Descending Devices for Long Rappels

[rcwild]

QUESTION SUBMITTED BY EMAIL:

Can you point me to information about how long of a descent the descenders are good/safe for i.e. can I use an 8 to rappell 1000 ft? (I know the answer is no, but where is the cutoff?)

[rcwild]

The device you use is only half the equation. Your technique is as important; probably even more important.

You CAN rappel 1000 feet with a figure eight ... IF your technique is smooth and the rope is set correctly to mitigate twisting.

CAUTION: There was a caving accident in Arizona several years ago that involved a figure eight. The subject was rappelling too fast, then came to a stop. The friction had heated his figure eight to the point where it melted through the rope when he stopped.

Use caution with any rappelling device.

The device that will be most forgiving of technique on extremely long drops is the rappel rack.

[fourfa]

this is something I posted to another canyoneering group, thought it would be of interest here as well.

After a weekend of hiking in Yosemite, I was
driving out of the valley and decided to stop at El Capitan, and climb up to
the base of the cliff for a look-see. On the way up I could just barely
make out a fixed line hanging off the summit, blowing around in the wind.
It was hard to see the end in the shade of the cliff, but looked *really*
long, but for all I knew it's a trick of the distance.

I run across some people hiking down, turns out it's their line and it's
THREE THOUSAND FEET long. They had a group of 33 Ohio cavers. A group
hiked up the backside, dropped down 3000 feet of pull cord, and hauled up
this rope. They were taking turns sending tandem pairs ascending up the
cliff face, camping at the top, then rappelling down the ENTIRE sheer face
of El Capitan in one shot. 3 or 4 hours ascending (at night, to avoid the
blazing sun off the white granite, on a nice caver rig with dual foot loops
and chest harnesses), and anywhere from 10 to 30 minutes screaming down the
rappel. The wind was severe enough to at times blow the rappeller 50 to 100
feet off the wall, even with a big guy securing the ground end, and spin him
or her around quite a bit. The guys said at times, the rope above you would
catch enough wind to actually lift the rappeller UP, even while letting rope
through. There hadn't been any injuries due to slamming into the face, but
all were wearing helmets and sturdy knee and elbow pads.

It was standard PMI 7/16" static line, white, formed with 3 or 4 splices.
Weighed 180 lbs, carried to the base by six guys carrying a 500-ft coil
each, joined by 20 ft of slack between. Rappelling on brake bar rigs with 6
or 7 bars. Packs slung below the brake bar. I watched a guy slide down in
about 15 minutes, blowing all over the place. That works out to 200 ft/min,
actually more since he stopped a few times. When he hit bottom three guys
worked very quickly to get his rig off the rope before it melted through -
blistering hot, as you can imagine.

They had a pair of videographers shooting the event for Discovery Channel.
Might see it someday.

[hubert]

People whom I've done long continuous rappels with (up to 1100') will sometimes, if the rappel is dry, hang a small squeeze bottle of water around their neck which they can use to squirt down their rappel rack when it gets hot. I've tried this but depending on the speed and length of the rappel, the rack can still end up steaming/sizzling hot. I imagine that a hose from a hydration system such as camelback/ platypus could also be adapted for this (might have to use your mouth to suck the water out of the hose first though.) Of course in a waterfall this is not an issue.

[mtngoat59102]

Extending my rap device from my harness and redirecting the rope between my harness and the rap extension and then back down to my brake hand has become my favorite method for long drops recently. (Long being 300' or 91m) It lets me use my regular device without the weight of a rack. In canyoning I find that the 'big' drops are usually not many, so I like being able to utilize the gear I already carry and rig specifically for the drop.

[hank_moon]

CAUTION: There was a caving accident in Arizona several years ago that involved a figure eight. The subject was rappelling too fast, then came to a stop. The friction had heated his figure eight to the point where it melted through the rope when he stopped.


I'm interested in finding out more about this - any documentation or a contact?

[rcwild]

I heard about it from a Forest Ranger named Jerry Trout. Sierra Vista, Arizona. Maybe 10 years ago. I think Jerry has retired.

[charlybldr]

.
I run across some people hiking down, turns out it's their line and it's
THREE THOUSAND FEET long. They had a group of 33 Ohio cavers. A group
hiked up the backside, dropped down 3000 feet of pull cord, and hauled up
this rope. They were taking turns sending tandem pairs ascending up the
cliff face, camping at the top, then rappelling down the ENTIRE sheer face
of El Capitan in one shot. 3 or 4 hours ascending (at night, to avoid the
blazing sun off the white granite, on a nice caver rig with dual foot loops
and chest harnesses), and anywhere from 10 to 30 minutes screaming down the rappel.


I recently attended the ITRS (International Technical Rescue Symposium) conference in Golden Colorado. One presenter showed slides of a rappelling accident on Baffin Island earlier this year. Mount Thor I think. The rap was over 4000 ft. pretty much overhanging the whole way.

The rappeller was using a brake rack initially rigged with three bars intending to add more bars as needed on the way down. In spite of being rigged with only three bars at the top there was so much rope weight the guy (as you might imagine) had to force rope into the rack just to move. The accident occured when shortly after starting down he began to accelerate out of control. He apparently got moving too fast too soon and was unable to employ additional bars. I think he made it to the ground in under twenty seconds.

The group was going for some kind of record rappel. All were experienced cavers with the exception of this unfortunate fellow. This was his first experience with a rappel rack.

Be careful out there.

[catware11]

I'm sorry to say I'm laughing out loud. That is wrong in so many ways. His first time with new equipment, standing on top of a 4000' rappel??

Sounds like they were at least able to set a speed record, if the guy walked away from it that is...

Rappelling down El Cap, now that sounds like fun!

[sonnylawrence]

He apparently got moving too fast too soon and was unable to employ additional bars. I think he made it to the ground in under twenty seconds.


Humm... what is terminal velocity?

[hank_moon]

I heard about it from a Forest Ranger named Jerry Trout. Sierra Vista, Arizona. Maybe 10 years ago. I think Jerry has retired.

Hmm. I doubt the info was correct. The "it got so hot it melted through the rope" legend is still a legend SFAIK.

[gartneraz]

Hey Neil, can you rig this up and send a pic?

Quote: Extending my rap device from my harness and redirecting the rope between my harness and the rap extension and then back down to my brake hand has become my favorite method for long drops recently. (Long being 300' or 91m) It lets me use my regular device without the weight of a rack. In canyoning I find that the 'big' drops are usually not many, so I like being able to utilize the gear I already carry and rig specifically for the drop.

[rudy118]

Sounds like a Z rig technique to me. But what do I know.