We will assess this incident next weekend and report what we found on this forum. If the guys who popped the bolt have it, we really would like to see it. It is disconcerting that neither Hoss nor I knew of the missing bolt until he encountered it.
PLEASE be responsible and report similar siuations IMMEDIATELY to me or any one of the Muir development team so that they can be remedied. How would you feel to know of this situation, but not report it, and then hear that Hoss blew the move and took a ground fall? Fortunately, that didn't happen.
"Rising" is officially CLOSED until the bolt is replaced. Do NOT climb this route. We may find it necessary to back up a bolt here with a cable leader to another bolt. In any case where a route cannot be protected with relative safety, the route will be unbolted and removed.
Thanks, Hoss, for reporting this to us.
Rick
The Rising @ Rebel Camp (Branch)
For those of you who are new to this forum or who may have missed some of our early pull-out testing of bolts, here is the link. It is long and technically boring, so a summary is given below.
http://www.redriverclimbing.com/viewtop ... sc&start=0
Summary:
Although there is no universally-accepted force value that bolted hangers should be able to hold, most hanger brackets have been UIAA tested to forces exceeding 25 kiloNewtons (about 5620 pounds). We've found that commonly-used anchor bolts fail at about 4500 pounds downward pulls when mounted on generally vertical walls.
When hangers affixed with 3 3/4- inch Dynabolt Gold expansion bolts are pulled straight out (in an direction parallel to the longitudinal axis of the bolt) of "average" Corbin sandstone, the resistance is only about 2200 to 3500 pounds. Longer bolts are only insignificantly better. This is because ALL 1/2 inch expansion bolts of this configuration use the same cone-in-a-sleeve design. When a outward force is exerted on the bolt, the cone pulls up into the sleeve, forming a buldge, and the buldge starts crushing the sandstone as it slowly exits the hole. It just takes longer for a longer bolt to exit its hole,
I can see where repeated whippers on a bolt in softer sandstone can gradually pull it out of its hole. It is important to note that this process stops when only about 2 inches of bolt is left in the hole. At this point, the rock itself, due to its very low tensile strength, usually breaks away.
Bottom line opinion: Here in the Red, on this weak sandstone where bolted hangers are placed under roofs where there is a large vector of force pulling straight out on the bolt, some type of back up would be a good idea. In Muir, we've tried to minimize the number of bolted hangers that can be subjected to high straight-out forces. Where these are absolutely necessary to protect a hard roof move or very steep surface, it might be good to back the hangers up with a cable draw over to another bolt. The Muir developers will kick this idea around and report back to this forum in a few days.
Rick
http://www.redriverclimbing.com/viewtop ... sc&start=0
Summary:
Although there is no universally-accepted force value that bolted hangers should be able to hold, most hanger brackets have been UIAA tested to forces exceeding 25 kiloNewtons (about 5620 pounds). We've found that commonly-used anchor bolts fail at about 4500 pounds downward pulls when mounted on generally vertical walls.
When hangers affixed with 3 3/4- inch Dynabolt Gold expansion bolts are pulled straight out (in an direction parallel to the longitudinal axis of the bolt) of "average" Corbin sandstone, the resistance is only about 2200 to 3500 pounds. Longer bolts are only insignificantly better. This is because ALL 1/2 inch expansion bolts of this configuration use the same cone-in-a-sleeve design. When a outward force is exerted on the bolt, the cone pulls up into the sleeve, forming a buldge, and the buldge starts crushing the sandstone as it slowly exits the hole. It just takes longer for a longer bolt to exit its hole,
I can see where repeated whippers on a bolt in softer sandstone can gradually pull it out of its hole. It is important to note that this process stops when only about 2 inches of bolt is left in the hole. At this point, the rock itself, due to its very low tensile strength, usually breaks away.
Bottom line opinion: Here in the Red, on this weak sandstone where bolted hangers are placed under roofs where there is a large vector of force pulling straight out on the bolt, some type of back up would be a good idea. In Muir, we've tried to minimize the number of bolted hangers that can be subjected to high straight-out forces. Where these are absolutely necessary to protect a hard roof move or very steep surface, it might be good to back the hangers up with a cable draw over to another bolt. The Muir developers will kick this idea around and report back to this forum in a few days.
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
None are so old as those who have outlived enthusiasm. - Henry David Thoreau
Faulty physics. Although there are a buttload of variables, the amount of force generated is related to the amount of rope that is out in proportion to the length of the fall. A longer fall, in itself, doe not produce less force.Saxman wrote:Take longer falls. Longer falls actually produce less force due to rope stretch. Too bad the ground is so close.
ZSpider
Are you expecting to snap some bolts soon? Did you gain weight or something?diggum wrote:This is not helping my lead head.
