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Is this a risky way to use the B52 in autoblock mode?
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spikeddem


Feb 25, 2009, 9:53 AM
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Is this a risky way to use the B52 in autoblock mode?
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Edit: I am using a Petzl Attache Carabiner.

The instructions for proper autoblock mode may be read here:

http://www.trango.com/pdfs/B-52FAQ.pdf

The only image on the second page shows the setup for autoblock mode with a B-52. Right above the picture the Q&A is

In reply to:
Q: "I set up a belay using the autoblock mode and it was really hard to pull the rope through. What’s
up?"

A: ". . . A highly forged carabiner has sharp angles which may add enough friction to the system that it becomes nearly impossible to haul the rope through the device. A key here is actively feeding the rope into the device with your guide hand as you pull it through with your brake hand."

Some of the ropes that my club uses are on the beefy side, and I was checking out whether or not they would work. I found a trick to allowing the rope to easily feed through and want to see if others see any safety issues that I don't see.

Place the right hand on the braking end of the rope and the left hand on the blocking carabiner. If you pull the carabiner straight down and pull on the brake strand, then slack easily slides through no problem. The nice thing is that if there is a tug on the climber side (i.e., a fall) then the carabiner is tugged back into the blocking position and the rope brakes properly. It is, of course, imperative that the belayer not be lifting the blocking carabiner upwards.


(This post was edited by spikeddem on Feb 25, 2009, 5:00 PM)


iron106


Feb 25, 2009, 1:35 PM
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Re: [spikeddem] Is this a risky way to use the B52 in autoblock mode? [In reply to]
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If one hand is on the blocking carabiner and you are belaying with the other, Do you ALWAYS have one hand on the brake? sounds like there could be a problem if you have the autoblock released and no hand on the brake.


colatownkid


Feb 25, 2009, 1:44 PM
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Re: [spikeddem] Is this a risky way to use the B52 in autoblock mode? [In reply to]
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spikeddem wrote:
The instructions for proper autoblock mode may be read here:

http://www.trango.com/pdfs/B-52FAQ.pdf

The only image on the second page shows the setup for autoblock mode with a B-52. Right above the picture the Q&A is

In reply to:
Q: "I set up a belay using the autoblock mode and it was really hard to pull the rope through. What’s
up?"

A: ". . . A highly forged carabiner has sharp angles which may add enough friction to the system that it becomes nearly impossible to haul the rope through the device. A key here is actively feeding the rope into the device with your guide hand as you pull it through with your brake hand."

Some of the ropes that my club uses are on the beefy side, and I was checking out whether or not they would work. I found a trick to allowing the rope to easily feed through and want to see if others see any safety issues that I don't see.

Place the right hand on the braking end of the rope and the left hand on the blocking carabiner. If you pull the carabiner straight down and pull on the brake strand, then slack easily slides through no problem. The nice thing is that if there is a tug on the climber side (i.e., a fall) then the carabiner is tugged back into the blocking position and the rope brakes properly. It is, of course, imperative that the belayer not be lifting the blocking carabiner upwards.

The action you describe is effectively the technique you use to lower a second in autoblock mode. In other words, if your brake hand never leaves the rope, this is technically not a problem. However, you should note that you're releasing the autoblock mechanism every time you do this, which pretty much defeats the point of having an autoblock in the first place.

Your best bet is to just do what the directions say: "feeding the rope into the device with your guide hand as you pull it through with your brake hand" It sucks on fat ropes, but there's not all that much you can do about it, unfortunately.

edit: grammar


(This post was edited by colatownkid on Feb 25, 2009, 1:45 PM)


altelis


Feb 25, 2009, 1:57 PM
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Re: [spikeddem] Is this a risky way to use the B52 in autoblock mode? [In reply to]
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Waiting for Mal in 5.......4.......3.......2.......1......

















(Don't fail me now, buddy!!!!!)Wink


spikeddem


Feb 25, 2009, 2:17 PM
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Re: [colatownkid] Is this a risky way to use the B52 in autoblock mode? [In reply to]
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See below regarding "releasing" the autoblock (which I am just quoting myself from above. I don't think this is really releasing the autoblock at all. Essentially, that was my actual question. As far as I can tell, the autoblock is automatically forced when there is a pull on the climber end of the rope.

In reply to:
sounds like there could be a problem if you have the autoblock released and no hand on the brake.

See below.


iron106 wrote:
However, you should note that you're releasing the autoblock mechanism every time you do this, which pretty much defeats the point of having an autoblock in the first place.

The second there is a pull on the climber end of the rope, the system is forced into autoblock mode.


(This post was edited by spikeddem on Feb 25, 2009, 2:21 PM)


trenchdigger


Feb 25, 2009, 2:22 PM
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Re: [colatownkid] Is this a risky way to use the B52 in autoblock mode? [In reply to]
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colatownkid wrote:
spikeddem wrote:
The instructions for proper autoblock mode may be read here:

http://www.trango.com/pdfs/B-52FAQ.pdf

The only image on the second page shows the setup for autoblock mode with a B-52. Right above the picture the Q&A is

In reply to:
Q: "I set up a belay using the autoblock mode and it was really hard to pull the rope through. What’s
up?"

