Is 30 degree rule for hanging hammock bunk?

[Stormstaff]

Where's Grizz with all the scientific mumbo jumbo?

[ckmaui]

for sure play and investigate and try things out but sometimes things are just what they are

now going out to design a new hammock that does not need a 30 or so degree hang and is not gathered end and is not a bridge and you have something like the exped or that other one from europe that is like a lounger that can recline

so go design something totally new

[SilvrSurfr]

Let me summarize the argument you're making:

If I hang my hammock between the earth and the moon then I will have the flattest possible lay because, in the grand scheme of things, I'm almost flat on the curve.

So find a tree on one side of the Grand Canyon and another on the other side. Yes, you will have achieved the flattest possible lay. Congratulations! Thirty-degree hangle debunked!

[hutzelbein]

You mean like this?





Honesty, I cannot really follow your logic. How would going high change anything that you would not achieve by tying the hammock at a close to 0° angle (and a short distance)?

30° does not apply to all hammocks. Not even to all camping hammocks. Brazilian hammocks and the likes usually get hung with a 45° angle. For some hammocks, I found that a shallower angle improves comfort. I believe, the longer the hammock body, the steeper the angle - the shorter the hammock body, the shallower the angle. Still, the angles are probably all between 20° and 50°. It's the nature of the hammock. If you don't believe it, do your own experiments.

The reason why you achieve a flatter lay in a gathered end hammock when you lie diagonal is the center of gravity. If you lie inline, you butt is the heaviest part of your body, and it will force the fabric to hang lowest. All body parts that are lighter are pushed up by the fabric. If you go diagonal, you create lots of different centers of gravity, thereby achieving a flat-ish lay. Unfortunately, I can't explain it any better - I'm not a physicist.

[K0m4]

One thing that works against achieving more flatness with longer suspension is the sag in it. A longer line, no matter the material, will always have some amount of give in it, as in the longer the line, the more the give. So if your want to achieve tighter and thus flatter, you need shorter suspension. I think.

The problem with this becomes that you will have neither fish nor meat. Since you will be unable to get it tight enough to remove enough give to be totally flat, but at the same time not sagging enough to achieve the flatness on the diagonal, you won't be comfy. Sag it enough to get almost totally flat on the diagonal, and you're money. The 30* is a starting point, not a rule. I'm probably more like 25* myself, but I don't worry too much about the numbers. I hang the hammock, lie down in it, and if I lie flat without calf ridges, I leave it as is. Otherwise, I adjust. And I don't think too much about it. I leave that to others, and then just soak in their posts on this forum

[OutandBack]

HolyCow hutzelbein I love that first shot and you even got the foot end higher than the head.
That's crazy.

[PDA]

[QUOTE=goober;1329203]How would it be tight? What I'm saying is that you give your hammock the maximum sag, which minimizes the curve.

But, as you can see in the photographs of a hammock suspended from trees 30' or so apart, the curve is not minimised, it just has a much larger diameter and the hammock is a much smaller cord or that circumference. The angle of the suspension is still about 25-30 degrees. Anyway. The reason for the "30 degree rule" is stress on the suspension lines (and tree). At 25-30 degrees, the stress on the line (on each side) is about your weight. As the physics 101 shows, lowering the angle to 5 degrees increases the stress exponentially to a level that would need seat belt strap material to support it and hammocks made from kevlar fabric. Most of us prefer to use 1" polyester webbing and 7/64" Amsteel, and 1.1 oz nylon for the hammock. The curve of the hammock itself has been found by experience (for gathered end hammocks) to correspond to a suspension angle of 25-30 degrees for the best compromise for comfort. Warbonnet, Hennessy and other hammock manufacturers put a fixed hammock ridge line which sets the length of the suspended hammock at 80-85 % of the flat hammock length. Conventional wisdom sets the distance at 83% (5/6) based on years of experiment.

[BillyBob58]

How would it be tight? What I'm saying is that you give your hammock the maximum sag, which minimizes the curve.

What I see is a lot of repeating the 30 degree rule, not any explanation.

(And I'm not arguing against the other 30 degree rule, the one that says you should try to lay diagonally)

That said, it certainly looks like I'm not winning any converts!

Oh we are a tough bunch to convert, so don't let it bother you! I do a couple of things that are quite different than most, and I've hardly won amy converts in 8 years here! But then again, who cares! Whatever works for them and whatever works for me. Whatever works!

Now with that said, let me say: I'm not quite sure what you are trying to say. "What I'm saying is that you give your hammock the maximum sag, which minimizes the curve." But, the sag is the curve. The more sag- or the looser- I hang my hammocks, the more curve there is in the hammock body.

The curve is what you want. So that you can lie flat. At an angle to the longitudinal centerline of the hammock. If you try to lie flat directly on the longitudinal centerline of the hammock, you will never lie flat. You will be a ba na na. That's because you will never be able to get it tight enough to lay flat in.

Goober, there are not really any rules around here. Just a whole bunch of us that have done a bunch of experiments over the years to find out how we can get max comfy with various hammocks. Used to be a lot of us, using our HHs with factory ridge lines, tightened the heck out of those same RLs. Straight as an arrow and then some more torque for good measure. Now this put huge stress on the trees and hammock ropes, but unless I managed to stretch the HH RL, which I did one time with a Hitchcraft, the hang sag of the hammock was about the same no matter if pulled tight or barley snug. Plus it seemed it was actually easier for me to stay high enough off the ground if I didn't pull so tight.

In the meantime, some of us were using either DIY or Speer hammocks with no RL. We quickly found that pulling them very tight gave a lot of shoulder squeeze and not enough room for a good diagonal lie. But it did not do much to get rid of the need for a diagonal lie, because there was no way to get it tight enough to avoid some banana curve in the hammock which stressed my knees. That is the actual main benefit/reason for the diagonal lay, to avoid extension of the knees on when flat on your back, or a waist hitch/pain if on your side. We are getting on the diagonal trying to get flatter to avoid that banana curve which hurts our knees or waist.

I think the 30* is mainly what a bunch of folks decided seemed to be a happy medium for most hammocks, one which minimized stress on the trees and hammock ropes/webbing. Even if your ropes are at 30*, if you are using a RL the amount of sag in your hammock can still vary gretaly depending on the length of your RL vs the length of your hammock. A popular place to start is, I think, RL 83% as long as the hammock- I think. But the point is, people here experiment to find the perfect RL length for their comfort and then lock that in. And some people like a whole bunch of sag, and others less. And one brand of hammock might need a lot more or less curve/sag than another. But most of those still end up hanging at about 30* rope to tree.

Here is an experiment for you: if you have hammock with no RL, or even with a RL, pick whatever trees you want- close together or far- and tighten it up straight, nice and tight, tight as you can get it. Then get inside it and see how that goes. (but caution! Too tight and you might break a RL, tear a hammock and/or rope/webbing, or stress a smaller tree.) Trial and error- there is a bunch of it around here. All kinds of experiments going on all the time. Experiment with various degree suspension tightness and let us know what you find. Plus,you will find what works for you. For most folks, starting with a 30* angle from the trees works pretty good.

[nothermark]

The first thing I noticed is he said 30 deg off vertical. The target is ~ 30 deg off horizontal. ;-)

Next thing is that as someone else pointed out it does not matter how long the suspension is as long as it is a 30 deg angle and the ends are high enough to keep off the ground the hammock portion of the arc will remain at the same angle. In fact we know we have to raise the tie points to the tree as the distance increases. Basic geometry.

It seems that since we all see the 30 deg off horizontal as a good place to be Goober is the one who needs to prove we are wrong, not the other way around.

[d_flo_yo]

The reason for the 30° hang angle (from horizontal) is that it minimizes the force on your suspension (and trees) to that of the body weight of the user. Refer to the chart below for further details

This is what I thought the 30 degree rule was about. The idea is that we are not subjecting our hammock suspension and hardware to forces outside of their ratings. Use a structural ridgeline to achieve your desired amount of sag every time. Even if, for some odd reason, you decided to hang with 0 degrees of sag your SRL will only allow the hammock to be stretched so far. This may have adverse effects on your equipment though.

My .02