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Re: Falling during rappel

PostPosted: Nov 15, 2012 12:19 pm
by LukeM
gindling, speaking for myself I wasn't referring to belaying experienced cavers. If these guys are using climbing devices for caving they aren't likely to be experienced vertical cavers (just guessing here). I will always give a bottom belay to first time rappelers and beginners who don't feel totally comfortable. I've seen way to many thoroughly-trained first timers still have trouble remembering to keep their brake hand on the rope and I know of at least one situation where a serious incident was prevented by a bottom belay. I too don't understand the issue with being pulled to the side a little while on rappel. I'd much rather pull someone into a waterfall (not a common thing on beginner trips) or the side of a pit than stand and watch as they break their legs.

Re: Falling during rappel

PostPosted: Nov 15, 2012 3:02 pm
by GroundquestMSA
gindling wrote:Figure 8s, ATCs, Versos, and all the other rock climbing/belaying gear is not cave worthy for descending in my opinion and will not be allowed on my rope during any expeditions that I run or cave trips that I lead, it is just not safe. Though I do use them when bolt climbing of course. Reasons? Not being able to tie off on rope easily and securely when descending, downright difficulty or impossibility of doing changeovers and rebelays, and twisting of rope (which with rebelays is unacceptable). That's enough reasons for me.


Tying off is very easy with a rescue 8 or an ATC. Changing over from rappel to frog or frog to rappel is very easy with an ATC or rescue 8. ATCs don't twist rope and rope twist doesn't matter anyway if you don't have rebelays or a big pile of rope on the floor. ATCs are delightfully small. Those are enough reasons for me to happily use these devices under the right circumstances.

Re: Falling during rappel

PostPosted: Nov 20, 2012 10:59 pm
by arcs
1. Pretty sure the correct use of the bachmann hitch, or prusik, klemheist et al., is to manage the hitch from below the hitch, not holding directly onto the hitch, or in the case of a bachmann, the carabiner. There is a long history of friction hitches failing because you hold onto the hitch, instead of minding the hitch from above or below the hitch, (depending on if you are ascending or descending). From your picture you look like you are using the bachmann incorrectly. The carabiner is NOT a handle.

2. The main benefit of a back-up is injury from rockfall. If a rock knocks you out or breaks your arm, you will (presumably) not fall to the ground, and can be rescued by your party, avoiding a ground fall.

3. You should not have to back up a petzl STOP, though I might back up a plain bobbin. A rack, presumably, will be set to a stiff enough friction that you would not need to back it up either, as it would lower you at the standard rate it is set to. You should probably not need to add much pressure, if any, to the rope in a properly set up rack configuration.

So, not trying to shellack you here, but look into how you use your bachmann hitch, and go from there. Read "Mountaineering: The Freedom of the Hills" from proper use of bachmann. For most Rockies caving, people use STOPs, because racks are heavy and our caves are high up, and (most) of our pitches are shortish.

Re: Falling during rappel

PostPosted: Nov 22, 2012 12:01 pm
by dutchcontractor
Rule #1; Never let go of your brake hand!
Rule #2; See rule #1!

While nothing beats experience, you basically have two options for backup. (Yes, there are more options but lets talk about the 2 that get used the most).

1: Backup your brake hand with a french wrap tied to your harness. There are other hitches that can be used but the French Wrap is easy to tie and it can be released under load. Here is a link that explains it : http://bats.varegion.org/downloads/newsletter/august2003.pdf

2: Bottom Belay, using a bottom J belay. You can belay away from the landing zone and still be effective when properly executed. This has saved lives at bridge day.

You can use both these options at the same time. Most of the time you can use at least one of them. Both options have saved lives in real situations.

Neither option will affect your rappelling in a negative way once you are used to them. They are not 100% full proof but certainly add a safety factor. Learning curve is fast, you should be comfortable with these backups after 3 or 4 rappels.

I didn't used to believe in backing up your rappel, but I was open minded and learned from the right people. Now you rarely see me on rappel without a backup.

PM me if you want more info.

Re: Falling during rappel

PostPosted: Dec 3, 2012 4:16 pm
by cavedoc
snowaydude wrote:... and I instinctively went to place my hand on the wall. Possibly to stop my face from hitting or who knows, but it was my hand from the belay device that reached out, therefore sending me rapidly downward.


A number of folks have already alluded to the problems of having a safety device that needs to be let go of when needed to engage. The other question I would ask though is what has led to the reflex of letting go of the rope. I don't know the Verso you are using. Is this a "let go as needed" type of device? There are a number of topics on the French wrap an other back ups. One of the concerns is that these devices can lead one to give up the "If I let go I'm going to die" mentality. IMO, using these devices can lead to bad habits, both in rappeling and in belaying. Less excrement is going to hit the fan while in a stable belay stance, but if it does, do you think your reaction of letting go will be similar? And if so, does that change the type of belay that you would do?

Re: Falling during rappel

PostPosted: Dec 4, 2012 5:30 am
by Mike Hopley
Snowaydude: you have several options for a rappel device.

However, safe rappelling is mainly about learning good habits, not using a magical piece of equipment. You should never (never!) let go the braking side of the rope, unless you are secure (locked off, clipped in, whatever). I'm sure you understand this in theory, but maybe it's not "in your blood" yet. Maybe you haven't practised enough.

