backing up a rappel with prussic

Dying because of rap and lowering errors really, truly, needs to stop. Knot the ends, send the first person down with a friction hitch back up and at minimum give following rappellers a fireman's belay. If you're lowering have all parties tie in for a closed system.

You can download the AAC's 14 page guide on rap'ing here: johnharlinmedia.com/know-th….

Doug S wrote:As Steve Levin put it, if you have an accident and lose control of your body, your leg could possibly lift up and bring the auto-block to the rappel device and make it fail, as in the scenario he described. I'd like to try this, but it sounds like he's right. Putting the auto-block between the belay loop and the ATC would remove one potential human error from the system. In other words, the block can't fail due to your body position. @ Steve: I'm curious how well this set-up works in practice and what size sling to use to extend the ATC... a single? Do you attach the auto-block at the lower tie-in loop or the belay loop? How easy is it to weight/unweight?

Steve could answer this but thought I would chime in. Hi Steve by the way.

Extending the rappel device is definitely the way to go and works great. As noted, rappelling accidents are one of the leading causes of serious injury and death and they are easily avoided.

The Hollow Block is great and there are all kinds of hitches that work well. I always say you should know a number of them and be comfortable with the different materials you regularly carry with you. Lately I've been a fan of the Penberthy. It's really easy to put on one handed and is small and compact on your harness. If you're using slings just keep in mind the limitations of dyneema/Spectra materials if you're carrying those skinny lightweight things. You want that backup to catch when it needs to.

Put that backup on the belay loop and extend the device with any number of slings. A single sling or a double sling that is doubled up and tied with an overhand knot work great. It's super easy to unweight this kind of setup because the backup is right in front of you. You can also use an anchor chain (PAS) or a quickdraw with locking carabiners. I love using an anchor chain when I rappel with my kids because it gives you a lot of easy adjustment options.

Thanks for the explanation guys.

FWIW every time I've backed up a rappel (which admittedly is somewhat rare) I've used a trango ultra tape sling (dyneema/spectra I think?) tied in an autoblock off a leg loop, with my atc extended with a double length sling + overhand. This set up has "caught" me every time -- granted I haven't actually fallen on it, just let go of the brake to fiddle with cleaning gear on rappel or something along those lines.

I know people say dyneema is too slippery -- maybe it's the width of the ultra tape that makes it work? I don't know if I'd try it with one of those skinny mammut dental floss slings...

As with most things, it comes down to personal preference.

I would advise to tie knots in the end of the rope and use a backup unless you are absolutely sure that the ropes reach the ground, that there is minimal risk of rockfall/lightning/bees or some other factor which could cause you to lose control of the rappel.

Prussic above the descent control device: the risk is getting it locked up or out of reach. Solution, use a purcell prussic which can be released under load (still risk of being out of reach). Also, wise to carry a set of purcell's so you can re-ascend to solve lock-up problems. Advantage is it may save you from rapping off the end of the rope (notice the 'may'). I think someone getting stuck in this manner shows that they really haven't spent enough time on rope though, if you are stuck, and don't have prussics, how about tying a loop in the rope below you, stand up in the loop, release the prussic, un-tie the loop, and continue down. Not always easy, but beats dying.

Autoblock below the device: the risk is having the autoblock tied too long, and have it auto-tend by the belay device. Solution, extend your belay device when using an autoblock. There is also the 'very real' risk that a newbie will have a death grip on the autoblock, and render it ineffective. This is also a risk with the prussic above, but because the autoblock may be managed by the brake hand, and because it's easier to tend, the risk is slightly higher.

Be careful out there.

Jake Jones wrote: If you use the leg loop, make sure you have your biner OUTSIDE the actual leg loop. Clip your biner on the piece of nylon running above the buckle to your lower tie-in point. This is to ensure that a load inside the leg loop doesn't pull your buckle loose. This is particularly important on non double-back or (SA) buckles.

Or I can pull Cliffhanger on ye all? Common now!

I used to be cavalier about whether my prussik backup was above or below the belay device, but last fall a friend and I did a freehanging rappel and both put our prussiks above the device, and had to struggle to feed the rope through the prussik. This was particularly a problem for my friend who had lower back pain due to a previous surgery, and the combo of freehanging rappel and fighting with the prussik caused her discomfort.

