Random thoughts: a case for smaller tree straps?

[MDSH]

I've seen this and I think that it's a product of two things: the friction of the tree will put more of the load there because it isn't a perfect world and the load isn't getting transferred the same all around, and the strap system generally constricts around that point so that the full width of the strap isn't there, it is smaller and mostly edge is against the tree like MDSH is talking about. To combat this you can put a sacrificial stick in that point as long as the stick isn't too soft so that the tree strap digs into it and breaks it.

A sacrificial stick -- what a great idea!

A 30* tapered stick on the back side of the tree would distribute the angled load for as long as the stick might be.

In fact, one could cut a 30* notch in a stick. Any wound left on the tree would be with the grain and not a perpendicular break in the natural flow of sap in the cambium.

I love this forum -- learning so much!

[dejoha]

Very, very interesting Sgt.Rock. Thank you for posting. Sometimes there are revelations in hammock camping that turn us on our heads. This is one. As HappyCamper stated, it's all about the science/math. I wish I were better at it!

I'm really curious about this because it could mean some "situational hammock ethics" when it comes to hammock suspension. On one hand, you have the AngrySparrow argument that stipulates a clear black-and-white model: practice and preach a method that can be easily recognized and reproduced. On the other hand we have situational analysis that says, "well, if you use _this_ suspension, you need to do it in _this_ fashion. If you use this _other_ suspension, you do it in _this_ way."

This reminds me of home rules vs. grandma rules. Some parents prefer their kids obey the same set of "home rules" when at grandma's house, while others don't mind the "when in rome..." mantra. A psychologist told me that it doesn't confuse kids to have two sets of rule books (e.g., home vs. grandma). I'm curious if the same could be true with hammock camping.

As I write this, I'm reflecting on my book on hammock camping. I could see me updating the book to explain this variance and diagram the correct method for thick vs. thin straps (or even rope, if the situation called for it). I think there is a case for supporting the science.

There may be a point in bringing up the "Florida State Park" argument, but I wonder if that's necessary. Let's say Florida accepts hammocks so long as they use webbing straps. That doesn't negate the validity of the science behind "small strap/rope = multiple wraps" technique, it just means "time-place-manner" if that makes sense.

I will defend the stance that webbing offers a clear _perception_ of protection, regardless of wether it turns out true that multiple turns of a rope has equal or less damage to a tree than webbing. It's easier to see and explain webbing than going into the force calculations if using small webbing or rope.

[dejoha]

This makes me feel more comfortable about my tests with the Toggle Rope.

> http://www.hammockforums.net/forum/s...ad.php?t=57085

The braided rope is 1/2 inch (1.3 cm) wide when taut, so I can presume it will follow the same calculations Sgt. Rock has laid out.

[Gredemeer]

like the discussion, also glad you have weathered the storm, though I am quite certain it is not over. Look forward to another group hang, enjoyed the slick rock group.

[SGT Rock]

Gredemeer, you were using mule tape weren't you?

[XTrekker]

Sgt. Rock I have a basic understanding of what you are talking about. And while you are probably theoretically correct on the math, I think there is one issue missing. While your math indicates the full length of the strap and the pressure spread out amongst the full length, I believe that you will not get equal pressure the full length due to friction. So you would still have a greater psi on the 1/2" strap initially no matter how many times you wrap the 1/2" around the tree then you would with the 1" strap.

I'm gonna have to agree with NightHauk. There is SO much friction as the strap wraps around the tree so the load is gonna mainly on one side. Unless you are some how able to put 200lbs of force on that strap as you wrap it around the tree, your not going to see equal load distribution. Unless that tree's bark is polished, load distribution will get worse for each additional wrap. Ill bet it comes close to equaling out between the 2 different types of straps for lbs/sq"

Side note: As that strap gets taught its gonna tear "laterally" along the bark, because of this I never double wrap trees. I noticed some damage done to the bark of an oak tree once when I did that and ever since I have kept to only single wraps. I will admit the straps we Nylon and that is probably the reason for the damage because the nylon stretched and ate away are the bark. As far as the damage done to the bark actually hurting the tree? Well, that's a whole other topic in it-self.

[Redoleary]

For arguments sake & from the tree's point of view: aren't you basically doing half as much damage over twice the area,if the straps aren't overlapped? OTOH maybe thats the difference between bruised and broken as far as the tree's vascular system is concerned? Personally I carry 12'x1" straps and multi wrap on small diameter trees; I've always assumed it was better but never really tried to prove it.

[SGT Rock]

Last night I slept up at campsite 30 in the Smokies. I did the multi-wrap thing with my 1" straps (as usual) and when I got home my mule tape order was here, so I made a set of straps to experiment with.

[MDSH]

If one were to do thermal imaging as you climbed in the hammock, loading the straps, there would be two hot spots: where the strap gripped the tree immediately upstream from the dutch on both sides. The wraps are not much help. If it was a greased pole multiple wraps would help but not on a surface as rough as tree bark.

A wrap might help to keep the strap in place while you set up but that function is served by any strap that is run through a loop because the free end is brought into contact with the rough surface of the bark.

[SGT Rock]

Possibly. I've decided the best way to test this is to get a fish scale that I can slide under the strap, then test how much effort it takes to lift the strap from the tree when under load with a volunteer to act as the sleeper.