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  1. #41
    if you do end up ordering that blackbird, i can sell you the 50' of 3mm amsteel blue (but in grey) that way you don't have to pay 2 shipping costs. i also have 1.75mm neon yellow zing-it guyline single braid dyneema as well

  2. #42
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    Am I right in thinking that with the clove hitch you are talking about going with webbing from the hammock, around the tree, and securing the hammock to the tree using a clove hitch?

    You'll have to forgive me for not going back and rereading everything, slow interent connection where I am at now.
    Is that too much to ask? Girls with frikkin' lasers on their heads?
    The hanger formly known as "hammock engineer".

  3. #43
    i think they are talking about using line, and clove hitching onto a biner

  4. #44
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    Quote from "The Ashley Book of Knots" regarding strength.

    Quote Originally Posted by Graybeard View Post
    As I recall, The Ashley Book of Knots has some good information on this topic but I can't check because my son made off with my copy a decade or two ago.
    From "The Ashley Book of Knots", 1944 edition, page #17:

    "The break in material almost invariably occurred at a point just outside the entrance to the knot, which is usual in all tests. A common statement that appears in many or most knot discussions is that "a knot is weaker than the rope in which it is tied." But since a rope practically never breaks within a knot, this can hardly be correct. It appears to be true that a rope is weakest just outside the entrance to a knot, and this would seem to be due to the rigidity of the knot. These experiments were not carried far enough to give conclusive results, but some of the results indicated were quite different from what is generally accepted."
    Noel V.

  5. #45
    Senior Member TeeDee's Avatar
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    Quote Originally Posted by koaloha05 View Post
    From "The Ashley Book of Knots", 1944 edition, page #17:

    "The break in material almost invariably occurred at a point just outside the entrance to the knot, which is usual in all tests. A common statement that appears in many or most knot discussions is that "a knot is weaker than the rope in which it is tied." But since a rope practically never breaks within a knot, this can hardly be correct. It appears to be true that a rope is weakest just outside the entrance to a knot, and this would seem to be due to the rigidity of the knot. These experiments were not carried far enough to give conclusive results, but some of the results indicated were quite different from what is generally accepted."
    Recent research, c.f., for example the New Journal of Physics for those so inclined, is pointing out the truth in this statement that a rope doesn't break inside the knot, but rather at the point of entry to the knot.

    To Quote:

    A new way of localizing the breakage point in a rope or string is described today in New Journal of Physics, published jointly by the UK's Institute of Physics and the German Physical Society.

    Spaghetti lubricated in olive oil is shedding light on why knotted ropes or strings used by sailors, anglers and mountaineers snap where and when they do.

    "Finding the breakage point on a rope with some degree of accuracy is very difficult. Materials like nylon break so fast that it is impossible to see where or why a break occurs, even with a high velocity camera. Instead, the best material to see a breakage turns out to be well cooked spaghetti," said Dr. Giovanni Dietler of the University of Lausanne in Switzerland.

    Mountaineers, sailors and anglers all recognize that knotted ropes break easily near to the site of the knot. By looking at why a rope or string breaks at that site, it is hoped that stronger fabrics can be produced that overcome this problem.

    The researchers, based at the University of Lausanne and at Poznan University of Technology in Poland, analyzed consecutive frames of film to see where the breaking process begins. They learned that the breaking point was localized at well-defined points close to the entrance to the knot, where the spaghetti was very bent.

    The researchers then carried out computer simulations of tightening knots to see what effect this had.

    "It was found that the breakage occurred where the bend in the filament was the greatest," said Professor Piotr Pieranski of Poznan University in Poland.

    Knowing that the higher the curvature in the rope, the more chance there is of it breaking can lead to producing materials with new weaving patterns that reduce the curvature. This same principle could also be applied to produce stronger plastics by minimizing the curvature in polymer chains or by avoiding knots within the molecule.

    "By comparing localization of breakage points in knotted spaghetti with those reported in molecular simulations of knotted individual polyethylene chains, we were struck by the conservation of the same basic physical principles from macro to nano scale," says Dr. Andrzej Stasiak from the University of Lausanne.

    The Institute of Physics is a leading international professional body and learned society with over 30,000 members, which promotes the advancement and dissemination of a knowledge of and education in the science of physics, pure and applied.

