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  1. #1
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    failing destructive testing, and dyneema/uhmwpe hints for european hangers (liros/kanirope)

    for your "entertainement":

    106483678_707974783359473_2668268262354866514_n.jpg

    how should i put this nicely, ahem, "the dyneema held strong"? (i tried this line with the girlfriend while she was dusting off from the inevitable pieces of wall covering everything, she didn't seem amused).

    entertainment aside, i found it very difficult in europe to find amsteel/samson dyneema products, all options seem to be either unreasonably pricey, or requiring import etc. the best option so far seems to be dyneema produced by a german company called "liros", it comes in various sizes and colors, and is easily available on amazon, which is pretty nice. there are issues though (see pic) :P.

    - this stuff (i've mainly been using the 3mm variety) is very loosely woven (the angle of the braid is quite shallow), this means that splicing ucr's is frustrating (all sizing instructions you find here and elsewhere for amsteel result in ucr's which slide at about 1% or so of rated line strength), it is similar with whoopie slings, but i guess less severe due to their construction (though i dind't play so much with those, as i dislike the idea)
    - it is really really slippery, from what i read around about what people do with amsteel and such, this is in a different league, my guess is because it is really pure dyneema fibers, with no coating whatsoever (in a way i like that, but it took a while to figure out how to make it work).

    as preliminary/guideline info (until i find a way to do destructive testing on what i spliced out of this liros dyneema, as opposed to on the house):

    - the burry length for the adjustable splice (ucr/whoopie sling) must be about 100xdiameters. if you want to test and prove me wrong, please do tell me what you found, but prepare to make a lot of soft shackles and continuous loops out of the too short burry sections you need to re-purpose (i'm becoming a soft shackle expert). if you want it to "just work", 30cm burry for 3mm line, and don't look back. sorry. (it does work very nicely then, see picture :/, i had a marker on the ucr, it didn't even budge. i wish i could say the same about the brick..)
    - the free end of the ucr burry must be tensioned properly, i tested a few configurations (more on that in a different post, if anyone would be interested), in general a dependable friction hitch is required, good news is there's a way to integrate it very nicely in the whole design, and it can be made out of the same line if desired (so using a different thinner line is not a must)

    in short: the liros dyneema can be used quite successfully, it just requires different sizing. i'm personally not bothered by the excessive length, when i need to go between very cozy trees, i will becket hitch the webbing to the hammock loop directly anyway, so a 10cm difference doesn't really matter.

    has anybody else been using the liros dyneema? did you get similar results, or am i doing something wrong? i couldn't find any info about anybody using this stuff for hammock suspension (and trust me, i did look, after i melted my first ucr), this is why i finally decided to at least write a few words about it.

    i would also like to ask the opinion of the many master splicers and riggers on here on something related to this: i am worried that, if the burry for an adjustable splice requires 100x instead of 72-74, the burry for a spliced loop would require a similar adjustment to retain full strength (so roughly 65x instead of 48x); now, i'm nowhere near to stressing this to the max (one metric ton does have the advantage of quite a bit of safety margin), but still, i'd like to know what i can rely on. destructive testing (joking aside) would be nice, but i don't have the means to pull test at such loads, and definitely don't have means to measure (no budget for load cells). yes, they do make a 1mm variant, yes i do have my eye on it, i'm just not..sure about the color.

    for reference, the 3mm line (liros d-pro, often sold by "kanirope") is supposed to be dyneema sk78, 12* strand, pre-stretched, 950DaN mbs, spliceable. it goes for just under 1euro/m if bought in 100m rolls. * looking at the 3mm one i want to say "yeah right, like samson, in this diameter it must be 8 strand", i just counted it now, it is indeed 12.

  2. #2
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    I've had good service from Brian at Henge Hammocks. My latest lines are using the Hengesteel and Hengeit.
    https://www.hengehammocks.com/make-your-own-gear

    If you want to proof load test a sling, so you can have confidence in using an identical one normally, rig it tight horizontally and then stand on it. A near horizontal sling sees about 6x the loading Vs a 30deg (recommend hang).

    Make sure your anchors are suitable to take 6x your body weight as tension though

  3. #3
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    Quote Originally Posted by Singlespeed View Post
    I've had good service from Brian at Henge Hammocks. My latest lines are using the Hengesteel and Hengeit.
    https://www.hengehammocks.com/make-your-own-gear

    If you want to proof load test a sling, so you can have confidence in using an identical one normally, rig it tight horizontally and then stand on it. A near horizontal sling sees about 6x the loading Vs a 30deg (recommend hang).

    Make sure your anchors are suitable to take 6x your body weight as tension though
    that is indeed the easiest way. and if you use only dyneema for the test, and rig it really tight, there's nothing to stretch, so you might get an even tighter angle.. and a brick. at least i have my tarp sorted out, so i can survive getting kicked out if need be.

