Structural Ridgelines & Tree Strap Safety

[FlyingAvocado]

Hello! I recently went out on my first weekend hammock camping trip, and I learned a lot and had a great nights sleep (the second night anyway.) After I came home I started searching around and learned that some hammocks have structural ridge-lines, so I decided to add one to my hammock using 7/64" AmSteel. I tried it out this weekend and there are a few things I am curious about.

I've watched a few videos where people have indicated that the structural ridgeline should have just enough slack to be able to give it a slight tug/twist. However, I also have seen some people say that a structural ridgeline makes it possible to not care about the hang angle of the suspension and be able to put near zero angle on the suspension and still get a comfortable hang, but my intuition tells me that this could be dangerous because I have read that the angle of the suspension also reduces the amount of sheer force on the trees. If my intuition is correct, should I be using my structural ridge-line more as reference to help ensure I put the straps at a correct height for a proper hang?

On the subject of suspension safety... I live in Southern California and throughout the state we have a serious issue with bark beetles destroying trees. Aside from avoiding infected trees, I am wondering what the best method is to prevent cross-contamination via tree straps. Is treating tree-straps with permethrin safe/effective for bark beetles, or does that potentially harm "good bugs" in the trees? What methods do you folks recommend?

Thanks!

[Phantom Grappler]

You’re right, tension on hammock ridgeline and angle of hang (of suspension-tree straps etc.) are interrelated.
A good starting point for length of hammock ridgeline is to multiply length of hammock in inches by .83
Derek Hansen’s book The Ultimate Hang: An Illustrated Guide to Hammock Camping, has a chart listing real forces on hammock, straps, suspension, corresponding to different hang angles.
There is no need to be perfect. Try to get around a 30* angle of hang for your hammock suspension.

Mainly do not have a flat-horizontal suspension!
Forces in pounds will be multiples of your body weight on each end.
This can cause hammock to break or rip in two
And/or it can snap you suspension and tree strap

Dropping you onto the hard ground

Things can be worse—your tree can snap from those forces and fall on top of your snoozing carcass

That said, I also have an amsteel hammock ridgeline and usually when I’m in hammock, that hammock ridgeline is pretty tight.
When your hammock suspension is at a 30* angle, the forces are your body weight on each end of your hammock.

My angle of hang is usually a bit more shallow than 30*
But, I never have a flat-horizontal angle of hang.

Good luck

If I got paid to tell lies
It just wouldn’t be as much fun

[cougarmeat]

FlyingAvocado, welcome to the forum. And congratulation on your research on Structural Ridge Line. You Got It! Yes, it allows for a less than ideal hang angle - if shallower, not deeper. And yes, it is better if you just use the snugness to measure, "... just about right ..." rather than have it tight enough to play a guitar cord.

Sorry - I don't know about the beetle issue. If they are large enough to see, then for that issue just a visual inspection might be enough.

However, you could have other things crawling down that line. Here is an alternative to permethrin some members use:

https://www.youtube.com/watch?v=mJZZNHekEQw
About 1 minute to 1:30 in

[SilvrSurfr]

On the subject of suspension safety... I live in Southern California and throughout the state we have a serious issue with bark beetles destroying trees. Aside from avoiding infected trees, I am wondering what the best method is to prevent cross-contamination via tree straps. Is treating tree-straps with permethrin safe/effective for bark beetles, or does that potentially harm "good bugs" in the trees? What methods do you folks recommend?

Bark beetles don't live on the bark; they burrow underneath the bark. Imagine two bark beetles burrowed underneath the bark, when they hear something:

"Hey Vinny, did you hear that? I think it's a hammock tree strap."

"Really, Joey? Let's burrow back out of the bark and jump on that tree strap so we can cross-contaminate another tree!"

"Let's do it Vinny. Bada bing bada boom!"

Sorry, but I don't think you have to worry about "cross-contaminating" trees with tree straps. Bark beetles are a serious problem, but I seriously doubt they're using tree straps as a vehicle for cross-contaminating (but it would be a sign of pure evolutionary genius, or insanity, for bark beetles to stake their future on tree straps). And even if that were a problem, its impact would be so minimal as to be non-existent. But you do you!

And why would a bark beetle want to jump on a polyester tree strap? Maybe there's enough tree sap to sustain them for a day or two, but what if the owner of said tree strap doesn't go camping for another month or two? What's a bark beetle to do?

