View Full Version : Walmart Carabiners on a Hennessy Hammock
http://www.youtube.com/watch?v=XrBjKbCH-7I
Fast forward to 0:27 to see a kid with no remaining dignity.
OMG!! Unbelievable!!!!!!!!
I am going to confess, right here and right now - in front of God and everybody....
I did EXACTLY the same thing with a Wal-Mart carabiner on the FT this weekend.
Do you think I'm not glad no one was there to see it?
I ordered some nano carabiners but they're in UPS-Limbo. I was impatient and making videos explaining to my family what the hell I do out in the woods.
I happened to catch this magical moment, which won't make the final cut. But I figure I'd let you guys see me make an ass of myself.
Rain Man
03-09-2010, 14:49
Maybe you are, but if not, you two need to be on Hammock Forums "educating" numbskulls there who continually are clueless about the physics of forces on horizontal riggings.
Glad no one was hurt!
Rain:sunMan
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JustaTouron
03-09-2010, 15:01
Walmart carbiners are great for key chains, securing waterbottle to pack, bear bagging. Rock climbing, hammock hanging or anyother time you are secure yourself vertically....not so good.
Better go to REI or MEC or someplace that has a clue and learn what 'biners are all about before trusting them with your life, or your thick skull. Also note that the forces in a hammock hang are about 2 - 4 times greater than the supported weight. Depends on the hang angle: flatter means more force. Completely flat means nothing will support that force = infinite. Vertical means just the simple weight (1X). If the angle of the rope at the tree is about 30* from horizontal, the force is about doubled. You have to have rope that will stand twice the supported weight. If you try to hang flatter than this, the force will rise fast. But luckily, it will stretch out the ropes and fabric so things will hang lower anyway. Not good for the hammock, or rigging, or the trees. The same goes for the biners. What you need are proper technical biners rated for your weight. Since you are not doing fixed protection on the face of the Eiger, you don't need special locking gates or anything fancy. Just good 'biners rated for human support. Equipment 'biners are not suitable under any conditions. They are meant for holding stuff for packing. Or for key chains.
Glad you didn't break anything more than your pride, and the dumb WalMart 'biner.
Better go to REI or MEC or someplace that has a clue and learn what 'biners are all about before trusting them with your life, or your thick skull. Also note that the forces in a hammock hang are about 2 - 4 times greater than the supported weight. Depends on the hang angle: flatter means more force. Completely flat means nothing will support that force = infinite. Vertical means just the simple weight (1X). If the angle of the rope at the tree is about 30* from horizontal, the force is about doubled. You have to have rope that will stand twice the supported weight. If you try to hang flatter than this, the force will rise fast. But luckily, it will stretch out the ropes and fabric so things will hang lower anyway. Not good for the hammock, or rigging, or the trees. The same goes for the biners. What you need are proper technical biners rated for your weight. Since you are not doing fixed protection on the face of the Eiger, you don't need special locking gates or anything fancy. Just good 'biners rated for human support. Equipment 'biners are not suitable under any conditions. They are meant for holding stuff for packing. Or for key chains.
Glad you didn't break anything more than your pride, and the dumb WalMart 'biner.
I said in the 3rd post that I already have Nano Biners on the way but that I got impatient :-P I knew this stood a high chance of failure (and actually, the walmart biners had supported me in the past, but I guess the tensioning was different this time, and I had a bigger breakfast
And I really was clueless and thought they would work. Shows what I know..
I have since been educated and it will not happen again.
Is knot tying a lost art?
beakerman
03-09-2010, 17:12
Is knot tying a lost art?
seems likely to me that it is...
JustaTouron
03-09-2010, 18:24
And I really was clueless and thought they would work. Shows what I know..
I have since been educated and it will not happen again.
Was that not in the instructions?
If not, IMHO, the hammock sellers ought have a warning in the instuctions to buy climbing grade and not key chain grade carabiners.
Just my two cents.
scottdennis
03-09-2010, 18:53
Don't those Wal Mart biners say "NOT FOR SUPPORTING WEIGHT" all over them? I don't even trust hanging my gear with that stuff. But I rappel and rock climb so usually have the real deal with me anyway.
Get you some 50Kn biners and you'll be good to go! ;) LOL!
JustaTouron
03-09-2010, 18:58
Don't those Wal Mart biners say "NOT FOR SUPPORTING WEIGHT" all over them? I don't even trust hanging my gear with that stuff. But I rappel and rock climb so usually have the real deal with me anyway.
Some do...some don't. I got two really crappy ones that came with a really cheap backpack that aren't labeled that way. And the other ones, say "not for climbing use" which should probably clue you not for hamacks either.
Was that not in the instructions?
If not, IMHO, the hammock sellers ought have a warning in the instuctions to buy climbing grade and not key chain grade carabiners.
Just my two cents.
to the best of my knowledge, the hammock instructions don't mention that you even CAN use biners for hanging... and some things just go without saying... this is one of them. stuff like this keeps lawyers employed...
climber2377
03-09-2010, 20:58
they dont say to use caribeaners, its a lashing through the webbing strap.