Lesson learned! Prussik attached to leg loop, belay device extended from harness via PAS, although I also learned a lesson about extending - if you extend up one loop from your harness it puts your belay device at face level, and if you have long hair and it's a windy day you can get hair sucked in to the belay device. I was fortunate in that I only lost a few strands.

The mammut smart alpine is my favorite belay device because it does not need to be backed up when rappelling. It simply will not let you lower without pushing the handle and lifting the weight of the rope.

IMO you need to be totally and absolutely proficient rapping WITHOUT a prussic before you really start using them

i see many people up here who never rap without a prussic ... most of them have poor rapping skills ... they are bouncing all over the place, having poor brake control, etc ...

they never develop the skill to rap smoothly and efficiently ... which as we know is quite important on less than optimal anchors ... and on longer multi raps

remember that its called a BACKUP for a reason ... one of these days you WILL find yourself without any prussik material when you are rapping ... you need to be confident and skilled ... (as a note if you know and practice the penberthy or other rope friction hitches you would NEVER be without a "prussik")

heres an accident where a newbie depended upon the prussik without the proper BASIC rap skills ...

youtube.com/watch?v=3T4FT2S…

bogley.com/forum/showthread…

On Thalehaha Falls in Rubio Canyon, Altadena, CA, my buddy rigged his autoblock incorrectly. When he slipped on the mossy face, he sadly instinctively let go of the brake line. He fell 60'. It was miraculous that he walked away with nothing but deep bruises. Credit the shallow pool, slight slope of the face, landing on his butt, and the redirection the autoblock created which contributed some friction.

I actually haven't rappelled first in ages, always the leader now and checking others' rigging. But he wanted me to get pics and video of his coming down. He has done about 25 rappels total in his canyoneering career, including the 100/120' Leontine falls in the same canyon. I was concerned, I cautioned him, but he insisted. So I went down.

His mistake, as verified by still from the video, was that he didn't clip his autoblock 'biner into the leg loop. Rather it was above the leg loop. Of course it slid up and couldn't cinch the brake line.

In hindsight, a fireman's belay would have prevented this. Such is the risk of a 2 man descent and the desire to get video/pics. I don't know if I should have insisted on going last, or forgone the pics and done a fireman's belay, or done like I did and granted that a canyoneer is responsible for themselves at some point in their career.

Thankfully his ego is the most bruised of all.

ask yourself WHY you are using the prussik? ...

- is it as a BACKUP .... which implies your rap skills with an ATC are solid and well practiced

- or is it as a substitute for good smooth CONFIDENT rapping technique with an ATC

just as most people who never give an grigri to someone who has poor belaying skills to make up for it ... one should never use a prussik to make up for poor rap skills ... a gri gri is not OK for someone with poor brake control, neither is a prussic

use it for stuff like rockfall or the possibility of effing up despite well practiced skills because you are cold/tired/hungry

i find it quite interesting that no one bats an eye on prussics, but some people go crazy over gri gris ... a fall is a fall ... youre kaput either way ...

;)

Dan Cottle wrote:The mammut smart alpine is my favorite belay device because it does not need to be backed up when rappelling. It simply will not let you lower without pushing the handle and lifting the weight of the rope.

be VERY VERY careful with the above

i own and use the mammut alpine smart daily for the last few years and wrote one of the first reviews of it on MP

mountainproject.com/v/mammu…

the smart is NOT autolocking, and not as secure as a prussik

depending on the rope i can slip easily, especially as you get close to the end of the ropes where there is less weight

soft, supple and thinner ropes will slip more readily ... even a new 10.2mm soft slick tendon rope can slip

on a single strand rap, all bets are off ... my smart will slip the entire length of a fixed mammut infinity 9.5mm line ...

although the assited braking helps with the rope control .... NEVER assume it is hands free

im actually waiting for an accident to happen because of this even though mammut warns explicitly about the issue


Is the prusik sling really necessary, bearing in mind the strong braking effect of
the Smart Alpine?

