Double Strand vs. Single Strand Rappel

Excluding situations where single strand rappels are necessary (LONG raps w/ a pull line): Do you all rap with both ends of the rope or Biner-block and rappel single strand?

I've always taken comfort in having both ends of the rope in my hands (when possible), however, after looking at quiet a few pictures on the forums it dawned on me that many of you will Biner-block and rap on a single strand even on shorter rappels. Is it an issue of rappelling smoothly? Is it a rope-wear issue?

Does anyone do anything different than the biner-block method? I saw that interesting occam release mechanism
http://canyoncollective.com/threads/occam-releasable-anchor.18356/ the other day. Anybody try that? the Fiddle-stick/stone knot idea is pretty cool too. Thoughts?

Personally, I don't see the point of using a biner block/ single strand rappel most of the time. If a canyon is super tight or for some other reason weight is a huge concern, I can see it, but not for something like Pine Creek (for example). Besides having an extra rope along is always comforting in case you get a core shot or something (which is rare, but does happen on occasion).

Just my opinion.

Most canyoneers I go with use the biner block method. Never saw that Occam weird thing. Benefits of biner block includes: keeping the pull line more clean (won't twist like double strand rap), can swim away with proper set rope length in a pool, many canyoneering devices are designed to use on a single strand (pirana, ats), plus you can also fix the pull side for effeciency or rescue.

That said I'll use double strand plenty for dry/short raps.

It depends.

Some argue carrying extra weight in rope is always worth it. Others argue the energy spent on long stemming/narrow canyon days can be more dangerous (fatigue/space) due to the extra weight, so carry a smaller and lighter pull cord.

For me, I don't like twisting the rope when/if using a non tubular rappel device; so setting the rope length is important.

Rigging releasable for all but the last person is usually a good idea.

I almost always go single strand. I generally use a BD ATC XP, and even on the low-friction side, I have trouble descending the rope if I use both sides (don't weigh enough).

"having an extra rope along is always comforting in case you get a core shot or something"
If your rope gets a core shot and blows out, you'll be falling regardless of whether you have a single or double strand.

As

Mike​

said above, the single-strand method allows you to set the rope length so you don't necessarily have to flake out your entire rope, or disconnect your device at the end of the rappel. It won't twist up and get tangled if you're using something like a figure 8 or a Pirana.

In a rescue situation, the extra strand unused by the rappeller can be used for a second person to descend the rope to assist the canyoneer in distress. If set up with a munter mule, a partner at the top could also lower their distressed partner to the ground. Proper training and experience is required to execute these contingencies, but having more tools in your toolbox is always a good thing

Both "strands" (not "ends") usually. I do most of my rappelling in climbing situations and nearly always go double strand. Even with a pull cord. With an ATC/Reverso type device, its fairly easy to keep the strands from twisting.

Situations where I use biner blocks are rare. In water flow, to set the distance to the pool, but, in those situation I nearly always rig for contingency.

I'll biner block to rappel single to avoid passing a knot (ala the rap in Englestead and/or Heaps with a 300 foot rope, and, two ropes tied together to pull down the 300 footer).

I typically use a knot block to rap single if I'm rappelling with a Gri Gri. Figure eight on a bite sometimes clipped back to the rappel line side.

What I've never understood, is, why folks who do the last rappel in Pine Creek, with a 60m rope, will biner block it instead of just rappelling double strand. Might have prevented at least two or three accidents (Jim, you out there? Chime in! Jim broke his back on that rappel going single strand).

In some groups, and, I like that they do this, its become common to slip the rope during a rappel to keep it from core shotting on a sharp edge. Not common amongst most folks. That requires a contingency rig that allows for a controlled slippage of the rope whilst on rappel. Most rig through a figure eight descender at the anchor. Slick, fast, easy to set up and break down, easy to inspect. That's usually a single strand rap.

I use both methods depending on the situation, as I evaluate it, at the anchor. We set up the last rap in Pine Creek with a contingency anchor since we wanted to be able to lower the second rappeller if needed. Once she was down, he tossed the other end and I confirmed it reached the ground and he may have rapped double strand or single (I don’t remember).
In North Wash, I used a short (80’ approx.) rope that I used double strand a bunch. I got my first stuck rope in Morocco with a biner block and had to ascend the rap end to un-stick it. I pulled the biner block out and went double, since the rope was long enough to do so. I didn’t use a biner block after that on most raps because I got a cleaner pull without having a biner scraping up near the anchor and most of the raps were so short anyway. I did have to use one on the last rap in Miss Piggy since my short rope would not have been long enough for double strand, however.

If your rope gets a core shot and blows out, you'll be falling regardless of whether you have a single or double strand.

Modern climbing/canyoneering ropes seldom blow out and cause falls. A core shot usually becomes long before an all out failure. The point was that if your rope gets a core shot, it's always nice to have second one along.

Even if you core shot a rope during a canyon, it's perfectly OK to use it as a pull cord and not have to pass a knot as you would if you core shot your only good rope.

Agree, might have, yes. That is one way. Regardless, he didn't have enough friction.

