breakaway flipline or harness

"pdfimages" and "convert", if you're a real geek, hahaha! I'll have a look. If the PDFs are modem-friendly I'll have a go at it for you.
 
The other day at work, we were pulling (through conduit) wire which has 61 strands of about 1/8" copper in the core (about 1-1/8" diameter) with a thin layer of plastic insulation around that, then a layer of rather foamy insulation about 7/16" thick around that, with another thin layer of plastic, then a copper foil wrap, then an 1/8" outer plastic jacket. A total of 2.35" diameter (type MV-90 EPR 1000 MCM). Three "strands" of this plus a 7/8" bare stranded ground wire in a bundle, 4 each of the total bundles were pulled separately. One pull length was 650' and the other pull length was 350'. The "basket type" pulling tools would be wholly insufficient for that!

Attached is a portion of the Greenlee catalog page depicting the breakaway swivels.
 

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I'll be able to find out tomorrow, I'm sure. One thing, Tom: even the small end would make one helluva projectile, but I suppose a couple of fingers off some old gloves could be zip-tied around it to make it mostly a bit cushier. I'd imagine they're stainless steel and will guess no less than 100 bux -- we'll see.

Glen
 
"In such situations, I use a lanyard with a french prusik adjuster as an auto block, for easy slack tending; I just clip a micro pulley and cord above the hitch. I then take the knot out of the end of the lanyard. If I need to bail out, I just grab the cord and everything takes care of itself - the pulley collapses the hitch until it pulls off the end of the lanyard. At least in pratice stunts!"- Lazarus2

what about using a tauntline hitch. i heard that these roll out, so if you do not put a stopper knot on it, is it possible that with enough force it will roll out if it gets caught. if there is reaction time, then grab it until it slides off the lanyard, if there is not enough time, then it might roll out and come undone and the lanyard will give out. this way you still have the comfort of a hitch that is usable, yet will give way without reaction
 
I like that term "mechanical fuse." That seems to be exactly what we're looking for here. And the ones glens looking into....hmmm...these show promise!

chicken89- Your idea of using a tautline hitch is good in theory. But we don't know at what strength the hitch will "roll out," if it even WILL roll out under a fast load, or if it DOES roll out, does it do it consistently?

I'd hate to have to rely soley on what I THOUGHT was gonna happen, only to find in that moment of need, that it doesn't work that way.

love
nick
 
I dug out my old contacts and gave one of my old suppliers a call, boy, was I wrong on the cost of the breakaway. The breakaway swivel glens and I have been mentioning from greenlee costs $230 for the swivel body and another $25 for the pin kit(10 replacement breakaway pins). Pretty darned expensive for something that's instance specific and very rarely used.

Has anyone given thought to using zip ties? They advertize a breaking strength on the package, how accurate that is, I'm not sure.

SC
 
That's cool, but it relies upon you having the time to notice and react correctly. Not everybody will be able to do that.
 
Chicken 89

The tautline hitch rolls as a steady process rather than suddenly when loaded. In steady doubled rope pull tests I did with the tautline, it gripped tight to over 2700kg. Then the bowline failed

http://www.treemettlenexus.com/pdfs/FrictionHitchCompilation.pdf


I have seen people get caught in barber chairs and pulled from sections taking the saw. One of the sections ripped the back handle off its av mounts away from the rest - luckily the climber had a beefy anchor.

In all of these situations, the danger was obvious and preventable or preparable. I use the prusik release system and prepare to grab the cord. You don't have to yank on it, as the piece pulls it just prevents the prusik grabbing.


Whatever you decide, just remember that a quick release might easily quick release when you least expect it. I would never consider general climbing with a quick release system because of that. Its easy to carry on working with it in place; even with the method I discribed, you could forget to re-tie your stopper knot.

Whenever I have used it, it is usually a fork that I've swung over to that is weak/storm damaged. I prefer to find somwhere to cut that I can cock a leg over a stub then disconnect from the lanyard.

I find I don't have to think or react when I want to let go - my leg just straightens automatically before the bowells have chance to loosen....................
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I am currently using a VT tied direct to the D for my lanyard setup. My lanyard is always backed up to the harness as well. This thread gave me an idea. Do away with the back up for the lanyard, have the steel/alum snap in it's traditional spot (for me on the right) and where the VT is have a slick line/throwline prussic adjuster. Your failure point will not have any shrapnel like projectiles, and you'll have a relatively predictable 'fuse'.
 

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You could also do what Gerry Beranek has done in an emergency. Clip into the belt loop on your pants and use that as a breakaway. Very simple and effective.

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Maybe with brand new jeans.
 
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I am currently using a VT tied direct to the D for my lanyard setup. My lanyard is always backed up to the harness as well. This thread gave me an idea. Do away with the back up for the lanyard, have the steel/alum snap in it's traditional spot (for me on the right) and where the VT is have a slick line/throwline prussic adjuster. Your failure point will not have any shrapnel like projectiles, and you'll have a relatively predictable 'fuse'.

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A variation of this, and one that I think I like- Stick with your normal setup, whatever it is- vt, prusik, etc. Take the stopper knot off the end of it. If you HAVE to, just pull the hitch and let all the rope through the hitch.

That would work but NOT be automatic.

love
nick
 
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I still like using a chainsaw break away lanyard best for this.

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Well damn, why didn't we think of that?

That sounds like the most practical, safest way to do it.
 
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