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  1. #1
    Senior Member Albert Skye's Avatar
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    friction hitches with Dyneema/Spectra

    [This thread split from One More Suspension Arrangement.]

    I have yet to acquire some coated (not sheathed) Dyneema/Spectra (like Cortland Plasma or Samson Amsteel Blue) and I'm requesting comments regarding its use with friction hitches. The following are particularly interesting to me.

    - Distel
    - Michoácan/Martin
    - Klemheist
    - Prusik
    - Blake's
    - Adjustable Grip Hitch

    Specifically, I'm thinking about attaching the hammock to a SLS by friction hitches, using closed loops of the same cordage (if a hitch slips, it just means more sag, not complete release from the SLS). I'm also considering the use of a friction hitch (like the Adjustable Grip Hitch) on the SLS to tie back to itself from the tree slings/huggers.

    Quote Originally Posted by GrizzlyAdams View Post
    It is typically recommended that where rope-meets-rope that the slipping rope be smaller than the standing rope, by a factor of 50%.
    I suspect that recommendation is primarily related to the relative stiffness of the rope (i.e., rope which is too stiff to easily bend to a 1:1 radius). In any case, I've been experimenting with these hitches on some old nylon braid and they hold well (though perhaps not as well if the rope were new).

    Incidentally, I don't see the benefit of Vectran for hammocks. As I understand it, it's primarily for applications which demand zero creep, and Dyneema/Spectra remains superior in strength:weight, UV resistance, and cost (though it has a very low melting point). Of course, I do understand curiosity in exotic materials. Thanks for your comments (and your videos) Grizz!

    I find the following links on knots and hitches to be quite useful.

    http://www.treebuzz.com/pdf/0505_geneology.pdf
    http://www.treebuzz.com/pdf/climbing_hitches.pdf
    http://www.isa-arbor.com/publication...s/Apr07-cc.pdf
    http://www.layhands.com/Knots/Knots_Hitches.htm
    http://www.animatedknots.com/

  2. #2
    Frawg's Avatar
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    Hi, Albert!

    Quote Originally Posted by Albert Skye View Post
    [This thread split from One More Suspension Arrangement.]... Specifically, I'm thinking about attaching the hammock to a SLS by friction hitches, using closed loops of the same cordage (if a hitch slips, it just means more sag, not complete release from the SLS). I'm also considering the use of a friction hitch (like the Adjustable Grip Hitch) on the SLS to tie back to itself from the tree slings/huggers.
    I've never been able to get a Klemheist, Prusik or Adjustable Grip Hitch to hold with Amsteel blue, though I've only tried the 7/64" line so far.

    One adjustable hitch I did have success with was the HFP Slippery 8 loop.

    Chuck

  3. #3
    Senior Member TeeDee's Avatar
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    I tried using friction hitches - could not get them to work. My basic arrangement was to run a single line from tree to tree and then try to use friction hitches to secure the hammock to the line. My thoughts were that the friction hitches would make securing the hammock to the line easy and would also make positioning the hammock betweens the trees very easy and adjusting the ridge line length very easy also.

    The limiting factor that I encountered is the rope diameter.

    With most of the friction hitches that I know of and tried, it is recommended that the main rope be at least twice the diameter of the rope with which the friction hitch is made.

    I found very quickly that this is not idle advice.

    I tried 2.8 mm Spyderline for both the main rope and the hitch line which was tied to the hammock.

    In every case the friction hitch would hold for a few moments after I had very, very, very gingerly gotten into the hammock and equally gingerly lay down.

    If I then moved or even if I didn't move, within less than 30 seconds the friction hitch would slide.

    In the case where I used 2.8 mm Spyderline for both ropes, the polyester sheath on both ropes had melted from the friction and fused the two ropes together.

    I experimented with 1/4" diameter polyester sheathed dyneema just to to see if the arrangement would work. It would. Using the 1/4" rope for the main rope and the 2.8 mm Spyderline for the friction hitch, the arrangement worked and I had no problem. After hefting enough of the 1/4" diameter rope to make a working arrangement, I eventually abandoned the use of friction hitches.

    I cannot remember now all of the friction hitches I experimented with, but I started with the Prussic, moved to the Icicle hitch and then searched the internet for other friction hitches.

    The best friction hitch I found by far is the "Death Grip Hitch". The Death Grip Hitch would hold for a few seconds longer than any other friction hitch, but again not beyond the 30 second limit.

    If you care to experiment with friction hitches, please do so and report your reports back. It will interesting to see if you have any better results than I did.
    Last edited by TeeDee; 06-19-2009 at 19:53.
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  4. #4
    Senior Member Albert Skye's Avatar
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    I did manage to get some friction hitches to hold my weight (the prusik worked best), but it required too many wraps. It becomes too difficult to keep the knot dressed properly and it no longer slides easily.

    However, for lighter loads (tarp, &c.), I think the prusik is useful (though I have not yet tested it in rainy/windy conditions).

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