because mice, i happen to quite like
in my quest for the ultimate hammock system (made possible and sped up mainly by the great information on here, on hammock forums), i ended up, uhm, changing a few things. yeah, again.
the whole setup is now basically ready, but before i find the time to put it all together in a "presentable" manner, i try to document bits and pieces that make it up, for people who might find them useful.
this time, i'll focus on the anchor points: the tree straps.
i'll try to first summarize what this "fixes" and why it's worth considering, and leave most of the development process aside
in short: all else being equal, this does two things: it halves the ammount of webbing needed, and provides an anchor point for the tarp ridgeline too (but more detailed explanation below)
a closeup of the rigging point
IMG_20200807_203133.jpg
and with everything setup, levitating tarp included
IMG_20200807_203213.jpg
first, this shows how the tree strap goes on the tree (under 30s):
this shows how the tarp ridgeline connects to it, and tightens (under 1 minute)
now for the boring explanations
the priorities are:
- maximum protection for the trees, given a certain width of strap used (nearly double protection with this method)
- better use of strap load capacity (to reduce the chance of failure because of wear, overload etc) (nearly double compared to usual method)
- better use of strap length to cover different tree sizes (you need about half the length for the same size tree. yeah, doble again, getting predictable)
- use of the same straps for both tarp ridgeline and main hammock suspension, easily. it's about twice as easy.. okay, joking.
- ease of use (i guess that's arguable, but if bundling the tarp anchor it does make it overall easier, without using it for the tarp is maybe a little bit more involved than normal tree straps, though imho still worth it)
what i didn't spare/improve:
- these are a bit harder to prepare/make at home, for the first time (so manufacturing is not easier)
- while easy to use, they are harder to understand at first glance (there's a learning curve, although a short one)
useage procedure (see video)
- adjust the friction hitches on the webbing to span about half the circumference of the tree. by "about" i mean very roughly speaking, it's not critical (in the video there was even no need for that, so i kept it short)
- throw the strap around the tree and catch the other end
- grab the button knot of the shackle and close it on the friction hitch that waits on the other side of the strap
- pull the cinch line reasonably tight (just one movement, no need to be neat); now the strap will stay where it was placed, and queietly wait for further instructions.
the basic design is as follows:
the tree strap goes around the tree and is loaded on both ends equally, this is the main design goal, and here's why: the current way we use tree straps (basically girth hitching the strap to the tree, by use of the fixed loop on one end of the strap), it means that all the load is transferred to the tree by the strap on one side, and is basically concentrated on the side of the tree where the active (loaded) end of the tree strap is. the tension along the strap will reduce due to friction on the tree trunk until it reaches nearly 0 (how soon that happens depends on the friction on the tree bark, but it will be before reaching fully behind the tree in most cases). this means that at least half of the length of strap is in fact useless to distribute the load.
by loading both ends, we nearly double the amount of strap used to distribute the load on the tree, or you could think of using two straps in parallel each taking half of the load, either way, the pressure on the tree surface is half what it would be by using the same strap in the usual way. so it's like instantly doubling the width of your strap, without any added weight (and you can do this right away with your existing tree straps if you want to test it for yourself, i'll explain in a bit how). this also means the load on the strap is halved, which means that, while it doesn't provide redundancy -- as it is still one strap -- it does reduce the likelihood of failure, by putting half the load on the strap; this i find quite important, as, although the straps we use should be rated for far above the expected loads, that capacity reduces drastically as they wear, sometimes not in ways which are obvious); but it gets even better:
as we're not girth hitching to the tree any more, there is no strangling action on the tree, all the load is on the "supporting" side of the tree (opposite the hammock) where it belongs. the side towards the hammock doesn't even touch the tree any more, so doesn't need to be webbing, it can be a dyneema dogbone, so you can have the same 1.5m/4ft strap, add a few grams of dyneema dogbone (about 2m/6ft say), and you can handle a tree nearly 1m/3ft in diameter, while doing less damage to the tree than before.
and if that's not enough, providing the anchor point for the tarp ridgeline means that there's no risk of damaging the tree with the ridgeline, as now the load is handled by the same tree strap as the hammock -- and the risk is there, if you calculate the pressure on the tree bark you will see it -- and also allows for saving some ridgeline length, as there's no need to go all the way around the tree any more (that makes a significant difference with big trees).
it is very easy to retro-fit an existing treestrap to make it suitable for this setup, so no need to buy yet-more-gear (which is why people like me will never be rich)
let me know what you think. does it seem a bit too complicated? is it worth the trouble?
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