A: ". . . A highly forged carabiner has sharp angles which may add enough friction to the system that it becomes nearly impossible to haul the rope through the device. A key here is actively feeding the rope into the device with your guide hand as you pull it through with your brake hand."

Some of the ropes that my club uses are on the beefy side, and I was checking out whether or not they would work. I found a trick to allowing the rope to easily feed through and want to see if others see any safety issues that I don't see.

Place the right hand on the braking end of the rope and the left hand on the blocking carabiner. If you pull the carabiner straight down and pull on the brake strand, then slack easily slides through no problem. The nice thing is that if there is a tug on the climber side (i.e., a fall) then the carabiner is tugged back into the blocking position and the rope brakes properly. It is, of course, imperative that the belayer not be lifting the blocking carabiner upwards.

The action you describe is effectively the technique you use to lower a second in autoblock mode. In other words, if your brake hand never leaves the rope, this is technically not a problem. However, you should note that you're releasing the autoblock mechanism every time you do this, which pretty much defeats the point of having an autoblock in the first place.

Your best bet is to just do what the directions say: "feeding the rope into the device with your guide hand as you pull it through with your brake hand" It sucks on fat ropes, but there's not all that much you can do about it, unfortunately.

edit: grammar

I've worn out two B52s and am working on my 3rd. The key is to find the right carabiner to use with it. Round stock 'biners like the Petzl Attache seem to work best. I've autoblock belayed on it with a 10.7mm PMI rope and it was a bit more work, but very doable. I frequently autoblock belay with it using a 10.2mm rope with no issues.


colatownkid


Feb 25, 2009, 3:24 PM
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Re: [spikeddem] Is this a risky way to use the B52 in autoblock mode? [In reply to]
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spikeddem wrote:
See below regarding "releasing" the autoblock (which I am just quoting myself from above. I don't think this is really releasing the autoblock at all. Essentially, that was my actual question. As far as I can tell, the autoblock is automatically forced when there is a pull on the climber end of the rope.

In reply to:
sounds like there could be a problem if you have the autoblock released and no hand on the brake.

See below.


iron106 wrote:
However, you should note that you're releasing the autoblock mechanism every time you do this, which pretty much defeats the point of having an autoblock in the first place.

The second there is a pull on the climber end of the rope, the system is forced into autoblock mode.

while true, this does not apply if you are still holding the blocking carabiner in the open position.

perhaps an analogy is in order (don't take this too literally, i understand that a grigri is not a plaquette.)

suppose you are belaying a leader with a grigri. the rope is too fat for the grigri, so in order to feed out slack, you hold the grigri's black handle in the open position. when you're not feeding out slack, you don't hold the grigri open.

if the climber falls, this is no big deal, because if everything works properly, the grigri locks up and you're good to go, whether or not your brake hand is on the rope. (again, this is not the grigri's documented design and use, but as i'm sure we're both aware, if you fall on a grigri hard enough, it usually locks up.)

but suppose that to feed the rope you always hold the handle open at all times. now if the climber falls, you are holding the camming mechanism open, so the grigri won't lock. suddenly, it's pretty damn important that your brake hand is on the rope.

the black handle on the grigri is the blocking carabiner in question. as long as you let go as soon as the rope is loaded and the biner blocks the B-52 you're good to go. if you hold onto that biner when the climber is falling, though, you better make damn sure your brake hand is on the rope.

conclusion: i'd be willing to say that there's nothing completely wrong with the method you propose, but i would not be jumping to call it the safest possible method.


spikeddem


Feb 25, 2009, 3:48 PM
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Re: [colatownkid] Is this a risky way to use the B52 in autoblock mode? [In reply to]
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colatownkid wrote:
spikeddem wrote:
See below regarding "releasing" the autoblock (which I am just quoting myself from above. I don't think this is really releasing the autoblock at all. Essentially, that was my actual question. As far as I can tell, the autoblock is automatically forced when there is a pull on the climber end of the rope.

In reply to:
sounds like there could be a problem if you have the autoblock released and no hand on the brake.

See below.


iron106 wrote:
However, you should note that you're releasing the autoblock mechanism every time you do this, which pretty much defeats the point of having an autoblock in the first place.

The second there is a pull on the climber end of the rope, the system is forced into autoblock mode.

while true, this does not apply if you are still holding the blocking carabiner in the open position.

Have you tried it? It sure seems to hold true. Experimentally it has gone back to autoblock mode whether or not I'm holding the carabiner down, and theoretically the rope is still pinching over itself, so it only makes sense that it would still function correctly.

