The purpose of an anchor depends on the situation. A rescue anchor is to save lives. Ever seen rescue anchors? They're super burly. Nobodies going to take that much time to build rescue anchors at every belay. It'd be a waste of gear, time, and effort. I'd much rather climb.
The purpose of most other climbing anchors is to reduce the likelihood of hitting the ground to an acceptable probability while being reasonable in it's use of available gear and time. I could build anchors that are practically indestructible. The problem is that it would take me so much longer and would be so gear intensive that I would never be able to do more than one climb a day. So the tradeoff for total indestructibility is some risk. Sorry you can't take out all the risk out of the sport without taking out some of what makes the sport enjoyable. At least that's what the waiver I make people sign says. Obviously you are willing to spend more time to decrease your risk. That's fine. In my opinion you are overly cautious, but my level of acceptable risk is apparently higher.
The purpose of an anchor depends on the situation. A rescue anchor is to save lives. Ever seen rescue anchors? They're super burly. Nobodies going to take that much time to build rescue anchors at every belay. It'd be a waste of gear, time, and effort. I'd much rather climb.
The purpose of most other climbing anchors is to reduce the likelihood of hitting the ground to an acceptable probability...
Yeah, 6%. *roll*
That a 6% chance of failure of a routine belay anchor is acceptable is arguably the most outrageous statement I have seen on this website.
Jay
(This post was edited by jt512 on May 28, 2009, 2:44 AM)
You don't climb much on soft rock do ya? Go climb in the Fisher's. You'd be grateful to find something with just a 6% chance of failure. Case in point, last tower I climbed, River Tower. First anchor had three pins and a quarter inch bolt in Cutler sandstone with that fine layer of mud. Two pins were moving, one slightly, the other significantly. All pins were corroded and very old. The bolt was a quarter inch bolt in sandstone and it was obviously not placed perfectly. I'd say most of those pieces were probably above the 50% mark for failure. The four pieces I placed above the anchor weren't much better. Then the fourty foot runout to the two tipped out cams and subsequent sixty foot runout to the anchor made for a no-fall kind of day.
Climbing is a risky sport by nature. The 6% comes from me not accepting pieces as bomber unless they have an individual failure probability of less than 25%. That is my personal feeling about what constitutes bomber. That doesn't mean I'll get to that 6% mark and call it good on a regular basis. It means I'll accept it if for some reason I do not deem it desireable, necessary, or possible to increase that probability. That actually fits in really well with that River Tower experience if you figure the probability of each anchor point failing at 50%. Put's the probability of total anchor failure at 6.25%. Oh God I tried to put in the pink tricam but it just wouldn't stay, I'm a horrible person and could have killed us all.
I would not do that on a regular basis. I also do not have your need for a tremendously high level of safety. I'm not going to place 3 pieces to increase my level of safety some minor percentage like .09%. Safety is relative, do try to keep that in mind.
How many three piece anchors do you come to sport climbing anyways? How do you inspect bolts visually, the vast majority of the material isn't visible for inspection?
That a 6% chance of failure of a routine belay anchor is acceptable is arguably the most outrageous statement I have seen on this website.
So sayeth the sport climber who thinks two bolts, torqued to spec with a torque wrench, is the standard.
Jay, you're a hella strong climber, and you've got experience. Because of those two facts, I'll say this once, and do so knowing that you understand the concept:
"Perfect" anchors that "won't fail" are an idealistic, but not realistic, concept in some trad routes and in most alpine routes. And, thus, sometimes "6% chance of failure" is the best you can ask for.
Or, more simply: "You roll the dice and you take your chances."
That a 6% chance of failure of a routine belay anchor is acceptable is arguably the most outrageous statement I have seen on this website.
So sayeth the sport climber who thinks two bolts, torqued to spec with a torque wrench, is the standard.
So sayeth the sport climber who climbed trad for 10 years before he ever touched a sport route.
In reply to:
"Perfect" anchors that "won't fail" are an idealistic, but not realistic, concept in some trad routes and in most alpine routes. And, thus, sometimes "6% chance of failure" is the best you can ask for.
