Rappelling on 8 mm mammut pro cord

Am I crazy to think of doing long rappels on 8 mm mammut pro cord? Single strand rappels w / pull cord? Thinking of getting a long length of the stuff to beat a canyon that just skunked me.

Thanks!

Why not just double line rappels? And having never caynonered...how does one get "skunked" by a rap?

I just tried a backcountry canyon in the sierras. Went out with two 60 meter ropes and a 60 meter pull cord. Came up short on a rappel and it looked the the rappels further on were even longer. I estimate I need to be able to handle 120 meter cliffs to pull it off. I could do that with one 120 length of 8 mm mammut pro cord and two tied together pullcords. Not sure if I like the idea though . . .

Pullcords? Unless I'm missing something can't you just tie your 2 60m big boys together, remember which side of your rap rings/station your knot is on and pull that end? Like I said let me know if I'm missing something

get the 8 mm as a pullcord, you'll have to pass a knot on rappel, check freedom of the hills or on here on how to do that. rapping just one 8mm doesn't have enough friction.

I just realized I wasn't clear, rig it so you pull the tied together 60s.

Royal wrote:Am I crazy to think of doing long rappels on 8 mm mammut pro cord? Single strand rappels w / pull cord? Thinking of getting a long length of the stuff to beat a canyon that just skunked me. Thanks!

Yes.

Keenan Waeschle wrote:rapping just one 8mm doesn't have enough friction.

Sure it does, if you do it right. You could rap on a strand of 1mm cordlette if you could get it to hold you. Here is how you do it. You rap on a munter hitch because a munter hitch will provide more friction than any ATC. To get even more friction you wrap the free end of the rope around the spine of the biner. Just keep adding wraps until you have as much friction as you need. I have rapped 25' on 6mm cordlette doing this.

As far as the OP's question goes, are you referring to using the 8mm as a tagline, or rapping directly on the 8mm? If you are talking about a tag line, I would go even lighter. I use a 6mm tag and it works great.

Royal wrote:I just tried a backcountry canyon in the sierras. Went out with two 60 meter ropes and a 60 meter pull cord. Came up short on a rappel and it looked the the rappels further on were even longer. I estimate I need to be able to handle 120 meter cliffs to pull it off. I could do that with one 120 length of 8 mm mammut pro cord and two tied together pullcords. Not sure if I like the idea though . . .

oh...I was thinking that there was something tricky about it rather than just "it was too short"

Rappelling on 8mm static rope is standard practice for canyoneers. Standard rappelling devices for this diameter rope are the Petzl Pirana or the Sterling ATS. Both devices have horns and allow you to add more friction on the fly.

A standard ATC with two carabiners rigged instead of one pinch the rope and can be used to rappel on 8mm.

I wouldn't rap on mammut pro cord. It would work well for the pull cord.

How does a pull line work? DO you tie a highwayman's hitch or something to pull it down?

Like a couple other posters I've done hundreds of rappels on an 8mm single static line canyoneering througout the West. Standard stuff. There are many methods for increasing friction in these situations, my favorite is just to add another carabiner to your ATC setup.

How to rig a single strand rappel.

use #1 this technique works to to create a "fixed" but still retrievable line for a single strand rappel(think your cleaning an anchor while spot climbing and the only rappel device you have with you is a gri-gri).

Use#2 In this set up the pull side of your rigging ie. pull strand is not a life supporting line, it is simply for retrieval of your rigging, this enables you to make a 60m rappel with one 60m climbing/static rope and one 60m pull cord(you could use kite string if you wanted to)saving you the weight of carrying two full strength lines.

Mike J. wrote: How to rig a single strand rappel. use #1 this technique works to to create a "fixed" but still retrievable line for a single strand rappel(think your cleaning an anchor while spot climbing and the only rappel device you have with you is a gri-gri). Use#2 In this set up the pull side of your rigging ie. pull strand is not a life supporting line, it is simply of retrieval of your rigging, this enables you to make a 60m rappel with one 60m climbing/static rope and one 60m pull cord(you could use kite string if you wanted to)saving you the weight of carrying two full strength lines.

You can also skip the butterfly knot all together and just tie the ropes together and rap on both of them. However, I would never do that with anything thinner than 6mm and I only do it if the knot wont feed through the anchor. I did pull test 10.5mm dynamic rope tied to 6mm cordlette with an EDK knot and the cordlette failed, the knot did not come untied or roll to failure, so I would call it safe. The advantage to this option is you dont have a knot and biner to hang up on flakes when you pull the rope down.

20KN,

From what I understand there have been a few incidents recently where a knot that would "never pull threw" did exactly that killing the person rappelling. I think there was an article in rock and ice about a recent death in Yosemite from a knot pulling threw a quick link with no back up in place.

I would be very interested to here more about the EDK testes you performed like what differences in rope size where tested, what kinds of loads were you seeing systems fail at, maybe a ratio of rated strength of system components Vs. failure lodes in various scenarios and mode of failure? I feel like many in the community my self included, have looked at an EDK suspiciously and it would give some peace of mind to know what they really do in high load situations.

Tom Moyer did some testing of the EDK knot.

His paper "Testing the EDK Knot" can be downloaded at:

user.xmission.com/~tmoyer/t…

Thanks Marty C.

Erick Vallerwrote: Pullcords? Unless I'm missing something can't you just tie your 2 60m big boys together, remember which side of your rap rings/station your knot is on and pull that end? Like I said let me know if I'm missing something

You can, but you have to carry two 60m ropes that are 9.8mm. A 60m 8mm with a 5mm pull cord is a third of the weight. Many canyons you get your roped wet, then there is exponentially more weight on your larger ropes. This is why canyoneering is a separate sport.