Send us a suggestion!

Tech Tip: Question Single strand vs. Double strand Rappel

Discussion in 'Tech Tips and Gear' started by Mountaineer, Jan 22, 2015.

  1. Mountaineer

    Mountaineer Is that an X slot?

    Messages:
    1,280
    Likes:
    976
    Splintered from the previous accident thread. Good comments from Scott, and others...


  2. Mountaineer

    Mountaineer Is that an X slot?

    Messages:
    1,280
    Likes:
    976
  3. ratagonia

    ratagonia

    Messages:
    3,589
    Likes:
    4,088
    Location:
    Mount Carmel, Utah
    "But this is the exception --- many more accidents do occur with single lines."


    Those who have a hammer see everything as a nail. Those who are not fond of single rope technique, have their bias confirmed whenever a single-rope accident occurs.

    Single - Double - Triple - Quadruple - the style of rappelling is not what caused the accident. What caused the accident apparently is that someone frakked up when they rigged the rope. Frakking up when you rig the rope is OFTEN the CAUSE of accidents.

    People who don't use Single line a lot, and/or are not well-trained or proficient in their rigging, are more likely to FRAK UP than when using techniques they are fully-proficient with.

    The more universal statement is: People who don't use ****** technique much, and are not well-trained or proficient in their rigging, are more likely to FRAK UP than when using techniques they are familiar with.

    Tom
    Sam G, John Styrnol and Canyonbug like this.
  4. Brian in SLC

    Brian in SLC Brian in SLC

    Messages:
    751
    Likes:
    776
    Location:
    Salt Lake City
    Cross posted from the other thread:

    Absolutely. Single or double.

    If I have a clear view of the rappel route, and, I'm doubling up a single rope for a double rope rappel, sometimes I'll thread the rope through the anchor and toss 'er down, with not as much regard for the rope ends. If I can see one of the ends is short, I'll "fix" that situation when I get there. I just lock that rope off and continue rappelling until the rope ends work to gain the ground. Fast and easy. Maybe not a technique I'd recommend for just anyone, but, its effective and its good to know that you can slip the rope through the anchor while on the rappel if need be.
  5. Brian in SLC

    Brian in SLC Brian in SLC

    Messages:
    751
    Likes:
    776
    Location:
    Salt Lake City
    Ok, so, back to this single v double debate....

    I rarely ever see a group rig for contingency. They put a block in and rappel single strand. When they could just do a double rope rappel. I don't get it. To me, if you're not rigging the rope for a contingency, why rappel single strand? Double is better control of friction, easier on the terrain, and, easier on the rope. Less chance of a rope groove in the rock, and, less change of tearing the sheath on your rope.

    It just seems like canyoneers have chosen to rappel single strand 'cause that's what the cool kids do. 99.9% of the time I see climbers out in the field, I nearly never see a single rope rappel and when I do, its only with a pull cord, or, then a line is set single from the top of an anchor to get folks to the ground quickly (and its tied off full length). And, there's way more climbers rappelling than canyoneers rappelling, based on the numbers folks say are out "doing it". Way more. Double rope rappelling is the way most of folks who rappel do it. Is it mostly because canyoneers just want to be different?

    I get it in water flow, where contingency is required. I get it for slipping a rope to prevent a sheath tear on sharp rock. But, mostly, I don't understand why folks block a rope, no contingency, then rappel single strand. Sure, the talented of us at an anchor might be able to semi-quickly convert a block to a lower, but, my bet is most who rappel single strand off a block can't do it effectively, at all. So, until you do know how and are prepared for it, why should it be the norm to rappel single strand?

    What say ye canyoneers who are married to the single rope rappel technique? Can you quickly convert a block to a lower? If not, why do you rappel single strand?
  6. Mike Zampino

    Mike Zampino Canyon season never ends.

