Let me see if I understand-- you pack for a maximum span of 20 feet and a maximum tree diameter of 2.5 feet; and with this latest hang method you use a 25 foot hang rope and two(?) 10 foot tree huggers to do that?Originally Posted by TeeDee
Let me see if I understand-- you pack for a maximum span of 20 feet and a maximum tree diameter of 2.5 feet; and with this latest hang method you use a 25 foot hang rope and two(?) 10 foot tree huggers to do that?
Youngblood AT2000
I think there is a personality issue that enters here as well. How accurate you need to be depends to one degree on another on how consistent you want to be and how precise your mind works. My brain has a margin of error factor that is almost off the chart. It would drive some of you math inclined folks to the edge of distraction. Alot of my stuff is "feel" and not numbers. The "feel" system drives the numbers. For others, the numbers drive the feel. One is no "better" than the other... except in the mind of the one making the assessment.
I like haviung these systems explained in ways I can understand them. But at the same time, knowing me, I wobn't be slave to any of them simply because my mind doesn't work that way. Plus if your mind does work that way you find the idea of being "slave" to it to be insulting or at best confusing.
Any way... I find this extemely interesting. But I don't have that mcuh to contribute to the details of how it works.
I may be slow... But I sure am gimpy.
"Bless you child, when you set out to thread a needle don't hold the thread still and fetch the needle up to it; hold the needle still and poke the thread at it; that's the way a woman most always does, but a man always does t'other way."
Mrs. Loftus to Huck Finn
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no doubt personality plays a role here, but it doesn't break down so cleanly as whether you're a quant or not. I'm quite sure given our discussion today that TeeDee and I have different tolerances when it comes to set up. I'm likely more like you than you know when it comes to personal comfort issues. But get functionality involved---like making sure my quonset hut tarp is at a height high enough so that my spreader bars clear and low enough so it reaches the ground, with my spreader bars high enough that my quilts aren't dragging on the ground---then I'll be as precise as I need to be to get the desired goal.
My sewing tends towards the "is it good enough to not fall apart" school of thought more than "would I ever let Dutch look at this piece of work" school.
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Grizz
Last edited by GrizzlyAdams; 08-07-2008 at 15:46.
Well yes and no. the max span is 20' the tree huggers are either 42" or 10' long depending on what I find at the trail head.
Remember the tree huggers do not add to the span capability of the hang rope.
The tree huggers encircle the trees only. The hang rope spans the distance only.
At each end of the hang rope, you have to allow for tying a slipped bowline. The slipped bowline takes approximately 1' of rope plus the excess needed for handling the rope in tying the bowline. Add in 5" of slack on each end and you are getting close to the nubbin end of that rope. I imagine that the excess at the end could be reduced such that I ended up with the end of the rope exactly peeking out of the bowline. I wouldn't feel comfortable with that though. So with a 20' span, the 25' leaves me 2.5' of excess on each end for the bowline plus slack.
The tree huggers are totally separate. Now as you know, a 2.5' diameter tree has a circumference of 7.9'. Add in about 6" which is where my Marlin Spike Hitch or Pile Hitch usually ends up being from the tree and you're now up to almost 8.5'. With 10' that leaves about 1.5' to tie the Marlin Spike Hitch or the Pile Hitch. Remember that you do need something at the end of the webbing/rope as a 'handle" for tying the hitch.
What do you use and what is your max span and max tree diameter?
I agree with Grizz and you - personality plays a huge role here, but then again it doesn't.
My personality drives me to be as lazy as I possibly can. I really do not like walking back and forth, from tree to tree, adjusting one end and then the other. I rather be doing something else. If however, I was convinced that walking back and forth was the best and only way to do it, then I would get on with life and just do it.
My personality is kind of like Grizz is here. If there is any danger to my equipment, then I will be as fastidious as the neat obsessed housewife or househusband with a dust cloth.
My experience was telling me that I didn't like all of that fiddling and walking back and forth and back and forth and back and forth and .... There should be a simpler way. That part of me drove me from rope and Hennessy lashing to webbing and buckles and then back to rope and the Carabiner Hitch and then to the hang rope. Is the hang rope the end of my quest? At this point I would say yes, but then again???
Also, I like to be as comfortable as possible. I don't believe that being one with Nature means that I have to be cold, sweaty, freezing, tired and exhausted and getting up in the morning feeling like one big ache with bruises from roots and rocks. That drove me to hammocks. It then drove me to the Bridge Hammock. It is also driving me to make the hammock as comfortable as I can and if the edge of my Bridge is too low, getting in and out is not comfortable. If it is too high, then the same is true. If it is not centered, then my feet/head are too low. Well I'm sure you know what happens if the hammock isn't adjusted properly. Your comfort suffers.
So being lazy I am driven to make it as comfortable as possible with as little expenditure of time and energy as possible.
Now you are a slave to your quirks and I'm a slave to mine. Our quirks are just different. I'm not being insulting in saying that I hope, because I don't mean it in an insulting way, just making an observation. I probably would not want to conform to your quirks and I'm sure that you wouldn't want to conform to mine.
