OZ wrote:OK. Then why not retorque everything to a greater degree?
We've found that in many placements it does not matter how tightly you torque the bolts. They will still loosen. The sandstone is soft (low compressive strength), and when the hanger is torqued repeatedly by falling climbers, it crushes the stone surface that engages the hanger and it eventually loosens.
Of course, if you torque too high -- say above 45 foot-pounds, then you greatly increase the chance of cracking the rock. Go higher than about 65 foot-pounds and you increase the chances of twisting the bolt head off.
No easy answers.
Rick
We cannot change the cards we are dealt, just how we play the hand. - Randy Pausch
None are so old as those who have outlived enthusiasm. - Henry David Thoreau
Andrew wrote:I would really like to see the strength of just a threaded rod. I don't know alot about different grades of metal, but you would think that there would be some threaded rods that are of a little higher quality metal. I bet your standard threaded rod would hold more than enough weight. I have seen standard threaded rods bend too, but usually in situations where there is some leverage. There is not a whole lot of leverage when all of the force is put on the rod right next to where it come out of the rock. I would think 5 or 6 inch threaded rod of a decent grade would be really cheap and strong.
I think I might start bolting some routes with wooden pegs. They worked in all the old barns that still stand today.
Good observation. We have tested threaded stainless steel rods (3/8-16) and found that they adhere really well to a drilled hole. The problem is that you must attach the hanger bracket with a nut. And this nut MUST be Loctited to the threaded rod. (If a nut ever loosened and spun off, the hanger would quickly follow, regardless of the quality of the bond between the threaded rod and the rock.) A loose bolt, on the other hand, can still hold several thousand pounds as it tends to tighten the cone in the manner of a Chinese finger puzzle as it is pulled. (Of course, both loose bolts and loose nuts are to be avoided.)
It is important to note that BOTH the bolted hanger and the threaded rod/nut hanger can be loosened by repetitive falls. Continual torquing of the hanger eventually crushes the sandstone surface that the hanger engages and cause it to loosen. But, now instead of merely re-tightening the nut as you would an expansion bolt, you must first loosen the Loctite bound that keeps the nut on the rod. To tighten the nut without Loctite creates a very dangerous and unacceptable placement.
The FIXE glue-in eye-bolt solves this problem by completely eliminating the hanger bracket from the equation.
Rick
We cannot change the cards we are dealt, just how we play the hand. - Randy Pausch
None are so old as those who have outlived enthusiasm. - Henry David Thoreau
JB wrote:interesting. i like the amount of work going into this, even though it seems like overkill a lot of the time.
lurkist, if you are talking about stock threaded rod, it is significantly weaker than a traditional bolt. I've seen threaded rod bend and break in situations where a regular timber bolt of a smaller diameter has held. I bet it would definitely bind with the glue well, but i don't knoe if that'd help it much.
everybody keep in mind that even when rick has an awesome system worked out for bolting, climbing will still be dangerous and stuff could happen. be safe. nothing is foolproof.
"Significantly weaker" is a relative term. We need to remember that the force it takes to fail 3/8-16 s.s. threaded rod or a 3/8-16 expansion bolt in shear or tension would rip our guts out long before the metal hardware would fail. Hardware strength is, indeed, an important part of the equation -- especially when looking at the long term effects of corrosion.
Remember that the human body is the weakest link in the climber/rope/rock/bolt/hanger chain.
Rick
We cannot change the cards we are dealt, just how we play the hand. - Randy Pausch
None are so old as those who have outlived enthusiasm. - Henry David Thoreau
Mboss wrote:It sounds like you are doing static testing to the point of bolt failure. Wouldn't it be more realistic to do dynamic testing where you are stressing the bolt multiple times (with a smaller load) rather than a single large load of force? Maybe the glue-in resists a single load of force better than the Dynabolt Gold but maybe this is not true of multiple falls. You must be certain that your mode of testing is accurate for the activity if you anticipate a large cost and time element associated with replacement of the hardware already installed.
Just something to think about.
Yes, you are partially correct. Actually, our tests are slow dynamic loading. But, "impulse loading" tests can be done, even though they are much harder to conduct and instrument. JJ and I have been working on a way to rig a rock of known weight to a large rock via heavy cable and drop it.
