Five Basic Principles of Going Lighter (not me... the great Cam Honan of OZ)
“If everybody is thinking alike, then somebody isn't thinking.” ~ Gen. George S Patton
Not sure that I do, however if one is worried about strap pressure on the tree there's less of it with the V than there is when a knot, Evo loop or other hardware is cinched right up to the tree.
The corollary is one that we all know and love, that the relaxed 30° suspension angle puts much less stress on the straps than a 10° angle.
Five Basic Principles of Going Lighter (not me... the great Cam Honan of OZ)
“If everybody is thinking alike, then somebody isn't thinking.” ~ Gen. George S Patton
The idea of the V in the tarp line was the hammock line could go between the V and center the hammock along the tarp ridgeline. BUT … now-a-days people see the (slight) benefit of bring their suspension off the side of the tree rather than the middle. Also, with a V starting at the end of the tarp, there isn’t space to scrunch any snakeskins. That could be solved by adding a short dogbone extension to the tarp. The skin can slide to that extension and the suspension V (split lines) can attach to the dogbone instead of the tarp. I don’t use split a split ridgeline so those are not issues for me. Every setup is a compromise with its own challenges/issues.
The benefit of the double tree wrap for the hammock is it doesn’t slip. The problem of the double tree wrap is it doesn’t slip. Unless you get the height just right on the first shot - doesn’t happen to me - there is usually some slight height adjustment to get it baby bear right. For me, that means one wrap AND some kind of disconnect - either a DutchClip or Evo Loop.
If you are worried about hurting the tree bark and so consider a double wrap, you could put a few vertical twigs between the strap and the tree instead. Or look for a different trees. When my straps look at the bark on Doug Fir and Ponderosa Pine, the straps shudder.
I”m guessing you’ve set up your hammock a few times and when you first get into it, there might be an initial slippage. It happens. But I’ve never had it lower me all the way to the ground. It just means I didn’t cinch the strap tight enough on the tree (and maybe keep a little tension on it) when I set up the hammock.
If I used the same hammock every time, and I could always choose trees that were mostly the same distance, then I’d know just the tree attachment height I’d need and might consider a double wrap. But that would be more the use up some extra suspension line so there is less to tidy up. Mostly a single wrap, cinched tight, does the job and yet allows me to easily loosen it when necessary for a refinement.
These are trees at Ozette Lake in the northwest corner of Washington - accessible only by watercraft. Good thing I brought my 15 ft straps. I didn't double wrap.
OzetteTree.jpg
Last edited by cougarmeat; 09-14-2021 at 19:22.
In order to see what few have seen, you must go where few have gone. And DO what few have done.
95% of the time, I make one wrap around the tree. I don't remember what I do the other half the time.
I have to say I am a bit confused why the V is good for the tree. I can see why it might be good for the force on the strap itself and might help with wear on stitching. But for force on the tree it has to be similar. Not saying you are wrong.
Sounds like most single wrap. Double wrap if you think you need it for anchor or if the bark is thin. My two wrap minimum is probably excessive.
Side note - If people really want to go in to the force on the tree conversation maybe we could start a separate thread as to the variables of interest. I actually am an engineer (microfluidics). And while I do not do FEA (finite element analysis) myself I work with the modeling team at my work pretty closely and bet I could get them to do some runs if the input file was relatively straight forward (I can help there or be pathetic enough they will bail me out). But I suspect it is pretty simple. I could make some free body diagrams if people want a simplified view of where forces are. But I could also probably get some super fancy color images of the modeled forces if there is a ‘clean’ experiment of interest. Though I think block and tackle with some frictional losses probably explains the system pretty well. I bet the rest of interest would be localized stress concentrations. And maybe there the V matters.
Empirically, perhaps one could make a rough, direct measurement using a luggage scale to tug the straps right where they contact the tree. With somebody in the hammock, of course. Which would require me to find someone almost as insane as I to assist.
The more I ponder it, however, the less inclined I am to be worried about it unless using marginally rated straps.
I suppose your professional colleagues have some simple formula to calculate actual number. In my little doodle below, assume that the hang angle in both cases is a perfect 30° and that the tree is 1 foot diameter.
Five Basic Principles of Going Lighter (not me... the great Cam Honan of OZ)
“If everybody is thinking alike, then somebody isn't thinking.” ~ Gen. George S Patton
I've read about this technique and have used it a couple of times when I had to use an Amsteel dog bone to extend the strap. Not sure how much good it does, but the same thing can be done with the suspension webbing as well. Or maybe it makes things worse by concentrating the force in a smaller area? Some things seem to be logical but do not stand up to rigid analysis.
Five Basic Principles of Going Lighter (not me... the great Cam Honan of OZ)
“If everybody is thinking alike, then somebody isn't thinking.” ~ Gen. George S Patton
Probably just the area where I camp, but many trees here in the PNW, despite being huge have delicate bark. It’s easy to pull bark off when removing the straps.
I generally have a ton more strap length than needed anyhow, so wrapping many times around just seems like the courteous thing to do for the tree.
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