So not being a slave to any system such as this one you are simply being a slave to rebelling against them.
TeeDee,
I have always used 18 feet as my maximum span because of the height I can tie off to with a 31 degree sag angle and no structural ridgeline. That seems workable to me for the forests I have hiked in. What I have used in the past was 12 feet of suspension line on both ends of the hammock. That 12 feet included tying the hammock knot, wrapping around the tree, and finishing off at the tree with either a multi-wrap knot or a slippery bowline. With that arrangement and the hammock lengths I have used, I could handle 1 foot diameter trees at an 18 foot span and 2 foot diameter trees at a 12 foot span.
Recently I have looked at small diameter, low stretch, ultra light weight line and tree huggers, like you are looking at. I have only played with this in my backyard but I picked 42 inch tree huggers because it takes me 4 feet of webbing to make each one, making them weigh in the 1 ounce range each. I was considering using an add-on tree hugger to handle a single 2 foot diameter tree on the occasions when I have to do that. Seems like anything more and I am regressing on saving weight over the suspension systems I used in the past, or at least that is what my spreadsheet programs are telling me.
What I have looked at for an add-on tree hugger is another 4 foot length of webbing but with only one sewn loop. I can easily tie the end without the loop onto the loop of one the tree huggers, extending its length. I don't know the name of the knot I'm using but it is like a slippery sheet bend where the blight is sewn closed. It seems to hold fine and release easily on the webbing I have tried it with. Again, I am in the early stages of looking at all this so my opinions are subject to changing quickly.
Youngblood AT2000
Okay, you don't have to handle large diameter and long spans at the same time then.
I went back to tree huggers really for at least 3 reasons:Recently I have looked at small diameter, low stretch, ultra light weight line and tree huggers, like you are looking at. I have only played with this in my backyard but I picked 42 inch tree huggers because it takes me 4 feet of webbing to make each one, making them weigh in the 1 ounce range each. I was considering using an add-on tree hugger to handle a single 2 foot diameter tree on the occasions when I have to do that. Seems like anything more and I am regressing on saving weight over the suspension systems I used in the past, or at least that is what my spreadsheet programs are telling me.
What I have looked at for an add-on tree hugger is another 4 foot length of webbing but with only one sewn loop. I can easily tie the end without the loop onto the loop of one the tree huggers, extending its length. I don't know the name of the knot I'm using but it is like a slippery sheet bend where the blight is sewn closed. It seems to hold fine and release easily on the webbing I have tried it with. Again, I am in the early stages of looking at all this so my opinions are subject to changing quickly.
- tree sap - keeping tree sap clear of the hammock pays big dividends.
- tree diameter doesn't increase my suspension length required. That makes the span and tree diameter requirements independent of each other.
- trying to keep the suspension wrapped on the tree while juggling the hammock and wrapping the second tree required more hands and arms than I have.
In going back to tree huggers, I started using the Marlin Spike Hitch as a point of attachment to the hugger instead of threading the suspension line through the end loop of the hugger or using a carabiner. I could thread the hugger through the loop on one end and pull the hugger tight and that keeps it in place. Then placing the suspension bowline over the Marlin Spike Hitch in the hugger is just so easy.
Now if I could just devise a method of using the small diameter high tech line as a tree hugger at all times, then I could leave all of that heavy webbing at home all the time. I'm still working on that, but not too hopeful right now. Everything I have come up with so far, just increases the weight right back to what the webbing itself weighs. Still less bulk, but no weight advantage.
I am usually a total gram weenie, but when I found how easy cinch buckles were to use I decided to carry the few extra ounces. I have the cinch buckles about a foot beyond the netting line attachment on my Speer. I have 10' straps with 2" loops and lightweight carabineers clipped on them. Depending upon the tree size I throw either one or two loops around it. A couple of slight pulls and the hammock is perfectly centered, having already paced the exact distance between the trees and then knowing the correct height to loop around to get the perfect 30 to 33 degree angle.
I ♥ my Warbonnet
I forget the big grin on my face when I posted..... I love seeing how other people solve their problems cause I am a recycler par excellance.... and when I don't have the zipper to do Grizz's u-shaped opening on his DMB I said, "I got enuf for two sides and two separate sliders." So that's what I did. And you know... it works great... for me.... So keep it coming.
I may be slow... But I sure am gimpy.
"Bless you child, when you set out to thread a needle don't hold the thread still and fetch the needle up to it; hold the needle still and poke the thread at it; that's the way a woman most always does, but a man always does t'other way."
Mrs. Loftus to Huck Finn
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I've done some very limited tests on the accuracy needed for:
- span distance - I actually simulated this by very accurately measuring the true span distance using a tape measure and my Leica optical rangefinder and then deliberately using incorrect spans distances
- slack amount - my hang ropes are calibrated to 3" increments. I ignored every other mark to simulate 6" resolution
- tree hugger height - here I simulated the error by just randomly (?) picking a height and measuring afterwards to see what the error was.
