Yes! That is actually helpful.Originally Posted by OCDave
Yes! That is actually helpful.
Thank you for starting my day with a big smile on my face.
Please take a look at the attachment and do your math again.
Admittedly, I'll need some help with that math. My physics teacher in college literally disappeared the day before classes started and the replacement wasn't exactly qualified for the job. I'm glad there's a physics guru on here to help enlighten us. I like to know why I make people laugh.Thank you for starting my day with a big smile on my face.
Please take a look at the attachment and do your math again.
That's interesting that this subject matter has come up just now. I was backpacking last weekend and as I was putting my 1'' webbing straps around the trees I was thinking to myself that I felt these were a little on the narrow side and I was surprised that a wider strap wasn't recommended. I'm generally a guy who chooses to err on the side of caution so I'm not too interested in having the discussion as to whether or not 1'' straps are sufficiently safe for the trees. Personally, I'd be okay with carrying 2'' webbing straps with me out in the woods. However, I will say that I have noticed zero damage from my 1'' straps and I have a few hammock backpacking trips under my belt now. I'm not sure how much a difference it makes, but I'm somewhat of a lightweight (155 - 165 lbs) so a thinner strap may be less of a problem for me.
Would carrying two small sections of 1/8'' thick CCF to put between the tree and the 1'' straps be an acceptable alternative? This just keeps me from having to buy new straps. Beyond that, I suspect I'd prefer to just have wider straps and not carry around two small sections of foam.
We do not go to the green woods and crystal waters to rough it, we go to smooth it. We get it rough enough at home. - Excerpt from Woodcraft by Nessmuk (George W. Sears)
These are originially posted by Zilla over in the DIY section, He had "Lost In Space" from readystrap.com make him a pair of 2" to 1" converted strap. The part that contacts the tree is 2", the rest is 1" allowing it to be compatible with clips, buckles, etc..
Seems like the best of both worlds.
LOLAdmittedly, I'll need some help with that math. My physics teacher in college literally disappeared the day before classes started and the replacement wasn't exactly qualified for the job. I'm glad there's a physics guru on here to help enlighten us. I like to know why I make people laugh.
I don't exactly picture myself as a "physics guru", but I'll try to present this as clearly as I'm capable to.
I'll put it in a separate thread tonight, but what it cooks down to is that (local) maximum pressure is governed by (1) the tension in the cordage around the tree (which depends very much on the type of hitch used; I'll come to that in the thread I'll start on this), (2) the width of the strap (neglecting the fact the suspension is under a 30° angle for now, but I'll touch on that later also) and (3) the *local* radius of curvature in the bark (which probably depends even more on the smoothness of the tree than it does on the angle the suspension is in).
With the local pressure referred to as "sigma", the crude formulas (realizing that for very small values of phi (lim(phi -> 0)): sin(phi)/phi=1) become:
sigma=T/(w*R)
in which
sigma is the local pressure
T is the tension in the cordage
w is the width of the cordage
R is the local radius of curvature
sigma(average)=2T/(w*D)
in which
sigma(average) is the average pressure
D is the diameter of the tree
There is a lot to be learned fro this, like it doesn't matter how many wraps are put around the tree. And that local pressure increases a lot when the suspension is wrapped around multiple thin tree trunks, instead of around one big one.
And please do realize that when the cordage is tied up to itself, like most hangers do, T equals the load on the hammock.
Which calls for new illustrations, I guess.
Last edited by JotM; 10-19-2013 at 09:59. Reason: Illustration added
I think I'm following you, but look forward to your more detailed explanation. Questions are forming but I'll wait to see what you post. Just to make things easy to follow, it'd be good to post a link to your upcoming thread here for future reference. Thanks for taking time to contribute.
Agreed!
Just thinking out loud hear.
A scenario played out for those of us that get tangled up in the math terminology would be great, say with a 200 lb load in a hammock to keep the numbers easy.
Better yet for the folks that may be steering policies, regulations,(ie:LNT, NPS, State Parks...) etc. a formula where #s can be plugged in and played with might be helpful. Maybe in an excel sheet or something.
Once I understand the math going on I would be willing to build it. I just have to get to the point of understanding it well enough....
I suppose at that point the scientific gathering of test hang data could begin by volunteers.... Something like here is a pic of the 10" Colorado Blue spruce I put 8 lb PSI on with my 1" strap.... or maybe I'm just over thinking the OP...
Hey the thought is worth every penny you paid for it. We can all go hang a nap again now.
Either way they will still have to find meif they want to be mad at my LNT efforts.
