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Tech Tip: Question 6mm "Ropes"

Discussion in 'Tech Tips and Gear' started by ratagonia, Jun 6, 2017.

  1. ratagonia

    ratagonia

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    This from Richard Delaney / Rope Test Lab

    6mm "rope"
    I need to talk about this as I know there are many considering ways to lighten their kits for rec, rescue, and tac operations.
    In short, if you slip or fall, it will cut. Completely. And you will fall.

    There are very good reasons why it is often only sold as part of proprietary systems with training (CTOMS/Trace, Petzl Exo, Sterling etc) and these all concern the very limited capacity, abrasion resistance, and life of this "rope".

    The abrasion resistance tests I have done (both vertical and lateral) gave results of up to 10minutes for some 11mm ropes. The longest result I got for any 6mm rope (not 6mm accessory cord) was 30sec and most cut completely in under 10sec.

    Based on my testing and experience, the only time I would use a 6mm "rope" would be when my immediate survival depended on it and there was no other option.

    The 6mm "ropes" used in the proprietary systems are not 6mm nylon accessory cords. They are often combinations of armamid (Technora), polyester, and some nylon. These "ropes" are expensive and are often given a maximum number of uses before retirement.
    Rapterman likes this.
  2. Scott Patterson

    Scott Patterson

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    Even if a 6 mm rope was strong enough to take a fall or abrasion, it seems that getting the right amount of friction could be challenging, at least for us big guys. It probably could be done, but the system would be more complicated, or so it seems?
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  3. Rapterman

    Rapterman

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    There ARE micro devices designed for ultra skinny rope used for emergency escape kits (as in a fire).
    I think Tom's point is that ultra skinny rope is extremely fragile.
    NOT durable enough for canyoneering.
    Thanks for posting, Ratagonia
    :)
    dakotabelliston likes this.
  4. AW~

    AW~

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    More like 'This is another sensational post from Richard Delaney / Rope Test Lab'.
    I think the 'rebels' look at his overall work and see that otherwise he is a fine educator....again.
  5. AW~

    AW~

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    Oh....and 8mm/9mm is not? Must be something faulty with the test I linked to last time.... when Tom said 4000lbs strength was good enough. As a response to the OP....when on face value, said they didnt want to do due diligence in buying a rope, and figured a stranger on the internet knew a 2 sentence answer to a complex question. At the rate Delaney is going, how long before he notices 'deadly' advice, and not just gear? In this one he basically is going after CTOMS and its buyers, which is him wanting to look silly. Im not a lawyer, but I consider his statements a sly attempt at defamation. But maybe he didnt even go to the CTOMS website...idk.
  6. SARguru

    SARguru

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    The CTOMS TRACe kits mentioned in the original is a fully tested system that was created by the same person who designed the 540 rescue belay device and the MPD. The device limits force to under 4kN using Sterling's technora/nylon 6mm rope. As indicated in the original they have a very limited life of 25 cycles. The system is used by USAF PJ and is capable of full rescue systems including high lines with reeves and also lead climbing. I lived 5 minutes from CTOMs and have spent a lot of time chatting with the crew at the shop who did a lot of drop test on the system. The system is intended for military and not your typical sport climber and can adjust for friction. The system is also quite popular with mountain guides. I took it off my dream list simply because the rope at about 3.00 a foot and having a 25 cycles life is simply not economically smart considering you could blow through a full life cycle of a brand new rope during one canyon trip. Interestingly in their testing using the system rope protection saved it from catastrophic failure


    Sent from my iPhone using Tapatalk
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  7. AW~

    AW~

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    Id say yes....as evidence, Id introduce someone who has been using their "ultralight" techniques for years.
    http://andreapucci.satellitar.it/?p=138
    Heres the google translation...condensed version...
    "....It's Sunday, February 21, 2016, and as usual we prepare our backpacks, carrying with us the ultra-thin strings that we have used for years, 6mm with Vectran core and Kevlar socks.....[3rd person descends 40ft waterfall on basalt, with no change in rigging]....[​IMG]

    The fall was high{30ft), but he rose from the pool and evaluated immediately if he had injured, was sore but miraculously {not dead}.....The {broken} rope is green, close to the node, at the point where the first basalt band strikes, not {yet} then on the edge of the waterfall....From the image you see clearly that the rope has dropped from the inside, so the curvature on the rock has only contributed to lowering the breaking load but it was not the trigger. The rope has shed internally, from the soul, you can see the squinted white strands, and then ripped off the outer green stocking.
    [​IMG]
    ratagonia likes this.
  8. Shmulik

    Shmulik

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    Well, even so they would cut really quick, the nature of this metirial's avoids the rubbing, as they are so static.
    What needs caution when you use then, is:
    1. Not to use long nylon ropes or low diameter for righing the anchor. (Try once using a 40 feet long 5 mm for anchor and you will feel it...)
    2. To make sure not to move sideways on the cliff.
  9. ratagonia

    ratagonia

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    Things that CAN be done sometimes, and CANNOT be done at other times, therefore, not generally useful.

    Tom
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  10. Shmulik

    Shmulik

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    It can be done if you anchor with static ropes and rapping carefully.
    I do agree that this size is not the first line.
  11. ratagonia

    ratagonia

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    Let me be more explicit about what I mean.

    YOU say you could safely use this as long as the geometry of the rappel meets certain criteria.

    I agree. However, in the canyons that I have done in the last 15 years, I would say that 95% of the rappels done do not meet these specific criteria (and cannot be made to meet these criteria). Therefore I suggest that "this specific system can be safely used on rare occasions" is not a useful thing to know.

    Perhaps you are doing canyons that are quite different than the canyons I am doing.

    Tom
  12. Shmulik

    Shmulik

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    You are right!
    I'm in israel i have been using just over 7 mm for about 40%. ^_^
    Tom Collins and ratagonia like this.
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