Let me understand this...if my caribiner says it is rated 350lbs....that is not really what it means? So....hypothetically speaking.....total hypothetical here...lets pretend for a moment that I am 200lbs, I need to be looking at things that are rated at least 800 lbs at the bare minimum? On everything having to do with suspension? And then if I want to be really safe, I'd multiply that by 10 and have to find things that support 2000 lbs?
I had hardware chain loops distort shape at 350# rating. I don't recommend anything but a climbing rated biner _unless_ it is purchased from a reputable hammock knowledgeable source. I think Treklight and ENO both use biners on their products. Not sure what they are rated for but I don't think they are climbing rated. And of course the Dutch clip. I'd be comfortable with those and good hanging technique. But anything else from the hardware store and such.... be careful.
For hammocking, I would not go with a factor of 10. As opie said earlier in the thread, a factor of 4 would do you well. So if something says breaking strength of 350lbs, then divide that by 4 to figure a safe working load. It's not official but not a bad rule of thumb to follow for personal safety.Originally Posted by DivaB
Don't let life get in the way of living.
Hardware store 'biners are for bird feeders. Small ones.
Dave
"Loneliness is the poverty of self; solitude is the richness of self."~~~May Sarton
No, that is really what it means, ... with a big "BUT." That "but" is that your static weight, measured 90 degrees above a bathroom scale, does NOT equate to your weight in a hammock. Try jumping up and down on the scales and see what it reads. That's "dynamic" weight (real life, in other words) and not "static" weight (static is the way carabiners and ropes are tested).
Next, factor in the physics of the hang, as was mentioned by the OP. The angle at which you hang your hammock can increased your real ("effective") weight by multiples.
Then of course you have to factor in how knots, d-rings, carabiners, etc., can reduce the effective strength of your rope. It can be over half with some knots and sharp bends.
What gets me is how some folks will risk their backbones over a few micrograms of line weight.
That is, it's not just a risk analysis, it's a cost analysis too, on both ends. Speaking of line, exactly how much pack weight is saved by halving the safety rating of my line or gear? How much does it "cost" me to haul an extra gram over a mountain? Nothing. How much extra safety does it give me? A lot. The wise decision is a no-brainer, IMHO.
YMMV. HYOH.
Rain Man
.
"You can stand tall without standing on someone. You can be a victor without having victims." --Harriet Woods
http://www.MeetUp.com/NashvilleBackpacker
.
Well, heck, I've got some hardware I need to take back! Thought for sure 350 lb carabiners on each end made it like 700 lbs safe. Then there was the thought process that 1/2 my weight on each hammock end still kept me well under the 350 lbs load limit which made them super safe. Don't even ask how I came about either of those figures. It is just embarrassing at this point. Glad I don't have a hammock yet and about killed myself! Stupid newbies! (that was to myself...not other newbies) Glad I read this thread. You all saved me!! I obviously have a lot more I need to learn....yet, and this was a huge one to learn and one I do not want to mess up!! I just want to get out there and hang!
No worries DivaB. We are all still learning every day.
At 30 degrees (the angle from your hammock to the attachment point on the tree), the amount of force exerted on each end of the suspension is approximately equivalent to your weight. So if you weigh 200lbs, at 30 degrees, each end is supporting 200lbs. As the suspension gets closer to horizontal, the amount of force increases exponentially. At 15 degrees it jumps up to about 386lbs on each end. At 10 degrees it is about 575lbs per end.
Don't let life get in the way of living.
I bought some of the Treklight biners, and they seem to be the same as the ones you can get from the Hammock Forums store, DIY gear supply etc. They are rated at 500 kg (1100 lbs) and no, not for climbing. But if you're only going to be 1 or 2 feet off the ground then it's perfectly fine. I've had suspension fail on me back when I used to use knots instead of Whoopies. It's a little embarrassing and you might get a bit of a bruise, but seriously, it's not like your life is on the line in a hammock. I would go with a safety factor of 3 or 4, although in practice it's usually more since I'm pretty light. I would understand the factor of 10 if it's for leisure in the backyard where kids might jump around in it, but for hiking it's just me and I'm careful with my gear.
Edit: also, while a smaller hanging angle is definitely going to increase the force on the lines, I've never been able to get it lower than 20 or 30 degrees (estimated). Even if you tie it as tight as you can, your weight will stretch the hammock and lines enough to increase the angle. If the trees are further apart, yes you will have to tie the suspension higher, but only because you will end up on the ground from the extra stretch if you don't.
Last edited by agrajag; 06-28-2011 at 00:04. Reason: more info
is the QC in the manufacturing process.
Climbing and Life Safety rated gear is EXTENSIVELY documented, from raw materials to fabrication steps to lot testing, and sub-standard items never see the light of day. Makes me feel all warm and fuzzy inside when I hang!
The "key chain" 'biners are spit out of third world factories with none of the QC mentioned. Some will hold a specified weight, some will fail at ridiculously low figures.
Some of our cottage industries sell lighter than life-safety rated 'biners, but I believe they do their own testing and I would use them, but I are a "heavy hanger" and I like the safety factor available with the good stuff.
I think that the message here is "Don't buy your 'biners as an add-on purchase while checking out at Office Depot or Dollar General!"
Jim
Because I use a structural ridgeline, I don't worry about setting up a 30 degree sag. In fact, in most situations, since a few of the islands I camp on regularly have trees spaced widely apart, I have to pull the whoopies really tight so that before I get into the hammock there is barely any sag at all. That keeps me from bumping into the ground when I get into the hammock. I don't have a ladder to climb up on to hang the suspension really high between far-apart trees. And I want my tarp high above the hammock. So I put the tree straps around 5 feet high and pull my whoopies really tight and let my structural ridge line give me the right sag in the hammock. I'm using the thinner, lower weight limit, variety of whoopies since I weigh just 155. Am I courting disaster? I'm hanging in a Grand Trunk Nano 7 if that matters.
Posting Permissions
Reply With Quote
Bookmarks