    Messages:
    541
    Likes:
    486
    Location:
    Phoenix, AZ
    Why do you think this? The pull would be the same regardless if you rap single or double. Having a biner on the rope doesn't cause the groves. Although they can get caught on top of the groves.
    Deagol likes this.
  7. Mike Zampino

    Mike Zampino Canyon season never ends.

    Messages:
    541
    Likes:
    486
    Location:
    Phoenix, AZ
    Yes, I climbed for 20 years before using a block. I didn't use one until I started canyoneering and did my first big (200ft) rap.
  8. ratagonia

    ratagonia

    Messages:
    3,589
    Likes:
    4,088
    Location:
    Mount Carmel, Utah
    "I rarely ever see a group rig for contingency. They put a block in and rappel single strand. When they could just do a double rope rappel. I don't get it. To me, if you're not rigging the rope for a contingency, why rappel single strand?"

    I realize that Rich has always pushed the idea of setting up a contingency. This is good in Class C (flowing water) terrain. However, with skills and practice, converting a blocked single strand to a lower takes about 3 minutes.

    Yes, few people have those skills and practice them.

    I find it hard to believe, Brian, you being a pretty smart guy, that you do not UNDERSTAND the arguments put out for preferring single strand (much of the time). I'm very comfortable with you disagreeing with the conclusion, but, c'mon - we've beat this horse into oblivion... please tell me you UNDERSTAND the arguments.

    Tom
    John Styrnol and Canyonbug like this.
  9. ratagonia

    ratagonia

    Messages:
    3,589
    Likes:
    4,088
    Location:
    Mount Carmel, Utah
    Not all rope-grooving is from the pull. Some occurs when the rappeller is on-line, shifting side to side and to some extent up and down. Sandstone is soft. Rapping on two strands decreases the pressure against the rock (by half), which seems to decrease the cutting factor by more than half.

    Same applies to cutting forces on the rope.

    Tom
    Deagol likes this.
  10. Canyonbug

    Canyonbug Outdoor Junkie!

    Messages:
    89
    Likes:
    101
    Location:
    Blanding, Utah
    This debate always comes up when teaching climbers canyoneering techniques, it's always a "Fun" discussion. Each side is always adamant that their way is better.

    I am a single rope junkie. I agree with Tom's points, and I agree with Brian's points. It's all about training, and comfort as well as rescue ability and practice, practice, practice.

    I use both when the situation warrants. Each canyon is going to be different. When we are teaching beginners in canyoneering we teach a single rope technique pushing the use of a contingency anchor. As beginners it looks better for them to have an option to lower someone to the ground if any item should hang them up on a rappel, get stuck or whatever. It's also easy to lower someone to the ground if the drop is sufficient enough that visualization of the rope reaching the bottom is not possible. Much easier to effect a rescue in this sense than to teach a beginner to convert a block or DRT into a lower if need be. We also teach ascending which is easier done on singe strand rope (I know it can be done on double).

    Double strand gives more friction and helps control a rappel which is a great thing. If you can't see that the ropes reach, not always a great idea for beginners who are unfamiliar with making the rope reach while on it, as well as rescue becomes a bit more difficult if need be. Throw in water and pools and swimming and un-clipping and this becomes a bit of a problem for beginners. Double rope may also complicate the pull if rappelling on a device that is twisting the two strands together.

    Mark and Tyler and Tom and any other experienced canyoneer after a while will learn when to use double or single and start working it out to use the best setup and how to fix the complications of the issues.

    Not to open another "Can", but it's a similar debate as whether to use an Autoblock, prussik, or whatever as a rappel backup. Is a back up a good idea, yes, but so is training and knowing how to do it without and being competent.
  11. Mountaineer

    Mountaineer Is that an X slot?

    Messages:
    1,280
    Likes:
    976
    Interesting. I can think of a method or two, but curious how you do this Brian. May be interesting. And after your conversion, how do you pull your rope?
  12. Mike Zampino

    Mike Zampino Canyon season never ends.

