|
pico23
Apr 11, 2003, 3:51 AM
Post #1 of 79
(6361 views)
Shortcut
Registered: Mar 14, 2003
Posts: 2378
|
Wondering where you place the backup knot on rappels. When I use one which is more often lately I place it above my belay device. I don't extend my belay device so I rap right off the harness. Most books, climbing guides and other climbers now recommend placing it below the belay device and extending the belay device with a sling.
Seems alpine climbers tend to do it above the device while craggers tend to extend and place it below. I don't think either way is incorrect but which is more effective?? Which has more advantages??
|
|
|
|
|
tenn_dawg
Apr 11, 2003, 3:55 AM
Post #2 of 79
(6361 views)
Shortcut
Registered: Mar 14, 2002
Posts: 3045
|
I personally put it above the rap device. Just make sure that it is short enough that you can reach it to unweight it after it catches. If it is too long, it would be a bitch to unload it, and get it sliding again.
I dont like to extend my primary attachment to the rope with anything. It adds an unnessessary piece of gear to your system.
Travis
|
|
|
|
|
bsignorelli
Apr 11, 2003, 4:04 AM
Post #3 of 79
(6361 views)
Shortcut
Registered: Feb 1, 2003
Posts: 415
|
In reply to: I don't think either way is incorrect but which is more effective?? Which has more advantages??
I think the theory is that if the backup is above the belay device, then it needs to be able to lockup and hold your entire weight.
But if it is placed below the belay deice then it needs to provide the same kind of force (to hold the rope) that your brake hand would provide.
This is because if it's below the device then it uses the friction that the device produces; above the device it has to produce all the friction itself.
Also, if its below the device, then the climber may not grab it in a panic. In a panic (uncontrolled rappell, brake hand slips away, etc) I think I've read that the climbers tended to grab the rope in front of them and would happen to grab the friction knot. By grabbing the friction knot, the knot doesn't grab the line and the climber continues falling.
PTPP had a few comments about this somewhere but a (pathetic) quick search didn't turn up the correct link.
|
|
|
|
|
coldclimb
Apr 11, 2003, 4:06 AM
Post #4 of 79
(6361 views)
Shortcut
Registered: Jan 14, 2002
Posts: 6909
|
Well in theory, below the device is better because the prusik doesn't hold nearly as much weight. It only has to pull the brake, whereas if placed above the rappel device, it has to hold your whole weight. I have less experience than a lot of people though, so if I'm wrong, please correct me. :)
|
|
|
|
|
shortfatoldguy
Apr 11, 2003, 4:11 AM
Post #6 of 79
(6361 views)
Shortcut
Registered: Nov 4, 2002
Posts: 1694
|
Autoblock below the device. And don't extend the device. You just need to make sure the cordage for the autoblock is the right length (spend five minutes at home getting it right).
http://www.wvclimbing.com/tradtips/autoblock.html
I'd be curious to hear a reasoned argument in support of a prussik above the device instead of an autoblock below it. I can't think of any.
|
|
|
|
|
valygrl
Apr 11, 2003, 4:15 AM
Post #7 of 79
(6361 views)
Shortcut
Registered: Jul 8, 2002
Posts: 247
|
I use the autoblock, below the belay device. I agree with bsignorelli and coldclimb about using it below because less force is needed. The autoblock is super simple and fast to set up, it does its job as a backup fine, and it is easy to release, and quick to untie when you're done with the rap. Just make the loop short enough, you don't have to extend the belay device away from you.
|
|
|
|
|
shortfatoldguy
Apr 11, 2003, 4:20 AM
Post #8 of 79
(6361 views)
Shortcut
Registered: Nov 4, 2002
Posts: 1694
|
Why do I bother to reply to these things? Somebody always comes along four minutes later and makes exactly the same intelligent, well-founded claims that I made.
I should stick to talking politics in Community.
|
|
|
|
|
number7
Apr 11, 2003, 4:23 AM
Post #9 of 79
(6361 views)
Shortcut
Registered: Oct 4, 2001
Posts: 175
|
Use the block below the device. Above the device (because it must stop all of the weight) it could slip considerably, causing the knot to "burn" off the rope; rendering it useless.
Peace,
M
|
|
|
|
|
valygrl
Apr 11, 2003, 4:30 AM
Post #10 of 79
(6361 views)
Shortcut
Registered: Jul 8, 2002
Posts: 247
|
hey shortfatoldguy...
"jinx"
;)
|
|
|
|
|
pico23
Apr 11, 2003, 4:59 AM
Post #11 of 79
(6361 views)
Shortcut
Registered: Mar 14, 2003
Posts: 2378
|
This is currently being covered in the gear section via another poster (don't understand the placement choice but I found it so it should cover my question).
