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  1. #11
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    I also have a ucr SRL just for experimenting with length and that is made from 1.8mm Marlow throw line SK78. The bury is 5in, again about 70 diameters. I've had it tight enough I can play tunes on it at times but it's not slipped yet. I have learned to keep the constrictor part at the foot end though, otherwise I slide my head torch or watch or other things dangling from prusiks on my ridgeline up too far and trip the ucr. Not a disaster but annoying in the middle of the night. I thought I'd replace it with a fixed SRL dogbone one I had settled on a length but I think I'll leave it because sometimes I'm in the mood to be a bit slacker than others...know what I mean?
    Last edited by Andy Pandy; 07-04-2020 at 03:09.

  2. #12
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    Quote Originally Posted by Andy Pandy View Post
    I also have a ucr SRL just for experimenting with length and that is made from 1.8mm Marlow throw line sk75. The bury is 5in, again about 70 diameters. I've had it tight enough I can play tunes on it at times but it's not slipped yet. I have learned to keep the constrictor part at the foot end though, otherwise I slide my head torch or watch or other things dangling from prusiks on my ridgeline up too far and trip the ucr. Not a disaster but annoying in the middle of the night. I thought I'd replace it with a fixed SRL dogbone one I had settled on a length but I think I'll leave it because sometimes I'm in the mood to be a bit slacker than others...know what I mean?
    samson/amsteel: yup, that sounds like what i keep hearing, it is definitely different from this liros stuff i'm playing with. will have to try it myself.

    regarding the half hitches on the remaining tail of the ucr: they are good only if you have no slippage or very little, so that you can see it happened, but as insurance they are terrible: if the burry starts to slip, the half hitch at the end will actually compress the burry (the opposite of milking it) and will make matters worse. for a "progress marker" i just use some thin line i make a prusik out of, and place it at the end of the ucr, if the ucr slides, the prusik will end up at some distance from the ucr, instead of flush against it, so very easy to see, and no damage to the holding ability.

    ridge line: i started with adjustable ucr ones too (made of stein throwline, 2.5mm), i am 100% with you, i'm not making fixed ones, i like to be able to adjust it sometimes, and i see no problems (just, as you said, don't grab onto the burry, or put the flashlight or what not on it -- like you i just make that end the foot end, and haven't had an issue yet)

    i initially used the stein 2.5mm as suspension too, it works nicely and it's compact (nice orange color too), but as i said, i'm unconfortable with the safety factor combined with all the possible things which might be imperfect (imperfect splice, damage from use, wear and tear, etc, it can add up), i like a bit of margin for error. the stated break strength is 450dan, i consider it "fine" for my (ultra light) gf, so she still uses it, but for all other adults i would rather go straight for 3mm, with 950dan i know most adults will get a nice 10:1 or better factor of safety, before splices and whatever "mistakes" (for instance, unnoticed overhand knot in the main line, oops, with dyneema that's down under 50% all of a sudden), and for my money, that's where it should start, given how light this stuff is anyway (10:1 and go from there). the other thing is, honestly, if i trip and grab or hit this line under tension (or somebody else does), 3mm is "almost bareable" , anything below seems like it would be too painful for most people. but of course, to each his own, i know i'm a little bit more paranoid than most when it comes to ropes (seems most of us cavers/climbers tend to be)

    thanks a lot for the data!

    edit: ugh, apologies, of course the stein is not 2.5, it's 2.2 (hence the 450DaN), i didn't have a 2.5mm option, so 3mm it had to be. with the 750dan or so of the 2.5 amsteel and the like, i guess it's more reasonable, even if i'm still feeling a bit better about the 3mm (thanks bob-w, your numbers forced me to re-check my assumptions)
    Last edited by nanok; 07-02-2020 at 16:47.

  3. #13
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    The half hitches cannot compress or trip the restrictor. They are at the hammock end and acting in opposition to your body weight. You'll never trip the constructor from that end with weight on it. I tested the idea by purposely not milking the bury and then putting full weight on the hammock. It's important that you have he ucr oriented the right way round i.e the safety hitches are at the 'bottom' not the 'top'. They simply stop too much tail passing through if you mess it up. They create a jamming stopper knot that 100% cannot pass through the constrictor.
    Last edited by Andy Pandy; 07-03-2020 at 02:14.