The reason the lowering mode lowers (aka doesn't break) is because the rope no longer pinches over itself. The rope continues to pinch over itself when using this method, and it accordingly snaps into the autolocking position when a pull is present on the climber end, even if I'm holding the carabiner directly down at the time.

That is to say that when holding the carabiner down, rope can only be fed one way through the device (taking in). Or so it would seem, which is why I'm asking this.


colatownkid


Feb 25, 2009, 4:07 PM
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Re: [spikeddem] Is this a risky way to use the B52 in autoblock mode? [In reply to]
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spikeddem wrote:
colatownkid wrote:
spikeddem wrote:
See below regarding "releasing" the autoblock (which I am just quoting myself from above. I don't think this is really releasing the autoblock at all. Essentially, that was my actual question. As far as I can tell, the autoblock is automatically forced when there is a pull on the climber end of the rope.

In reply to:
sounds like there could be a problem if you have the autoblock released and no hand on the brake.

See below.


iron106 wrote:
However, you should note that you're releasing the autoblock mechanism every time you do this, which pretty much defeats the point of having an autoblock in the first place.

The second there is a pull on the climber end of the rope, the system is forced into autoblock mode.

while true, this does not apply if you are still holding the blocking carabiner in the open position.

Have you tried it? It sure seems to hold true. Experimentally it has gone back to autoblock mode whether or not I'm holding the carabiner down, and theoretically the rope is still pinching over itself, so it only makes sense that it would still function correctly.

The reason the lowering mode lowers (aka doesn't break) is because the rope no longer pinches over itself. The rope continues to pinch over itself when using this method, and it accordingly snaps into the autolocking position when a pull is present on the climber end, even if I'm holding the carabiner directly down at the time.

That is to say that when holding the carabiner down, rope can only be fed one way through the device (taking in). Or so it would seem, which is why I'm asking this.

your sure seem to have made up your mind. if you did not want my opinion, you did not have to ask.

have i tried it? yes and no. i have used both the petzl reverso and the black diamond atc-guide. however, i have not used the trango b-52. i assume that it works in the same manner as both of the autoblocking belay devices i mentioned above. granted, my assumption may not hold true, but i'd bet willing to be it is.

that being said, in my experience, holding the blocking carabiner open places a plaquette in lowering mode. by definition, lowering mode must allow the rope to move both directions. otherwise, the rope is not actually in lowering mode.

(a caveat: maybe there's something special about the b-52 that i'm not aware of. perhaps what you're suggesting somehow disengages the rope enough to let it slide freely without actually placing the device in lowering mode.)

i am not suggesting there is anything wrong with what you're proposing. if you don't hold the carabiner open when the climber falls, it doesn't matter in the slightest where your brake hand is. however, if you're holding the biner open when the climber falls and are not holding the brake hand, you will drop the climber.

granted, this issue is easy to fix. if you are holding the biner open and the climber falls, simply let go and the device will in fact return to autoblock mode and arrest the fall. (in theory anyway. i've never tried to stop a freefalling climber by simply letting the blocking biner catch them.)

so, is your proposed method "safe?" yeah, it will probably work just fine as i'm sure you're smart enough to put the biner back into blocking mode if the climber falls. i'm merely trying to tell you to be careful and to fully understand what you're doing. and, as always, keep a brake hand on the rope. that's it.

i still say that if you have to use two hands anyway, why not just do it how the manufacturer recommends and not take a chance.

ultimately though, it's your belay and your partner. you get to decide.


altelis


Feb 25, 2009, 4:36 PM
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Re: [colatownkid] Is this a risky way to use the B52 in autoblock mode? [In reply to]
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the "wave" or "M" (for lack of a better term) pattern of the underside of the b52 tends to mean that biner choice is really key, as certain biners really bind on the part of the device that dips down. my experience, like already mentioned above, is that a petzl attache works very well for this. my guess is if you tried switching you won't have a problem....


adatesman


Feb 25, 2009, 4:43 PM
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spikeddem


Feb 25, 2009, 5:05 PM
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Haha, for all the replies that mentioning switching to a petzl attache carabiner, I currently use that carabiner. It's my fav, after all.

I'll respond to some other comments later, but for now I'll just note that feeding it through carefully DOES work, but some of the fatter spots on the rope just suck trying to pull through.

The increase in ease with which it feeds is comparable to the difference between the B52 used normally in autoblocking mode and a gri-gri. A gri-gri pulls through like butter, but can't easily multi-task like the B52 can (or any other autoblocking belay device). However, when I use the B52 in this fashion, it pulls through almost as smoothly as a gri-gri.


Adk


Feb 26, 2009, 3:46 PM
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Re: [spikeddem] Is this a risky way to use the B52 in autoblock mode? [In reply to]
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My bestestes climbing partner uses a B-52 and loves it!
That is why I just bought a ATC Guide. I can't use all the same gear.Wink
Use it as described and you will be fine. I feel very comfortable when he belays me while he is using it. It's a great piece for sure. There is a reason behind the name!


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