Do you trust one bolt?

Equalizing the load on anchors that each can hold 4000 to 8000lbs (5-10X factor of safety) really doesn't matter. That issue applies to trad anchors built from sideways RPs. At least in the US the cost to build an anchor with 2 rings isn't prohibitive, but it is a real good idea to wrench the quicklinks so that they aren't so easy to swipe.

MJMobes wrote: my only problem with the vertical setup is that a 1/4"-1/8" one way or the other and only one bolt takes weight for its whole existence of being an anchor. basically the amount of accuracy needed to get the two bolts perfectly equalized would be easier to do in a shop with a drill table setup. ...a "v" style anchor is easier to equalize.

I completely agree ^^^!

Another problem with absolutely vertical installations (at least in remote or low use areas) is that when viewing the anchor from the ground it is not always possible to verify that there are two bolts.

Tzilla Rapdrilla wrote:Equalizing the load on anchors that each can hold 4000 to 8000lbs (5-10X factor of safety) really doesn't matter. That issue applies to trad anchors built from sideways RPs. At least in the US the cost to build an anchor with 2 rings isn't prohibitive, but it is a real good idea to wrench the quicklinks so that they aren't so easy to swipe.

Yeah, the words "doesnt really matter" means its ok that its not perfect, it still works. Well, not too many people involved with jobs in any trade from building a car to a house can tell that to a customer and expect them to be extremely happy. In this case we are the builders and the customers so perfection should be a no brainer.

Either way if the anchors are just for rappel it really is no big deal but if a bunch of TR gang bangers are going to use and abuse it all year round it should be perfectly equalized.

MJMobes wrote: Yeah, the words "doesnt really matter" means its ok that its not perfect, it still works. Well, not too many people involved with jobs in any trade from building a car to a house can tell that to a customer and expect them to be extremely happy. In this case we are the builders and the customers so perfection should be a no brainer. Either way if the anchors are just for rappel it really is no big deal but if a bunch of TR gang bangers are going to use and abuse it all year round it should be perfectly equalized.

You could use mussey hooks. If they are slightly uneven, the one taking the load will wear down to equalize it eventually.

Oh gee, I don't know what to think! There's so many knowledgeable people here saying so many different things!

don'tchuffonme wrote:Oh gee, I don't know what to think! There's so many knowledgeable people here saying so many different things!

chuff on over to the water(death) knot thread if you really want to learn from the masters

Tug the shit out of the bolt then you know its bommer and can rapp of it without worrying if its going to break.

William Turner wrote:Tug the shit out of the bolt then you know its bommer and can rapp of it without worrying if its going to break.

see, someone here knows how to test an anchor. when you get to them ,pull out on them as hard as you can chuff

one bolt hummmm.... I feel pretty damn good about one glue in. Or one exceedingly good 1/2x4in expansion bolt.

One bolt will probably hold you.

There is more to consider than just the theoretical strength of steel. In almost any form of human activity there is greater than a 1 in 100 chance of human error. That is, there is a chance of error in every operation around placing an anchor and clipping into it. I like a little redundancy for safety.

Does anyone know if the steel rap rings are pull tested to, say, half their rated strength? If so, seems like the only issue would be wear over time, and not skepticism of a botched internal weld.

Mitch Musci wrote:Does anyone know if the steel rap rings are pull tested to, say, half their rated strength? If so, seems like the only issue would be wear over time, and not skepticism of a botched internal weld.

I doubt that they all are, probably just quality control pull testing to failure is done, but it doesn't really matter since even a ring that is NOT even welded will still hold way more than you will ever put on it while rapping.

MJMobes wrote: Yeah, the words "doesnt really matter" means its ok that its not perfect, it still works. Well, not too many people involved with jobs in any trade from building a car to a house can tell that to a customer and expect them to be extremely happy. In this case we are the builders and the customers so perfection should be a no brainer. Either way if the anchors are just for rappel it really is no big deal but if a bunch of TR gang bangers are going to use and abuse it all year round it should be perfectly equalized.

