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  1. #1
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    the levitating tarp

    ok, maybe that's a bit ambitious. but it must look weird at first glance, based on what i see most people do with tarps.

    IMG_20200629_121013.jpg-small-sig3.jpg

    i threa^H promissed i would talk about "other weird things" i do with the tarp, in the other post i showed the tensioning system. the pic shows the setup from last weekend (which was nicely tested by some kind 10+ m/s gusts, or over 22mph, or 19knots).

    you can see hopefully the continuous ridge line which looks parallel to the hammock suspension. why i think it is worth discussing are the following:

    - the attachment to the trees is the same tree friendly straps as the hammock, this removes the need to carry other straps (or risk hurting the tree when overtightening the ridgeline)
    - the ridgeline is made of some very tightly braided 2mm nylon "accessory line" found in climbing shops, it's is quite strong, but also very stretchy. this is a good thing in this case (and one reason why i don't think dyneema is a good idea for rigging tarps)
    - the attachments to the tree straps are quick release, so when the tarp needs to come down and away from the straps (once the hammock is safely stowed away), it is nice and fast.

    i know it's common for dyneema lashit/zingit rdigelines for the tarp to be considered the rolls royce for hammock tarp ridgelines, so this is a bit of a paradigm challenge, but my experience so far is that this works much better, and the flexibility of the line adds safety and versatility to the setup, so that you can easily bring the tarp close in on the hammock (as can be seen), even if, with the tiny load from the tarp alone, especially with the extreme tree spacing in this case, the tarp would be hanging 2m above the ground; the stretch of the ridgeline allows to bring it as close as desired, by using the guylines (with the tensioning system shown earlier), without any risk of over-straining the tarp itself, and still with a lot of room left to absorb wind gusts.

    what do you think? should i go into any more detail, does it look useful?
    Last edited by nanok; 07-02-2020 at 17:51.

  2. #2
    Senior Member cmoulder's Avatar
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    Nothing per se "wrong" with it as long as it does what you want it to do, assuming the nylon cord doesn't stretch more after pitching and leave you with a sagging tarp.

    I use low-stretch Lawson Glowire and Guywire and once I pitch the tarp it stays taut and I don't have to touch it again. The ridge line is not so taut that it would damage a tree. I use Midshipman's hitch for tensioning and it's easy to get it just so with no hassle or extra hardware.
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  3. #3
    Phantom Grappler's Avatar
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    Great technique, getting tarp close to hammock ridgeline. Maybe I can see better if you made a video.
    When it rains, I like to get tarp close to hammock ridgeline. But my tarp is three feet longer than my
    hammock ridgeline not counting the prusik loops extending from both ends of tarp.
    There may be no hope in my current rig.
    Good to see new ideas here! Thanks!

  4. #4

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    It's interesting to see something so different.

    Quote Originally Posted by nanok View Post
    - the attachment to the trees is the same tree friendly straps as the hammock, this removes the need to carry other straps (or risk hurting the tree when overtightening the ridgeline)
    So in this case, is the tarp ridgeline attached to the exact same straps as the hammock? Or do you mean the same type of straps? It looks like there's another strap on the far tree in this pic, but I can't tell if that's for the foreground tarp or the tarp on the left.

    - the ridgeline is made of some very tightly braided 2mm nylon "accessory line" found in climbing shops, it's is quite strong, but also very stretchy. this is a good thing in this case (and one reason why i don't think dyneema is a good idea for rigging tarps)
    Does the line stretch more when wet? That's the biggest potential downside I see to this setup.

    ... so that you can easily bring the tarp close in on the hammock (as can be seen), even if, with the tiny load from the tarp alone, especially with the extreme tree spacing in this case, the tarp would be hanging 2m above the ground;
    Not sure at all what you mean here. With a more typical "straight" ridgeline, you'd just put the ridgeline attachment points down on the tree to get it closer to the tarp.

    Still, having some horizontal stretchiness might be good in a storm. I've experienced winds that bounced my two trees around such that I was sure the ridgeline would snap. (It didn't -- like cmoulder said, it wasn't that taut, and the prussik knots holding the tarp to the ridgeline would have slid first, and probably did.) Looked pretty wild though.
    Last edited by KBr00ks; 07-02-2020 at 19:31. Reason: formatting

  5. #5
    Senior Member ibgary's Avatar
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    I connect the tarp ridgeline to the carabiners on the hammock tree strap.

    Sent from my SM-T720 using Tapatalk

  6. #6
    Senior Member cmoulder's Avatar
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    Quote Originally Posted by ibgary View Post
    I connect the tarp ridgeline to the carabiners on the hammock tree strap.