[WV]

When discussions about the forces on a hammock suspension with a true structural ridgeline come up, I always look back to the great work that Youngblood did, starting on Ed Speer's hammock forum and continuing here, but I've just been searching HF again, and I'd like to add Warbonnetguy to the short list of people with reliable opinions. Brandon adds practical experience to the theoretical logic, noting that you can't pull a suspension tight enough by hand to generate the huge forces that alarmists predict with a 5 or 10 degree angle from the tree once you get in the hammock. I once hung between trees almost 30 feet apart, and tried to pull the main suspension flat. It looked like I got less than 5 degrees, but when I got in the hammock, someone measured the angle and it had dropped to 15 degrees. In practical terms, that means you could maybe double the force on the main suspension lines (and the trees), but not more than that. I still wouldn't hang that tight on a whim, though. (Your structural ridgeline will be taut at any angle less than 30 degrees if that's how your hammock is set up, but that's okay if the ridgeline is just as strong as the hammock lines. It's line from the hammock suspension and ridgeline to the tree that handles greater forces.) Here's one of Brandon's posts, touching on that.
https://www.hammockforums.net/forum/...ll=1#post93779
What about twisting a ridgeline 90 degrees? That's a useful test for a ridgeline that serves as an indicator, not a structural ridgeline.

[Phantom Grappler]

WV, what you describe might be closer to reality than what I had parroted.
Double the stresses on suspension rather than multiples of those stresses on suspension could be a more accurate description of what is happening.

We have your observation of your hammock with trees 30 feet apart, coupled with a nearly flat-horizontal suspension angle.
And I’ve seen many hammocks in campgrounds strung bowstring tight between two trees.
Those hammocks probably were not used for sleeping overnight. There was no insulation-quilts etc., and no tarps
But they were probably loaded at least once.
Someone probably got in those hammocks at least once——-and they did not rip, suspensions did not snap, and trees did not fall over.

However, if there were any failures, I would not have seen them as I walked through campgrounds.

When you first got in your strung tight hammock, could the initial forces on your ridgeline have been in the multiples of your body weight? And then when your hammock suspension sagged lower to a 15* suspension—could those forces been reduced as your hammock sagged lower?

I don’t know
It’s interesting

Maybe there are instruments or gauges that can measure actual stresses on hammock suspensions.

Measuring and testing might show us exactly what is happening at various hang angles.

WV, I hope to see you at Grayson Hang this fall.

[cmoulder]

I concur with the above wrt structural ridgeline tension.

Mine almost always end up a little — and sometimes a lot — tighter than what is frequently suggested for passing the "ideal" SRL twist test.

While it is a good indicator and a useful tool, IMO it unnecessarily frustrates a lot of new hangers who are under the impression is has to be "just so" or it's not right. Combined with correct sit height, head/foot height, centering (which is also fungible) and compensating for tree distance and webbing stretch... wow, that's a lot elements to put together for folks with little or no experience.

At least the number of questions on this topic on HF suggests that.

Bark beetles I don't know about but I doubt that spreading them from one tree to another via hammock webbing is a problem.

[Recalc]

(Your structural ridgeline will be taut at any angle less than 30 degrees if that's how your hammock is set up, but that's okay if the ridgeline is just as strong as the hammock lines. It's line from the hammock suspension and ridgeline to the tree that handles greater forces.) Here's one of Brandon's posts, touching on that.
https://www.hammockforums.net/forum/...ll=1#post93779
What about twisting a ridgeline 90 degrees? That's a useful test for a ridgeline that serves as an indicator, not a structural ridgeline.

Appreciate the practicality of this thread. Would this mean a Zing-It structural ridgeline is not robust enough for trees 20 feet apart?

[Shug]

Some hammock and ridgeline intel offered up.......
Shug

[cmoulder]

Appreciate the practicality of this thread. Would this mean a Zing-It structural ridgeline is not robust enough for trees 20 feet apart?

Good point. I have some hammocks (Half Wit and Chameleon) with Zing-it SRLs and am a bit more careful with them because of the 400lb break strength, which is not hard to exceed with dynamic loading such as plopping down on the hammock. 7/64" Amsteel @1500lb rating or Dynaglide 2.2mm... not so much.