359201_medium_9ff536.jpg)

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!

Title: Re: Climbing Physics Puzzler
Post by: strandman on November 07, 2013, 09:45:36 am
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
Title: Re: Climbing Physics Puzzler
Post by: JakeDatc on November 07, 2013, 10:32:26 am
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. 
Title: Re: Climbing Physics Puzzler
Post by: DLottmann on November 07, 2013, 11:37:01 am
Why Clovehitch one piece when using the sliding x?
Title: Re: Climbing Physics Puzzler
Post by: JakeDatc on November 07, 2013, 12:17:29 pm
If a strand gets cut then the whole thing fails.   clove hitch keeps it a closed system. 

this is the link the RC.com thread  but all of the inline pictures got messed up when RC did away with them so the thread is kinda stupid now.

http://www.rockclimbing.com/cgi-bin/forum/gforum.cgi?do=post_view_flat;post=1306133;page=1;sb=post_latest_reply;so=ASC;mh=25; (http://www.rockclimbing.com/cgi-bin/forum/gforum.cgi?do=post_view_flat;post=1306133;page=1;sb=post_latest_reply;so=ASC;mh=25;)
Title: Re: Climbing Physics Puzzler
Post by: DLottmann on November 07, 2013, 12:26:53 pm
I must not be picturing this correctly then. If you clip the sling to both bolts and make your magic ask how does one Clovehitch at one of the bolts make it redundant?
Title: Re: Climbing Physics Puzzler
Post by: JakeDatc on November 07, 2013, 12:51:41 pm
Maybe i remembered the setup wrong.   the whole thing hurt my brain so i went back to my usual stuff..   maybe it only works if the piece blows out not the sling gets cut. 
Title: Re: Climbing Physics Puzzler
Post by: lucky luke on November 07, 2013, 02:09:16 pm
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.

I am surprise that they don't talked about the use of a gri gri on the belay!!!.
Title: Re: Climbing Physics Puzzler
Post by: frik on November 07, 2013, 03:26:25 pm
For this to be a real physics "problem", you have to add a caveat like...
Assume the relationship of cord stretch to cord length is linear.
Title: Re: Climbing Physics Puzzler
Post by: DGoguen on November 07, 2013, 03:34:05 pm
Hey Luke
I think you are misquoting people above, unless Steve had a stroke.
Title: Re: Climbing Physics Puzzler
Post by: Bill on November 07, 2013, 09:15:50 pm
Dave say it ain't true!

Jake had a brain cramp and Steve experienced a stroke.  I'm so damn confused!!!  I hope everyone recovers completely and quickly!  BTW are you doing any climbing these days Hikin' Jake?

Title: Re: Climbing Physics Puzzler
Post by: JakeDatc on November 07, 2013, 11:25:19 pm
Not much Bill..  biking more..  should get to 3k miles this year :)    going back to school so time for going places is hard so biking is easier
Title: Re: Climbing Physics Puzzler
Post by: triguy on November 08, 2013, 08:00:50 am
Question: what is of bigger concern in a leader fall directly onto the belay - protection failure or sling/cordalette failure?
Title: Re: Climbing Physics Puzzler
Post by: Admin Al on November 08, 2013, 09:12:59 am
good discussion... FWIW I have a pre-made-up equalette that I use a lot. between that and a cordelette I feel pretty well covered.
Title: Re: Climbing Physics Puzzler
Post by: strandman on November 08, 2013, 10:48:16 am
Question: what is of bigger concern in a leader fall directly onto the belay - protection failure or sling/cordalette failure?
Belayer failure
Title: Re: Climbing Physics Puzzler
Post by: sneoh on November 08, 2013, 11:25:18 am
Question: what is of bigger concern in a leader fall directly onto the belay - protection failure or sling/cordalette failure?
Belayer failure
I agree with John.  Can get real nasty in a hurry.
Title: Re: Climbing Physics Puzzler
Post by: triguy on November 08, 2013, 11:48:09 am
Assuming the belayer can arrest the fall......my question still stands.
Title: Re: Climbing Physics Puzzler
Post by: strandman on November 08, 2013, 12:10:24 pm
Since I don't use a cordalette, I would feel a bit more concerned about the gear..esp the top piece. Always belay through something helps as well..the top piece of gear, first one on the next pitch,etc  always. 

I can't imagine a 7mm cord in good shape failing however
Title: Re: Climbing Physics Puzzler
Post by: DLottmann on November 08, 2013, 12:33:48 pm
Question: what is of bigger concern in a leader fall directly onto the belay - protection failure or sling/cordalette failure?