No one is arguing that. But in all the climbing I have ever done, I have exactly once had to settle for less than a bombproof anchor. That anchor consisted of a single ¼-inch bolt in sandstone with a semi-hanging belay. I cannot think of a single anchor before or since that wasn't, for all practical purposes, 100% reliable.
I realize that this standard cannot be attained in alpine routes or tradding on junk rock. I've not claimed it can.
In all those years you can only think of one anchor that was less than 100%? Either you have access to some really bomber rock or you make your decisions on which routes to climb very carefully. I've been climbing trad half that long and can already think of several. Granted most of them were due to crappy rock but wow only one?
I can't think of any times on good rock where I thought any anchor I or a partner built was l less than essentially 100%, two piece or more. I'll fail to include any one piece anchors in those times.
The purpose of an anchor depends on the situation. A rescue anchor is to save lives. Ever seen rescue anchors? They're super burly. Nobodies going to take that much time to build rescue anchors at every belay. It'd be a waste of gear, time, and effort. I'd much rather climb.
The purpose of most other climbing anchors is to reduce the likelihood of hitting the ground to an acceptable probability...
Yeah, 6%. *roll*
That a 6% chance of failure of a routine belay anchor is acceptable is arguably the most outrageous statement I have seen on this website.
Jay
Assigning made up failure probabilities is ridiculous. 1%, 10%, 25%.... whatever. Its all made up and completely meaningless.
All you have is 'bombproof' and then you make up some logic and fabricate numbers to come up with a probability that suits your notion of bombproof.
The numbers are utterly meaningless. Stick with bombproof.
May 29, 2009, 2:05 AM
Post #134 of 143
(6840 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
Re: [jmeizis] Two piece anchors are plenty strong! Poll!
[In reply to]
Report this Post
Average:
(0 ratings)
Can't Post
jmeizis wrote:
Why did you quit trad climbing?
I haven't completely quit trad climbing, but I enjoy sport climbing a lot more. The movement is more interesting and less encumbered by gear.
In reply to:
In all those years you can only think of one anchor that was less than 100%? Either you have access to some really bomber rock or you make your decisions on which routes to climb very carefully.
Mostly a function of good rock: Yosemite, Tahquitz, J Tree, and assorted lesser granite crags.
In reply to:
I've been climbing trad half that long and can already think of several. Granted most of them were due to crappy rock but wow only one?
Yep. A single quarter-inch bolt in sandstone at a semi-hanging belay. I didn't have a bolt kit, and I didn't know enough to back off.
May 29, 2009, 3:08 AM
Post #135 of 143
(6830 views)
Shortcut
Registered: Jul 6, 2006
Posts: 266
Re: [pendereki] Two piece anchors are plenty strong! Poll!
[In reply to]
Report this Post
Average:
(0 ratings)
Can't Post
It all depends on the stance. I've felt more safe with 1 bomber piece and a great seated spot than I ever have on any 4 piece, equalized, hanging belay that I've constructed.
So I guess to answer the question, at a hanging belay I usually stop building after 3 bomber pieces. If I can only get 2 bomber pieces I still feel ok about it because it's redundant. Less than that and I just do the best I can, maybe yell down to my partner to try not to fall, and keep the belay nice and tight to minimize the force on the anchor. Of course you do have to draw the line somewhere on what can be considered a belay, at which point downclimbing becomes the more attractive option.
If I'm at a sweet ledge I often plug 1 solid piece and start pulling up rope. I belay off my harness and just use that piece as a backup in case I'm pulled forward. But you'd be surprised how much weight you can hold without being moved. The fact that the force is being applied to your harness, which is around your center of gravity, allows you to hold someone much heavier than yourself.
The purpose of an anchor depends on the situation. A rescue anchor is to save lives. Ever seen rescue anchors? They're super burly. Nobodies going to take that much time to build rescue anchors at every belay. It'd be a waste of gear, time, and effort. I'd much rather climb.
The purpose of most other climbing anchors is to reduce the likelihood of hitting the ground to an acceptable probability...
