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New Nick's SRT thread

Discussion in 'Commercial Tree Care and Climbing' started by murphy4trees, Apr 29, 2004.

  1. murphy4trees

    murphy4trees Addicted to ArboristSite

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    For some reason I AS won't accept a reply to the 2nd SRT thread..
    Since it could be a matter of life or death I started a new thread...
    I like this conversation... its good to focus on safety issues...
    So here's my 2c

    How about this possibility:

    Rope looks set properly but it snags on a twig out of sight...

    Up you go and halfway up the twig snaps, so you freefall until the slack comes out and shock loads that side loaded caribeener...
     
  2. a_lopa

    a_lopa Overhead downunder

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    probably the main thing i look for while climbing especially something big girthed and out of site you can never be 100%sure sometimes
     
  3. Tree Machine

    Tree Machine Addicted to ArboristSite

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    Yes,I had problems posting on the SRT Wassup? thread

    I see where you're coming from with that, but I must admit, it's a stretch.

    I appreciate you stating the conditions under which you would use system 'a la Nick'. Coincidentally, that mirrors exactly my conditions for ascending 'a la Nick. Do you inspect your gear each and every time you use it? I thought so, as do I. And do you take careless risks during your climbs. No. Do you double check, and then triple check your rigs before a cut, Yes. Tied in twice before cutting, yes. Point being, we don't take unnecessary risks. We think safety, and if we question the safeness of a technique, then we don't do it. MM clearly questions the safety of method 'a la Nick', and probably should not do it.

    Quite honestly, I have done 'ascent a la Nick' only a few times. If I've crowned out a tree and I need to come down, I will 'a la Nick' it from up top, with two biners and then abseil, but that's the known as an 'inverted Nick'. The times I use traditional 'a la Nick' is when I need to pull a tree over. Bigshot the shotbag up, over, and trace down, and rig 'a la Nick'. Cut. Pull tree over.

    When you speak of 'shockloading' a 40 - 65 kN steel triple lock, do you understand the actual forces behind those ratings? They're far beyond a static 5,400 lb, and well beyond the strength of your rope. Even what lateral forces you can subject it to 'a la Nick' are a fly's sneeze compared to what the caribiner can handle. This is heat-tempered steel we're talking about here. As for the gate popping open accidentally, that's why we have triple lock biners with good, strong springs in the gate mechanism. Personally, I would like to see a quad-lock.

    I use retired steel biners, on occasion, to pull bush stumps out of the ground using my truck and a chain. I have a short length of steel cable, thimbled at one end and eyed at the other. I wrap the eyed end around the stump, use a steel caribiner to complete the choker. Hook up chain and POW! That, gentlemen, is improper dynamic sideloading of a caribiner. Under these exteme conditions I have messed up a gate sheath, but never have bent or broken a steel caribiner. Will my weenie weight ever approximate those levels of force? Simply impossible.

    This does not serve as 'proof' of steel triple lock integrity, used 'a la Nick'. We can only call it empirical observations.

    Murphy, very good point about the small branch letting loose while on the ascent. That's something to always watch out for, 'a la Nick' or any method.

    ps I need to go on a short vacation, so I'll be leaving y'all for 5 days. Don't bash me too bad in my absence.
     
  4. Tree Machine

    Tree Machine Addicted to ArboristSite

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    The trustworthiness of the steel triple-lock

    Hey Rocky, what are your thoughts on sideloading biners. These are some of your words from another thread that reflect my thoughts exactly:
    A lot of guys are practicing this, just as do you and I. Why?? Because it's very quick, very easy, very swift. Tell us, in all honesty, have you, in lowering limbs using a caribiner choker or caribiner cow hitch, ever had a caribiner break, bend, deform or just plain fail?

    In lowering limbs, we do everything to avoid shockloading the system, but some pretty severe strains will occur, manyfold beyond what a man can put to it during a regular climb. Steel triple-locks are an engineering marvel to me. I rank the actual risk factor, when used sensibly and properly, lower than getting popped in the gourd by a lightning strike;)

    But those are just my thoughts having used these methods for over a decade.

    I am not recommending SRT 'a la Nick', nor the inverse; lowering limbs with a spliced eye and a caribiner. KKnow, though, that teaching how to open the gate of a triplelock steel caribiner will take approximately ten seconds.
     
  5. Kneejerk Bombas

    Kneejerk Bombas Tree Freak

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    TM, what is the breaking strength of a randomly selected, steel, triple locking, side loaded, carabiner?
     
  6. Tree Machine

    Tree Machine Addicted to ArboristSite

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    Oh, that's easy

    The breaking strength is exactly equal to the massive application of force that it would take to break it.
     
  7. TheTreeSpyder

    TheTreeSpyder Addicted to ArboristSite

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    i think that it is not best to use a carabiner so; i think that there is also a component of the rope not necesarilly forcing the load to be carried properly on the backspine of the carabiner. Once again reminded of that simple point by the extreme/simple example of RescueRob's proper muenter alignmeant to do so.

    So, a carabiner could not only be leveraged in that position, but not pulling on it's strongest back axis either. The differance between a quicklink and carabiner here is that the gate on the carabiner is not a solid/solid link of dependable strength.

    So a quick link would be smaller/less leveraged and carry properly if ya wanted to go that route. But, i know might as well tie a bowline:D . i whip out the DBY's pretty quick, so don't bother me none!

    i have an idea of how to lessen the evil, come around the line with the carabiner and gather a quick/tight clove or girth from line on it. So as to make a larger eye, that split the load and the carabiner position would only carry 1/2 the force. Also the knotting would force that load to be carried over the back spine if so forced?

    Other thought as to structure effects of side loading wood, metal, rope as one topic in single legs, and expanded considerations of dual leg links.

    Or something like that.........
    :alien:
     

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