C. Scrambled Organs.

Seriously, a true factor 2 will break the climber's body. You'd almost wish the gear and cord failed.
Title: Re: Climbing Physics Puzzler
Post by: pappy on November 08, 2013, 01:41:20 pm
Question: what is of bigger concern in a leader fall directly onto the belay - protection failure or sling/cordalette failure?

C. Scrambled Organs.

Seriously, a true factor 2 will break the climber's body. You'd almost wish the gear and cord failed.

yeah. what bugs me about all of these kind of on line debates is that assuming you have competent climbers who have set up an anchor with good gear then pretty much all the BS about how it lashes together and whether in the real world it actually makes a difference is so far out on the margin that it's not worth thinking about. If the leader is going to run it out off the belay where it really matters then you had both better be experienced enough to understand the risk and you'll probably do a good enough job not to require the schematic. It almost creates a false sense of security if you have your anchor system set up perfectly according to Largo when the only thing that really matters is whether your nuts and cams are placed intelligently (or that the bozo who placed the bolts knew what they were doing), and if not having everything else perfect probably won't matter.
Title: Re: Climbing Physics Puzzler
Post by: SA on November 08, 2013, 02:36:36 pm
There are very few climbers here that have been around long enough to experience the " cement block"  drop. The MIT outing club had a setup, near the Uberfall, in the Gunks, in the mid-60's, where a 200 lb. block was hauled up via pulleys, with plenty of slack out, to give the belayer practice in catching falls, using a body belay.

You would be ripped pretty violently off the ground. Perhaps that kind of practice would be more important, than all this emphasis on making things more "complicated".
Title: Re: Climbing Physics Puzzler
Post by: sneoh on November 08, 2013, 02:55:18 pm
SA, Old Eric, bring back the AMC's "BUCKET".
Title: Re: Climbing Physics Puzzler
Post by: OldEric on November 08, 2013, 03:07:43 pm
SA, Old Eric, bring back the AMC's "BUCKET".

It's still here!  Sitings are rare but it makes it's annual appearance in late April in the Quincy Quarries.  Seems to be more of a sport climbing bucket these days though as it's weight has dropped from a stout 175 pounds to ~125.  It does share a common heritage to the MIT bucket as the same cast of characters were involved in creating each.

When teaching with it I need to remember to swap out my teaching-in-the-gym-nice-soft-catch hat to my teaching-trad-get-tight-and-inline-with-the-anchors hat.  I think we need to have Champ as a guest lecturer speak on the perils of giving a  sport belay in a trad context (which is  almost as bad as the oppopsite in my experience).
Title: Re: Climbing Physics Puzzler
Post by: DLottmann on November 08, 2013, 03:47:53 pm
yeah. what bugs me about all of these kind of on line debates is that assuming you have competent climbers who have set up an anchor with good gear then pretty much all the BS about how it lashes together and whether in the real world it actually makes a difference is so far out on the margin that it's not worth thinking about... It almost creates a false sense of security if you have your anchor system set up perfectly according to Largo when the only thing that really matters is whether your nuts and cams are placed intelligently (or that the bozo who placed the bolts knew what they were doing), and if not having everything else perfect probably won't matter.

I agree that individual gear placements are more important than what one of dozen different ways you use to join them together to build anchor, except, when climbers are relatively new.

It is my experience that learning to place good solid pro is really hard for most folks to "catch on" quickly. Especially if they've never aid climbed. I know people who have been climbing trad for the better half of a decade and still struggle with their gear placements. In this situation, having anchors over designed can really compensate for 1 or 2 marginal placements...

Instead of Lucky Luke's "Don't Boulder before Trad", I bet "Aid Climb, then Sport Climb/Boulder, then hard Trad" would work great...
Title: Re: Climbing Physics Puzzler
Post by: lucky luke on November 08, 2013, 05:18:43 pm
Instead of Lucky Luke's "Don't Boulder before Trad", I bet "Aid Climb, then Sport Climb/Boulder, then hard Trad" would work great...

I don't think so. Sport is very interesting in that way that the focus is on movement. You learned to have reflex to use with some obvious piece of protection, fix or cam, to make the harder move.

The reflex that you learned is what you are going to do when the brain don't have time to make a clear decision.

Trad climber begin byeasy route where they are safe and gradually learned what they need. They work there weak aspect. It could be protection, it can be control of yourself, it can be strenght and it could be move. Actually, me level of safety is higher than before. But I have a plateau at 5.x. I want to climb 5.x+1. So, I need to do sport to master the technique. Actually, movement is my weaker part.

Conclusion. sport and trad are equal in quality as a sport. If you want to trad, acquire the reflex of trad. If you like to sport, acquire the reflex of sport.
Title: Re: Climbing Physics Puzzler
Post by: Bill on November 08, 2013, 10:30:32 pm
Yikes! What a thread! 