Single strand contingency is efficient for those that get in trouble half way down and can't continue without help. Double strand toss 'n' go conversion takes some additional steps and rope.

Ill go double if the pull isn't clean. A biner block is great when the biner has a clear shot to the bottom, otherwise, I find that the section of rope around the biner gets unnecessarily chewed up by being dragged over rock. Not only that but a biner block increases the likelihood of sticking your rope.

On rappels with deep rope grooves, a biner block is useful so you can set your rappelling rope in a different groove from the pull side. Cllimbed 150' of 8mm Canyon Pro using tiblocs the day I learned this!

Tom

Being able to separate the strands for pulling is the main reason we usually go single strand. We are usually rappelling on pirana's etc and they tend to twist the ropes which make the pull difficult.

My buddy tad had to ascend the Abby arch rappel one time to fix a pull problem and from that day on it was single strand for us.

When going double you usually need to haul a longer rope. Which means one dude has to be a mule instead of spreading the weight around. A rappel of 110' double strand needs a rope length most do not have. Hauling a 300' for that rappel seems burdensome. Lots of ways to skin a cat on a 110' when going single. Before I learned about the biner block we would tie a figure 8 on a bite in the rope and clip it off to the anchor. Last guy would convert to knot block and rappel down. I personally like to biner the rope and hear the bag hit the ground. Nice sound.

I do both depending on the situation, but lately mostly single strand. Many times I carry a short 50 ft rope that gets you down most the short drops. It is easy to handle (no rope bag) and will often just go double stranded. Once the big rope is out, I biner block with it on anything under half the rope length...mostly for speed of re-bagging the rope. We usually complete the canyons at or under the lower time range. Efficiency is a big part of that.

Uh, well... not really. Can always have a knot at the top, no need for the full double-length to be continuous.

And as a general topic - there is a mixing of topics in this (good) discussion. There are a variety of techniques mixed together, and while many are associated with using Single Rope or Double Rope Techniques, many of the techniques can be used with either single or double ropes - though those in the SRT 'camp' tend to use one set of techniques, while those in the DRT tend to use a different set, with considerable overlap. For instance, using a pull cord (a non-rappellable cord) cannot really be used for DRT, it CAN be used for SRT, but is often not.

While I am an advocate for SRT, I rarely use a pull cord, and rappel double-strand quite often, just because.

Really, my main evangelical point is that canyoneers SHOULD (as in, have a moral responsibility to) develop proficiency in many aspects of the craft of canyoneering, including knowing how to rappel single or double on pretty much any rope presented to them. You never know what is going to happen out there...

The original posted question is a curious one (though spurring interesting discussion is always a good idea). Rather than polling friends, acquaintances and/or internet-experts-in-their-own-minds, may I suggest that one should acquire proficiency in both techniques, and then make choices based on what works for each person, each circumstance and one's personal TASTE. In addition to many wrong ways to do stuff, there are many right ways to do stuff also. I think the question and discussion are good for pointing the canyoneer toward things to consider and take note of while developing that proficiency.

There was an accident in Heaps a couple years back. Young guy lost control about 100 feet from the ground on the last rappel and came in HOT, his buddy on the ground (who was not paying attention) getting some bottom belay on him at the last moment. Broke a couple vertabral processes, maybe a couple other bones. While one should have compassion for the individual, there are a few things to note: A. the 290 foot last rap in Heaps was his FIRST rappel on a single strand; B. his friend below was doing something other than providing a bottom belay; and C. at the ripe old age of 25, this was the third time he had "broken his back".

Tom

The original posted question is a curious one (though spurring interesting discussion is always a good idea). [/quote]

Just drawing from the experience of others... It's been quite nice sorting through the discussions. Thanks everyone for sharing!

As for me: Currently I carry 200' of 9.3mm and will always use a double strand rappel through an ATC-XP if the drop is <100ft. If > 100ft than a bring a 8mm pull cord (as it could be used as a primary in a pinch, although NOT ideal).

I've seen a TON of photos with folks who have biner-blocked the mid-point of a rope rappelled down one side. Maybe because it is more compatible with the piranha? The rope wear thing also seems reasonable but in the end safety is far more important than the longevity of my rope.

More likely, because they prefer rapping single strand. ATC, Pirana - whatEVER! No matter.

In places where rope wear is a specific issue, rope longevity is enhanced by going double-strand. With Single Strand Technique, CAN easily shift the rope a bit after each rap, or, in extremus, creep the rope while people are rappelling. But in general, your double-strand rap will decrease the cutting force on each strand by more than half. Stone that double-rope, and you have two independent lines. Shift the rope after each rappeller - not too hard.

"The rope wear thing also seems reasonable but in the end safety is far more important than the longevity of my rope."

Curious statement, since I think of protecting the integrity of my rope as a very important part of my safety system.

Tom

Interesting... this seems so long ago, and yet, this was the "situation" in 2013!

Tom

I stumbled into the sport in the fall of 2012, and found the Collective in March of 2013.

It's been interesting watching it develop by leaps and bounds over the last decade.