[size=75]You are as bad as Alan, and even he hits the mark sometimes. -charlie
"Not all conservatives are stupid, but most stupid people are conservative." - John Stuart Mill[/size]
"Not all conservatives are stupid, but most stupid people are conservative." - John Stuart Mill[/size]
rhunt's experience was at Torrent....I am terrible with route names there, but it was on of those routes around the right side that start above that 10 foot drop off..about 3-4 routes left of Seek The Truth. First bolt blew, and the dude landed with his head over that ledge. close call. His name was Mike from Columbus. Happened 6-8 years ago.
Positive vibes brah...positive vibes.
Saturday, JJ and I checked out Rising. Very strange. The hanger and bolt had been removed, although the inner sleeve and cone were left in the hole. The hole was in perfect condition, and the sleeve and cone had only mild corrosion of the zinc plating. Almost insignificant after a year in wet rock. Again, the bolt did not fall out. It would have to be unthreaded over one inch to do so. It was removed for some reason.
JJ removed the sleeve and cone and put in a new bolt and hanger bracket. So, the route is open.
Please folks!!!! Hanger brackets and bolts are NOT booty.
If you find a loose bolt in Muir (and you will sometime) please either tighten it or report it to us. Some of the brackets are placed in such a way that eventually repeated whippers will loosen them. Retightening them will bring them back to their original integrity.
Rick
JJ removed the sleeve and cone and put in a new bolt and hanger bracket. So, the route is open.
Please folks!!!! Hanger brackets and bolts are NOT booty.
If you find a loose bolt in Muir (and you will sometime) please either tighten it or report it to us. Some of the brackets are placed in such a way that eventually repeated whippers will loosen them. Retightening them will bring them back to their original integrity.
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
None are so old as those who have outlived enthusiasm. - Henry David Thoreau
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marathonmedic
- Posts: 1557
- Joined: Fri Feb 20, 2004 3:01 am
I had an interesting incident at Roadside a year or two ago. I was on Stay the Hand and leading up it just fine being belayed by AirCanada. I was at the 2nd to last bolt when I looked down and thought, "That looks odd, like the rope is arcing way back from the cliff to my belayer." When I finished the route and was cleaning it, after asking AirCanada if he wanted to do it, to which he answered, "No thanks." I came down to find out that the first bolt had simply wiggled out of the cliff due to the rope vibration when I was about half way up 
He didn't say anything b/c it didn't matter when it finally came loose as I had clipped a few other bolts; however, I did do that difficult lower section with just that bolt clipped 
Good thing I didn't fall, although the bolt may have held due to the caming force placed on a bolt when you fall on it, unless it is in a roof where the force is straight down...whcih brings me to that bolt in the roof on Manifest Destiny at The Solarium... a little loose and wouldn't suprise me if it blew.
It was quite a sight to see the draw clipped to the rope against the gri-gri just hanging there with the bolt hanger, bolt and nut just hanging in space on the other side of the draw.
I have been climbing since 1993 and this is the first time I have ever witnessed a bolt "blowing", but not the first time I have heard about it. This is always a risk, just like trad gear blowing, and I would venture to say more of a risk at the Red than other crags due to the softer nature of the corbin sandstone.
Just use good judgement at all times and you'll be fine.
He didn't say anything b/c it didn't matter when it finally came loose as I had clipped a few other bolts; however, I did do that difficult lower section with just that bolt clipped Good thing I didn't fall, although the bolt may have held due to the caming force placed on a bolt when you fall on it, unless it is in a roof where the force is straight down...whcih brings me to that bolt in the roof on Manifest Destiny at The Solarium... a little loose and wouldn't suprise me if it blew.It was quite a sight to see the draw clipped to the rope against the gri-gri just hanging there with the bolt hanger, bolt and nut just hanging in space on the other side of the draw.
I have been climbing since 1993 and this is the first time I have ever witnessed a bolt "blowing", but not the first time I have heard about it. This is always a risk, just like trad gear blowing, and I would venture to say more of a risk at the Red than other crags due to the softer nature of the corbin sandstone.
Just use good judgement at all times and you'll be fine.
Lest we all forget... climbing is a mostly meaningless pursuit that we do for fun.
That's it. It was on pocket pussy before all of Torrent was rebolted. My friend Mike just ask for a take at the first bolt and when he sat down..BAM..it blew. He landed on the ledge unharmed. He has kept the broken bolt and hanger. The bolt did not pull out but sheared at the head/hanger.
pigsteak wrote:rhunt's experience was at Torrent....I am terrible with route names there, but it was on of those routes around the right side that start above that 10 foot drop off..about 3-4 routes left of Seek The Truth. First bolt blew, and the dude landed with his head over that ledge. close call. His name was Mike from Columbus. Happened 6-8 years ago.
"Climbing is the spice, not the meal." ~ Lurkist