Thanks for the replies though
|
|
|
|
|
pico23
Apr 11, 2003, 5:02 AM
Post #12 of 79
(6361 views)
Shortcut
Registered: Mar 14, 2003
Posts: 2378
|
In reply to: I dont like to extend my primary attachment to the rope with anything. It adds an unnessessary piece of gear to your system. Travis
Totally agree which is why I like it above. My thoughts are if it looks up I while I am sure it will be a pain I can use another friction knot to free it up and get some slack. Like I said a total pain in the ass but not unfixable.
|
|
|
|
|
duskerhu
Apr 11, 2003, 5:03 AM
Post #13 of 79
(6361 views)
Shortcut
Registered: Apr 13, 2002
Posts: 1023
|
There is absolutely nothing wrong with using a friction knot above your belay device attached to your harness.
I prefer the kleimhiest (sp?) with/of a 2ft. runner. Attach it to your harness belay loop with a locker. With the proper number of wraps, it's right in front of you, chest to neck high, and grabs immediately as soon as you let go of it. It does not slip nor "burn" off the rope, in fact, it won't even melt because its constantly in a "grab mode" unless you're pulling it down with you. It works for single or double strand raps but you will need to practice to find the proper number of wraps for your weight.
It does create plenty of friction and will eventually make the runner fuzzy so don't use the same one for 10 years... Change it every year.
duskerhu
|
|
|
|
|
arlen
Apr 11, 2003, 5:09 AM
Post #14 of 79
(6361 views)
Shortcut
Registered: May 3, 2001
Posts: 127
|
In reply to: I'd be curious to hear a reasoned argument in support of a prussik above the device instead of an autoblock below it. I can't think of any.
Not sure if it's solid reasoning, but lots of alpine raps consist mainly of safe, moderate grades with a couple steep drops. A prussik above is a little easier to slide (for me, anyway) in the fast walking parts than an autoblock, which makes it hard to feed into the rap device quickly.
For sustained steep raps, the autoblock below the device is better, especially if you need to stop and use yr hands.
|
|
|
|
|
alpnclmbr1
Apr 12, 2003, 6:37 PM
Post #15 of 79
(6361 views)
Shortcut
Registered: Dec 10, 2002
Posts: 3060
|
there is a very good reason not to put your backup above the rap device
Here is some beta I found from a cavers site.
If you use the backup above your rappel device and you lose control with your brakehand, the natural human response is to grab the rope, in which case you disable the prussik backup by pulling on it with your hands.
A surprising number of cavers have decked this way and they no longer recommend this method. Cavers rap a lot.
my best advice is that if it is at all possible, find the walkoff.
|
|
|
|
|
illimaniman
Apr 12, 2003, 7:38 PM
Post #16 of 79
(6361 views)
Shortcut
Registered: Oct 21, 2002
Posts: 128
|
In reply to: I'd be curious to hear a reasoned argument in support of a prussik above the device instead of an autoblock below it. I can't think of any.
Here's an attempt:
With the prussik above the belay device, you're protected even if your belay device were to fail (pretty sure that's not very likely). The prussik will keep you attached to the rope, and suspended.
On the other hand, placing an autoblock below the rappell device relies on the device. If the device fails, you have nothing backing you up.
I know, probably 99% of rappell accidents are from user error or anchor failure, and not device failure, but at least this argument seems reasonable.
|
|
|
|
|
punk
Apr 13, 2003, 2:13 AM
Post #17 of 79
(6361 views)
Shortcut
Registered: May 28, 2002
Posts: 1442
|
I never used it I find it more hassle then good
If u apply good amount of friction with adequate belay device u don’t need it
:wink: :)
Here is what Dr. Gary D. Storrick have to say about that
|
|
|
|
|
matthew
Apr 13, 2003, 6:37 AM
Post #18 of 79
(6361 views)
Shortcut
Registered: Apr 13, 2003
Posts: 7
|
Use a buchman knot (spelling? ohh well) clipped into your leg loop. The reason for NOT putting it above your device is that it can EASILY get out of your reach. Also, try weighting one prussic then unweighting it...its hard...really hard without another one to put weight on. Now im making no since...im done...you get what i mean hua?
|
|
|
|
|
timstich
Apr 14, 2003, 4:59 AM
Post #19 of 79
(6361 views)
Shortcut
Registered: Feb 3, 2003
Posts: 6267
|
In reply to: there is a very good reason not to put your backup above the rap device Here is some beta I found from a cavers site. If you use the backup above your rappel device and you lose control with your brakehand, the natural human response is to grab the rope, in which case you disable the prussik backup by pulling on it with your hands. A surprising number of cavers have decked this way and they no longer recommend this method. Cavers rap a lot. my best advice is that if it is at all possible, find the walkoff.
Yeah, I recall reading that accident analysis of rappell accidents involving cavers. There was a similar problem with user error with the Petzl Stop, a rappelling device that you grip to release.
As for puting the autoblock or what-have-you above your rap device, try it on a short practice rap and then fully weight the autoblock. Now try to get your weight off it to unlock it. Just bouncing up and down, huh? Jesus, now I have to tie an overhand loop to make a step up. Nnnngh! That was real fun.
In short, it can be a real bitch to unload you prusik, autoblock, etc. if you put it above your rap device. If you put it below, it unlocks with ease.
|
|
|
|
|
timstich
Apr 14, 2003, 5:05 AM
Post #20 of 79
(6361 views)
Shortcut
Registered: Feb 3, 2003
Posts: 6267
|
In reply to: On the other hand, placing an autoblock below the rappell device relies on the device. If the device fails, you have nothing backing you up.
If you rappell with no backup, you have one attachment point to the rope. If you add any backup knot or use a Shunt, then you have two attachment points. Whether you put it above or below your rap device is irrelevent. If one fails then the other is there backing you up.
|
|
|
|
|
coldclimb
Apr 14, 2003, 5:28 AM
Post #21 of 79
(6361 views)
Shortcut
Registered: Jan 14, 2002
Posts: 6909
|
I'd advise you all to check out the link in Punk's post. That explains it pretty well. I'll summarize:
If the friction knot is above the device, and you begin to lose control, instinct is to grab harder. This disables the friction knot, until you let go, which is against natural instinct. If the knot is below the device and you lose control and clamp down tighter, that extra clamping merely applies more breaking force, stopping you. If you completely let go, you are stopped in either situation.
Adding and subtracting the pros and cons, I'd go with below the device.
|
|
|
|
|
tori
Apr 14, 2003, 5:35 AM
Post #22 of 79
(6361 views)
Shortcut
Registered: Feb 23, 2003
Posts: 141
|
the reason i put it above the device is mostly because it is easy, simple, and fast compared to setting it up below. it does take some finger strength to release the knot when weighted, but we are all climbers so that should be no problem. i have released such a knot several times, even in free space all you have to do is pull yourself up a tiny bit with your left hand, and catch that little bit of slack with your brake hand. below the device you must get it the right length so it won't get into the device, and/or extend the device away from you which takes time and a runner. at the top of a climb is when available gear is at a low point so i don't want to use too much stuff to extend my belay device. i know some of the new books teach the below the device method, it is probably better for new climbers who feel they need a backup.
i only back up a rap if i am going to have to stop on the way down to do something unusual, like get to a bolt anchor way over to one side or in under an overhang where you have to do that kick and swing deal. for these limited times the speed and simplicity of the over method works best for me. like everything else learn all the pros and cons of each method and the limitations of each, that will be more important than which method you use.
|
|
|
|
|
diligence
Apr 14, 2003, 2:02 PM
Post #23 of 79
(6361 views)
Shortcut
Registered: Apr 14, 2003
Posts: 4
|
Tori and others,
"it is probably better for new climbers who feel they need a backup"
I humbly suggest that we all need to back-up our rap's all the time...just like we all tie knots in the end of the rope, all the time.
In the past, I've backed up rap's probably 75% of the time. However, this past winter while rapping off an ice climb, I took a large chunk of ice right on the head. I was wearing a helmet, but the force of the impact "stunned' me for a couple of seconds. If I would not have had my rap backed-up with a klemheist below my device, I would have decked. The back-up knot caught me and allowed me to regain my composure. I will NEVER EVER AGAIN, rappell without a back-up. Either a belay from above, self belay with a friction knot or a fireman's from below.
Cheers,
D
|
|
|
|
|
dirtineye
Apr 14, 2003, 2:51 PM
Post #24 of 79
(6361 views)
Shortcut
Registered: Mar 29, 2003
Posts: 5590
|
EXCELLENT post diligence, thank god you used your backup then and always, as it should be.
It takes about 10 seconds at the most to tie an auto block with a 2 foot sling below the device throught your leg loop. BE SURE to set your auto block before rapping, this knoe must be set to work.
I keep a 2 foot sling girth hitched and a locking biner on my leg loop as standdard equipment.
|
|
|
|
|
rgold
Apr 14, 2003, 3:55 PM
Post #25 of 79
(6361 views)
Shortcut
Registered: Dec 3, 2002
Posts: 1804
|
I am one of those who thinks rappel back-ups have some problems that mean using them is very far from a no-brainer. The major issue is harness hang syndrome. If you don't know what this is, do a Google search and you'll find lots of references. In brief, if you hang motionless in a harness, your mental state degrades rapidly and death can ensue in as little as 5 minutes. There's nothing theoretical about this, it has happened a number of times. This means that if you are using a friction knot rappel back-up to save you in case something causes you to lose consciousness, the scenario you have in mind had better be a momentary loss of consciousness, otherwise your back-up knot may well kill you and place the rest of your party in a very difficult rescue situation. Think about how hard it will be for the rest of the party---maybe just a single person---to get to an unconscious person hanging in mid-rappel, get the weight of the unconscious person off the rope, and lower them to the bottom of the rappel.
This means that, as with many other things in climbing, you have to balance different types of risks in arriving at a decision about what to do, and there is no obvious best solution that is good 100% of the time.
By far the safest practice, although you almost never see any party do this, is to lower the first person and have them provide a "fireman's belay" for the others in the party. Certainly, once the first person is down, the "fireman's belay" is preferable to any knot or device that will lock an incapacitated climber in position in mid-rappel.
|
|
|
|
|
|
|
|
|
1