Okay, let's clear up this myth once and for all. It's not that equalization "doesn't really matter", in the context of modern bolted anchors, equalization doesn't matter at all, not even slightly. Equalization is only important when building anchors out of marginal gear. A modern bolt rated to 5000+ lbs DOES NOT NEED TO BE EQUALIZED FOR ANY REASON.

The only reason that a second bolt is a good idea is for redundancy, not equalization. The next argument is of course going to be "but what if one of the non equalized bolts blows, you'll shock load the anchor". So let's dispel that myth as well, THERE'S NO SUCH THING AS SHOCK LOADING AS LONG AS THERE IS A DYNAMIC ROPE IN THE SYSTEM.

So then the next argument of course is that since only one bolt is being loaded it's going to fatigue and wear out, but once again, this just isn't the case. The number of millions or billions of cycles that would be required to fatigue a bolt by rapping or TRing off of it is so high that it would be many lifetimes away on even the most traveled routes.

In reality, a well placed single bolt in good rock is perfectly fine to rap or lower off of. The reason for the second bolt is in case the first bolt isn't well placed or the rock it is placed in is bad. I have rapped off of many single bolts (The Frankenjura) and have absolutely no problem doing it. Obviously I will look a little more closely at the single bolt than if it were a two bolt anchor, but it is perfectly fine.

As has been noted before in this thread, when sport climbing you are relying on a single bolt to catch your falls (much higher forces than rapping or lowering) until at least the third bolt, and many times even higher than that depending on how the route was bolted. I've whipped many times onto a bolt where I would deck if that bolt were to blow, that's just one of the risks that you have to accept if you are sport climbing. Obviously don't do anything that makes you uncomfortable, but let's at least try to have some common sense and stop having totally irrational fears.

No I don't. I've seen bolts break in half while being tightened after placement more than once (not by me).

Who's to say the bolt you're trusting isn't 1/100th of a turn close to snapping because it was placed wrong? You can't tell by looking at it, that's for sure.

Mitch Musci wrote:Does anyone know if the steel rap rings are pull tested to, say, half their rated strength? If so, seems like the only issue would be wear over time, and not skepticism of a botched internal weld.

We did start out with ideas of pull-testing rings (to 12kN if I remember correctly, I´ve the jig for doing it lying around somewhere) but there´s loads of problems with partial or even full proof testing.
With rings the big problem is they are supposed to be round and even doing it with a complicated round jig they won´t be after they are pulled.
The next problem is after you´ve proof tested a few hundred and destruction tested them as well you quickly work out there isn´t any relationship between the two and proofing is just a waste of time.
Proof testing is anyway something which isn´t real popular in the climbing industry since a large number of items would be either destroyed or rendered unusable if they were full proof tested and partial proof is generally worthless.

Internal flaws in the weld are irrelevant in that if you can see any weld at all somewhere on the join the ring is strong enough, the first tack weld on an 8mm ring is enough to get over the requirements (25kN) and for the thicker rings no weld at all will do nicely.
Stainless rings are interesting in that once you get past about 70% weld the ring fails on the other side away from the weld anyway. The weld metal is softer than the rest which has become work-hardened during bending, the weld stretches putting more of the load onto the unwelded side which breaks first.
Testing the thicker rings (10mm & 12mm) is incidentally quite a problem, to attatch to the tester you need to be able to get two bits of metal strong enough throught the ring which for small diameter rings is completely impossible which is generally why the rated strengths stop long before the real breaking strength.

Jim Titt wrote: Internal flaws in the weld are irrelevant in that if you can see any weld at all somewhere on the join the ring is strong enough, the first tack weld on an 8mm ring is enough to get over the requirements (25kN) and for the thicker rings no weld at all will do nicely.

So what you are saying is 3 sigma testing would be kind of stupid in this instance. There is no chance a ring can fail outside the requirement with a simple visual inspection, whereas the 3 sigma test would say a more uniform welding standard would reduce the chance a product will fail outside the requirement.

