Catching high fall factor falls - back up knot(s)?

Matty H wrote: I am going to have to disagree with you on the gri gri. Unless on sport, I will not use a gri gri. The reason Why: geir.com/mythbuster.html . Go down to number 7 on his myth list. Basically It states that because gri gris lock up automatically they put more force on the ropes than a tube style device. Minimal, Yes. Arbitrary, maybe, but hey we are talking a bout high FF falls, and that could possibly be the difference in gear pulling out. Just my thoughts.

All true. But the potential for the belayer to get smashed into to the rock is so high, or just to catch their arm on something as they get pounded that unless you also think the gear is poor, a grigri can I suggest be a good idea.

After all, plenty in the USA climb trad on single ropes, when half ropes would put less strain on the gear.

Logan Schiff wrote: Really? Physics and math are definitely not my forte at all, and that does make sense intuitively, but I thought that the impact force of the fall depends entirely on the fall factor? Or am I confusing two separate concepts?

Two separate concepts.

Impact force depends on fall factor.

Energy in the system that needs to be dissipated is going to be depend on the actual falling speed of the climber, and generally a longer fall will result in a faster falling climber, which means more energy to dissipate. This means holding the high force for a longer time; or if a bit of slip through a device is happening, this slip goes on for longer, with more chance of rope burn, losing control, etc.

David Gibbs wrote:In a couple recent threads on belaying ( mountainproject.com/v/not-a…) and belay devices ( mountainproject.com/v/alpin…) there has been repeated comments, especially from rgold, but also from others about the difficulty of catching high-fall factor falls on a traditional tube device (e.g. an ATC), or even a more recent (nominally) higher-friction device such as an ATC-XP or ATC-Guide. So, if you have chosen to use such a device for belaying a multi-pitch climb (cost, weight, usability as a rappel device, or other such reasons), might the choice of tying one or more backup knots below the belay device help with this? They would limit how far the leader could fall, should the belayer lose control of the brake strand in a high-fall factor fall. Of course, the clearest disadvantage I see would be the belayer needing to untie the knot (or knots) as they approach the belay device.

David - Why wouldn't you just use a freakin Gri Gri? And the whole prussic idea sounds great, NOT. Why not just use a gri gri? becuase weight is more important than safety? We're talking about .17 of a pound of weight? You can rap with gri gri.. what's wrong with you people? REally? tie knots in your rope vs just using a gri gri??? Whatever ur smokin i want some...

And the whole prussic idea sounds great, NOT. Why not just use a gri gri? becuase weight is more important than safety? We're talking about .17 of a pound of weight? You can rap with gri gri.. what's wrong with you people? REally? tie knots in your rope vs just using a gri gri??? Whatever ur smokin i want some...

Maybe you don't have a GriGri. Maybe you arrive at a pitch where there's an unexpectedly high chance of rockfall. Maybe your leader is getting pumped at the end of the day and you want a back-up. Lots of possibilities that don't involve smoking anything.

Maybe you don't have a GriGri.
Then sell a cam and go buy one so safety is first.

Maybe you arrive at a pitch where there's an unexpectedly high chance of rockfall.
And why would this make one choose an ATC with knots in the rope over say a GriGri? I would INSIST the belayer must use a GriGri in case of rockfall and they get knocked unconcious or worse (climber still has a catch).

Maybe your leader is getting pumped at the end of the day and you want a back-up.
So why the bleep wouldn't u choose a gri gri if both of you are tired and more likely to make mistakes and your leader is taking off on a route with the potential for a FF2 fall?

What are you, a GriGri salesman? I have one and I use it sometimes and it works great. But there's a million reasons you might not have one at every belay. You might drop it. You might just not like using one and prefer a tube-style device. And saying that the Gri is, in all cases, the safest device to use is just a lie. It depends on the situation, belayer preference and technique, and a ton of other variables.

I'm just trying to ask, hypothetically, if you were using a tube-style device, would a prusik tied above the ATC work reasonably as a back-up?

and to quote a regular here----->

ur gonna die...

OK, here is an idea for the perfect catch of a factor 2 fall that everyone here is familiar with.

Use an ATC with gloves on for a soft catch with an autolocker below the brake hand backing that up for when you let go!

ahh, midwinter on the proj!

why use a new-fangled ATC when you have a perfectly good ass for a hip-belay?

You might drop your ATC, but you always have an ass.

David Sahalie wrote:why use a new-fangled ATC when you have a perfectly good ass for a hip-belay? You might drop your ATC, but you always have an ass.

how are all the old dudes still alive after all those years of hip belays with hemp ropes?

Anyone advocating backup knots or a friction hitch below the belay device has clearly not tried this or really thought about it. It is a ridiculous idea. Either make certain you are not in a position to create a high factor fall (several ideas to prevent this have been discussed above), and/or make sure you are using an appropriate belay device/gloves etc. to handle it if it does happen.

I'm not advocating it - the prusik above the ATC was just an idea that popped into my head that was along the lines of the OP's original question. You're right, I've never used it and probably never will. Most likely a huge PIA. I was just wondering aloud, if the OP were in such a dire predicament that he wanted a belay backup for whatever reason, wouldn't a friction hitch above the ATC work better than knots below it? Even though it is a ridiculous idea.

