Anchor Rigging Questions

[moab mark]

Good noob questions.
There is a nice little canyon in moab called Rock of Ages. The first mandatory rappel has two bolts placed about 6' off the ground about 18" apart. They seem well placed but due to the layout of the rappel they are a little under tension. I have used them numerous times. The pieces are standard fair with rings. When they were first placed they had webbing on them that was set up in an american triangle. The webbing is gone now. Oldno7 has a picture that he could possibly post.

The question is without adding webbing and just using the 2 rings what is the best way to rig this?

Here's another, in Snake Alley outside ZNP. ZAC's has an anchor setup that is 2 hefty glue in's in the wall that are about 2' apart and are set one above the other. Could hold a truck. What is the best way to rig this one?

Mark

[oldno7]

as per request

[Brian in SLC]

There is a nice little canyon in moab called Rock of Ages. The first mandatory rappel has two bolts placed about 6' off the ground about 18" apart....The question is without adding webbing and just using the 2 rings what is the best way to rig this?

Here's another, in Snake Alley outside ZNP. ZAC's has an anchor setup that is 2 hefty glue in's in the wall that are about 2' apart and are set one above the other. Could hold a truck. What is the best way to rig this one?

For the first, replace the sling in the pic with a rope. Voila. Or, am I missing something?

For the second, here's how they'd do 'er in Belgium (Freyr). Note the picture on the far right:

[jman]

for snake alley, you said 2 feet apart from each other; so it's not this one? Unfortunately, no other pics.

[ratagonia]

Good noob questions.
There is a nice little canyon in moab called Rock of Ages. The first mandatory rappel has two bolts placed about 6' off the ground about 18" apart. They seem well placed but due to the layout of the rappel they are a little under tension. I have used them numerous times. The pieces are standard fair with rings. When they were first placed they had webbing on them that was set up in an american triangle. The webbing is gone now. Oldno7 has a picture that he could possibly post.

The question is without adding webbing and just using the 2 rings what is the best way to rig this?

A little under tension - not a problem. Something to be aware of, but...

The way you stated the question, there are only two solutions: use one bolt, or use two. Without webbing (or a long chain of rapid links), what other option is there.

Personally, I am not a fan of the up, cross, down configuration with the rope this would create. When pulling the rope through this, it tends to twist the rope some, and the squiggly-pigtail and jam at the last moment. If the rings are big this is unlikely - on some sports climbs with chains it can be more of a problem.

You don't show the rest of the rap. Is the long webbing there to bring the rappel point (the rappel ring) out over an edge, so that the rope pull does not create grooves? Is this the first rap with a fairly accessible start, so the rope can be fixed and retrieved later? Should this be omni-slinged so that the rope does not need to be pulled through?

Certainly the big huge loop of webbing is excessive. Could replace the huge loop with a huge single strand, Y'd at the top to semi-equalize to the two bolts.

Assuming the bolts look stout, could backup one bolt to the other (using webbing), then rap off the ring of one bolt. Doesn't 'equalize', but equalization is over-adored (when the anchors are stout).



Here's another, in Snake Alley outside ZNP. ZAC's has an anchor setup that is 2 hefty glue in's in the wall that are about 2' apart and are set one above the other. Could hold a truck. What is the best way to rig this one?

Mark

This is the first anchor in Snake Alley. We use this for rigging practice. Notice the grooves on the wall below it. The rappel makes a dog leg, so without webbing on the bolts (even though they are glue-ins), the pull is difficult, though not impossible. A good teaching opportunity. Also a good opportunity to teach the courtesy rappel.

Best to rig this with about a 3' finished length Y sling that gets the rapid link past the grooved up piece of rock. Then clip the ring back to one of the big burly bolts for all except the last person. It is usually rigged quite a bit shorter, to make it easier for beginners to get on rappel. Threading through the rings directly is not advised, as the pull is difficult, and eventually it will wear out the rings, which ARE the bolt hangers in this case.

Using a rapid link on the bolts directly is good, because then the guide, coming down last, can open the rapide, put in a couple extra twists, then re-close the rapide and rap, creating a rope twists around the edge problem for the students to solve - but don't tell anyone.

Tom :moses: