Breaking Strength Required for Structural Ridgeline?

[angrysparrow]

Hmmmmmm ... you are making me think differently! I always thought a structural ridgeline created a maximum amount of sag.

You can always increase the amount of sag in the hammock causing the ridge to be loose but a tight ridge line is generating a set minimum, by hanging the straps even higher or trees closer a loose ridge line becomes non-functional and will let you go more and more sag all the way to the hammock ends touching (the max sag possible)

I think we're talking the same language, Rain Man, and you understand the concept. I just phrased it in a way you had not yet considered. I think it's an important point.

Paul nailed it, though. It is a minimum sag created, because even with a ridgeline you can create *more* sag by increasing the severity of the angle from the tree supports to the ends of the hammock....thus creating a loose ridgeline and an even looser hammock body.

[SGT Rock]

I don't consider my ridge line structural since I can hang without it. I originally tried mason twine on mitten hooks, the strategy was if I put too much stress on it, it would pop off on it's own. It popped off too much. Then I tried some Zline from Zpacks that has a 200 pound strength which I assumed would be enough, but it couldn't be spliced so everything had to be done with knots - so it broke at a knot. As I understand it a knot reduces line strength by 25%-50% so it only had 100-175 pound strength at that point and it ended up failing as well. FWIW I am 175. Finally I went with Arrowhead equipment 1.75mm line which is rated to 400 as I recall. Everything is done with splices except a stopper knot. So, as I understand it, the line is rated at about 300 pounds now. It has worked VERY well. It only weighs 4 grams and is probably the best all around solution for lightness, ease to make a line out of, and durability without being a big honken rope.

And to be in full disclosure - I do count every gram.

[GrizzlyAdams]

Hmmmmmm ... you are making me think differently! I always thought a structural ridgeline created a maximum amount of sag. Back to the drawing board.

Since I recently bought my wife a double ENO, this has taken on more interest for me, than in the past when all I had was a HH.

Rain Man

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Hey Rain Man, think of it this way...

If you somehow hung the hammock so that the two ends were 3 ft apart, you'd have some serious sag, which you might measure as the distance from the bottom of the hammock (supposing here that it is not dragging on the ground!) up to an imaginary line between those two ends.

Now pull the ends farther and farther apart. The hammock middle comes up, reducing the distance to that imaginary line. i.e., as you increase the distance between the hammock ends, you decrease the sag.

So now if there is a real line between the ends---a ridgeline---once the ends pull the ridgeline taut the sag cannot get any smaller. You've hit the minimum amount of sag possible in the system.

but I bet you really understood that, and did a bit-flip on the maximum/minimum thing....I get random bit-flips all the time...

[Knotty]

Good explanation Grizz.

You can never have less sag than a fully stretched rigeline permits.

But since it's a ridgeline, not a ridgebeam, you can always have more.

[Rain Man]

So now if there is a real line between the ends---a ridgeline---once the ends pull the ridgeline taut the sag cannot get any smaller. You've hit the minimum amount of sag possible in the system.

Now I see, ... said the blind man. Thanks.

Now ... my next project is adding a ridgeline to my wife's double ENO. Ah, things to do, things to do.

Rain Man

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