Yeah, 6%. *roll*
That a 6% chance of failure of a routine belay anchor is acceptable is arguably the most outrageous statement I have seen on this website.
Jay
Assigning made up failure probabilities is ridiculous. 1%, 10%, 25%.... whatever. Its all made up and completely meaningless.
All you have is 'bombproof' and then you make up some logic and fabricate numbers to come up with a probability that suits your notion of bombproof.
The numbers are utterly meaningless. Stick with bombproof.
DMT
It seems to me that you have it backwards; that "bombproof" is meaningless without some numbers.
Jay
(This post was edited by jt512 on May 29, 2009, 3:29 AM)
The purpose of the anchor is to save the lives of the climbing party in the event of a fall, not reduce their chance of death to only 6%.
In reply to:
It's why, when I build anchors, I build ones that I think have essentially no chance of failing.
But a million to one? Not in your wildest dreams are you going to construct such a robust anchor on a trad climb in the real world.
Why? You don't think that there are placements that have a probability of failure of 1%?
Jay
I guess I don't really know what a 1% piece is J. What does that even mean?
I'm using it to mean that if you judged a zillion pieces to have a 1% chance of failure, then 1% of them would fail.
In reply to:
In terms of our discussion, correct - I do not think there are typically 3 independant 1% pro opportunities at each belay. I think the failure % is likely to significantly higher for the 'average' belay anchor.
Well, there you go. You do have an opinion about the failure probabilities of anchors. You think that most of them are greater than 1%.
In reply to:
Look I'm not objecting to the notion of building solid anchors, bombproof even. What I am voiceing is my gut feeling that many if not most trad anchors would ultimately fail your bomb proof test.
But the question is, is that because of inherent limitations of anchors, or because people aren't building anchors as well as they ought to be.
In reply to:
And I'm also voicing the caution that in trad the expectation of bomb proof anchors is at least part of the time is a fool's hope.
No one has suggested that that is the case, so I wish people would stop interjecting comments to that effect. That said, I think that the necessity of having a less that bombproof anchor is much rarer than people on this forum suggest. I think, rather, that many climbers, at least on this forum, romanticize the image of risky climbing, and exaggerate the relevance of these bad anchors in their own climbing. I've climbed above a bad anchor exactly once in my climbing career, and I'm willing to bet that that is one time more than 99% of climbers on this site ever have, except possibly due to their own incompetence at anchor building. Yet reading these discussions, instead of concentrating on principles of safe anchor building that apply to the vast majority of anchors encountered by users of this site, the talk always gets steered to the supposedly always crap alpine anchor, the anchor in junk sandstone, etc.
I was trained that the belay anchor must not fail, and I strongly suspect, that, for 99% of anchors, there is no reason that it should.
Jay
(This post was edited by jt512 on May 29, 2009, 3:57 AM)
tricams make great anchors, usually don't want to fiddle with them on lead if it will take a cam, and they are bomber for building anchors. the number 4 in the pic got replaced with a tricam slightly above when my 2nd arrived. guess the climb for bonus points, it's a classic in eldo. link: http://img29.imageshack.us/img29/8560/p1030638.jpg
I'm posting this in the hope that, perhaps, some notes might be helpful in the future.
Your anchor is almost certainly OK.... but it has some seriously worrysome aspects:
1) The blue cam is in a somewhat flaring crack. Yeah, it'll probably hold, but remember that a while back some folks at Metolius found that good looking cams fail something like 1 in 20 times... and this cam doesn't look all that good, owing to the flare.
2) your blue tricam looks terrible. Maybe there's a part of the crack we can't see, but the tricam's being pulled sideways in not a great way. yuck.
3) It's not obvious that your cordalette will maintain its integrity if a single piece pulls (ie. are there appropriate twists in the segments going to and from each piece?). Moreover, this type of connection, even if set up correctly here, is hard to inspect in general. Finally, there's no extension limiting or redundancy with respect to the cordalette - if any part of the cord gets knicked by a rock, well, the entire anchor goes. This was an anchor in eldo....