So I can catch Eric who probably weighs 125 on a good day but XYV (unnamed to protect their identity but they do have a significant ice cream addiction) who is on the far side of 200 is SOL?!?!?!  But wait I have already caught him successfully a couple of times.  (For the record: That would be every time a couple of times. No kersplat. Yet!)  I'm so confused!     

Very confused by the MIT reference!  Does it matter if you are catching a MIT grad Eric? If so, is it a plus or minus factor?  Dave and Susan, if you are out there pay attention to Eric's response!

However since some of you seem to be taking this thread seriously, please consider this.  As a leader do you clip the master point as you head up or depend on the belayer to take the fall off the harness?  Pluses and minuses of each scenario?
 
Recall the OP had the leader clipping the master point.  Sorry Champ if you clip the master point it isn't a FF2 onto the anchor.  But hell let's not get hung up on silly petty details at this point.

I won't be coy about my position. If the anchor is marginal in any way; yeah it does happen, sometimes your don't have a choice; I'm taking it off the harness. And for bonus consideration I would have constructed the anchor with slings (assuming I had any left after the lead) utilizing  sliding-X's.  What do you think? Plus, minus, why? Or screw it, are you are going to the fridge for more ice cream. If so, what flavor?

BTW currently out in Tinsel Town on business.  Drinking some Racer 5.  Can you carry this hops thing too far? (Note: the subtle link to the Beer thread).  Got to go.  Got to hit super taco Friday while drunk thread. (Note: subtle link to Super Topo)
Title: Re: Climbing Physics Puzzler
Post by: DLottmann on November 08, 2013, 11:17:26 pm
...As a leader do you clip the master point as you head up or depend on the belayer to take the fall off the harness?  Pluses and minuses of each scenario?...

Wow Bill, quite a post there!

Will Gadd had some good stuff on your question there;

1) http://willgadd.com/anchor-clipping/

2) http://willgadd.com/anchor-clipping-2/

PS You can never have too many hops... Triple IPA FTW!
Title: Re: Climbing Physics Puzzler
Post by: strandman on November 09, 2013, 09:34:28 am
Bill- you want to hit A HOKIE DOG in LA  it may kill you, but it's good

Always belay off the harness..THROUGH a piece and you'll be OK
Title: Re: Climbing Physics Puzzler
Post by: pappy on November 09, 2013, 11:16:29 am

Always belay off the harness..THROUGH a piece and you'll be OK

Must be an old guy thing. I always belay off my harness: I used a Perverso for a few years and invariably someone would climb to the belay and say some variation of 'I can show you how to rig that to auto-block' and my response was always, 'So?'

Besides, it helps lend urgency to your voice when you shout for the second to f*&king get back on the rock.
Title: Re: Climbing Physics Puzzler
Post by: JakeDatc on November 09, 2013, 03:37:32 pm

Always belay off the harness..THROUGH a piece and you'll be OK

Must be an old guy thing. I always belay off my harness: I used a Perverso for a few years and invariably someone would climb to the belay and say some variation of 'I can show you how to rig that to auto-block' and my response was always, 'So?'

Besides, it helps lend urgency to your voice when you shout for the second to f*&king get back on the rock.

I thought we were talking about lead belaying...  which you can't do off the anchor. 

i go back and forth with it bringing a 2nd up.  mostly depends on the route and who i'm climbing with. 
Title: Re: Climbing Physics Puzzler
Post by: DLottmann on November 09, 2013, 03:55:51 pm

I thought we were talking about lead belaying...  which you can't do off the anchor. 


You can. Read Will Gadds blog. I think in some situations belaying a leader off an anchor with a GriGri might be even a good choice, however Atc off the waist is 99% the way to go for leader belay 

Forget belaying seconds off the waist on anything but moderate mountaineering routes. For vertical rock climbing direct harness belaying of second sucks IMO, no advantages.
Title: Re: Climbing Physics Puzzler
Post by: steve weitzler on November 09, 2013, 07:00:10 pm
Call me stupid John; but what is a Hokie Dog?? :( :( :(
Title: Re: Climbing Physics Puzzler
Post by: lucky luke on November 09, 2013, 10:06:16 pm

I thought we were talking about lead belaying...  which you can't do off the anchor. 

leader fall, broken arm, one pitch from the top, belaying and they are at the top or doing seven rap in the dark: in trad, there is always a solution. some times we don't have the intelligence to find it...or the time. But belaying a leader from an anchor is possible with one hand.
Title: Re: Climbing Physics Puzzler
Post by: Admin Al on November 10, 2013, 04:26:57 pm

I thought we were talking about lead belaying...  which you can't do off the anchor. 

leader fall, broken arm, one pitch from the top, belaying and they are at the top or doing seven rap in the dark: in trad, there is always a solution. some times we don't have the intelligence to find it...or the time. But belaying a leader from an anchor is possible with one hand.

