1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Multi-level extendable hammock posts

  1. Jun 13, 2016 #1
    Hi folks,

    I recently moved to a new house with a small backyard/patio. It's roughly 25ft x 25ft, mostly concrete bordered by an L-shaped earth area. I'd like to place three hammock posts as shown in the first image.

    We like to dream big and want these posts tall enough to support two hammocks per pair of posts. One side of the patio is fenced and faces the neighborhood. Due to HOA, we can't have our posts permanently visible over the fence, so I came up with the idea of a buried steel square post with a larger square post that fits over the top can slide up to a second position with a quick release pin. I tried to draw this in the second image.

    I got a quote from a local steel yard for three 3"x3"x8' and three 3.5"x3.5"x5' posts for an unsurprising but hefty ~325$. What I'm trying to do is calculate whether I can accomplish the same setup safely with 2"x2" base steel posts and 2.5"x2.5" steel sleeve posts. I found some engineering calculator resources online but they are for column load, not transverse load. I also don't know how to calculate how much the beams should overlap and what kind of load limits the combined extended posts will have. Any suggestions?

    *Forgot to mention that all tube thicknesses are 3/16 in.

    Attached Files:

    • hm1.png
      File size:
      1.2 KB
    • hm2.png
      File size:
      8.4 KB
  2. jcsd
  3. Jun 13, 2016 #2


    User Avatar
    Gold Member

    Just out of curiosity, how do you plan to get in and out of the upper level of a double-decker hammock? I'm sure it's been done, but it seems to me like more of a pain than it could be worth.
  4. Jun 14, 2016 #3
    We've done it before on camping trips. Definitely not as graceful an entry as the main level. The main benefit is having a hammock village with a bunch of pals.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted