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useyourfeet
May 2, 2007, 7:15 PM
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I'm putting a rap anchor on a new route. I've been advised not to use chains and so to make it more low-profile I'm just using a quick link in each hanger. What is the optimal distance for this set-up?
I'll admit I'm not sure. Since the bolts will be used for a toprope anchor, it seems like the bolts want to be about a foot apart (making a sliding x with a shoulder-length runner). But when its time to rap, do you really want the bolts to sit that far apart? What is the best balance between these two uses of the bolts?
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trenchdigger
May 2, 2007, 7:42 PM
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Depends on rock quality, but I believe most wedge bolt manufacturers recommend a minimum "critical" distance of 10-12 diameters in concrete to achieve full strength. That's about 4 to 5 inches depending on your bolt diameter. The harder/stronger the rock, the less the critical distance should be. To keep the anchor low-profile, it would be advantageous to keep the bolts closer together. Having them close together doesn't effect top-rope setup. There's no need to have them further apart unless the rock dictates it.
I'd suggest double quick-links or quick links with steel rings or you'll end up with nasty rope twist when you pull your rope.
Another, lower profile option is to use the Metolius Rap hangers.
Edit: Why does it need to be a rap anchor if it's just a top-rope anchor?
(This post was edited by trenchdigger on May 2, 2007, 7:52 PM)
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caughtinside
May 2, 2007, 7:48 PM
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trenchdigger wrote: I'd suggest double quick-links or quick links with steel rings or you'll end up with nasty rope twist when you pull your rope. Another, lower profile option is to use the Metolius Rap hangers.
what he said. Fixe ring anchors are another good alternative.
Or just use a short length of chain, and spray paint it.
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tradmanclimbs
May 2, 2007, 8:37 PM
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Fixe rap hangers are lowest profile longest lasting set up. Single quick link is horrid. best chain option is 3 links of 3/8" logging chain. Short. low profile and orients correctly to pull rope through last link. fixe ring anchors are excelent as well but wear out quickly if abused. the chain wears out quick as well butv easy to replace.
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rocknice2
May 3, 2007, 12:28 AM
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I use two Fixe rap hangers, one 6-8" above the other and 2-3" apart.
Easy to pull rope , doesn't twist rope, still good for TR setup, replace only 1 ring when worn
See attachment below.
(This post was edited by rocknice2 on May 3, 2007, 12:31 AM)
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Anchor.jpg
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useyourfeet
May 3, 2007, 4:31 AM
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rocknice2 wrote: I use two Fixe rap hangers, one 6-8" above the other and 2-3" apart. Easy to pull rope , doesn't twist rope, still good for TR setup, replace only 1 ring when worn See attachment below.
That looks like Fixe's "Traditional Anchor" only without the chain. Here is my question: With the bolts only 2-3" apart, doesn't that create too sharp an angle for a sliding X? Plus, with the bolts at different heights, the two quickdraw method seems out of the question as well.
I'm obviously a little new to drilling anchors. But it seems to me that your set-up places a lot of weight on the top bolt while using the lower one as a back up (which would be shockloaded should the upper one break)
Am I off base? I appreciate everybody's insight!
Skyeler
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trenchdigger
May 3, 2007, 4:34 AM
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useyourfeet wrote: rocknice2 wrote: I use two Fixe rap hangers, one 6-8" above the other and 2-3" apart. Easy to pull rope , doesn't twist rope, still good for TR setup, replace only 1 ring when worn See attachment below. That looks like Fixe's "Traditional Anchor" only without the chain. Here is my question: With the bolts only 2-3" apart, doesn't that create too sharp an angle for a sliding X? Plus, with the bolts at different heights, the two quickdraw method seems out of the question as well. I'm obviously a little new to drilling anchors. But it seems to me that your set-up places a lot of weight on the top bolt while using the lower one as a back up (which would be shockloaded should the upper one break) Am I off base? I appreciate everybody's insight! Skyeler
You sound like a little new with building anchors in general.  Maybe it would be wise to find someone in your area that has some bolting experience to help you out.
(This post was edited by trenchdigger on May 3, 2007, 4:35 AM)
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papounet
May 3, 2007, 6:22 AM
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trenchdigger wrote: useyourfeet wrote: rocknice2 wrote: I use two Fixe rap hangers, one 6-8" above the other and 2-3" apart. Easy to pull rope , doesn't twist rope, still good for TR setup, replace only 1 ring when worn See attachment below. That looks like Fixe's "Traditional Anchor" only without the chain. Here is my question: With the bolts only 2-3" apart, doesn't that create too sharp an angle for a sliding X? Plus, with the bolts at different heights, the two quickdraw method seems out of the question as well. I'm obviously a little new to drilling anchors. But it seems to me that your set-up places a lot of weight on the top bolt while using the lower one as a back up (which would be shockloaded should the upper one break) Am I off base? I appreciate everybody's insight! Skyeler You sound like a little new with building anchors in general. Maybe it would be wise to find someone in your area that has some bolting experience to help you out.