    Sent from my SM-T720 using Tapatalk
    How do you get the tarp low enough (close to hammock SRL) for storm mode? Does attaching the ridge line to the carabiners tend to loosen the hammock suspension around the tree?

    By pitching the tarp low, I find that pretty good coverage can be had even with a basic hex tarp with no doors. I've ridden out some fairly nasty storms with this setup, yanking out the trekking poles and quickly re-tensioning the tarp guy lines if necessary.

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  7. #7
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    Quote Originally Posted by Phantom Grappler View Post
    Great technique, getting tarp close to hammock ridgeline. Maybe I can see better if you made a video.
    When it rains, I like to get tarp close to hammock ridgeline. But my tarp is three feet longer than my
    hammock ridgeline not counting the prusik loops extending from both ends of tarp.
    There may be no hope in my current rig.
    Good to see new ideas here! Thanks!
    thanks mr Phantom, i'll think of making a video, i don't have for this one. i might try a diagram first though, maybe.

    the tarps in this photo are both what i would call "too small", the long side is 3m (so less than 3ft longer than the ridgeline of the hammock, actually it's so close to the hammock ridgeline length that centering is quite essential), the shorter side is 2.80 iirc. it rained that night for about 3h straight, both held up nicely, with no leaks or such, but it was mostly "vertical" rain.

    so there is hope, but for serious stuff, more coverage is required imho. with your 3ft of extra coverage, you should be well clear of "no hope", and safely into the "gotta set it up just right" range. mine has probably 1ft extra if that.

    Quote Originally Posted by KBr00ks View Post
    It's interesting to see something so different.



    So in this case, is the tarp ridgeline attached to the exact same straps as the hammock? Or do you mean the same type of straps? It looks like there's another strap on the far tree in this pic, but I can't tell if that's for the foreground tarp or the tarp on the left.
    the exact same straps, that's the whole point, to not carry and have to manipulate another set of straps, but still get the benefit of protection the straps provide. the other strap in the pic is indeed from the other hammock (the tarp on that one is setup in the "classic" way, under the hammock tie in.

    Does the line stretch more when wet? That's the biggest potential downside I see to this setup.
    it is no problem in this setup, to see why it maybe helps to explain how it is setup.
    the procedure is the following:

    - set ridgeline between the two straps, pull reasonably tight (the tarp is now way above the hammock, depending on the tree distance, but it will certainly be above the hammock ridgeline)
    - center the tarp over the hammock, with the prusiks or what have you there
    - stake down the corners of the tarp loosely
    - bring down the corners with the line adjustments to wherever you like (you know the drill, if it's raining and crappy, ridgeline on ridgeline, if it's nice and sunny and such, elevated porch mode, or anything in between)

    at this last step, you're taking the ridge line from a reasonably taut, "straight" pitch, to a trapezoid with two angles in it of up to 30degrees or so, this will add a lot of stretch into the ridgeline, to accomodate the new required length. it can rain cats and dogs, it won't make much difference (it will reduce the tension a bit of course, but there's plenty there to spare); we can do this safely because the tree straps will take that tension and distribute it nicely, as a minor fraction of what the hammock would put on the straps anyway.

    keep in mind though, my tarp, although a cheap one, has proper reinforcements on the tieouts (made in the hammock labs here of course, the piece of junk came with gromets, and of course they ripped out after not long), so if you're not confident about the tieouts, it would be wise to use a separate line to bring the ridgleine down (instead of doing it directly through the corner tieouts). i've been meaning to take a pic of that setup too, but it doesn't look that different from this

    Not sure at all what you mean here. With a more typical "straight" ridgeline, you'd just put the ridgeline attachment points down on the tree to get it closer to the tarp.
    (i don't know why, multi-quote removed the text you were quoting)
    what i mean is probably more clear now after the explanation of the procedure above. because, as you say, we didn't tie in the tarp below the hammock, the tarp will hang "freely" way too high above the hammock (with the ridgeline straight). this is fine, because now we'll use the stretch of the ridgeline in order to bring the tarp exactly where we like. this is very nice because you have infinite adjustment, without moving any attachment point, it's just adjusted seamlessly from the tieouts (this is one reason why i like the "single handed" adjustment system i showed previously, makes this process a lot faster)

    Still, having some horizontal stretchiness might be good in a storm. I've experienced winds that bounced my two trees around such that I was sure the ridgeline would snap. (It didn't -- like cmoulder said, it wasn't that taut, and the prussik knots holding the tarp to the ridgeline would have slid first, and probably did.) Looked pretty wild though.
    [/quote]

    exactly, i like to have that stretch buffer in high winds, i think it is necessary to have something to dampen/absorb the gusts. the only problem is the risk of resonant vibration, but that can be fixed, regardless what kind of line you use, by weighted tieouts (so you have a component of constant tension regardless of the amount of pull -- but i think that's suitable for a different topic of itself )

    Quote Originally Posted by cmoulder View Post
    Nothing per se "wrong" with it as long as it does what you want it to do, assuming the nylon cord doesn't stretch more after pitching and leave you with a sagging tarp.

