Too much stretch (a whole 8"!!!)

[snarlbuckle]

I hung my hammock recently in the usual testing of new gear, and for once I had someone around to critique my setup. The trees were easily 20'-25' apart, and we noticed an excessive amount of stretch in the suspension. I measured each part of the suspension with and without load applied. The ~20' section of amsteel that I use as a continuous ridgeline had stretched almost 2" over the whole 20'. It was more than I expected, but didn't account for the extreme amount of drop we were experiencing. My homemade tree straps (1" poly webbing) had stretched 3-4" EACH. I calculated that under load, the netting was increasing in length by 1/6th of the original distance from tree to cordage. All together, we were getting roughly 8" of stretch, and it was mostly coming from the tree straps.

So my question to you hammock pros is this: What material can I use that is as abrasion resistant as tree straps, but also very stretch resistant? I'm open to using doubled up cordage because I have never seen any kind of mark left on a tree from people using that method.

[pgibson]

You say that your straps are poly....but which kind? Polyester or Polypro? Pro will stretch the first few uses and then not much after that. Polyester should have very little stretch.....The length of you hang is also going to put a lot of extra stress on the suspension which will lead to some un-natural stretching and sagging.

[WV]

One nice thing about using a MSH on tree straps is that you can put the toggle close to the tree, minimizing stretch of the straps. Wrapping the straps several times around smaller diameter trees will also shorten straps and enlist friction to help minimize stretch. 25 feet is a big distance between trees, testing the limits of the whole setup.

[BillyBob58]

Also, it always seemed to me that the how tight the suspension is adjusted is a factor. IOW, puling it real tight, in an attempt to stay high enough above the ground, always SEEMED to me to lead to even more sag upon loading. More than enough to become a net loss of distance above the ground. Anyway, that is what I remember, but it has been a long time since I pulled the ridge line really tight.

20-25 ft is a long stretch. I always found that the longer the distance between the trees, the further down I would sag towards the ground after loading. When I first got my HH, using my trees separated by ~21 ft , it was almost impossible to stay off the ground. The most helpful thing for me is to just get the tree huggers far enough up into the tree. Again, it has always seemed to me that the more angle between the tree and the hammock, the less sag after I get in. ( MORE angle? Is that right, or do I have terms it reversed? I mean the opposite of if you had things pulled tight towards a straight line tree to tree)

Of course, I am talking sag, you are talking stretch. This may not be the same. I guess I have had some stretch problems with some hammocks when first using them. For example, when I 1st used my JRB BMBH, it was nearly impossible to stay off the ground. This has polypropylene webbing. I never seem to have that problem anymore with this hammock. I also used to have the problems with the HH Explorer UL, but not after I slept in it a few times. Does that mean suspension/huggers and hammock stretched permanently thus no more problems? Maybe so. Or did I just learn how to hang them right? Not sure.

Some hammocks I have used have had much less sag problem right off the bat than others I have used. Number 1 in that category is the GrizzBridge( though a used one) with huggers and Amsteel, and a close 2nd is my Claytor No Net with, amazingly, stock nylon(I think maybe) webbing. These are among the very few hammocks that are real easy to use with my Vario hammock stand which itself flexes like crazy, making it hard to stay off the ground. But not with these hammocks. Does that mean that they stretch less than others?

But with any hammock, whether stretch or something else, the closer the trees, the easier to stay somewhere near where I started and off the ground. And if I can't get the trees close enough, next best thing is hang high in the tree rather than lower and tighter. Maybe the stretch will decrease with time.

[snarlbuckle]

I'm pretty sure the webbing I'm using is made of polypropylene. The extra stretch from the sheer length of the suspension should be entirely isolated to the amsteel, and I'm ok with that.

These polypro tree straps seem to retract when the load is removed from the hammock. It almost makes me think they were mislabeled at the store because they are behaving an awful lot like their nylon counterparts. That said, they have a very different texture and luster than the nylon straps I bought early on in the custom suspension project.

As a side note, the crazy amount of length is due to the design of the suspension. It has a continuous ridgeline that is made out of a single 25' strand of 1/8" amsteel. The ends of the ridgeline can then be pulled through a pair of rap rings on each tree strap to get the tension just right. The tree straps are each made out of an 8' length of 1" polypro webbing with water knots tied in each end, and a pair of rap rings in one of the loops. Once the strap has been slung around the tree, the rap rings go through the empty loop an the tree strap is loosely cinched down on the tree, which does a good job of holding it in place while I go about the rest of the setup process. While easy to setup, the straps unfortunately isolate most of the stretch on one length of webbing at each tree that can be up to 4' long.

Anyone have ideas for alternative materials for the tree straps? An alternate design might be helpful too, but I want to keep the rap rings and the ability of the straps to hug the tree without load applied.

Also, what is an MSH?