Hint:
1. Unknows about Rock Quality MANDATE that bolt be 8 inch apart at least , yet you can not have too great horizontal separation because:
a/ on a horizontal setup, you could have force multiplication (cf. american triangle), this is the reason for the length of chain of a Fixe anchor
b/ the rope is a bitch to recall
c/ 2 bolts straight above each other are not good because of the rope path if the rope is threaded in both
2/ Is it a rap anchor or a TR anchor or a belay in a multipitch route?
a/ If it is a rap anchor, who would leave a sliding X set up on it ?
b/ A 2 draws setup sound awfully like a cheap DANGEROUS to do a Top-rope. Even a professionnal guide like Patrick Vallencant died when the rope twisted out of a 2 draws setup
c/ if used on a route, offset bolts leave a lot of flexibility: put one locker each or put a locker in the bottom one and a draw in the upper one which should be in the direction the route will continue,
3/shockloading won't matter much if the climber are connected via a dynamic rope, and the force on a rappel are not that big. Anyhow, for you could use a loop of rope of the right length to connect the top bolt to the quicklink placed in the bottom bolt a la
http://www.fixeusa.com/trad.htm
4/ use quicklinks (easier to replace than chain) and provide additionnal wiggle to recall the rope. Not all quicklinks are equal, choosethe right one. If using a chain, use the righjt one also, Cheap chain bought at the hardware store will have verw low resistance
5/ for people that do not like to see chains, a piece of sling with one rappel link hanging from 2 bolts will get uglier and uglier as people will add slings and tat, better to PAINT the anchor.
6/ if using a bolt hanger and a quicklink, make sure that one can still put a locker through the bolt
7/ to prevent quicklink easy removal by thiefs, put a dab of Expoxy onto the quicklink thread.
An permanent anchor setup is more than just 2 bolts. it is about stance, and route.
Above are some of the issues I find important.
I would second trenchdigger in suggesting that you find someone with experience and a record of good anchors. (beware of some anchors-happy guys who do a shitty job).
(This post was edited by papounet on May 3, 2007, 6:36 AM)
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binrat
May 3, 2007, 2:00 PM
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Personally when I do anchors at the top I use combination quicklinks / chain / quicklinks. For me it's more important to have bomb proof bolts. I go with 2 anchors about a foot apart (depending on the rock) in a near vertical orientation (upper anchor either 11:00 or 1:00 compared to lower) I use 1/2 dia bolts for this. The threads on the quicklinks are covered with red locktite so nobody can easily take them but still can be replaced with some work. The chains are painted afterwards to help cam them up.
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pmyche
May 3, 2007, 2:21 PM
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You can't have everything. If you want minimal impact (i.e., bolt/screwlink x2), you'll have lack of equalization (vertical, as shown) or extra wear (horiz orientation).
ASCA's Clean Anchors capmaign uses just this (horiz) set up, and some of those anchors have shown more wear and tendency to loosen than would a vertical or extended set up. Boltdude might want to weigh in here...Greg?
As suggested by others, I think the best m.o. is vertical orientation with painted chain extension.
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tradmanclimbs
May 3, 2007, 10:41 PM
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Correction on my earlier post. The low profile heavy duty won't wear out hanger is the Metulios rap hanger. Wicked burly. they pull a little stiff but that keeps the wankers from top ropeing through them.
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billcoe_
Feb 29, 2008, 12:21 AM
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papounet wrote: b/ A 2 draws setup sound awfully like a cheap DANGEROUS to do a Top-rope. Even a professionnal guide like Patrick Vallencant died when the rope twisted out of a 2 draws setup
Oh wow, first I'd heard of this. I guess i need to get out more. That sucks big. I would have thought for sure he'd bite it on some random steep 60º north face slope when he hit an ice patch or a rock.
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majid_sabet
Feb 29, 2008, 12:57 AM
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If you never installed any bolt then you should go with someone who has placed a few so you could understand the procedures. Setting up anchor bolt is like holding people’s lives in your hand. Most climbers do not question the anchor setup assuming whoever place those bolts knew what he was doing so just be careful when establishing a fix anchor.
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pro_alien
Mar 2, 2008, 1:37 PM
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useyourfeet wrote: Here is my question: With the bolts only 2-3" apart, doesn't that create too sharp an angle for a sliding X? Plus, with the bolts at different heights, the two quickdraw method seems out of the question as well. I'm obviously a little new to drilling anchors. But it seems to me that your set-up places a lot of weight on the top bolt while using the lower one as a back up (which would be shockloaded should the upper one break)
First of all, shock load is limited by using a dynamic rope. Think of it in terms of energy, you just have the climber falling an extra few inches.