Mind over matter,
if you don't mind, it don't matter
wow awesome thread.
Whats a tree strap.
Sounds a lot heavier than my chainsaw, mallet and 2 ft stakes I carry. oh yeah and the gas can.
I cut the tree down with my chainsaw at about eye level, drive the stakes in with my mallet and connect my suspension to the stakes sticking out of the stumps.
Never seen any bark damage this way. Again if these so called "tree straps" become the rule/law then and only then will I leave the gas can at home.
Just kidding for those of u with no sense of sarcasm.
Has the LNT ever done any studies on how many baby trees don't make it because of all the ground clearing for the past 100 years of tenting. And they are just babies. they cant fend for themselves like the big trees. I pulled the saw out one day on a big old oak the next thing I knew I came to in the hospital. no idea what happened. witnesses said I could take a hell of a punch though.
this is just a new way for someone to make some money (tickets) off of honest people who do the best they can to cause minimal impact to the trees. If it becomes a regulation.
Locks only keep honest people out anyways. meaning we (Hammock Forumers) will follow the rules while the people that do all the damage either on purpose or due to lack of education will still do it.
Just my opinion, and u know what they say about opinions.
Wow.
Lots of complaining, conjecture, and good points in this thread but at the end of the day there’s a problem. None of us have done any peer reviewed published studies on this topic. Maybe we can present a good pro-hammock vs. tent argument or even a ‘small webbing is just fine’ argument, but what proof do we have for any of this?
We might think we know, but we’re just guessing based on what, how the tree looks after we remove the straps in the morning?
How did the tree fair over the next few years compared to similar neighbors beside it?
I will say that since upgrading to Amsteel and down to 1” straps I almost always notice some scuffing on the bark. In a high use area this would probably lead to trees that look like the exposed roots in a city park. They get rubbed and scuffed enough they start to look almost polished. Was the damage more severe than superficial scuffing? Did I actually hurt the tree? Honestly, how would I know?
I’ve mentioned this a few times. The manufacturers need to get together and hire a group to lobby for this market. Contact someone like NC State University which has a respected forestry program and see if we can get them to do a study to find out what size straps are really needed. We probably won’t like the findings. The results will be recommendations for the greatest common denominator. Which means if those of us that weigh 300lbs need a 4” strap for the most fragile trees that will probably be the recommendation across the board. The park ranger isn’t going to put you on a scale to see if your straps are adequate.
I think this whole hammock thing has started to hit critical mass. It’s getting pretty common for me to see other hammocks in the parks. That means we are a threat to any traditional gear manufacturer out there. Coleman doesn’t make hammocks. Coleman probably has buddies in DC. If someone like them presents a paper decrying the damage our horrible hammocks are doing to the USFS, DNR, DOI, NPS, or LNT, not to mention the state level equivalents, it could be a deathblow to this industry with little chance to prove ourselves. We need to be dragging these officials outside to show them the benefits of using a hammock and we need to be showing politicians how many new businesses this niche has created.
In the mean time, if LNT has devised a guideline for straps, people should be sticking to it. The manufacturers should be adopting these recommendations even if they’re hoping to change them. If I buy tree straps from wherever.com they should include a handy list of how to use them in accordance with LNT. If nothing else it’s a show of good faith that we’re trying to be responsible with this. If I buy an Eno and it comes with no straps, it should at least come with the LNT recommendations included so I know better than to buy climbing rope.
I think hammocks and LNT go together nicely, but we have no lobby, no ambassador, and no organized voice to make that point. That needs to change to protect our hobby and the livelihood of our cottage manufacturers. Once established it will also potentially bring in more companies that might not currently think there’s a long term market worth investing in right now if there’s the potential that NPS is going to freak out and ban hammocks after bignamebrandcompanyx shows them pictures of a tree damaged from using straps that were too small, or no straps at all.
So what can the average user do? We’ll this is out of my league but a great place to start would perhaps be to put together a petition the average user can sign that we can forward to the various manufacturers out there. Ask them to comply with LNT, to post the LNT strap recommendations on their product pages, and include them with their actual products.
If you are a cottage industry manufacturer then start talking to your buddies and your competitors. My previous recommendation was that if we could successfully demonstrate the benefits of hammocks to a group like the Sierra Club, they’d have every reason to promote our interests. If not, then the hammock industry made need to form its own trade association.
Maybe I’m just clueless and there already is one?
The gram weenies among us (myself included) can hope we can eventually prove 1” webbing is just fine, but until we can get LNT on board, we need to be complying with their recommendations to made sure we don’t find ourselves sleeping on the ground again.
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