Now, when you get into repetitive load cycling, that gets pretty hard to do. Remember, this ain't no money-making laboratory. All this test equipment and hardware comes out of my pocket, and there is a limit to time and resources. Anybody want to offer your services or lab?
Rick
Last edited by weber on Thu Apr 13, 2006 1:36 am, edited 1 time in total.
We cannot change the cards we are dealt, just how we play the hand. - Randy Pausch
None are so old as those who have outlived enthusiasm. - Henry David Thoreau
Maybe i am dumb, but why would a threaded rod have to have the nut loctited on. Is the loctite really necessary. Do you really believe people will go around and steal hangers, or will it really loosen up all the time. Maybe I have been away from the red for too long, but I remember seeing threaded bolts on routes and they weren't loose. I see threaded bolts on routes in NC all the time and the aren't that loose either, I know the rock is much harder. but they are all 15 years old.
Andrew wrote:Maybe i am dumb, but why would a threaded rod have to have the nut loctited on. Is the loctite really necessary. Do you really believe people will go around and steal hangers, or will it really loosen up all the time. Maybe I have been away from the red for too long, but I remember seeing threaded bolts on routes and they weren't loose. I see threaded bolts on routes in NC all the time and the aren't that loose either, I know the rock is much harder. but they are all 15 years old.
Would some folks steal hangers? Absolutely! We've had about 12 quicklinks removed in the past 4 months. Some real wackos out there.
Yes nuts will loosen. And bolts will loosen. And not just in MV as some whinners contend. A loose hanger was found on a Porter Jarard route last weekend. There are loose hangers in all parts of the Red.
Babys cry. Shit happens. And, bolts and nuts loosen.
I sure as hell would prefer to be on a loose bolt than a loose nut. The bolt will probably hold - especially if it is generally at right angles to my fall. But, a couple turns of that loose nut, and the hanger and I are gonna fly.
Rick
We cannot change the cards we are dealt, just how we play the hand. - Randy Pausch
None are so old as those who have outlived enthusiasm. - Henry David Thoreau
Rick, the only possible concern that I might see is with the anchors. Is there going to be a problem with the different metal types if you put quick links on the Ti eye bolts for anchors? For example, with SS quick links and Ti eye bolts will there be any corrosion or anything other type of chemical reaction between the two that will compromise their strength?
By no means did I mean that all threaded bolts had tight nuts, and I definitley didn't mean the Muir has worse rock or poor bolting quality. I love climbing at Muir, it has the best looking bolts I have ever seen or fallen on. I am used to climbing on 15 to 20 year old 3/8th and 5/16th rusty bolts. Half with spinning hangers. I was just wondering if it was more cost effective to use cheaper threaded rods and loctite nuts or not loctite them and tighten occasionally. I agree with whole heartedely, shit happens and bolts loosen. If you think something is unsafe, fix it yourself or don't climb it.
Maybe we should label the placements on all the trad routes while were at it.
lordjim_2001 wrote:Rick, the only possible concern that I might see is with the anchors. Is there going to be a problem with the different metal types if you put quick links on the Ti eye bolts for anchors? For example, with SS quick links and Ti eye bolts will there be any corrosion or anything other type of chemical reaction between the two that will compromise their strength?
I think the galvanic reaction between dissimiliar metals in the case of eyebolts and quicklinks is insignificant compared to other factors. Just my opinion.
And, of course, with only an s.s. glue-in eyebolt and no other metallic hardware required, there is no reaction to worry about.
Rick
We cannot change the cards we are dealt, just how we play the hand. - Randy Pausch
None are so old as those who have outlived enthusiasm. - Henry David Thoreau
Andrew wrote:By no means did I mean that all threaded bolts had tight nuts, and I definitley didn't mean the Muir has worse rock or poor bolting quality. I love climbing at Muir, it has the best looking bolts I have ever seen or fallen on. I am used to climbing on 15 to 20 year old 3/8th and 5/16th rusty bolts. Half with spinning hangers. I was just wondering if it was more cost effective to use cheaper threaded rods and loctite nuts or not loctite them and tighten occasionally.
Thanks, Andrew. Sorry, my usually thick skin has been getting a little thin in places lately. As for the cost of threaded rods, we are concerned first about using the best, safest possible anchor. Cost is secondary.
Rick
We cannot change the cards we are dealt, just how we play the hand. - Randy Pausch
None are so old as those who have outlived enthusiasm. - Henry David Thoreau
