Can all belay devices do a single line rappel?

Someone was reluctant to relocate a belay position the other day, by lowering themself off a short column. This made me wonder, are any devices particularly bad at this? Yes, it's almost the same as lowering....but not quite. Lowering a climber, there's always an anchor of some sort and some friction. A rappel, is full body weight and only the friction the device gives, or you add in some way.

Are any devices specifically not to be used to rappel?

Just curious!

Best, Helen

Yes

You can do an impromptu rap with a single carabiner, too. No specialized device is required for a short rap, just knowledge. A climber wouldn't want to make a habit out of it as it will certainly twist the rope in undesirable ways, but it astounds me how many climbers don't know how to do it.

On a warmer day with a single strand, especially on a new skinny rope, rappelling is kinda scary.

An extra biner at the device and an extra on the leg loop will fix it.

As others have implied, it's a knowledge limitation, not gear limitation.

Old lady H wrote:

Someone was reluctant to relocate a belay position the other day, by lowering themself off a short column. This made me wonder, are any devices particularly bad at this? Yes, it's almost the same as lowering....but not quite. Lowering a climber, there's always an anchor of some sort and some friction. A rappel, is full body weight and only the friction the device gives, or you add in some way.

Are any devices specifically not to be used to rappel?

Just curious!

Best, Helen

This doesn't answer your question, but is related.

The Mammut Smart is designed to rappel off of with an ASSISTED locking mechanism.  Generally, with two rope strands, this device holds my body weight.  When rappelling off of one rope strand the assisted locking mechanism doesn't work and the rope slides through.  Of course, this is then no different as rappeling with an ATC when you have to have your brake hand and/or a prussick on the strand.

Yoda Jedi Knight wrote:

Yes

Or to say it in a way that actually answers the question:

The Kong gigi isn't the best at rappelling because it has so little friction compared to more common devices. 

The Revo is pretty bad with rapping but it works.

The munter hitch is fine for rapping but horrible for your rope. Same with a figure 8 device. 

The Hewbolt works but I'm not a fan of the method

To really cut to the bottom line - if you have a rope - even if that’s ALL you have - there is never a reason you can’t rappel. 

Fail Falling wrote:

Or to say it in a way that actually answers the question:

Or to say in a way that doesn't make me look like a condescending ass, yes, all belay devices can do a single strand rappel.

Not Hobo Greg wrote:

I haven’t had any issues rapping with a GiGi except for having to remember not to let it drop since there’s no keeper cord (easy to add one though). Is that what you mean by it doesn’t rap well?

Tbh I was mixing up lead belaying vs rapping when thinking about the gigi (I've corrected above). 

So to correct: the gigi is horrible (if not impossible) for lead belaying. It's not the best choice for rapping because it has so little friction, and in the case of someone being freaked out about rapping a single line (for whatever reason) I'd put them on a munter or a double carabiner brake first 

If we are speaking of regular and assisted-braking plates (as opposed to locking-cam devices like the Grigri), then the idea that a device catches falls so must be ok for single-strand raps seems sensible, but it can be wrong.  First of all, "catches falls" involves a big spectrum of impacts.  Most climbing falls are relatively mild on the impact spectrum and friction in the system can help considerably.  Then there is the fact that the duration of the load is extremely brief, so requires only a momentary grip reaction.  Taken together, these things can add up to a very nasty surprise when one tries a single-strand rappel with a device thought to be adequate by virtue of its climbing fall performance.  Of course the peak load is not going to be as high as for a climbing fall, but the rappeller is going to have to maintain a controlling grip for a relatively long time, and without enough friction from the device, pumping out is a definite possibility.

The sad reality, learned the hard way by many climbers who have had mini-epics, is that some device-rope combinations are inadequate for single-strand raps.  The problem is usually with ropes at the lower end of the manufacturer's recommended diameters.  I've mentioned many times before, but it can't hurt to repeat that these recommended diameters are very optimistic, and probably only the middle 2/3 of the range is reasonable.  Some sheath treatments and some carabiner cross-sections make things even worse, and a heavy pack or haul bag can push a marginal situation over the edge.

