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  1. #1
    Senior Member Frolicking Dino's Avatar
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    Various ways to set the sag of a hammock

    This discussion has been moved from another discussion at the request of another poster. Both variable and fixed length ridgelines were used by Mayan Indians which are credited for having invented the hammock about 1,000 years ago.

    Below is a reenactment of the typical hammock setup used by travelling Mayans


    I agree the line in the photo does not do what TH's ridgeline does, but it does have the potential to set the sag.

    Is the pic below a structural ridgeline? It definitely limits the sag of this Thai hammock. Granted, it does it in a different way than the HH, but it does by design make it so the hammock will set up the same every time.


    While HH certainly has one type of structural ridgeline, I really don't think the idea of a structural ridgeline should be limited to HH's method. There are many ways that have been used for centuries to set the sag and those are virtually all some sort of structural ridgeline - be they wood, bamboo, webbing, cord or some other material.
    -------------- after someone questioned the above being a structural ridgeline
    Are you saying that simply setting the maximum length that the ends of the hammock body can attain is not what sets the sag or not a structural ridgeline (even if it is a permanent part of the hammock as in both pics above)? As you note, in the second pic, the hammock is not acting as a structural ridgeline, but that it easily could is apparent.
    -------------- after someone opined that unless the ridgeline was shockcord or very weak, it was a structural ridgeline:
    I'm fairly sure shock cord wasn't around 1,000 years ago . The ropes used to make the travel version of the Mayan hammock were woven as single rope to a point just before where the hammock body attached. The rope was then split and the ridgeline formed from one portion of the rope and the rope portions were rejoined at a point just beyond where the over end of the hammock body was attached. It is inconceivable that the Mayans would have made the upper portion of rope so weak as to only be sufficent to hold up bugnet -- they were using heavy animal hides or large leaves cut from local flora for rain protection.
    ---------------- after someone suggested I get a lawyer and challenge the HH patent:
    Some of the manufactures may want to research Mayan hammocks and challenge the patent(s), but I have no dog in that race.

    I'm not trying to find a way to challenge TH's patents, but to understand what does and does not constitute a structural ridgeline and how it could be implemented. I'm not a manufacturer so it would serve no purpose for me to challenge TH's patents. My sole motivation for entering this discussion was developing a thorough understanding the concept of a structural ridgeline and considering all ways to implement it in my designs - designs which are DIY projects with features not needed by most hammockers. I design for myself, Mother Nature and a handful of others with disabilities or back problems.

    In the first pic, the ridgeline limits the length the hammock body can attain because it is shorter than the hammock body. What makes that piece of rope that connects the just above the hammock body ends different from a rope that connects in the whipping itself? If I used the piece of rope holding up the bugnet to determine how far my hammock body would be stretched, would it miraculously become a structural ridgeline?

    Are structural ridgelines load bearing (do they actually take on some of the weight when the hammock is occupied?) or do they simply serve to limit the maximum distance the hammock body can spread (and incur strain from holding the supporting cord or webbing in the proper place)?
    Last edited by Frolicking Dino; 06-02-2007 at 11:39.

  2. #2
    Senior Member Frolicking Dino's Avatar
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    Guys, please don't make this about TH or his designs -- it is about various ways to set sag. Setting sag - or actually limiting sag - are vitally important to those of us with problems getting in and out of hammocks and with various ortho injuries or degenerative problems.

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    In looking at the pics, I would not refer to either one as structual ridgelines. I think the first one can limit the sag, but it does not set it. The hammock could be hang with more or less sag depending on how the support ropes are tightened.

    The second pic looks only to hold up the bug netting and does not effect the sag at all. It looks like the hammock is pulled really tight.
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  4. #4
    GrizzlyAdams's Avatar
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    Quote Originally Posted by Frolicking Dino View Post
    Guys, please don't make this about TH or his designs
    I suppose I'm the one who steered the discussion that way, influenced by discussions on other threads. I was reading what you were saying, what ryndel was saying with his quiz through the lens of "Is this a structured ridgeline as claimed by TH", noting the presumed irony.

    Given the reported history of Tom's defending his patents, I'm interested in what they claim or don't claim, what impact that might have, or not, on the hammocking crowd. I have more than one hammock sold by him, like them quite a lot, and some other time will relate an astonishingly good bit of customer relations I've enjoyed with his company. I wish HH much success. But if his patents over-reach, then that's something that affects certain ones of this community, and seems to me to be a topic for reasoned discussion in this forum, if not this thread.