If you are abseiling / rappelling with the Smart Alpine in combination with the right
carabiner and rope, it is easy to believe that the device is self-locking – so the added
safety of the prusik sling might seem unnecessary. However, this added safety
really is essential. The braking effect gradually falls, especially towards the end of
the rope when the lower rope weight reduces any locking function applied by the Smart Alpine. For this reason, and also because the system is so dependent on the
particular carabiner and rope used, the prusik sling is an indispensable safety
enhancement.

d1qxh2iwg385ci.cloudfront.n…

:O

Steve Levin wrote:Good points Beerbreeder. I should note in a pre-rigged guided scenario clients should generally NOT use a third hand friction hitch; they are better belayed with a Fireman's.

i was actually going to add that point steve

just in case the rock hits your client, you can control the descent down to you rather having them stuck in a harness while you ascend the rope and transfer to a tandem rap

;)

Steve Levin wrote:If you got clocked by a rock and became unconscious, your body will naturally "collapse" into a sitting fetal position, and voila, the hitch will hit the rap device, no matter what length the friction hitch cord is.

That is an excellent point/suggestion, and something i hadnt thought of, about body positioning being different and going into the "fetal" position when you are actually blacked out or perhaps on the edge of conciousness or whatnot.

How does your body position differ when pretending to be unconcious (ex. letting go of the rope close to the ground to see how the prussik or klemheist locks the rope) vs when you are actually blacked out!

It might be a fetal position or it might be where you are tipped back because of heavy backpack, laying in your harness close to being horizonal to the ground. Either way your leg (assuming you are using leg loop to attach your backup knot of choice) will come close to an ATC (or your device of choice) and fail (by atc preventing the prussik to lock up vs when you are in a sitting rappel position.

Now the more I think, I realize that I am always pulled backwards. Now it could be my harness, could be because I'm top heavy (esp with a backpack) BUT I ALWAYS have to "WORK" to keep my self upright sitting rappel position. EVEN more so when rappelling (as we tie into the rappel loop vs tie in points (which help you sit correctly).

Gives me something new to practice with prussik lenght.

and (not to sound arrogant) why are you guys saying that if your prussik or w.e locks up above the device, you need prussiks or some form of hitch to unload the device... Why not just tie a bight in the rope around knee level(but it depends how high and out of reach the locked prussik is), step into the loop, stand up, unload the device, slide it down or undo, while keeping tension drop your knee to slowly lower your self onto the ATC? This sounds way easier and faster. in theory anyway. I might try this out at home and post it up.

Roman G wrote: and (not to sound arrogant) why are you guys saying that if your prussik or w.e locks up above the device, you need prussiks or some form of hitch to unload the device... Why not just tie a bight in the rope around knee level(but it depends how high and out of reach the locked prussik is), step into the loop, stand up, unload the device, slide it down or undo, while keeping tension drop your knee to slowly lower your self onto the ATC? This sounds way easier and faster. in theory anyway. I might try this out at home and post it up.

it might be done that way ... depending on the conditions ...

however a prussic can be very hard to release with a single hand after being loaded ... especially if the rope is wet (its raining, ice raps, etc) ... especially if you have a limited time releasing it while standing up for a brief period (which is why many prefer the kleimheist)

and as you suggested a catastrophe knot is recommended, as you can lose control while trying to undo the prussic

IMO there are very few instances when you would rap with a prussic above the device ... prerigging a knot pass is probably the best reason ...

it is not a bad idea to rig the upper prussik with a MMO or a mariners if you are going to use it this way ...

note that either way has issues ...

here are an accident where rigging above has lead to a fatality ...

It is not known exactly what caused Haydon's predicament. He may have experienced difficulty passing the lip of the overhang. This is where a trailing Prusik knot usually escapes the climber's grasp and jams. However, Haydon was several feet below this point when he got hung up. There is reason to believe that he may have stopped momentarily to untangle rappel lines below him. The ropes had to be untangled about 15-20 feet above the ground during the rescue effort. If this was the case, then Haydon may have set his Prusik while he accomplished this task. He possibly exhausted himself in strenuous efforts to release the knot and then panicked when the pain became severe and breathing difficult. This was when he called down to the hiker for help.


stanford.edu/~clint/pin/acc…

Mr Larry Penberthy of MSR famed introduced the prussic under the device decades ago ... but he recognized back then the main issue ...

One alternative that seems better than the chest Prusik (but still not adequate to me) was presented by Larry Penberthy in Off Belay No. 16, pp. 10-11. Since "The trouble with the chest/Prusik system is that a beginner [anyone - gds] may lose control, start to slide rapidly, panic and then grasp the Prusik even tighter, thus preventing it from working. It is contrary to instinct to let go of the rope to gain security". So, "At an MSR 'working' field trip, we devised a new method of security for rappel The rope from above passes through a [rappel device] and then down to a security knot [Mr. Penberthy recommends either a Penberthy or a Penberthy-Pierson knot, not a Prusik - gds] attached to a webbing loop around one thigh [nowadays, attach to the harness - gds]. When descending normally, the braking (lower) hand grips the knot to prevent it from grabbing, and simultaneously applies enough friction to control the rate of descent.

