UT: North Wash No Kidding: An Intro to SandTraps

Finally checked this one off. Took a bunch of noobs to ghosting/sandtraps/etc and they loved it. Snow flurries during the descent made for an amazing experience.

Finished No Kidding descent and exit in just under 4. Then dropped East Lep. Total time was about 6 hours car to car. Fantastic day.


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Conclusion:

Paul Stovall 9/25/2014
 These results show that if you are rappelling at a constant rate of speed the load on the anchor
is equivalent to the weight of the rappeler regardless of their speed.
 As the rappeler accelerates up to a comfort rappelling speed the load on the anchor is reduced
during that time period.
 If you are rappelling at a high rate of speed, caution must be taking during the deceleration
period. When the rappeler is decelerating, the load on the anchor increases with respects to the
rate at which they arrest the decent, sudden stops should be avoided whenever possible.
 The claim that rappelling faster reduces the load on the anchor is false, the only time that the
anchor load is reduced is during the rappeler’s acceleration period.

Kind of an interesting concept to ponder. Load dynamics.

Reminds me of a tow strap...as in a snatch or recovery strap. If you see them work, you build up speed until you stretch the strap, then, the moving vehicle stops, the stretch in the straps starts to pull the stuck vehicle...slingshot kinda thing.

So, if you descended off a sketchy anchor, with a dynamic enough rope...accelerate through the descent but stopped just short of the bottom, the force on the anchor might be enough to blow it up, but, you're a foot off the ground when that happens.

Reminds me of roadrunner and wile e. coyote...

Kind of a deadpoint at the load transfer. Er something. Stepping off at the bottom of a bungee jump. The slight pause when a slinky flops over.

Be fun to try over deep water (!). Maybe.

Then there's "creep". Maybe that's why some folks feel like they need to get off a sketchy rappel asap...

With that concept in mind, if you can't do a continuous acceleration through the entire rap, then maybe should go at a slow speed just in case something happens and you need to stop as to put less trauma on the anchor?

Speaking of stretching, deep water, and sandtraps... I believe @Kip Marshall has a video regarding the three concepts merged...

I've gotten into the habit of teaching this "bending" style.
My mnemonic is "place the rope where it will be" as you go over the edge.

Reason being, if you go over the edge and the rope is high on a slope, it will eventually skitter to the low point. And that skittering cuts the sheath and blows out a coreshot.

These days its less important as I exclusively use aramid sheath'd ropes. But it still makes me cringe when I see a noob skitter my ropes along an edge...

"place the rope where it will be" times 200

Keeping in mind that you sometimes (planned or unplanned) are required to ascend a rope.
Knowing the last person down placed the rope where it “should be” offers a lot of peace-of-mind to the “ascendee”!

The trick with sandtraps is not usually making them bomber enough to hold a rappeller. Barring an absolute dearth of sand (even with farming from above and below) and a terrible slope, you can usually make it hold. The trick is making it retrievable. Because you're not just leaving behind a sandtrap. You're leaving behind a sandtrap and two ropes.