Thanks Jim, very useful info. If there was ever any doubt in my head about rapping on a single 50kn ring linking two bolts, it is gone now.

kennoyce wrote: Okay, let's clear up this myth once and for all. It's not that equalization "doesn't really matter", in the context of modern bolted anchors, equalization doesn't matter at all, not even slightly. Equalization is only important when building anchors out of marginal gear. A modern bolt rated to 5000+ lbs DOES NOT NEED TO BE EQUALIZED FOR ANY REASON. The only reason that a second bolt is a good idea is for redundancy, not equalization. The next argument is of course going to be "but what if one of the non equalized bolts blows, you'll shock load the anchor". So let's dispel that myth as well, THERE'S NO SUCH THING AS SHOCK LOADING AS LONG AS THERE IS A DYNAMIC ROPE IN THE SYSTEM. So then the next argument of course is that since only one bolt is being loaded it's going to fatigue and wear out, but once again, this just isn't the case. The number of millions or billions of cycles that would be required to fatigue a bolt by rapping or TRing off of it is so high that it would be many lifetimes away on even the most traveled routes. In reality, a well placed single bolt in good rock is perfectly fine to rap or lower off of. The reason for the second bolt is in case the first bolt isn't well placed or the rock it is placed in is bad. I have rapped off of many single bolts (The Frankenjura) and have absolutely no problem doing it. Obviously I will look a little more closely at the single bolt than if it were a two bolt anchor, but it is perfectly fine. As has been noted before in this thread, when sport climbing you are relying on a single bolt to catch your falls (much higher forces than rapping or lowering) until at least the third bolt, and many times even higher than that depending on how the route was bolted. I've whipped many times onto a bolt where I would deck if that bolt were to blow, that's just one of the risks that you have to accept if you are sport climbing. Obviously don't do anything that makes you uncomfortable, but let's at least try to have some common sense and stop having totally irrational fears.

You are ignoring different rock qualities and assume its all bomber. At least in chossy sandstone when the lower bolt does start wearing out the hole its sticking in it WILL be equalized eventually eh?

lets let this guy explain the problem here-

limpingcrab wrote:No I don't. I've seen bolts break in half while being tightened after placement more than once (not by me). Who's to say the bolt you're trusting isn't 1/100th of a turn close to snapping because it was placed wrong? You can't tell by looking at it, that's for sure.

whos to say both bolts werent over tightened?

kennoyce is assuming every bolt ever placed was done to perfection

I was liking this vert. anchor thing at first but now have changed my mind, I'll stick with the old V with chains on most anchors even if it does cost a bit more. Its certainly not the single steel ring that bothers me, I've rapped on plenty of 5/16 quick links with the threads going the wrong way and live to tell.

MJMobes wrote: You are ignoring different rock qualities and assume its all bomber. At least in chossy sandstone when the lower bolt does start wearing out the hole its sticking in it WILL be equalized eventually eh? lets let this guy explain the problem here- whos to say both bolts werent over tightened? kennoyce is assuming every bolt ever placed was done to perfection I was liking this vert. anchor thing at first but now have changed my mind, I'll stick with the old V with chains on most anchors even if it does cost a bit more. Its certainly not the single steel ring that bothers me, I've rapped on plenty of 5/16 quick links with the threads going the wrong way and live to tell.

I'm not ignoring different rock qualities or the fact that the bolts may have been installed improperly, that's why you need redundancy with the second bolt. Even in the scenario's you've listed equalization doesn't matter for the reasons that I covered previously.

In fact, your point about chossy sandstone is a great reason to have non-equalized bolts. With non-equalized bolts in this situation, you will wear out the hole that the loaded bolt is placed in, and then when that bolt fails, you still have a perfectly good bolt that's never even been loaded. In the case of equalized bolts in chossey rock, who's to say that the repeated loading isn't going to loosen both bolts at the same rate until they both pull simultaneously? The probability is extremely low that this would happen, but it's certainly higher than with un-equalized bolts.

Now if we're talking about bolts that have been over-tightened to the point of almost breaking, again, that's why you need redundancy, so that hopefully the second bolt was placed well and not over-tightened. Again, equalization doesn't buy you anything.

Personally, I generally place v-style anchors because I hate the fact that you have to replace the entire anchor system with the inline fixe's, but I don't do it out of some irrational fear over the two bolts not being equalized, or the fear of a single 50kN ring braking.