Trango Alpine Equalizer- is it just a gimmick?

[iain]

hey! that trango thing's exactly like what a mountain rescue unit I know does with a 10m piece of cord.

[chucK]

So what's up with that thing? As far as I can tell it is a compromise between sliding X and tieing the knot. In Iain's fig (and the trango thingy) a single piece blowing will allow extension, just not as much as the sliding X is that right?

[iain]

yes it is a compromise between extension and allowing for some shifting loads. It's complicated to set up and usually only worth it for a rescue where you have some time while the litter is being rigged, patient treatment and whatnot. I'm sure many people know this but you can lessen the extension of the X'd webbing shown before by tying knots in each leg.

[catbirdseat]

Chuck, I'd agree with that assessment.

[iain]

but man I really wouldn't want to blow out an anchor on a load-shifting setup, much better to tie off w/a cordelette in my opinion but that's me. The above is also illustrated in "On Rope", a caving rigging book that is quite excellent for all kinds of vertical work.

[catbirdseat]

Iain, I agree. When you think about it, it makes you realize how important the INDIVIDUAL placements are to the overall anchor system. If at all possible, you'd like to have each of them bomber, since any one of them might take the majority of the load (if the pull comes from some direction other than that for which the anchor was equalized).

 

Here's another dumbass question. When you want to redirect the direction of the rope from your belay device to the climber so that you can face the rock, do you 1) clip a biner to one of the pieces comprising your anchor, or 2) clip a biner to an entirely separate piece from your anchor?

[slothrop]

It seems to me that you can have a no-extension anchor or an automatically-equalizing anchor, but not both. Only a compromise between the two is possible.

 

I'd prefer a method that gives you the flexibility to easily rig according to which the more important feature of your anchor at the time. For sketchy gear, I'd say you want to minimize extension. I don't really see how an automatically-equalizing system (sliding X, unknotted cordelette, the Trango thingy) is that useful if you have a belay stance you can hang out at and not move around a lot.

 

The anchor is for the belayer, anyway, so the load shouldn't be on the anchor if the leader falls, sideways or not. If you know the leader's gear is going to cause you to be pulled sideways, arrange your anchor appropriately.

 

A cordelette is nice because you can statically equalize the pieces very easily, then eliminate extension with a figure 8. The webbing used in a sliding X is just like a cordelette, anyway, just shorter and usually without a knot. Tie a knot in the X and you eliminate extension, too.

[slothrop]

I've only used a directional for belaying a second, in which case any falls are like on top-rope: low forces. Your anchor should be safe enough to take such forces (doubled, as they are, by the pulley action of the directional), so you could just run it through the anchor for convenience.

 

But why not throw in another piece for the directional, anyway? That's what you expect the leader to do ("protect the belay").

[chucK]

Moderators please break this into a new thread, or append it to one of the past ones dealing with the slingshot belay question.

[Dru]

iain said:

hey! that trango thing's exactly like what a mountain rescue unit I know does with a 10m piece of cord.

 

 

looks like a more high tech version of the American Death Triangle to me

[catbirdseat]

Or append it to the Flogging a Dead Horse thread.

[iain]

Dru said:

looks like a more high tech version of the American Death Triangle to me

what's high-tech about it?

[Paco]

Alright, maybe I haven't thought this one all the way through yet, but how bad is it (in terms of increased impact force) really if there is some extension in you anchor if a piece fails. I agree that you want to minimize the extension, which can be done when using the death x configuration by simply tying overhand knots in the runner, but the whole reason for "no extension" is so that you don't "shock load" any piece. By "shock loading" a piece I think we all mean loading a piece statically.

