Quote Originally Posted by Schneiderlein View Post

I think the reduction in safety margin can be quite substantial, if you can increase your force from 200lbf to 800lbf just by attaching lower. That reduces your safety factor from 6 to 1.5 if the weakest link in your suspension system is rated at 1,200lbf, as is the case with my straps. Even with high-tech straps and rope, I'd still be concerned about taking down a tree.
Do you have any calculations on what angles would be needed to increase the force from 200 to 800??

MY girlfriend was curious some time back on the angles after I had been reading some the posts here and so we went to a park with a DIY hammock (all our hammocks have ridge lines) and some spare line. Strung the spare line tight between trees and then the DIY hammock suspension on top of the spare line, i.e., the tree huggers on top of the spare line. I pulled the DIY suspension moderately tight as I usually do, got in the hammock and she proceeded to make measurements and informed me that the angle was about 25 degrees ( maybe 26) and could I make it less. We figured that the only way to make it less was to pull the suspension tighter. I'm not Arnold Schwarzenegger, but I'm not the 90 lb weakling either ( 165 lbs and I can do 200 marine style pushups and have done so on my morning exercise regimen) , but I pulled the suspension as tight as I could manage. Plucked the suspension and got a nice note from the Spyderline. Gingerly got in the hammock. That was okay. Bounced around a little getting more energetic as my confidence increased. No problems from the suspension. I settled down and she proceeded to make her measurements again. Guess what? The smallest angle I could get with as much pull on tightening the suspension as I could muster was about 20 degrees. Maybe a degree or 2 less. Minimum would be 18 degrees.

From that I very, very seriously doubt that there many people around that could get anywhere near 90 degrees. I doubt that there are any that could get close to 90 degrees with a loaded hammock, say 180 to 200 lbs, to seriously affect the safety margin on modern ropes.

Oh the trees were slightly under 16' apart. Cannot remember the exact figures from the experiment, but I do remember approximately. The wider the separation, the further from 90 degrees you will end up.

Quote Originally Posted by Schneiderlein View Post
I think what Youngblood posted actually applies to hanging your hammock whether you use a structural ridgeline or not. The forces increase dramatically as the angle between suspension line and tree becomes closer to 90 degrees. Withou a structural ridgeline, you wouldn't hang that way because it would be very uncomfortable. As I see it, the only potential problem with a structural ridgeline is that it does allow you to hang that way in comfort, but it doesn't mean you have to. So, they are not inherently unsafe, but you should use proper caution.
Agreed.

I had a few more thoughts on why we decided long ago to always use a ridge line besides having a preset sag:

  1. chair height. We both like our hammocks hung so that it is about hip high when nobody is in it. That way when we grab the edge and turn around to sit down, the hammock settles down to about chair high which makes it very comfortable to just sit down.

    That also, makes getting out of the hammock very easy. Just like standing up from a chair.

    If the hammock is too high, we have to climb down out of it which isn't too bad. What is worse is having the hammock so low that we have to climb up out of it. If the hammock ends up much below chair height getting out involves more gymnastics and if a lot below chair high, we end up literally crawling out onto the ground and then standing up. Not comfortable.

    So, with a ridge line, maybe we just naturally like to hang higher than other people. Without a ridge line, we would be hanging even higher on the trees and may not even be able to reach high enough to do so. We could hang lower and be uncomfortable, but then why do that if the ridge line allows us to hang where we are comfortable?
  2. tree separation - About the minimum we can hang our DIY hammocks is about 14' and that is a real squeeze. We try for about 16' to 18', but have had to settle for up to 20' to 22' and a couple of times even more. Unfortunately the trees were not very accommodating when they seeded and didn't do so a uniform 17' apart.

    With a 16' separation, I have measured that we wrap the tree huggers over 5', about 5' 4" to 5' 6", above the ground. By standing back and eyeballing the hammock and where the hammock angle would cross the tree without the ridge line, it would do so above my head. Very close to 7'. At 18', it would be higher than I can reach. If now we had to settle for that 20' separation, we would be physically incapable of hanging the hammocks. We could never wrap the tree huggers high enough to keep the hammock off the ground without a ridge line. Even with the ridge line, the hammocks end up closer to the ground than we like.

    I notice on Youngblood's diagram, he projects the 30 deg suspension angle out to 18' and it is already up to 6' 8". I can reach high enough for that, but my girlfriend would need a ladder. I would be willing to bet that a lot of people would besides her.

    The ridge line lets us use wider separation and thus gives us a lot broader site selection. By limiting us to separations of say 14' to 18' max, we would have to choose less than desirable sites at times. Not often, but then why limit ourselves artificially when the ridge line frees us from that?


Anyway. I like ridge lines and wouldn't have a hammock without one.
Fortunately modern technology is such that we can have them with no problem.

I am more than willing to use modern technology if it makes my life easier and better. Having said that I still keep my cell phone turned off 98% of the time