Guided Rappel at Cascade Creek

[Mountaineer]

From Tom's rave at Ouray: http://www.canyoneeringusa.com/rave/...ugust-16-2012/

From the report, it sounds like you have the contingency plans covered with a good outline of the pros and cons in your situation a) jugging b) lower from the top c) relaxing the guideline tension. Maybe if Kevin had a long sling, webbing, or pull cord, perhaps he could have attached that to the taught guide line (replacing the original) and slowly lowered himself to the waterfall, unhooked from the guide line, then continued as a normal rappel.


It wasn't clear what you meant about "As a result of the geometry at the on-rappel spot, the rappel line crossed over the guide line below the rappeller." But, we all know, ropes tend to get crossed quite a bit. However, if there were people below the rap, wasn't it possible to make sure the ropes were separated before the rappel?


Thoughts?

[ratagonia]

From Tom's rave at Ouray: http://www.canyoneeringusa.com/rave/...ugust-16-2012/

From the report, it sounds like you have the contingency plans covered with a good outline of the pros and cons in your situation a) jugging b) lower from the top c) relaxing the guideline tension. Maybe if Kevin had a long sling, webbing, or pull cord, perhaps he could have attached that to the taut guide line (replacing the original) and slowly lowered himself to the waterfall, unhooked from the guide line, then continued as a normal rappel.

It wasn't clear what you meant about "As a result of the geometry at the on-rappel spot, the rappel line crossed over the guide line below the rappeller." But, we all know, ropes tend to get crossed quite a bit. However, if there were people below the rap, wasn't it possible to make sure the ropes were separated before the rappel?

Thoughts?

It is often hard, on a guided rappel, at the start, to figure out the right relationship of the guide line and the rappel line.

It is a 300 foot rappel, and the get-on spot is 15 feet below the anchor point, in a precarious position. From below, we could not see the rappeller until they were 20 feet down the rappel, and certainly we could not see how the ropes lie.

One takeaway should be: make sure the ropes below you are straight. If they are not straight, stop, tie off, and get them straight.

Tom

[Mountaineer]

You are assuming that the person on rappel knows how to straighten out the ropes, or would look for it (as you stated).

Would a single rope setup as retrievable simplified things (less rope)? I realize those on top may not have known how to set this up.




This is your drawing (tattooed to my forehead). Very handy...

[Brian in SLC]

Interesting and I appreciate the write up.

Seems like the guided rappel was to prevent a core shot? Only? And, they had 2 300 foot ropes. So, why didn't they just rappel double strand?

Or....contingency anchor and slip the rope a bit (which could be done if the second rope were rigged to slip by setting up to lower the knot/first rope).

For my money, in low flow, and, for an issue with a sharp rock edge, a guided rappel would have been a lower priority choice for keeping the rope from getting damaged.

Always the benefit of hindsite...

Thoughts?

[ratagonia]

Interesting and I appreciate the write up.

Seems like the guided rappel was to prevent a core shot? Only? And, they had 2 300 foot ropes. So, why didn't they just rappel double strand?

Or....contingency anchor and slip the rope a bit (which could be done if the second rope were rigged to slip by setting up to lower the knot/first rope).

For my money, in low flow, and, for an issue with a sharp rock edge, a guided rappel would have been a lower priority choice for keeping the rope from getting damaged.

Always the benefit of hindsite...

Thoughts?

Given the angle, it is barely a guided rappel. 300 foot rappel, bottom out 50' at most (functionally less). Obviously enough to create problems.

Contingency Anchor? Creeping? Those are advanced techniques beyond the training of the participants...

T

[Brian in SLC]

Rappelling double strand shouldn't have been...? And they had two ropes. Did they think they needed the extra rope for contingency? Or, was it just to pull down the other rope?

I'd think a "barely" guided rappel, the feller should have been able to pull the rope over the guide line? Heavy, and, a bunch of it...so...easy to say, harder to put into practise!

After seeing a rope or two get core shot on wet rappels, I like either creeping the rope, or, just rapping double strand.

We ruined a first day use, brand new and very nice rope in Italy in Mengasca during our flood event where the rope and rappel line was re-directed out of the flow. Luka slipped it and swore, as the last guy down I recall, that it wasn't damaged, but....later inspection after another group rappelled on it, showed it fairly f'd up and the owner cut it in two. We ponied up for it, gladly.

Anyhoo...seems a bit tough to rig a guided rappel for a 300 footer in the circumstances provided. The lesson or take away for me would have been to just have rappelled double. Were the folks that inexperienced that rappelling double would have been risky, and, if so, maybe inexperienced folks shouldn't be rappelling a 300 foot waterfall?

Quite the scenario. Glad no one was hurt.

[ratagonia]

Rappelling double strand would be a big help to reducing the tendency to core shot.

But, do people have the tools and know how to use them to rap double on a 300'er?
-Matched 8.3mm ropes would be a good choice there. The group had one 8.3 and one 9.2 (ie, mismatched).

At the flow rate shown, there was not much flow. In significant flow, hanging two ropes in the flow tends to make them twist around each other.

The participants were mostly using ATC-XPs. Not a good choice for twisted ropes.

Tom

[sonnylawrence]

For the retrievable guided rappel, the rappel rope should be clipped into the anchor with a carabiner. That way if the guide line blows out, the person still has an intact rap rope. It will be a wild ride! The last person unclips it. He/she is the only one at risk. But meanwhile the guide line has been thoroughly tested.

You are assuming that the person on rappel knows how to straighten out the ropes, or would look for it (as you stated).

Would a single rope setup as retrievable simplified things (less rope)? I realize those on top may not have known how to set this up.




This is your drawing (tattooed to my forehead). Very handy...