Of course, a device that is hard to control on a single-strand rappel is probably not going to be adequate for big fall-factor climbing falls either, but such falls are rare and so the device may never be tested for such circumstances and so thought to be ok.  I think every climber should test their chosen belay device with an overhanging single-strand rappel on the thinnest ropes they plan on using, so that they know ahead of time what to expect and whether, in fact, they should be using the device at all with the equipment they've chosen.  BD, for example, makes an ATC Guide with narrower slots for thin ropes.   Of course the test should be performed with a belay.  

One thing to learn from the test is whether the carabiners used to attach the device to the harness should be doubled or tripled--this for friction-only devices like the Reverso, Pivot, and ATC-XP; you can't double up carabiners on assisted-braking devices that use the carabiner as a cam to pinch the rope.  Of course one wants a third-hand backup for such rappels, and it will add a little friction, but I wouldn't count on it being sufficient.  If one isn't in the habit of extending the rappel, this is the time to do it, because you'll get a bit more angle on the brake strand with the device higher up and so a bit more friction.  

There is an even more important reason to rap with the device extended and the autoblock on the harness belay loop.  I think everyone should have a robust strategy for adding friction once hanging on rappel, and the best one I know, starting with the extended set-up just mentioned, is to put a carabiner on the brake-hand side leg loop and a carabiner clipped to the carabiner holding the device.  (It is a good idea to do this before starting the rappel, but it is also good to know about it for cases when the amount of friction turns out to be unexpectedly low.)  The brake strand is then run down to the leg-loop carabiner, up to the carabiner at the device, and then back down to the brake hand.  This puts two 180 degree bends in the brake strand after it exits the device, and greatly increases the friction. If that still isn't enough (I've never encountered such a situation), the brake strand can be wrapped again from lower to upper and back down.   This can be installed and undone while hanging, and the autoblock lives between the harness belay loop and the rap device and so is out of the way of installing and dismantling the set-up.

There are more primitive ways to add friction, for example by passing the brake strand around your back and braking with what is usually the non-brake hand.  Rope burns are a possibility, but are better than dying.  Also, if one person is already down, they can help a struggling subsequent rappeller by providing and engaging a fireman's belay.

Thanks, everyone! The device my friend has, is an old cinch. But, I've run into old belay devices more than anything else. Now, there are even more devices.

I own four devices myself, and had one more, briefly. I'm comfortable enough with what I have, but still primarily use an ATC. Outside, I have a grigri on my harness at locations other than my local stuff. 

But? As a (sorta) beginner, it's really easy to find yourself on someone else's setups. I only do what I'm comfortable doing, and have no problem saying no. But, I'm willing to do what I'm not familiar with, which means applying previous knowledge or experience to a new situation. 

Information on here, definitely helps!

Best, Helen

A long free rappell on a skinny single strand with a heavy load can be tense using an ATC.

highaltitudeflatulentexpulsion wrote:

An extra biner at the device and an extra on the leg loop will fix it.

Or just looping the brake strand around one leg to add friction.  Takes 2 seconds, no gear

As others have implied, it's a knowledge limitation, not gear limitation.

A big fat YES to this.

jbak x wrote:

A long free rappell on a skinny single strand with a heavy load can be tense using an ATC.

Sure, it's tense if you do not know what you're doing.    

Adding a biner or two is an easy way to add friction as HighAltitude mentioned.  Wrapping the brake strand around a leg will give you more control, and wrapping it several times around your leg will allow you to go hands-free (although your leg will "go to sleep" after a few minutes).

One major drawback to rapping with your belay device is that they get so fucking hot.   But that's another discussion...

Yes, but not all ropes can.  Some ropes will have their sheaths slip when doing single rope rappels and get flat spots where the sheath extends past the core.  That is an extreme case though and usually only happens with full rope length single rope rappels.

 In my experience, the auto block is always the "solution".  Any sling wrapped around the rope and attached to your leg loop will do.  You can safely descend any rope ( even 5mm perlon) with a carabiner and an auto block, but a belay device is easier.  There should never be any reason someone can't descend 10-20 feet with any belay device.  200' rope stretchers on vertical terrain on a single rope will be different.