  4. #4
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    I was going to suggest Henge Hammocks - I ordered some straps from them and because of the current situation they gave a delivery estimate of ten days but they arrived in two

    There's also DD Hammocks, I got my Amsteel from them, 1/metre but seemingly only in black (Henge do multiple colours) - https://www.ddhammocks.com/product/a...ue?from_cat=29. 8 strands, 2.5mm or 7/64 diameter.
    Better weight than wisdom, a traveller cannot carry - Viking proverb

  5. #5
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    Dyneema is easy to find in the UK as it's used loads on sailing yachts. Checkout Marlow and English braids product for starters. I use Marlow dyneema throw line for tarp CRL and guy lines. Samson Amsteel is available from DD hammocks too.

  6. #6
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    Here is a great article on dyneema load testing.
    https://web.archive.org/web/20160715...s.com/load.htm

  7. #7
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    Quote Originally Posted by Andy Pandy View Post
    Here is a great article on dyneema load testing.
    https://web.archive.org/web/20160715...s.com/load.htm
    thanks Andy! indeed the uk sailing shops are the only source i found, but it's a bit "far" and often expensive (dd hammocks i missed somehow, maybe they were not selling by the meter when i checked?). i also found the range of options in small diameters to be lacking, but maybe i didn't look hard enough. marllow and such is the first alternative aside from the readily available amazon/liros indeed (assuming we won't have to pay import taxes/wait for customs to clear stuff after brexit :( )

    as to the starzingers site: oh yeah, i could quote most of the stuff there in my sleep, amazing work, after i discovered about dyneema, i spent a lot of time reading all their tests, the development and results of knots and the discussions on igkt. it's a s pity they took the site down, it is a treasure imho. thanks for the excellent hints, it's plain to tell when you're in quality company somewhere, when people recommend valuable stuff.

    edit: i note you too made your own ucr's, what line did you use and what was the size of the burry you had to use, with wath kind of weight did you test it so far? i'm wondering if it would make sense to maybe makeup some semi-standardized test, so we have a comparative guideline for different dyneema products (so that once somebody here figures it out through trial and error, the guesswork can be skipped for the others)
    Last edited by nanok; 07-02-2020 at 06:36.

  8. #8
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    Quote Originally Posted by Bob-W View Post
    I was going to suggest Henge Hammocks - I ordered some straps from them and because of the current situation they gave a delivery estimate of ten days but they arrived in two

    There's also DD Hammocks, I got my Amsteel from them, 1/metre but seemingly only in black (Henge do multiple colours) - https://www.ddhammocks.com/product/a...ue?from_cat=29. 8 strands, 2.5mm or 7/64 diameter.
    hey, thanks (you and singlespeed both) for pointing me to henge, i didn't know them. both henge and dd have the same issue for me: limited choice. at the beginning especially, i wanted to experiment a bit with different diameters etc. right now, honestly, my conclusion is that the only one allowed to hang on 2.5mm uhmwpe (anything bellow 3mm) is my girlfriend (and most children under 12 i guess). for the rest of us, the safety factor goes too tight for comfort (not to mention we often hang in twos ). however, henge is really cool, because it seems i can easily get amsteel from them and compare it myself, so thank you!

  9. #9
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    I'm 86kg and use the 2.5mm amsteel with no problems (so far!). I think the safe working load is around 145kg, that's for a 5:1 safety ratio
    Better weight than wisdom, a traveller cannot carry - Viking proverb

  10. #10
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    Quote Originally Posted by nanok View Post
    edit: i note you too made your own ucr's, what line did you use and what was the size of the burry you had to use, with wath kind of weight did you test it so far? i'm wondering if it would make sense to maybe makeup some semi-standardized test, so we have a comparative guideline for different dyneema products (so that once somebody here figures it out through trial and error, the guesswork can be skipped for the others)
    My main suspension ucr's are 2.5mm amsteel with a bury of 7in. That's about 178mm or approx 70 diameters. I am about 75kg and I like to swing in my hammock - it's a joyous thing. They don't slip dry or wet, at least not yet! They have only had around 20 uses though so we'll see if they slip hen they're old and worn. On one end of the constrictor is a spliced 2in locked brummel loop with a 3in bury, and on the other end is a tiny locked brummel loop with a 1in bury formed into a larks head around the adjustable part. This provides just enough friction to act as a failsafe and tighten the constrictor and stop, or at least slow your rate of descent when you forget to milk the bury properly ��. I got the idea from a Jeff Myers video on YouTube. You can also put a half turn in the tiny loop instead of the larks head which may even grip better as it would have a crossing point. If you were anxious about it then you can secure that end with a prusik made from thinner line but I've not found it necessary. When I'm set for the night I use the long remaining portion of the ucr to put a couple of slipped half hitches around the working part. This serves as a failsafe because if the it slips the knot will tighten up and jam it, and also makes an excellent drip line / water break under the tarp close to the hammock. I've garden hose tested that and slept through a whole night of rain and nothing got past the two slip half hitches snugged up against each other. In the morning, I can check the half hitches and see if they've tightened up. If they have, it means the ucr has slipped a bit. It hasn't happened yet.

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