Your Verso belay device is a poor choice for typical caving. It is tricky to lock off; it could be dropped at rebelays or pitch heads; it has relatively low friction on single rope (especially thin rope); and rapid wear from gritty caving rope could compromise its integrity. I'm not saying you should never use it for caving -- just recognise that it will only be suitable in a narrow range of circumstances. In practice, you're better off with a caving descender -- most likely a bobbin or a rack.

The Petzl Stop is the most common auto-locking caving descender (and the main descender used here in the UK). It is a much better descender than your Verso, but the auto-lock has the same panic-grab problem as your Bachmann hitch. It is better to think of the auto-lock as a convenience feature, not a safety feature.

If you really want a fail-safe rappel backup, you could use a double-brake descender -- such as the Kong Indy, Anthron Double Stop, or SRTE Double Stop [PDF]. These are immune to the panic-grab reaction, but they are correspondingly bulkier, heavier, and more fiddly to use than a simple descender.

For the ultimate in rappel safety (or paranoia :wink:), get yourself a Petzl ASAP, as used in industrial rope access. It is effectively a modern, mechanical version of a knot backup -- but unlike your Bachmann hitch, it's completely reliable. It's also expensive, heavy, and bulky.

I use a Petzl Simple, which is the most common descender in Europe. It is normally used without any rappel backup. It has proved sufficiently safe when used correctly, because we don't have a trail of dead bodies leading back to it. :wink: The same can be said of using racks without a backup.

Summary: it is possible to fix the problem with magical equipment, but this equipment can be annoying or impractical for caving. Most cavers fix the problem using technique and training instead, so that they can be safe using a simple descender (such as a rack or bobbin).

Re: Falling during rappel

PostPosted: May 3, 2013 11:28 pm
by snowaydude
does the STOP work well with icy/dirty rope?

Re: Falling during rappel

PostPosted: May 7, 2013 6:07 am
by Wormster
snowaydude wrote:does the STOP work well with icy/dirty rope?


It will, although you might have to force the rope through the descender, it also depends on the type of dirt, if you've got a muddy rope, then you can wipe off most of this using your right (controlling) hand, mind you if you have a rope embedded with say slate dust, it will be a bit stiffer.

I have no experience with icy ropes mind!

(oh yeah the stop is a good bit of kit to invest in - no I don't have shares in Petzl)

Re: Falling during rappel

PostPosted: May 7, 2013 10:25 am
by ian mckenzie
snowaydude wrote:does the STOP work well with icy/dirty rope?

Yes and no. Whether a change in friction is due to mud, ice or a different rope diameter, the Stop is essentially a non-adjustable device and must be used with caution. Many people use a redirecting carabiner on their central maillon just below the Stop attachment (or even clipped onto the lower part of their harness) with the brake hand on the rope below that, so that they can control the angle the rope goes thru that biner and adjust friction that way.

Muddy ropes are pretty common here, but they tend to slow you rather than speed you up. Icy ropes are pretty rare unless the anchor is at the warm surface and the rope is in a sub-zero zone (possible in the Flathead, where many caves are in permafrost).

Which cave were you in (your first post)? There are several in the Flathead that have icy bits.

Ian

Re: Falling during rappel

PostPosted: May 7, 2013 4:25 pm
by caver.adam
FYI, the Petzl Stop suffers from the fact that when you squeeze for dear life it won't lock. It also does not work well on ropes that are too small, and you may not know the rope is too small until you are fully loaded on the rope. That being said, I often use a Stop and focus on making sure the rope is large enough and making sure that I remember to let go of the red handle in an emergency.

Alternatively there is another petzl device used in industrial applications called the "Petzl ID" which is both self braking and protects the user who accidentally grips too hard in an emergency.

I primarily use a Rack however and concentrate on maintaining good rappeling technique.

Re: Falling during rappel

PostPosted: May 21, 2013 9:55 am
by hank moon
gindling wrote:Like I said, give me an example of when you would belay an experienced vertical caver in a non-rescue situation that isn't bolt climbing and why? I just can't think of one, though I'm willing to learn. I guess it all depends on the pit and passage type that would dictate whether or not pulling someone out of plumb would cause problems. But you're right. In a large, round pit it wouldn't really matter.


Exploration

Re: Falling during rappel

PostPosted: May 21, 2013 4:00 pm
by NZcaver
caver.adam wrote:FYI, the Petzl Stop suffers from the fact that when you squeeze for dear life it won't lock. It also does not work well on ropes that are too small, and you may not know the rope is too small until you are fully loaded on the rope. That being said, I often use a Stop and focus on making sure the rope is large enough and making sure that I remember to let go of the red handle in an emergency.

You make a good point here, but perhaps you need to rethink the role of the Stop. "Remembering to let go of the red handle in an emergency" is extremely difficult for most people, as grabbing is a reflex option. If you spontaneously lose consciousness during a rappel, well... maybe. But I prefer to think of the handle on the Stop primarily as a parking brake convenience NOT a fall arrest feature. Therefore DO NOT let go your hand on the rope below unless stopped and locked!

Alternatively there is another petzl device used in industrial applications called the "Petzl ID" which is both self braking and protects the user who accidentally grips too hard in an emergency.

I own an ID and it works well, but it has a semi-sealed clutch mechanism and is generally not recommended for caving and other very dirty environments. If you really feel the need for a double-brake anti-panic stop action, there is also the SRTE double brake Stop, the Anthron/Singing Rock DSD, Kong Indy, Troll Pro Allp, etc.

I primarily use a Rack however and concentrate on maintaining good rappeling technique.

Good plan.