John Byrnes wrote:

Sure, it's tense if you do not know what you're doing.    

Adding a biner or two is an easy way to add friction as HighAltitude mentioned.  Wrapping the brake strand around a leg will give you more control, and wrapping it several times around your leg will allow you to go hands-free (although your leg will "go to sleep" after a few minutes).

One major drawback to rapping with your belay device is that they get so fucking hot.   But that's another discussion...

Hmmmm...

So would a single rope create less heating than a double rope rappel? Half the amount of rope? Doesn't matter, just curious yet again.

I recently saw a Metolius belay device, BRD, with fins for cooling. Dunno if it works for that or not. The guy said he's had it 16 years. So, that's part of what made me pop this up. Belay devices might be kept for many, many years. 

Rope around a leg just kills me, lol! Too much weight in unfortunate locations maybe? 

Best, Helen 

Mark Pilate wrote:

To really cut to the bottom line - if you have a rope - even if that’s ALL you have - there is never a reason you can’t rappel. 

I'm completely stumped. I've been trying so hard to picture this, but I just can't figure it out. Any leads, please?

The image I have in my mind is Mark heading to the cliff with a rope and nothing else. No biners, no slings. On top of that, no harness or shoes. Of course he is shirtless, but also throw in no socks or underware and the situation starts looking dire. Maybe you can create a youtube demo?

Patrik wrote:

I'm completely stumped. I've been trying so hard to picture this, but I just can't figure it out. Any leads, please?

The image I have in my mind is Mark heading to the cliff with a rope and nothing else. No biners, no slings. On top of that, no harness or shoes. Of course he is shirtless, but also throw in no socks or underware and the situation starts looking dire. Maybe you can create a youtube demo?

Right now I’m hanging on a cliff testing my micro puff and down jacket for emergency bivy at -25 F.    Battery dying.  I’ll explain  later ....

Edit Update:  Micro Puffs are awesome.  Nepal’s are a tad nippy for a night out at -25 F.    Reactor is a no go.  All Petzl and BD steel and aluminum screw versions place equally and surprisingly easy in this cold.   BD picks fuse solid to the ice and won’t clean.  No issue at all with Nomics. Gotta take advantage of good extreme cold test weather....

Back on topic:  don’t be mistaken Patrick.  Stout underwear is critical kit for a dulfersitz rappel!  

But yes, when temps are above 35, I strip down to rope only.   Light is right  

I could see a short or low angle dulfersitz rap in a pinch.

Full rope lengths on steep or even free rappel situations? Not a chance. 

The common annoying situation where the anchor is at you feet so you've got to crawl over the edge to get started? On a dulfersitz. Not for me.

I think of it as a good trick to know in case you're in the Swiss Alps in the 40's. 

highaltitudeflatulentexpulsion wrote:

I could see a short or low angle dulfersitz rap in a pinch....

Was that pun intended?  

Old lady H wrote:

Hmmmm...

So would a single rope create less heating than a double rope rappel? Half the amount of rope? Doesn't matter, just curious yet again.

Physics says that the heat generated is the same regardless of single or double rope.  It's determined entirely by your body-weight and the distance you travel downward.     Less heat on Mars or Luna, however.

I recently saw a Metolius belay device, BRD, with fins for cooling. Dunno if it works for that or not. The guy said he's had it 16 years. So, that's part of what made me pop this up. Belay devices might be kept for many, many years. 

It works to a point.   The "other discussion", and I'm sure to catch shit for saying this, is that I've always used a biner-rig to do long rappels instead of a belay device.   You can adjust the amount of friction it provides by adding biners for skinny ropes or heavy haul bags, it has lots of metal and surface area so you don't burn yourself or melt things, and it's smooth running not jerky, as many devices are.

Rope around a leg just kills me, lol! Too much weight in unfortunate locations maybe? 

   Nope, just put it between your legs and then over one of your leg-loops so it won't burn you.  Quite comfortable actually, and easy to control.