Water knot failure!

Discussion in 'Search, Rescue and Technical Skills' started by McKROB, Feb 23, 2017.

  1. McKROB

    McKROB Member

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  2. Strigidae

    Strigidae Moderator Staff Member

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    How horrible.
     
  3. Bushman5

    Bushman5 Member

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    sad. Hope the kids didn't witness it.

    Correct me if im wrong but I thought the water know had been phased out of the climbing/mountaineering communities knot repertoire???? for this very reason....
     
  4. Reno Lewis

    Reno Lewis Knot-A-Challenge Champion

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    It hasn't.

    We use the water knot for all of our slings, which we use for anchors.

    That is just horrible...
     
  5. Bushman5

    Bushman5 Member

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    your not using sewn slings? :confused:
     
  6. Reno Lewis

    Reno Lewis Knot-A-Challenge Champion

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    Not for our anchors, no.
     
  7. Jeff Randall

    Jeff Randall ESEE Knives / Randall's Adventure & Training Staff Member

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    Just from reading the report it appears the knot didn't have long enough tails nor was it properly set. My bet is the type of webbing he was using caused this more than the knot being improperly tied. Not sure if he was using flat or tubular webbing but I've found that flat webbing won't set as securely or quickly as tubular webbing, and if you load and unload it a few times without a good hard set, then it can start creeping.
     
    Reno Lewis and Strigidae like this.
  8. james gormley

    james gormley Member

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    That was a terrible accident, Hanging over a cliff and your tether lets go.
     
  9. wilas101

    wilas101 Member

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    I was not aware of the "water knot". I looked up how to tie it and see that it's basically two interlocked overhand knots.... are the "tails" that were mentioned supposed to be secured with half hitches or something?
     
  10. Jeff Randall

    Jeff Randall ESEE Knives / Randall's Adventure & Training Staff Member

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    Most instructors do say tie a safety knot. With that said, as long as you have enough tail then you really don't need the safety knot. In fact, a lot of instructors are going away from teaching safety knots. Dressing, setting and leaving enough tail will save your butt every time.
     
  11. wilas101

    wilas101 Member

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    Is it safe to assume the loading/unloading they talk about is not once or twice and that a person should be checking the knots periodically?
     
  12. Jeff Randall

    Jeff Randall ESEE Knives / Randall's Adventure & Training Staff Member

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    Any time we are using knots in a life line system, we always periodically check them. I simply don't believe this water knot would have come loose if it had been properly dressed and set to start with, but again it depends on the stiffness of the webbing. Some ropes and webbing are very difficult to get a hard set on.
     
  13. Jeff Randall

    Jeff Randall ESEE Knives / Randall's Adventure & Training Staff Member

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    I think there's more to this story. For example: not sure how many times this tied tether was loaded or unloaded on this trip. If they're practicing good techniques then every piece of gear (personal or team) is visually inspected after each trip / class /rescue. Seems to me it would have been caught if this was the case. To me (with my very limited knowledge of this event) it seems the tether may have been tied shortly before it was used on this trip (or during the trip). Then it would make sense if it was a stiff piece of webbing that wasn't set tight with very short tails, then a few times of loading or unloading could have easily caused it to come untied. Leaning out on a knot is usually not what causes it to fail. Shock loading will cause it to fail a lot quicker but no one said he fell on the tether, so it wasn't shock loaded. Again, I think it was simply a case of bad knot tying and nothing more.
     
  14. wilas101

    wilas101 Member

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    I really ought to get re-introduced to rappelling/climbing /etc given the part of the country I moved to. Wasn't much call for it in north missouri but you never know out here.
     
  15. Guyon

    Guyon Member

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    Recently, I picked up a couple of lengths of flat webbing--one from OnRope1 and one from Karst Sports. The lengths are identical manufacture best I can tell, and they are indeed harder to dress/set than tubular. I've noticed many in the climbing community steer away from flat webbing for just this reason.

    I bought the stuff partly because of this chart that shows flat webbing combined with a basket anchor has some crazy breaking strength: http://www.cmcrescue.com/one-inch-webbing-anchors-minimum-breaking-strength/

    That said, CMC is referencing its own flat webbing, about which it states: "While not all flat webs will hold knots securely, the CMC Rescue Flat Webbing has been specifically selected for the suppleness necessary to allow knots to be set securely. Flat web also tends to be easier to untie after a heavy load than the softer tubular web. While the flat web is bulkier than the tubular, it does provide a significantly higher strength." Source: http://www.cmcrescue.com/equipment/flat-web/

    I need to get some of CMC's stuff and compare it to what I have.
     

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