[BrianWillan]

MSH is Marlin Spike Hitch. It is commonly used in whoopie sling suspension as the method to attach the whoopie sling to the tree strap.

Do you have pictures of your setup. I'm having a hard time visualize your setup. Is it some sort of single line suspension setup?

Cheers

Brian

[snarlbuckle]

Here are a couple pictures of the part of my setup that is in question.

As a note, these pictures were taken months ago and there are a few changes.

1) when the amsteel ridgeline has been tensioned, a small knot is tied in the part that comes between the rap rings. This eliminates any possibility of slippage.

2) The trees in this picture are somewhat larger than the ones I am having so much stretch on. Any tree whose circumference is more than half the length of the strap will have this exact setup, and the ones on the smaller side of that spectrum will leave more extra webbing and therefore more stretch. The trees on which I am getting so much stretch happen to be right in that sweet spot.

Perhaps I should just sew loops every 8" or so on the side opposite of the rings? It would be significantly heavier, but I would eliminate much of the portion that is prone to stretching.

[Peter_pan]

Judging from those picture the stretch is not in the webbing but in the constriction of the loaded amsteel....

20-25 feet is an abnormally long span for routine hanging...It requires you to place the anchor points on the tree up at 8-9 feet off the ground...Any thing lower is an improper hang angle and to stretch a suspension tightly in hopes of not sagging to ground is to induce great force as your suspension adjusts from zero * down angle to 30* down angle when you get in....

It is these overly tight, straight line hangs that resulted in snapped ridge lines etc a few years back when the use of cinch bucles and descending rings as tensioners and not just convient adjustable buckles in a system was all the rage...

A fixed or "structural" ridgeline is not intended for straight lining a suspension.... It is intended for setting a constant distance between the hammock ends....From the tree anchor points to those hammock ends should still be at 30* down angles....When these principles are in use very little "stretch" occurs... and it is easily reduced to zero stretch as more normal hang distances of 13-15 feet are approached.

Pan

[snarlbuckle]

Judging from those picture the stretch is not in the webbing but in the constriction of the loaded amsteel....

20-25 feet is an abnormally long span for routine hanging...It requires you to place the anchor points on the tree up at 8-9 feet off the ground...Any thing lower is an improper hang angle and to stretch a suspension tightly in hopes of not sagging to ground is to induce great force as your suspension adjusts from zero * down angle to 30* down angle when you get in....

It is these overly tight, straight line hangs that resulted in snapped ridge lines etc a few years back when the use of cinch bucles and descending rings as tensioners and not just convient adjustable buckles in a system was all the rage...

A fixed or "structural" ridgeline is not intended for straight lining a suspension.... It is intended for setting a constant distance between the hammock ends....From the tree anchor points to those hammock ends should still be at 30* down angles....When these principles are in use very little "stretch" occurs... and it is easily reduced to zero stretch as more normal hang distances of 13-15 feet are approached.

Pan

Brilliant! I hadn't thought of the math involved in going from near 0 degrees to 30 degrees. Without load applied, the system would be almost perfectly horizontal. When the load is applied, tension would increase until an angle is reached at which there can be equilibrium. The problem isn't in the distance between the trees exactly, but that attempting a setup at such a distance often requires a very taught setup and THAT is what applies more tension than usual and will cause 'stretch' or 'sag'.

If I remember to do so this evening, I will set the system up again and measure everything I can think of. I'd like to see exactly what sort of angles I am working with and just how much tension I am putting on these lines that is making them stretch so much. I will hopefully post on this thread again tomorrow with some updates.

[Roadrunnr72]

Judging from those picture the stretch is not in the webbing but in the constriction of the loaded amsteel....

20-25 feet is an abnormally long span for routine hanging...It requires you to place the anchor points on the tree up at 8-9 feet off the ground...Any thing lower is an improper hang angle and to stretch a suspension tightly in hopes of not sagging to ground is to induce great force as your suspension adjusts from zero * down angle to 30* down angle when you get in....

It is these overly tight, straight line hangs that resulted in snapped ridge lines etc a few years back when the use of cinch bucles and descending rings as tensioners and not just convient adjustable buckles in a system was all the rage...

A fixed or "structural" ridgeline is not intended for straight lining a suspension.... It is intended for setting a constant distance between the hammock ends....From the tree anchor points to those hammock ends should still be at 30* down angles....When these principles are in use very little "stretch" occurs... and it is easily reduced to zero stretch as more normal hang distances of 13-15 feet are approached.

Pan

When the OP mentioned the Amsteel stretching, the first thing that came to mind was that it was constricting, which would make it seem like it stretched. But for only 2" if 20 ft, that sounds pretty good.

And when he said that the trees were 25' apart, I was wondering how high he would have to hang the straps. So I went to the Hammack Hang Calculator and punched it the numbers. Pan is right, about 9' high.

? to the OP, how do you carry that extention ladder with you to reach your straps?