    I use low-stretch Lawson Glowire and Guywire and once I pitch the tarp it stays taut and I don't have to touch it again. The ridge line is not so taut that it would damage a tree. I use Midshipman's hitch for tensioning and it's easy to get it just so with no hassle or extra hardware.
    sagging is definitely not an issue, the picture is taken after a whole night of rain, and there was no noticeable issue, because of how much stretch is already stored in the ridgeline (which is perfectly safe to do when using tree straps).

    i'm afraid we commonly underestimate the tension we put on tarp ridgelines, and the damage we might be doing to trees, it's very easy to underestimate it if we don't look at the numbers, as it is not that intuitive. i will take some measurements one of these days to clarify this, but my guess is it's at least 20DaN(roughly 20 kg force, or 44lbs force) after staking down the corners. doesn't sound like much at first glance. now, people commonly use under 2mm line for the ridgeline, but let's call it 2mm. the actual contact patch of a round line is much smaller than it's diameter, i'll call it 1mm here (but it's actually considerably less), this is why we use tree straps and not climbing rope for the hammock suspension.so now we have a (very approximate, very conservative) 1mm patch with 20gk/44lbs of force, on a hammock we tipically expect to have at least a 1inch webbing (25mm) and up to about say 100kg on average (220lbs).

    so we have a "lengthwise pressure" (i just made that unit up, but you get the idea) of 20kg/mm for the tarp, and 4kg/mm from the main hammock suspension. that's a factor of 5 in the direction of making the tarp more "evil", and that's without taking into account wind gusts (and make no mistake, on a taut line without sag, any deflection will increase the tension spectacularly, especially if the line has low stretch, like, say dyneema). i personally have a bit of a problem with that.

    given i carry the straps because i do care about the trees, i find it absurd to not use them to protect them from the thin tarp ridgeline, while i have them with me. so this is partly what i'm trying to fix with this setup,but i also want to find a way so that it's actually nicer to setup, and at least as functional, as the more common setup, so that it's an "all round win", and i do think that, with the level of expertise on this forum, that is indeed doable.
    Last edited by nanok; 07-03-2020 at 05:55.

  8. #8
    Senior Member ibgary's Avatar
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    Quote Originally Posted by cmoulder View Post
    How do you get the tarp low enough (close to hammock SRL) for storm mode? Does attaching the ridge line to the carabiners tend to loosen the hammock suspension around the tree?

    By pitching the tarp low, I find that pretty good coverage can be had even with a basic hex tarp with no doors. I've ridden out some fairly nasty storms with this setup, yanking out the trekking poles and quickly re-tensioning the tarp guy lines if necessary.

    ?2, no attaching to the hammock suspension does not loosen it, unless you over tighten the tarp ridge line.
    I use zing it for the TRL (tarp ridge line), one end is attached using a prusik knot (spelling) the other end is a wasp so it only takes a few seconds to adjust. Put some slack into the TRL and tighten it to the HRL by tightening the tie outs. Being in contact with one or both of the ridge lines I think gives the tarp better support in wind than being between them.

    Sent from my SM-T720 using Tapatalk

    Last edited by ibgary; 07-03-2020 at 07:53.

  9. #9
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    ibgary: indeed, using dyneema is possible if you leave the ridgeline somewhat slack to begin with, so it only gets tight once you tighten the corner tieouts, but it seems unnecessary when a stretchy line just does a much better job overall. but perhaps i'll find a reason why it is something to consider?

  10. #10

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    Thanks for the thorough explanation, nanok.

    Another question (for ibgary as well): With the tarp ridgeline running under the tarp, do you find that the downwards tension from the guylines makes the ridgeline more apt to abrade the tarp on the underside, especially at the edges?

    In a "traditional" setup the ridgeline is also running under the tarp (I do this too), but exits at a more "flat" angle and doesn't contact the tarp with much pressure.

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