Second, equalization is not a must when dealing with bolts. To me it is much more important that you can tell when one of the bolts is going bad.
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rgold
Mar 2, 2008, 4:59 PM
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various posters wrote: ...shockloading won't matter much if the climber are connected via a dynamic rope, and the force on a rappel are not that big... ...shock load is limited by using a dynamic rope. Think of it in terms of energy, you just have the climber falling an extra few inches.
Everyone used to think "shock loading" (a term that is far from clearly defined) had to be avoided at all costs. Now, more and more, we are hearing that it doesn't matter if there is dynamic rope in the system.
I submit, the Sterling tests notwithstanding, that we really don't know what the effects of shockloading will be in different scenarios, and there are ample theoretical reasons to be extremely cautious about dismissing shock loading as a concern. Until these theoretical concerns can be tested practically (something the Sterling tests did only very partially, and not in a way likely to reflect actual practice), I would suggest that, as the only source of information available, the theoretical concerns should be viewed as decisive.
The Sterling tests showed, as the theory has predicted for years, that a drop that is small compared to the amount of dynamic rope available for energy absorbtion will not produce worrisome loads on the remaining anchors. But this completely avoids the question of what happens when the drop is not small compared to the amount of absorbing rope. Top-ropers are probably always going to be ok, but all bets are off if one of the bolts fails at the moment a rappeller weights the anchor (something that I recall has indeed happened with fatal consequences). In this case, it is possible that there will be a significant fall factor, even though the rappeller is only falling a few few inches, because there may only be a few inches of rope (from rap device to anchor) to absorb fall energy. Making the situation worse is the fact that the usual double-rope rappel provides a much stiffer energy-absorber.
The purpose of vertically oriented chain-connected bolts is to eliminate shock-loading as a major concern, even if at the expense of equalization, which is (or should be) far less critical with bolts than it is with passive gear.
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billcoe_
Mar 11, 2008, 7:47 PM
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rgold wrote: but all bets are off if one of the bolts fails at the moment a rappeller weights the anchor (something that I recall has indeed happened with fatal consequences). In this case, it is possible that there will be a significant fall factor, even though the rappeller is only falling a few few inches, because there may only be a few inches of rope (from rap device to anchor) to absorb fall energy. Making the situation worse is the fact that the usual double-rope rappel provides a much stiffer energy-absorber.
Perhaps you can show a link to where a rappel anchor failed thusly RG? I had "heard" from a buddy @ 20 years ago, that the Route Anchors Away" in Yosemite which was subsequently named "Anchors Away" after the anchor failed on rap for during the FA.
I later got the low down that the 2 guys were jugging a line on a single 1/4"er to their high-point they had rapped off of earlier, said bolt failed and killed them both.
That being said, the citation guy makes above that spacing 10X the anchor diameter isn't too bad of a rough rule of thumb IMO. (So 2 - 3/8" diameter anchor bolts would be approx 8" or so apart .375 x 2 = 3.75" x 2) As important, check and eyeball the rock closely for any fractures or strange cracks or striations and make sure you get good rock. Point is the closer you put the bolts to each other, the weaker the placement. All of the anchor mfgs specs get tested and listed - you can check any of their sites to get this info. The Fixe chain anchor that has a vertical orientation is about 8", which is in line with that rough rule of thumb. 
They claim that the vertical orientation is vastly superior to the usual US horizontal thing, however, you could debate that as they only have a single ring to rely on and at some point it's gonna wear.
Here's the Powers site for some formulas.
http://www.powers.com/...mechanical/07424.pdf
Look at p9 in the Powers attachment for the math formula on critical spacing and distance.
I don't know if you need to sweat donkey balls over it though, as a single 3/8 wedge anchor is usually in the 4000 lbs range, and you slap 2 of them in good rock....maybe R gold can site a failure, but I don't know of any. Pay close attention to the torque needed to properly set a bolt. I have a torque wrench for this very thing, and find that for me, a 6" Crescent wrench, real snug, duplicates the 25-30 ft lbs that the Mfg of the product I use recommends. Note that Powers is suggesting a lower torque of 20 ft lbs. If you over torque it is an equal evil as under torquing for an anchor IMO. If you don't think you can nail the torque thing or you have doubts at all, go with a 1/2" diameter bolt. Fixe sells a 13mm hanger for that size anchor stud.
And use Stainless steel OK? Don't cheap out.
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healyje
Mar 11, 2008, 10:03 PM
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tradmanclimbs wrote: Correction on my earlier post. The low profile heavy duty won't wear out hanger is the Metulios rap hanger. Wicked burly. they pull a little stiff but that keeps the wankers from top ropeing through them.
They are currently not available due to Metolius' efforts to keep up with the demand for their Ultralights and cranking up the Master Cam line. I hope they sort out the problem by summer as I'm in need of a dozen of them myself for anchor replacements.
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