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tolman_paul
Trad climber
Anchorage, AK
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Topic Author's Original Post - Oct 13, 2011 - 06:53pm PT
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Since I’m getting back into ice climbing this season, and introducing the chidrens to the joys of the mechanized masochism that is ice climbing, I figured that one of the most popular routes just outside of town could use a freshening up of it’s rap anchors. It’s a ½ pitch WI 2 route that is literally just off the highway, couldn’t ask for a better first route. The ice flow doesn’t go to the top of the road cut, so there are a couple of bolts to rap off of. It’s been several years since I’d done the route, and I wasn’t overly sketched by what I'd rapped off of the several times I'd done the route.
I hiked out today at lunch to rap down and upgrade the rap station. My wife chides me for my ability or rather lack thereof of off trail hiking. I didn’t disappoint. Yesterday I tried to do the same thing, but didn’t think to drive the base of the route to get some waypoints to line myself up with the route. I hiked in nearly a mile with ~40#’s of gear, and was several 100 feet off. I’d figured I could easily make out the route from above, but nooooo. So after hiking back to the car, I drove by the base and figured out there is a light post pretty much directly across the highway.
So I headed back today, still managed to set the anchor off route, and had to reset it. I finally got myself to the right spot, tied off to the rope and clipped into the bolts. I tapped around the rock with my hammer to try and find solid rock. I fired up the beast, and sank two ½”-6” bolts with 3/8” high test chain.
Then since I had another ½” bolt and a welded cold shut, I added a third anchor where the chains meet. Perhaps overkill, but having an extra bolt to clip in while setting up a rap or tr anchor won’t hurt.
But the real reason I’m posting is what I discovered after putting in the new bolts. I figured I should remove the old ones. The one of the left was an old thin smc hanger with a 3/8” stud of some sort, and the one on the right was a home made loop of steel, ~1” wide bent into a circle with a hex union instead of a nut (I’ll post a pic later) I have no idea how old the bolts are, but I’m guessing ~30 years. I couldn’t get a wrench on the 3/8” stud because it was nestled into a corner, so figured I’d hammer it out. It took a surprisingly few number of back and forth blows to crack off the bolt, and looking at the surface where it sheared there was definitely some corrosion occurring around the threads by the hanger. I’ve had ¼” bolts that take a lot more effort to break off. But the real surprise was the mank supreme home made special. One blow of the hammer and the flake it was drilled into blew off! The bolt was a self drive, so short for it’s dia.
The only saving grace is there was a loop of 1” webbing going around a pair of small birch trees on the shelf above as a backup anchor.
I could tell the rock around the self drive was not good when I tapped it with the hammer to find where I was going to place the new bolts, but it didn’t register in my gord that the bolt was in crap rock.
So carrying a small bolt kit with you is never a bad idea. Don’t ever hit a bolt with a hammer unless you are going to replace it. But, gently tapping the rock near where the bolt is placed will quickly let you know if it’s good rock, or hollow rock. Good rock has a higher pitched sound and your hammer rebounds back like you are hitting an anvil. Bad rock has lower pitched hollow sound and the hammer won’t rebound as much.
And through a few ducats ASCA’s way, the arse they save just might be yours!
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Clint Cummins
Trad climber
SF Bay area, CA
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Oct 13, 2011 - 08:40pm PT
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Are your new 1/2" bolts stainless?
(Your description does not say).
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MH2
climber
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Oct 13, 2011 - 08:45pm PT
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Children ice climbing? What is this world going to?
But by children, I am sure you must mean anyone under 48.
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tolman_paul
Trad climber
Anchorage, AK
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Topic Author's Reply - Oct 13, 2011 - 08:47pm PT
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Which would be the whole lot of us.
They are teens, so not quite children, but definately not adults!
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TGT
Social climber
So Cal
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Oct 13, 2011 - 08:51pm PT
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The problem with the 3/8 five piece bolts is that they have a 5/16"-16 nut and stud.
That's only 10% more minor diameter than a 1/4"-20 stud (the old 1/4" split shafts) It also means there really isn't any more corrosion allowance than with a 1/4".
When I was doing industrial /municipal contracting I never bought 5/16" hardware. When it comes to load limits it might as well be 1/4"
The saving grace of the five piece is that the hanger is almost always in shear with both the sleeve and stud increasing the loaded area effectively to the full 3/8". In tension it's a completely different story,but it's almost impossible to load an anchor with a full on factor 2 tension load.
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tolman_paul
Trad climber
Anchorage, AK
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Topic Author's Reply - Oct 13, 2011 - 08:53pm PT
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But with a 5 piece rawl, the threads are not in sheer. You get the full dia of the 5/16" bolt with no stress risers created by the threads, at the point the hanger puts a sheer load on the bolt.
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TGT
Social climber
So Cal
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Oct 13, 2011 - 08:54pm PT
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That's what I said.
the real issue is the corrosion
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