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How to Simul-Rappel   

Tagged in: Alpine Climbing, Rappelling, Trad Climbing
by Liz Drummond
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Get down faster with this emergency rappel technique  

As Ed Viesturs famously said, “Getting to the top is optional. Getting down is mandatory.” And sometimes getting down safely means doing it quickly. Simultaneously rappelling, or simul-rapping, is an advanced skill where two climbers descend one rope at the same time (or two ropes tied together: and one climber’s weight counterbalances the other.

The margin for error is small, but it’s a good trick to know. It’s useful for bailing during a sudden, dangerous storm, or for rapping off opposite sides of a fin or spire where there are no anchor points, which is common in places like the Needles of South Dakota’s Black Hills. The setup is the same as a standard rappel (clip your device onto the rope and descend by letting the rope slide through in a controlled manner), but instead of putting both strands of rope through the device, you take just one. Your partner will take the other, and you will each descend a separate, single line at the same time. We talked to four AMGA guides who have used this technique, and they gave us the lowdown on how to do it safely and properly.

Note: This is an advanced technique only to be employed by experienced climbers who are proficient with rappel systems.


  • Weight (and unweight) the rope simultaneously. If one person weights the rope without the counterbalance of his partner's weight, he will fall and pull the rope through with him. Stay clipped in to the anchor until you’re absolutely sure that your partner is weighting the rope. Do this by pulling slack through your rappel device and locking it off until it’s clear the rope is taut and holding you both. There should be some slack in your personal tether. It helps to communicate something like “1, 2, 3, weight.” This also goes for unweighting the rope at the next anchor: Make sure you are both secured to the next anchor or safely on the ground before unclipping from the rope.

  • Communicate. You need to rappel at approximately the same speed and be very aware of what your partner is doing.

  • Tie knots in the ends of the rope. If one person rappels off the end of the rope, the second person will fall because his weight is no longer being off set. This should be a normal practice when rappelling—unless your rope is touching the ground.

  • Consider weight differences. If one person is heavier by about 45 pounds or more, he may descend at a quicker pace and potentially pull the rope through the anchor with him. The heavier person should rap on the side that pulls the knot into the anchor, and slightly below the lighter person, with a double-length sling connecting the climbers.

  • Use an assisted-braking device (e.g., Petzl Grigri or Trango Cinch) or a friction-hitch rappel backup, aka “third hand” (e.g., Klemheist hitch or auto-block). If one person loses control for any reason (gets hit by a rock, has a seizure, etc.), the second person loses his counterbalance, and the consequences will be devastating.


  • Don’t use only webbing as a rappel anchor. Always rappel off a metal point, like a quick link or rappel rings. The rope slides back and forth through the anchor with any rappel, but there is more movement with simul-rapping. That additional movement, plus the added weight (two people on the rope and anchor), creates more heat and friction; webbing can be easily sliced in two, and the whole system will fail.

  • Don’t get too far apart. Stay less than 15 vertical feet apart so you can maintain good communication, and you don’t risk knocking rocks down onto your partner. Never rappel off a questionable anchor. This is true any time you descend, but simul-rapping will put more force on the anchor, so it’s crucial that it’s a bomber anchor.

  • Avoid simul-rapping on difficult terrain. If the terrain is loose, you increase the likelihood of kicking debris onto your partner. Ropes running over sharp edges can be severed more easily with the added weight. You also want to know exactly where you’re rapping to and that your rope reaches.

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Comments on How to Simul-Rappel Add Comment
By George Bell
From: Boulder, CO
Jul 11, 2014
In general, I don't think Simul-Rappeling is worth the extra risk. Rappelling is tricky enough, and this doubles the load on the anchor. There are many things that can go wrong, and rapping on a single rope there is less friction that you may be used to.

The only time I would advocate simul-rap is when there is no other way, like descending off an arch or spire. Also, simul-rapping can be easier when the rappel is very low angle, so two ropes give too much friction.
By BSU_Zac
Nov 10, 2014
I agree with George that it increases the risk but it isn't a skill to learn for "fun". If you have ever had to get off a face as fast as possible with a storm coming in, then simul-rapping is the way to go. It's not to be used for fun, just to avoid epics and everyone should know how to do it.
By Top Rope Hero
From: Was Estes Park, now homeless
Jan 3, 2015
Uhhhhmmmm, look. To be sure, simul-rapping is, like, more complex and shit than single repelling. Sure. Maybe like on the order of, say, using a spoon to spread peanut butter when you forgot all your knives. It's SA-LIGHTLY more complex, yes. But we're not talking about cold fusion here.

In fact, simul-rapping is a perfectly awesome, wholesome, easy-to-set-up and easy-to-use system that can shave gobs of not-drinking-a-beer time off your day.

If you've ever climbed Time Wave Zero down in the Mex (23 pitches), if you've ever been cramped up behind team gumby, plodding down the stations of Crimson Chrysalis, if you've ever been anywhere of any height up in Rocky Mountain National Park when the sky starts juicing and lighting starts hammering down, or if you just hate standing there, doing nothing, contributing nothing, achieving nothing at another belay station ...then you know that simul-rappeling can be your bestest of best friends.

It's NOT complicated. It's NOT unsafe. There's no rule carved in the sky that says this is ONLY for "emergency" situations. And if you are in any way worried about doubling a static weight on any anchor system, you sir are on the wrong anchor system.

Or? Whatever. Keep throwing down with those ancient, flat-earthed ways. Me and partner will be passing you on simul-rappel and drinking cold ones while you're still shouting your off-rappels...
By George Bell
From: Boulder, CO
Aug 15, 2016
Clearly, opinions differ regarding this topic. YMMV!

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