ACE anchor replacement: Chockstone Chimney

New anchors for the Chockstone Chimney rap. 1/2" x 4.5" SS Power-bolts with SS double-ring hangers.
The previous hardware was 3/8" x 3.5" carbon steel with Metolius fat hangers. Both were spinners.

(I unfortunately botched much of the video by having it pointed too high. All you get is 30 seconds:)
youtube.com/watch?v=WK98_oV…

In addition, Matt replaced the anchors on Darkness 'til Dawn last Saturday:

Short and rusty. They're 2.5" long, but only about 1.5" was in the rock and they were both very bent.

New 1/2" SS hardware. Much better.

your tha man!

Thanks Gregger and Matt!

Thanks guys! Any luck with removing those mammut ring bolts (besides using a dremmel)?

Monty wrote:Thanks guys! Any luck with removing those mammut ring bolts (besides using a dremmel)?

Yes.
You are left with a shallow 5/8" hole. The next bolt would need to be a glue-in and not a mechanical bolt. We still have some questions about whether our method pulverizes/weakens the rock at the lip. We are still refining the method before using it on a route.
Here is the jig we tested successfully in February along with some early failed experiments in core drilling around stud bolts:

youtube.com/watch?v=l6WQcGv…

Interesting video on the ring bolts. Luckily there's not too many of those around to worry about. Coming from a guy who has no experience with glue in's; In theory would the glue solve the issues of weakened rock (unless of course it was a large fracture internally).

Thanks again for researching these methods and putting them to use. It's awesome to think that same hole replacements aren't limited to triplex and 5 piece bolts.

Locker wrote:Where is it that you are doing that "Testing"? Public land?

I was able to Greg and Matt access to the North Quarry on North Table to conduct these tests.

Monty wrote:...In theory would the glue solve the issues of weakened rock (unless of course it was a large fracture internally)...

I have no experimental data to go on, but my guess would be 'no'.
I suspect you could get a failure like the soft rock crushing situation on page 4: safeclimbing.org/education/…
The hydraulic punch driver can press against the rock with several thousand pounds of force. The ring bolts are beefy enough to sometimes hold until the ring flattens and breaks - that's a scary huge load. The 3/8" studs have all slipped out or snapped off at much lower forces.