    Messages:
    541
    Likes:
    486
    Location:
    Phoenix, AZ
    Sure side to side wears the stone, but it would not be the cause of deep vertical groves. I imagine the up and down from say bouncing is negligible for groove wear compared to friction caused by the rope pull.
  13. Mike Zampino

    Mike Zampino Canyon season never ends.

    Messages:
    541
    Likes:
    486
    Location:
    Phoenix, AZ
    I beleive (correct me if I am wrong Brian) that he temporarily ties off the short end and continues to rappel. This will cause the rope to be adjusted as the tied off end will progress with the rappeler. Once the ropes are even or both ends reach the ground you untie and proceed as normal. It isn't a conversion - just a temporary one sided tie-off.
    Canyonbug likes this.
  14. hank moon

    hank moon lovely ligatures

    Messages:
    1,189
    Likes:
    1,292
  15. ratagonia

    ratagonia

    Messages:
    3,589
    Likes:
    4,088
    Location:
    Mount Carmel, Utah
    Well, it depends.

    In the softest rock canyons, we tend to use the Sandtrap and Fiddle Stick, so we do NOT pull the rope through. But we still create (mild) rope grooves. This is from the rope moving up and down as the weight comes and goes on the anchor.

    Tom
  16. Mike Zampino

    Mike Zampino Canyon season never ends.

    Messages:
    541
    Likes:
    486
    Location:
    Phoenix, AZ
    Interesting, yes I imagine the low angle when using a sandtrap puts a lot more friction on the lip then if the anchor was higher on say a tree, bolt, etc.)
  17. Mountaineer

    Mountaineer Is that an X slot?

    Messages:
    1,280
    Likes:
    976
    Thanks Mike. Maybe semantics, but tie off? I could see putting a knot on the short end of the rope while using an ATC or similar device, the knot would block there, then you rap single while the rope slides through the rap ring above. Obviously you need enough rope overall. However, I was more curious on the "tie off" method.
  18. Canyonbug

    Canyonbug Outdoor Junkie!

    Messages:
    89
    Likes:
    101
    Location:
    Blanding, Utah
    Mark,
    You want to start this whole process way before the end of the rope is at you and knotable at your Rap Device. You've set yourself up for issue if you wait that long. Once you are over the edge and start seeing that the rope lengths are no even, tie off the short end, lock off or what ever method you want to use to secure it. Then continue on the long end until the two lengths are somewhat even. Undo the lock and continue with the double strand together.
    Mountaineer likes this.
  19. Scott Patterson

    Scott Patterson

    Messages:
    939
    Likes:
    801
    As Tom said, it depends. If a rappeller sets too much friction on the rappel and there is a lot of bouncing up and down, he or she can easily cause a deep rope groove very quickly, probably even more so than retrieving an unweighted rope. Unfortunately, yes, I have seen this.
  20. ratagonia

    ratagonia

    Messages:
    3,589
    Likes:
    4,088
    Location:
    Mount Carmel, Utah
    "Double strand gives more friction and helps control a rappel which is a great thing."

    This statement always drives me completely CrAzY!!!!

    Really? The ROPE determines how much friction you get? Let me tell you dude, if YOU don't control how much friction you get, then you are already in trouble, destined to become talus food, and should take up stamp collecting or something.

    Tom
    Taylor and Wes1 like this.
Similar Threads: Single strand
Forum Title Date
General Discussion Double Strand vs. Single Strand Rappel May 10, 2013
Archives - Yahoo Canyons Group TECH~ Stein/stone knot for isolating single strands with one locking biner Feb 24, 2005
General Discussion Poll: Single line or double line Jul 25, 2017
Tech Tips and Gear Fiddlestick - Single Rope, Middle at Top Jun 17, 2015
Archives - Yahoo Canyons Group Looking for a single partner to April 2011 (Escalante canyons) Dec 16, 2010
Archives - Yahoo Canyons Group Petzl Self Braking Descender for Single Rope Jan 19, 2010