8

I want to hang up a hammock. There are vertical square tubes made of galvanized steel of 10cm x 10cm. I want to hang up my hammock by using ropes (polyester, ⌀6mm, 9500N) and shackles. The rope should remain attached to the square tubes. The shackles are for fast and easy mounting and dismounting of the hammock. I also bought some thimbles.

  1. What is the best knot or method to attach the rope to the square tubes. With:

    • Preferably highest knot strength.
    • No slipping down of the rope, since the square tubes are vertical.
    • The square tubes must not be modified. No drilling, etc.
  2. What is the best knot or method to attach the Rope to the shackle?

    • Using a thimble?
    • Using a rope loop instead of a rope ending to increase the holding force?
    • If yes: How to mount the thimble to the rope loop?

I am generally able to hang up the hammock. What I am asking and interested in is what would be the best knot or method to do so. Taking into account knot strengths and other factors about knots and ropes I have no clue about.

  • Why can't the tubes be modified? That would make things 100x easier. – whatsisname Jul 1 '15 at 2:49
  • Also, does this question belong more on diy.se? – whatsisname Jul 1 '15 at 3:46
  • 1
    See my answer here - substitute carabiner with shackle, webbing with rope (add extra wraps as necessary), tree with square tubing, and discard thimble. 1. Set up hammock. 2.Weight hammock. 3.Apply duck tape to rope around post. 4. Voila. Alternatively, wrap an old bicycle inner tube around the post to provide friction for the rope to grab. – ShemSeger Jul 1 '15 at 4:47
  • @whatsisname The square tubes can't be modified, since they aren't my property. I can use them, but not modify them irrevocably; Only temporary. – PJT Jul 1 '15 at 17:08
5

Coming from a climbing background, I would propose the following:

  • Tie the cord/rope into a loop, for example using the One-sided overhand bend or the double fisherman's knot
  • Secure it around the pole using a Prusik knot. Note that the english wikipedia entry is only about climbing; the german version also mentions that this friction knot can be used e.g. to drive stakes into the ground (and has some images of that, section "Heim und Garten"). So I would assume that this knot would work for you, maybe with a few more loops to make it "grab" the tube stronger if it slips down when you load it.

  • Put the shackle into the remaining loop of cord of the Prusik.

I haven't yet tied a Prusik around a square tube, but I would assume that it should hold well enough. The upsides of this method is that the rope would easily be removable (just in case), and that you can move it along the tube as long as it is not loaded.

  • 1
    Oops, missed the size of the tubes... While my answer is valid for poles with a smaller diameter, it might require too much rope for larger ones. However, if you try the method that @ShemSeger suggested in his comment and the rope slips down, this might be one of your only options. These frictions knots really produce a lot of what the name suggests ;-) – anderas Jul 2 '15 at 9:39
  • I've deleted my answer because I think my reasoning was incorrect. However, I've tested a Prusik for this purpose, and it doesn't seem to do what you want when applied in this way. I tied a Prusik around a small vertical piece of box tubing on a banister in my house. When I pulled on the cord, it held. However, when I tensioned it with one hand in the horizontal direction, it was still easy to slide the knot up or down the post with the other hand. So it's unclear to me what would happen if you used it for the hammock. I think the hammock might slip downward when not under tension. – Ben Crowell Jul 3 '15 at 12:39
  • Hm, then it might depend on how much tension is desired on the hammock. My reasoning here was basically that the downward force when PJT uses the hammock should be high enough for the knot to hold and that I would expect the Prusik (or other similar knots) to hold better on straight poles than ShemSeger's solution. Though I might be wrong here, I sadly don't have a hammock and poles to try it... PJT, feel free to correct my answer if it proves wrong :) – anderas Jul 3 '15 at 14:04
0

Would you be amenable to using webbing? Webbing either in triple girth hitch, wrap 3 pull 2 or tensionless hitch works well. If the poles are sharply cornered, wrap an old foam thin piece over the sharp edges. Then make a simple "masterpoint" from the web and carabiner to hammock end - works great. For very slippery wooden square poles, simply use a small knife to slightly notch the wood before setting up.

  • This does not address the question properly. The OP asked about about a steel pole that can not be altered, so it is slippery and notching is not an option. Also question 2. is not addressed. – imsodin May 17 '16 at 18:10

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.