The Phoenix wrote:Maybe you don't have a GriGri. Then sell a cam and go buy one so safety is first. Maybe you arrive at a pitch where there's an unexpectedly high chance of rockfall. And why would this make one choose an ATC with knots in the rope over say a GriGri? I would INSIST the belayer must use a GriGri in case of rockfall and they get knocked unconcious or worse (climber still has a catch). Maybe your leader is getting pumped at the end of the day and you want a back-up. So why the bleep wouldn't u choose a gri gri if both of you are tired and more likely to make mistakes and your leader is taking off on a route with the potential for a FF2 fall?

Hey Im not going to argue about which is better, I prefer ATC setups. Everything You mentioned, I believe I can handle with an ATC setup. Who is right? Neither, or both. Its just the way you were taught. If you want to argue about this PM me so we avoid drifting off topic.
The ATC simply reduces Fall Factor, Thats why I mentioned it.

folks you CAN do it ... and not it WONT damage the rope, at least not more than anything else if you do it properly

1. as with the petzl documentation above ... tie a series of knots as you flake in the rope

2. HOWEVER rather than using overhands ... use SLIP KNOTS ... this makes it fairly easy to untie as the rope comes through ...

3. remember that it doesnt require as much force to hold the fall when its through the ATC already ... similar to a prussic below the device ... the slip knot on the biner will hold the fall ...

4. use a large size biner like a willliams or a boa

if i am on an ATC and a high factor fall is a serious possibility, i will do this .... or at the very least tie one or two slip knots to a biner to the estimated length of the first piece

note that this system also means you arent dropped the entire way if your belayer gets konked out by a rock

does it take more time and effort? ... sure ... but with practice it works fine and provides an additional margin of safety against high factor falls and rockfall ... doesnt mean youll use it on every pitch

;)

Matty H wrote: Hey Im not going to argue about which is better, I prefer ATC setups. Everything You mentioned, I believe I can handle with an ATC setup. Who is right? Neither, or both. Its just the way you were taught. If you want to argue about this PM me so we avoid drifting off topic. The ATC simply reduces Fall Factor, Thats why I mentioned it.

I act like a sales guy on this point because I think it will save a life, I know it has in my life. Matty - we're not drifting and I'm not arguing we just had a whole thread about this. David mentioned in that thread that ego plays a big role and in your statement I think the ego is apparent when you state, "Everything You mentioned, I believe I can handle with an ATC setup."

Quite simply you cannot belay if you have been knocked unconscious or seriously injured from rock fall. If you think you can your ego is getting in the way. I do agree that atc might help reduce fall factor with some slippage, but a good dynamic belay can mitigate that difference.

bearbreeder wrote:folks you CAN do it ... and not it WONT damage the rope, at least not more than anything else if you do it properly 1. as with the petzl documentation above ... tie a series of knots as you flake in the rope 2. HOWEVER rather than using overhands ... use SLIP KNOTS ... this makes it fairly easy to untie as the rope comes through ... 3. remember that it doesnt require as much force to hold the fall when its through the ATC already ... similar to a prussic below the device ... the slip knot on the biner will hold the fall ... 4. use a large size biner like a willliams or a boa if i am on an ATC and a high factor fall is a serious possibility, i will do this .... or at the very least tie one or two slip knots to a biner to the estimated length of the first piece note that this system also means you arent dropped the entire way if your belayer gets konked out by a rock does it take more time and effort? ... sure ... but with practice it works fine and provides an additional margin of safety against high factor falls and rockfall ... doesnt mean youll use it on every pitch ;)

or just use an autolocking device... say a gri gri - sorry can't help myself.

have a nice weekend everyone

The Phoenix wrote: or just use an autolocking device... say a gri gri

its up to people what they want to use ...

on sketchy gear leads where the belayer in anchored down a grigri may not be the best option

i use a smart most of the time personally ... but what other people use when they climb with others is their own bizznisss

however should someone request i use an ATC on a multi lead for its more dynamic properties, at least i know the techniques to prevent a full "fall the entire rope length" even on a tube style device ... its their azz on the sharp end on sketch gear, im not going to tell em that ill only belay em on a grigri

these are basic skills IMO .... one of these days you will drop that gri gri, or other belay device on multi should you climb enough, or something else ... and youll need to know the techniques to make up for it

PETZL usually tests and use things before they recommend it in their literature

;)

Not to beat the unpopular dead horse, but there are times when falling just isn't going to be an option. I deal with the results of really bad falls more than most, and there really isn't anything that I've seen to dissuade that knowledge.

Logan Schiff wrote: Really? Physics and math are definitely not my forte at all, and that does make sense intuitively, but I thought that the impact force of the fall depends entirely on the fall factor? Or am I confusing two separate concepts?

On paper, yes the impact force of the fall depends on fall factor and weight. In real life, fall distance plays a role, although not as much as fall factor. However, I am talking about a different concept all together. I am talking about the total amount of energy involved in the fall, and not the peak load. For example, a 10' FF1.5 fall might produce 1,500 lbf on the top piece, but only for a small amount of time, say 10mS. A 30' FF1.25 fall might only produce 1,200 lbf on the top piece, but the load duration is going to be longer. The peak might hold for 25mS.

As a result, a belayer might be able to arrest a high load for a short duration, but when presented with a slightly lower load for a much longer duration, the belayer could loose control of the belay. Thus, fall distance affects the total energy involved, and it affects the likelihood of the belayer loosing control of the rope. However, yes, fall factor is more important. The idea, though, is that a 40' fall is going to be harder to arrest than a 10' fall of the same fall factor (in an FF1+ environment).