Discussion Topic |
|
This thread has been locked |
Greg Barnes
climber
|
|
|
Topic Author's Reply - Mar 3, 2017 - 06:40am PT
|
Yes I've seen the video, that's amazing he could make an accurate tester so inexpensively!
That could be a good way to test thread head bolts that we don't know anything about. But luckily we still have most of the FA folks around to just ask them! That's what I want to do for the 3/8" split shaft list (and 5/16" buttonheads which also can be easily spotted by climbers). We don't need the list for Pinnacles since 3/8" split shafts are already noted in the back of the old Rubine guide (unless someone knows of an error in that list).
But if any FA folks remember using those 3/8" split-shafts, it'd be great to get a list!
Or even just your name and when you were using them, that way rebolters know to prioritize checking those routes. As Bruce noted, you can just look at the threads/non-threaded section of the bolt (usually by unscrewing the hanger a bit). Also you can spot the threads-to-solid section of the bolt directly if there's been bad spalling (which is kind of common with 3/8" split-shafts).
Also if people remember other folks who used to use them. The ones I already have were part of a big pile of FA gear donated by Alan Hirahara, but I don't know how often (if ever) he used the split-shafts, I think he was using mostly 5-piece.
So if you used 3/8" split-shafts please let us know!
|
|
BruceHildenbrand
Social climber
Mountain View/Boulder
|
|
Some information on the story behind the bolt tester that Dan Merrick designed in the video posted above by Bob Steed.
Professor Paul Helyiger at Colorado State University, who is also a climber, has been testing "used" bolts for a few years now. By "used" I mean bolts that have been pulled during rebolting. I sent him a number of 5-piece bolts which I pulled in Clear Creek Canyon in Colorado which had been in the rock for 15+ years. Even though the bolts had surface rust they all test close to rated numbers for shear strength.
Of course, the more difficult problem is testing bolts for pull-out strength since the bolt needs to be in place to do so. Enter Dan Merrick and his new bolt tester. Nice!
|
|
mcreel
climber
Barcelona
|
|
I'm pretty sure that the original bolts on the route "The Fin" at Wright's Lake in the Tahoe area were 5/16" split shafts, and from what I've heard, they have not been replaced.
|
|
JimT
climber
Munich
|
|
Testing pull-out of threaded bolts you just need a torque wrench really.
For testing glue-ins I made a pass/fail puller for the German Alpine Club some years ago which used Belleville washers and you could just as well put a couple on a bolt-in to test them.
|
|
|
SuperTopo on the Web
|
Let us know!