 

Picture this: Two pieces equalized in said death X configuration with a 48" runner. The pieces are right next to each other so if one failed the anchor would extend 24". If a climber is out 30ft from the anchor and falls he falls 60ft, it's a fall factor of 2. If one piece fails then he falls 62 ft a fall factor of just a little over two. So the impact force in this case is just a little more than double on the single piece then each would carry if one piece did not fail. The system still does not get statically loaded because the rope stretches and absorbs the impact force. The only way the death x will statically load a piece if another piece in the anchor fails is if the climbing rope is not a part of the system.

 

You can add a fat belayer into the equation because said belayer would be conected directly to the anchor. If one piece fails then the fat belayer would statically load the anchor, but how much force does this generate if the belayer weighs, say, 200 lbs?

[chucK]

Unless you're a real anchor-building doofus, the only reason one of the points would fail is because there's a HUGE force on it. The only way a fatty belayer is going to get pulled up at any speed is if there is a HUGE force on her. Maybe there'll be some stretch left in the rope, but probably not.

[catbirdseat]

Paco said:

Picture this: Two pieces equalized in said death X configuration with a 48" runner. The pieces are right next to each other so if one failed the anchor would extend 24". If a climber is out 30ft from the anchor and falls he falls 60ft, it's a fall factor of 2. If one piece fails then he falls 62 ft a fall factor of just a little over two. So the impact force in this case is just a little more than double on the single piece then each would carry if one piece did not fail. The system still does not get statically loaded because the rope stretches and absorbs the impact force. The only way the death x will statically load a piece if another piece in the anchor fails is if the climbing rope is not a part of the system.

Paco, there is something you are missing. The fall factor 2 fall is on the rope, which is dynamic, i.e. elastic. If a piece pulls, the 2 ft extension force falls not on the rope, but on the remaining strands of the cordalette, which are highly inelastic and cannot absorb energy. Hence, a large force is transmitted to the remaining pieces of pro. It is the same as if you fell 2 ft on your spectra daisy chain. It is something to be avoided.

[Tod]

I would hate to have a piece blow on a self equalizing anchor like that. It would put quite the shock on the other two anchors along with the rope and the climber. I think your better off having something that is directional, yet static once you set it.

 

Something that else that improves dramatically on the cordalette yet protects from the shock of a piece blowing is the Web-o-Lette by Mountain Tools. This thing rocks. It's light and versatile like a cordalette, but easier to use and untie than one since it's not as bulky and made out of webbing.

 

Check it out at:

www.mtntools.com/cat/mt/webolette/webolette.html

[Greg_W]

I used one in Squamish a few weeks ago for a toprope gear anchor. It was nice. I wouldn't carry it on an alpine rock climb; a standard cordelette is more versatile and lighter. I would worry about extension of the strands if a piece blew; the anchor I set up was pretty phuckin' bomber.

 

All in all, useful in certain situations, not it others.

 

Greg W

 

P.S. To answer the question, of course it's a gimmick, fuck-o. Why do you think they're pushing it?

[Beck]

that funky metolius product fern posted is some type of super daisy, all the pockets (there's only five) all rated at 27kn or something up there-

 

its meant to be a full strength daisy AND anchor equalizer- something you can be clipped in, and use any loop in any configuration at full strength-

 

its a great no brainer tool, if it was sized differently, more like a traditional daisy, it would catch on more quickly, maybe.

 

metolious is into this "full strength from everything" mantra you will see in their harnesses, and this uber daisy/anchor slingy.

 

lets the user just clip in however, tie in to the haul loop, or a leg loop, and its all full 20+ kn, every last little piece, even the gear loops.

[chucK]

I think that thingy Fern posted is cool. From my internet shopping viewpoint it appears to kick ass on the metolius thingy CBS posted. If metolius sent me a free one, I'd gladly spray on CC.com about it.

[allthumbs]

chucK said:

I think that thingy Fern posted is cool. From my internet shopping viewpoint it appears to kick ass on the metolius thingy CBS posted. If metolius sent me a free one, I'd gladly spray on CC.com about it.

shameless hussy

[chucK]

Trask = paid Hooters hukster.