4) finally, and this is hard to tell without more context, the pieces are all levered against a single large chunk o' stone - i can't tell if that's a wedged boulder and possibly loose, or what. From this image, though, it is conceivable that that piece of rock could shift and wreak havoc with the entire anchor. Or, alternatively, that piece of stone could be completely bonded with the rock around it, totally voiding this part of the critique.
You didn't ask for an anchor critique, but, well, your anchor seemed to need it, anyway. No offense intended - just trying to spread good information...
tricams make great anchors, usually don't want to fiddle with them on lead if it will take a cam, and they are bomber for building anchors. the number 4 in the pic got replaced with a tricam slightly above when my 2nd arrived. guess the climb for bonus points, it's a classic in eldo. link: http://img29.imageshack.us/img29/8560/p1030638.jpg
I'm posting this in the hope that, perhaps, some notes might be helpful in the future.
Your anchor is almost certainly OK.... but it has some seriously worrysome aspects:
1) The blue cam is in a somewhat flaring crack. Yeah, it'll probably hold, but remember that a while back some folks at Metolius found that good looking cams fail something like 1 in 20 times... and this cam doesn't look all that good, owing to the flare.
2) your blue tricam looks terrible. Maybe there's a part of the crack we can't see, but the tricam's being pulled sideways in not a great way. yuck.
3) It's not obvious that your cordalette will maintain its integrity if a single piece pulls (ie. are there appropriate twists in the segments going to and from each piece?). Moreover, this type of connection, even if set up correctly here, is hard to inspect in general. Finally, there's no extension limiting or redundancy with respect to the cordalette - if any part of the cord gets knicked by a rock, well, the entire anchor goes. This was an anchor in eldo....
4) finally, and this is hard to tell without more context, the pieces are all levered against a single large chunk o' stone - i can't tell if that's a wedged boulder and possibly loose, or what. From this image, though, it is conceivable that that piece of rock could shift and wreak havoc with the entire anchor. Or, alternatively, that piece of stone could be completely bonded with the rock around it, totally voiding this part of the critique.
You didn't ask for an anchor critique, but, well, your anchor seemed to need it, anyway. No offense intended - just trying to spread good information...
he said the #4 [the cam] got swapped for another tricam in the crack above. i was gonna say the pink below the pin, the pin and another piece in the smaller crack above the cam would completely suffice---
---and you wouldn't have a rat's nest linking everything [or would you?]
---and are you the one that keeps fixing pinks at eldo?!
Thanks for the advice! I was actually hoping someone would critique my anchor.
1) I realised the blue cam wasn't great with the flare, but threw it in anyways because it's a #4 and fit. I'll make sure to think about flaring cracks more in the future.
2) The only way the blue tricam would fit in that part of the crack was well... jammed in that way.
3) The cordalette does have twists between pieces and I have heard that as long as you only tie into the anchor with your rope it won't get shock loaded if one piece fails? There is also a sling equalized between two pieces (blue and pink tri's) with both of the figure 8's backing up the clove hitches on the main tie in point.
4) If i remember right the top of the boulder was bonded with something else and not going anywhere.
May 29, 2009, 5:00 AM
Post #141 of 143
(6785 views)
Shortcut
Registered: Jul 27, 2007
Posts: 16
Re: [no_email_entered] Two piece anchors are plenty strong! Poll!
[In reply to]
Report this Post
Average:
(0 ratings)
Can't Post
no_email_entered wrote:
he said the #4 [the cam] got swapped for another tricam in the crack above. i was gonna say the pink below the pin, the pin and another piece in the smaller crack above the cam would completely suffice---
---and you wouldn't have a rat's nest linking everything [or would you?]
---and are you the one that keeps fixing pinks at eldo?!
nope, have yet to lose any gear... or see a fixed pink (only climbed there once on a foggy/rainy day). If I did see a fixed pink though I would take a sling or rock to a nut tool and pop it out... I like booty. And the chick working the front gate that day was hot.
Fair enough. God I miss granite. I need to quit climbing on this crap sandstone so I don't have to keep increasing the number of sub-par anchors I climb above.
80 /
37%
It's really the Adirondack Death Knot