LOOK... there is always the possible occasion when you need to do something that changes the equation due to a "situation". however, as I understand it in this thread we're talking about the norm. personally I always belay a leader off my harness, and I always clip into the master point as the first until the leader gets in a good 1st piece up there somewhere. those of you who feel differently, do whatever you want, but I have absolutely no interest in trying to hold a leader fall on my harness right off the belay with no gear between me & the leader!
Title: Re: Climbing Physics Puzzler
Post by: snowleopard on November 10, 2013, 09:52:26 pm
Word!
Title: Re: Climbing Physics Puzzler
Post by: Bill on November 10, 2013, 11:52:55 pm
Wow!  Has someone hyjacked Al's account?  Has the real Al ever used all caps for a word before such as LOOK.  Love the passion Al.  Sorry if I was apparently out of line in sketching out the scenario of an anchor that doesn't fall in within the "norm" range as stated by the OP in using the term "bomber".  With a anchor that falls with the "norm" range I do, at least if I remember to do so, I clip through the master point.  Perhaps it would have been better form to start a new thread.  My apologies.

That said, with an anchor outside to the "norm" I will not clip the master point. I will be sure my belayer is cloved in to the master point with no slack and in position to take the fall directly in line with the anchor.  The idea is that the inclusion of the additional elasticity due to an the climbing rope from the belayer's harness to the anchor and the elasticity added by the belay loop on the harness being in the system will help to reduce the force on the "marginal" anchor.  Additionally it eliminates the multiplier effect of the pulley on the anchor created by clipping through the master point. 

Properly positioned catching a fall directly on the belay, although it may drive you to your knees, should be reasonably doable.  For the record,  I nor any belayer of mine has caught such a fall. So no, I have not yet done the experiment.  Maybe I am fooling myself and being a little anal-retentive about the entire thing but it does, at least for me, eliminate a bit of the anxiety generated by climbing above a marginal anchor prior to placing and clipping the first solid piece.
Title: Re: Climbing Physics Puzzler
Post by: Admin Al on November 11, 2013, 09:55:10 am
here's my thought about clipping the power point while the leader gets to their 1st piece:

1) anything is better than nothing

2) I'm right handed. if I'm belaying off my harness and the fall on my left side I MAY be able to hold the fall. if they fall to my right I almost certainly will not be able to hold the fall as the belay device will be providing no friction at all.

3) yes, there is a possibility of the anchor blowing. however, I think that if it is a solid redundant anchor it's not as likely to fail as it is for me to not be able to hold the fall if the leader falls on my right.

4) NOTE: once the leader gets in their 1st piece off the belay, or second if the 1st isn't great, I remove their draw from the power point.
 
this is more of a worry for me on rock, where protection possibilities are often limited, than on ice where hopefully the leader will be able to get in a piece quickly. after all, on ice, if you have solid enough ice for a good anchor, you should be able to place a solid screw right off the anchor.

as always YMMV...
Title: Re: Climbing Physics Puzzler
Post by: Pete Jackson on November 11, 2013, 10:35:37 am
here's my thought about clipping the power point while the leader gets to their 1st piece:

1) anything is better than nothing

+1. Once the "jesus nut" is in place, do you un-clip the master point or leave it in? In terms of the physics, getting that factor 2 out of the equation as soon as possible strikes me as wise.
Title: Re: Climbing Physics Puzzler
Post by: Admin Al on November 11, 2013, 05:37:45 pm
+1. Once the "jesus nut" is in place, do you un-clip the master point or leave it in? In terms of the physics, getting that factor 2 out of the equation as soon as possible strikes me as wise.

yes I do, thnX. I edited my post to reflect that point.
Title: Re: Climbing Physics Puzzler
Post by: strandman on November 11, 2013, 09:19:29 pm
Once anyone holds anything near a F2 fall,  they won't let it happen again..trust me
Title: Re: Climbing Physics Puzzler
Post by: Admin Al on November 11, 2013, 10:31:35 pm
Once anyone holds anything near a F2 fall,  they won't let it happen again..trust me

+
Title: Re: Climbing Physics Puzzler
Post by: sneoh on November 12, 2013, 10:12:22 am
Once anyone holds anything near a F2 fall,  they won't let it happen again..trust me
I can imagine.  I have no desire to have this happen to me; leader or belayer!!
Title: Re: Climbing Physics Puzzler
Post by: lucky luke on November 14, 2013, 01:20:50 am
Once the "jesus nut" is in place, do you un-clip the master point or leave it in? In terms of the physics, getting that factor 2 out of the equation as soon as possible strikes me as wise.

If the jesus not pop out!!!