"As the climber descends, the rope slides upwards through the security knot, and then through the friction device. If the climber lets go with his braking hand completely, the knot grabs and stops him. If he grips the control knot tightly in panic, the extra braking friction force stops him, assuming the friction device has a high enough friction ratio."

But there is a problem, and Mr. Penberthy recognized it: "CAUTION: The security knot must not be able to touch the [rappel device]. If it does, the security knot will not grab". My experience suggests that this disadvantage is enough to be a problem, so I do not use this technique.

storrick.cnc.net/VerticalDe…

theres been at least one accident where using a hard to release knot below the device has resulted in an incident ... a kleimheist would not have this issue generally


In the December 1997 NSS News, American Caving Accidents (p414-5), there is an account of an accident involving the use of the "friction hitch below" method. The group involved had marked their ropes at various intervals with duct tape. As one man descended, his prusik caught on the tape and became stuck. The man was unable to rescue himself, and a dangerous hour long epic ensued. Clearly, this man's inability to rescue himself from such a relatively benign predicament was a contributing factor. However, had the prusik (or the tape!) not been there in the first place, this incident wouldn't have happened. There is a solution. Aside from removing any globs of tape from your rope, it's a good idea to use a Penberthy or an auto-block instead of a prusik. The prusik provides too much friction and can lock up, causing unneeded hassles. A Penberthy or auto-block with several wraps provides adequate friction and is easy to release, even when weighted. Experiment and see how many wraps work best for you. (To make a Penberthy, take a strand of cord (5- 7mm), tie overhand bights on both ends, wrap the cord around the main rope in a flat spiral several times, and clip both overhand loops to a carabiner. To make an auto-block, take a closed loop of cord, wrap it around the main rope several times in a flat spiral, and clip both bights of the looped cord to a carabiner.)

caves.org/section/vertical/…

for an excellent discussion on the pros and cons of prussics above, below, at all ... go to the two links i posted

all this was hashed out decades ago ... nothing new at all

;)

Personally, I like to rap with a gri gri. It's not as redundant, but you can go hands free whenever you want. For most raps, I either simul rap or tie off the rope with a clove hitch to fix a single line

A "problem" I've noticed with beginners who always use prussiks is that they assume that you MUST always have a prussik. I did a lot of no-backup rappels before getting into the prussik habit, and I agree that it is great to have solid rappelling abilities with or without a backup.

Ryan N wrote:Not to hijack the thread, but what about extending your atc from your harness? I had never done it before last weekend (and I've been climbing nearly 10 year's) and it was sweet. I might make it a habit. Do any of you do it? Pro's and cons?

I do this with a short prusik on my belay loop. It is great because there is no chance of the prusik being released by pushing against the device, and I have also gone no-hands a few times, without any problems when I had to release it. The only thin is make sure that the device is not too far away from you, or it would be very difficult to rappel over an edge or overhang

Extending the Rappel device is one of the things I like most about using a PAS. I clip my rappel device into the top of the first loop of my PAS and my prussik into my belay loop. This also allows both hands to be comfortably below the rappel device on the brake.

Belay device extension à la Petzl.

I like the extended rappel and backup below the device from my belay loop.

Details on how I use it:

I extend with a 48" nylon runner (not dyneema sling because of sharp edges) and tie it offset so one tail is longer than the other. This allows the short side to be used for rappelling and the long side to be used as a tether on multipitch rappels.

One additional trick I use as a guide and think is GREAT at the end of long days with friends when mistakes happen is to get both my partner and myself on rappel before either heads down. The extension allows the upper person to sit comfortably without being jerked around and then they are already checked and on rappel as soon as the lower climber hits the ground/ledge below. Also great for new rappellers.

My wife uses a Petzl Shunt. Both the Shunt and the extended ATC are on the belay loop:

Yes, it's another piece of equipment to carry around but it is great at what it does. 'Let go to stop' is a wonderful feeling. The only issue that I have with the device is that you need to completely unclip it from everything in order to put it on the rope, which leaves open the possibility of dropping it. If a tiny lanyard could be added it would improve it quite a bit.