Is knot tying a lost art?
I'm sure it isn't. Carabiners make good drip rings, and they make it easy (for me, at least) to put my sleeping bag over my hammock.
Just because:
I use simple tiedown straps with a spring loaded buckle from Lowe's to hang my hammock (with the carabiners). They are rated at "100 lbs. max". I weigh 220. No problems in the past 6 uses (all over soft ground just in case).
So, according to the physics, if the rating on the webbing is correct, I'm in violation of some sort of logical "law". ?? Hmmm......
JustaTouron
03-09-2010, 21:08
to the best of my knowledge, the hammock instructions don't mention that you even CAN use biners for hanging... and some things just go without saying... this is one of them. stuff like this keeps lawyers employed...
I have a jar of peanut butter that has a warning telling me it may contain nuts. My iron has a warning telling me not to iron my clothes while wearing them. The hair drying has a warning not use while in the tub.
I would dare say a recommendation regarding using climbing grade biners is no more obvious.
Just because:
I use simple tiedown straps with a spring loaded buckle from Lowe's to hang my hammock (with the carabiners). They are rated at "100 lbs. max". I weigh 220. No problems in the past 6 uses (all over soft ground just in case).
So, according to the physics, if the rating on the webbing is correct, I'm in violation of some sort of logical "law". ?? Hmmm......
No, not a law. Just at risk of catastrophic failure someday. There are many ways to rate the safe load on a rope or tackle. Usually, this is an overproof system of some sort, meaning that the gear is tested to failure some number of times, and then the lowest failure, or some statistical measure of the tests is used to determine a most probable failure rating, and the recommendation is set at some fraction of that, perhaps 50% or less. In climbing gear ratings, and safety gear, this determination is very conservative, meaning that the risk of failure at the rated stress is very low, and overstressed gear is not expected to fail at several times the rated stress. However, gear, especially ropes, which has been loaded to over proof stress is then derated. So old ropes are not used for primary protection after an event like a fall or abrasive use. However, hammock hanging rigging is not ordinarily subject to kinetic loads (as in arresting a fall), and the most probable overload failure would come as a result of abrasion of the woven jacket, or fibre breakage at knots and bends. So a hammock rig is probably safe at more than the rated stress of climbing harness, for example. It would be quite reasonable to use old climbing rope in a hammock rig. But if the hammock rig shows signs of abrasion or fibre breakage, it is probably time to replace it.
Your 100# tie downs supporting you at 220# means that half your weight is supported at each end, times 2 for the angle of hang = 220# at each end. The strap also has an angle of stress multiplier of maybe 2X. That means we're up to maybe 440# stress on the webbing, but there are two legs to the webbing support, so back to 220# stress. That is a rough estimate of the load, so you are maybe 120% overloaded for that material, depending on the exact angles, loads, etc, and considering the extra stress at the buckles, knots or loop terminations. I don't know what the standard is for the load rating, but over 100% overload is maybe a bit much for a tie down. It is not completely surprising that you haven't fallen down yet. Whether you will fall down in the middle of a trip is another matter. The reason this is not a simple one to one calculation is the geometry of the hang system. So YMMV. By the way, that calls for about a 2Kn stress ring or biner. That's a small fraction of a 50Kn climbing biner rating. Also gives an idea of how overbuilt climbing gear is.
take-a-knee
03-10-2010, 23:56
These are the lightest "hammock-rated" carabiners. I've used them for 30+ nights with no issues. And yes, I know how to tie all manner of knots, including that stupid Hennessy lash.
http://www.treklightgear.com/catalog/pc/Trek-Light-Carabiner-Pair-7p15.htm
I just got me my Nano Carabiners and tested them out. WEEEEE! I didn't die!
Walmart carbiners are great for key chains, securing waterbottle to pack, bear bagging. Rock climbing, hammock hanging or anyother time you are secure yourself vertically....not so good.
If you're planning to use Wal-Mart carabiners for rock-climbing, you better have base-jumping gear.
Rain Man
03-11-2010, 15:38
...That's a small fraction of a 50Kn climbing biner rating. Also gives an idea of how overbuilt climbing gear is.
And yet, I was still always scared ****less when on a rappel into a cave or prusik climb out!!!
Rock climbing ropes do have to stand up to a great deal of kinetic (dynamic) stress in a fall. But that doesn't mean hammock hanging isn't subjected to dynamic stress itself. No one can get into or stay in a hammock with zero dynamic stress, so (in my mind) it does have to be taken into account.
In short, as you summarized too I believe, it simply is not a simple-minded one-to-one analysis. There is a reason that professionals often use a 10-to-1 rule of thumb for rigging that human life and limb depend on.
Rain:sunMan
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SGT Rock
03-11-2010, 16:04
I think it might be possible to use these sorts of carabiners as a toggle instead of a carabiner if you were using a toggle style connection between straps and a rope - like when using whoopie slings. I ain't willing to be the test dummy on that though.
Rain Man: If you used to do Prussic ascents, my hat's off to you. And the rest of my kit, too. You can carry it for me, ok?
Rock: Just don't set up over a big old rock, Rock.