    When I quipped "Get thee to a lawyer", I didn't seriously mean to suggest that you (or anyone) should, or would. A throw-away line based on a famous Shakespearean quote from Hamlet. Perhaps I should have accompanied it by one of these iconic smileys, although my taste runs to the ascii version of the hatted bespeckled bearded smiley C|8^)*

    I've said too much on this already, speaking out of the wrong end of my anatomy.

    Grizz out
    Last edited by GrizzlyAdams; 06-02-2007 at 12:42. Reason: I can't spelll

  5. #5
    Senior Member blackbishop351's Avatar
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    As I posted on the other thread, neither of these seem to be examples of structural ridges. I'll leave my original reasoning for others' perusal.

    I've noticed something additional in the first pic, though - upon a closer examination of the hammock ends, it doesn't appear that the "ridgeline" is actually a ridgeline at all. The support ropes (yellow) look like they're attached to a black support line that's just barely visible, which is what's supporting the hammock. I think all of the "ridgeline" (white) is interconnected, which would imply that it's all part of a separate bugnet system - having nothing to do with the hammock itself.

    FD - I'm curious how you think the ridgeline in the second pic could limit the sag of the hammock? It's completely separate from the hammock as far as I can tell, even to the point that it has its own separate tree attachments.
    "Physics is the only true science. All else is stamp collecting." - J. J. Thompson

  6. #6
    Senior Member Frolicking Dino's Avatar
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    BB, you are correct re: the first pic. My old eyes could not see this - I've enlarged it to 300% so other old eyes can see it.

    BB, the second pic hammock would affect sag the same way my 1.5 webbing strap does (see illustration in TeeDee's thread). By attaching the hammock body to an overhead suspension system (webbing, cord, bamboo, wood, or other material) at exactly the same point, the sag of the hammock is limited to a certain maximum. It will not limit it to a certain minimum, however. This assumes the webbing on the bugnet is actually weight bearing. If it isn't, this system would n't affect the sag at all.
    Last edited by Frolicking Dino; 06-02-2007 at 13:36.

  7. #7
    Senior Member Frolicking Dino's Avatar
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    Have any of you ever seen a hammock set-up similar to this? I'm thinking it might solve some of the problems I've been having with designing something for a friend.
    Last edited by Frolicking Dino; 06-03-2007 at 13:35.

  8. #8
    Senior Member Just Jeff's Avatar
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    Shoulder squeeze.
    “Republics are created by the virtue, public spirit, and intelligence of the citizens. They fall when the wise are banished from the public councils because they dare to be honest, and the profligate are rewarded because they flatter the people, in order to betray them.” ~Judge Joseph Story

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  9. #9
    Senior Member blackbishop351's Avatar
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    Quote Originally Posted by Frolicking Dino View Post
    BB, the second pic hammock would affect sag the same way my 1.5 webbing strap does (see illustration in TeeDee's thread). By attaching the hammock body to an overhead suspension system (webbing, cord, bamboo, wood, or other material) at exactly the same point, the sag of the hammock is limited to a certain maximum. It will not limit it to a certain minimum, however. This assumes the webbing on the bugnet is actually weight bearing. If it isn't, this system would n't affect the sag at all.
    In your setup (from what I get from your descriptions of it), the suspension and ridgeline are one and the same. This is in effect (of course) a structural ridgeline situation. In this pic, the hammock isn't even connected to the "ridgeline" as far as I can tell.
    "Physics is the only true science. All else is stamp collecting." - J. J. Thompson

  10. #10
    Senior Member Frolicking Dino's Avatar
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    BB, this is my current set up (used for testing only as I often need to modify the sag to test different structural elements).

    The hammock in post above is a second design and is not connected to the ridgeline in this pic - I am examining ways to set the sag and don't give a hoot if they use a structural ridgeline or not as long as they work.

    JJ, would a spreader bar at the top fix the shoulder squeeze problem in you opinion? Would moving that support above where the head would be work? I'd like to keep at least one of the 'hanging straps' near enough to the midline of the hammock body to be used by the occupant for getting out. This design is an idea I'm working up for a man - 6'1", 210 lbs who is an amputee (mid thigh). His hip is also damaged which makes it difficult for him to get in and out of a hammock - even more so than for me - but he has termendous upper body strength thanks to using a wheelchair a lot. He will not be using this to backpack so weight isn't as much of a factor -- he will be using it to be able to take his two young sons car camping.
    Last edited by Frolicking Dino; 06-03-2007 at 07:31. Reason: Added link to first design

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