    It has a worldwide membership and is a major international player in: scientific publishing and electronic dissemination of physics; setting professional standards for physicists and awarding professional qualifications; and promoting physics through scientific conferences, education and science policy advice.

    The Institute works in collaboration with national physical societies, plays an important role in transnational societies such as the European Physical Society, and represents British and Irish physicists in international organizations.

    In Great Britain and Ireland, the Institute is active in providing support for physicists in all professions and careers, encouraging physics research and its applications, providing support for physics in schools, colleges and universities, influencing government and informing public debate.
    Some fascinating work being done and I'm sure that we'll learn more in the future.

    I've read other research results looking into the mechanism of breakage in the fractured material by examining the fracture surfaces. Knowing the fracture mechanics could conceivably lead to even better materials than the spectra/dyneema and vectran we have today.

    Don't know if the results will eventually lead to an unbreakable rope, but the thought of 3 mm rope capable of loads exceeding several Imperial tons is inviting. Especially if it has high abrasion resistance also - something that plagues vectran.

  6. #46
    Senior Member Graybeard's Avatar
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    Hmmmmm. Sounds to me like fairly elementary beam theory.
    b
    bob

  7. #47
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    Flatten Amsteel Blue & Garda hitch.

    The flattening though not permanent of AmSteel Blue when using rings & Garda hitch got me a bit concerned. Enough to abandon the ring/Garda set up when using Amsteel blue as a suspension line. Not sure if the the flattening causes a sharper bend in the line fiber than a rope that stays more round. If it does and the above citation is true wondering how much strength the Amsteel blue decreases. Never noticed a flattening situation on the Spyderline (?3.8mm & heavier weight/ft) which I think is a polyester sheathed Dyneema line. Something other than work to think about over lunch break.
    Noel V.

  8. #48
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    heres a photo of my new (for me) SLS using a whoopie on each end of the hammock, note the pull ring on each end to tighten the slack. Its all made or 4,000 pound spectra from ebay.

    it is descibed in the suspension forum "structural ridgeline and whoopies".
    Jim S

  9. #49
    New Member mikewilkinson's Avatar
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    Just thought I'd share my method of single line suspension with everyone.

    Photos attached probably explain it better.

    But basically on a sinle line of 4mm Dyneema SK75 (will be chaning to 3mm or possibly 2.5mm SK78 soon) I use two Karabiners and a welded steel ring (SMC ring is probably better) to hang between two tree huggers.

    At one end I tie an Evenk(Siberian) Hitch to the Karabiner on the Tree hugger

    At the other I use the ring with 3 or four wraps of cord to tie an adjustable truckers hitch(release tension slide ring to position, re-tension)and secure with a simple slipped half hitch.

    I don't tension the line to much as I need some slack to attach my hammock hanging karabiners.

    The Karabiners for hanging the hammock are attached anywhere along the suspension line by forming a clove hitch around the karabiner (you could also use the wrap method like the ring, however the clove hitch will defintely not slip), I then simply clip the hammock in to these karabiners, Sag can be adjusted by removing the karabiner and re-hitching in place somewhere else.

    I've attached images of a long and short hang set up with a fixed hammock sag.

    I am currently investigating the use of Nacrabiners to replace the karabiners on the tree huggers and to just stick a couple of marlin spike hitches in the line and hang the hammock directly off them, although I cannot beat my current method for speed of hang.

    Hope this is useful to some people, looking to hang from a single line.
    Attached Images Attached Images
    "Coz I find strength in pain, and I will change my ways, I'll know my name as its called again"

  10. #50
    sr1355's Avatar
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    I received my order of 50' of Amsteel Blue 7/64" over the weekend and had a chance to set this up in my apartment... GF thinks I'm a little NUTZ but aren't we all.... Anyways, I want to have hammock quickly removable from the entire system and don't want to introduce much weight to the system.... I'm thinking of a carbonfiber arrow toggle and larks head that would allow me to removal hammock for adding DIY peapod system... Not sure how much weight the CF shaft can take in this position... Have 0 and 25 degress sleeping bags that have foot box zippers installed so all I need to do is address hood area... Tried one on the hammock this weekend and it was perfect apart from hood hanging down... With a peapod style fleece bag liner I can see some pretty cold weather hangs....

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