  4. #14
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    Oh yes I ended up on 2.5mm amsteel as it seemed the best compromise of weight nd breaking strain. The 1.8mm I use for guys and RL could be used (probably doubled up) as suspension if for some reason I broke or lost my main suspension but as you saycthe safety margin is not quite enough for regular use especially if I've eaten a lot of pasties on the trip ��

  5. #15
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    Hi nanok, I just I saw your picture in the levitating tarp post https://www.hammockforums.net/forum/...evitating-tarp , and I think that you might be using your UCR differently to me. That might be why the idea is not making sense? I have the outer constrictor part attached to the hammock, and the long inner part attached to the tree. In your photo the constrictor looks white and the inner looks grey. However the dangling piece also looks white so I'm not exactly sure what's going on there. Might just be the light in the photo. Let me know if you want to know more about how I'm doing it or want photos or video. I can assure you the hitches do not contact the constrictor until you have slipped a couple of inches and by then your constrictor will not save itself before you hit the ground so the jamming saves you from getting muddy at that point. The idea of a gripper knot on the tree end of the constrictor being able to fully stop slide with full body weight on the hammock did not work in my tests. Maybe with a much longer bury it would but with 70 diameters and full body weight then if you are already slipping because you forgot to milk the bury then you're going all the way down unless there's a stopper somewhere in the system. Apologies if my explanations are confusing!

  6. #16
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    Quote Originally Posted by Andy Pandy View Post
    Hi nanok, I just I saw your picture in the levitating tarp post https://www.hammockforums.net/forum/...evitating-tarp , and I think that you might be using your UCR differently to me. That might be why the idea is not making sense? I have the outer constrictor part attached to the hammock, and the long inner part attached to the tree. In your photo the constrictor looks white and the inner looks grey. However the dangling piece also looks white so I'm not exactly sure what's going on there. Might just be the light in the photo. Let me know if you want to know more about how I'm doing it or want photos or video. I can assure you the hitches do not contact the constrictor until you have slipped a couple of inches and by then your constrictor will not save itself before you hit the ground so the jamming saves you from getting muddy at that point. The idea of a gripper knot on the tree end of the constrictor being able to fully stop slide with full body weight on the hammock did not work in my tests. Maybe with a much longer bury it would but with 70 diameters and full body weight then if you are already slipping because you forgot to milk the bury then you're going all the way down unless there's a stopper somewhere in the system. Apologies if my explanations are confusing!
    i get your explanation, not confusing at all, i just think i dind't make myself clear enough: basically, i don't like the fact that the half hitches would disable the constrictor completely in the case of a slide, instead of giving it a chance to catch and lock. it's clear the half hitch cannot go through the constrictor, i just find it "ugly" and "counterproductive" (so aesthetics), but that's not to say that it doesn't work. that's partly why i ended up with a 30cm burry though i guess :D

    i also tie the long end to the tree and constrictor to the hammock (this way the adjustment stays at the hammock, where i want it), in the picture it might be confusing, as that's one of my early "experimental" ucr's :)

    thanks for helping clarify
    Last edited by nanok; 07-04-2020 at 17:14.

  7. #17
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    i just had a closer look at the specs of various rope available. in short, the 3mm sk78 dyneema i'm using seems to be the closest to the 7/64in amsteel blue (2.5mm), the moral of the story being: look at break strength and mass/length, not diameter.

    here's the long and boring details:

    - there's a 2.5mm kanirope/liros available (newly? i don't know), but looking at the break strength, it seems something is fishy: 580DaN, instead of samsons 650 (or 760, depending how you read it)
    - on closer inspection, the 2.5mm kanirope is 350g/100m, while the 2.5mm samson is 450g/100m; obviously, that cannot be if the material is the same, and it explains the difference in rating as well; the problem is how manufacturers measure the line is, ahem, a little bit negociable (do you measure loaded or unloaded? if loaded how much loaded? how much perpendicular pressure on the line when measuring? in all cases the tightness of the braiding will matter to the final result)
    - the 3mm kanirope is listed as 460g/100m, and 950dan. i always thought it was below 3mm, but how much... see above about measuring standard (line thickness has always been a bit of a rough estimate if we're fair, even in climbing it's been a problem, i somehow thought that, dyneema being so static, line diameter would be a lot more stable, i should have known better)

    it's quite interesting that they are getting 950DaN out of 460g/100m, it must mean either they are using a different material (could it be sk78 vs sk75? i thought it was only the stretchiness which was a bit better with sk78?), or they are using a different gram, or different meter. if we assume the material is the same and there's no magic in the fibers or the braiding, then we can assume the cross section of the rope (so square mm) is proportional to the strength, which means, if the density would be the same, the 950DaN kanirope should come closer to 560 than 460. (ok, that's enough of a difference that i will have to weigh some)

    so best to look at break strength rating, and weight/length, when shopping from different sources/manufacturers, instead of being lazy and trying to shortcut it by just using diameter (of course, if you know you want 7/64in amsteel blue, blue, and you can get it, you don't care about all lthis)

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