I haven't really compiled anything into engineering data or tried to run an error analysis or anything sophisticated. This was more to answer for myself the question Grizz raised about how accurate the span distance, slack amount and tree hugger height placement really needed to be. Since I haven't done any analysis, this is just my intuitive feel of the results.
First for the span distance - here I ignored the fine markings and just looked at the markings for 1 foot increments. Doing that I was only able to measure the span distance to the nearest foot. I thought that doing that would be okay since I round accurate measurements to the foot anyway to get the slack amount for the desired sag angle. Well, that is correct, but not the whole story. In my "correct" procedure I round to the foot to get the slack. However, I use the span distance as measured to within 3" and the slack amount to within 1/2" when setting the end of the hang rope.
In my simulation, since I only had the span distance to the nearest foot, I was only able to set the end of the hang rope to the nearest foot on each end. Even if I had the rope marked to a higher resolution for setting the end, knowing the span only to the nearest foot meant that where I set the end of the rope and tied the bowline was in error by as much as 6". That is 6" on each end which came out to an error by as much as 12". I didn't experience any errors by that amount, but I did experience approximately 3" of error on both ends which was approximately 6" of error for the total. Now since at a 16' span, the slack for 30 degree sag angle is 6" that meant that the my sag angle came out to actually approximately 40 degrees. Since it was obvious very quickly that the slack was wildly incorrect, I didn't measure the real sag angle since I wasn't able to occupy the hammock - it was on the ground and had to surmise what the sag angle was by using my slack table.
Thus by obtaining the span distance with an error of as much as 12", the hang rope length error can be as much 12". In practice it will be probably be much less than that using the hang rope to measure since if you have 1' increment markings you could estimate to within 6" of error and the set the hang rope length with slack to within 6" of error.
It became obvious to me though that this is still not good enough since a 6" error can lead to a hang rope length error of 3". Doesn't sound like much, but that is half of the total slack amount needed for a 30 degree sag angle at 16'. That could give you sag angles anywhere from 22 degrees to 36 degrees. Not good enough.
I quickly stopped doing the slack amount error simulation. By examining my slack amount table a little closely:
I quickly realized that at 16' even a 1" error in the slack amount can lead to a 2 degree sag angle error. Looking at the table closely, you soon realize that small amounts of slack lead to big changes in the sag angle.Code:Slack Amount - sag angle vs. tree separation Ridge Line Length: 114 Tree Separation -> 12 13 14 15 16 17 18 19 20 20 -- 1 1 2 2 3 3 3 4 4 22 -- 1 2 2 3 3 4 4 4 5 24 -- 1 2 3 3 4 4 5 5 6 26 -- 2 2 3 4 4 5 6 6 7 Sag 28 -- 2 3 4 4 5 6 7 8 8 Angle 30 -- 2 3 4 5 6 7 8 9 10 32 -- 3 4 5 6 7 8 9 10 11 34 -- 3 4 6 7 8 9 11 12 13 36 -- 4 5 6 8 9 11 12 13 15 38 -- 4 6 7 9 10 12 14 15 17 40 -- 5 6 8 10 12 14 16 17 19
That is why in my experience to date, my desired 30 degree sag angle has varied between 26 degrees and 32 degrees. I traced the source of my problem there to the bowline knots. They were tied correctly, but I had not been compensating for the rope used in the formation of the knot itself. I have estimated that each knot, in my 3 mm dyneema, shortens the rope between 1/2" to about 3/4" and maybe as much as 1". For larger diameter rope the shortening would be even more.
I stopped my testing and did another test: I tied the bowline knots compensating for the shortening of the rope induced by the bowlines themselves, i.e., I added 1/2" on each end to the slack amount when tying the bowlines. This brought my sag angles to 30 degrees with at most a 1 degree error.
So, small errors in the slack amount leads to larger errors in the sag angle.
I continued my testing with the tree hugger placement error. These experiments quickly confirmed what I thought I had known previously: If my hammock height if incorrect by 3" or more it is immediately noticable and greatly affects the comfort of entry/exit of the hammock.
Also, tree hugger placement error translates directly into hammock height error.
If both tree huggers are 3" too high, the hammock is 3" too high. Conversely if both tree huggers are 3" too low, the hammock is 3" too low.
If the tree huggers are not at the same height, I have a line level on the hang rope and this error is quickly detected and easily corrected.
Tree hugger height is quickly and easily remedied by moving the tree huggers up or down.
Thus an error in the tree hugger height is the easiest of the three to spot and fix.
So what I decided from these tests is pretty much what I had sensed during the development of the hang rope: knowing the span distance as accurately as possible and being able to set the slack amount accurately is essential.
Now you could ask what I mean by "essential".
Essential:Then what is accurate?The ability to set-up the hang rope so that no adjustments are needed or that any adjustments that are needed are limited to moving the tree huggers up or down less than 3".So setting the hang rope length for the sag angle and placing the tree huggers could be done with much less accuracy and maybe even quicker, but that then leads to having to "adjust" things to get the desired and "correct" hang for the hammock. For that the hang rope may be of some value, but others and myself have been doing for a long time using other means as Grizz pointed out.Well my experience to date indicates that my original marking of the hang rope at 3" increments is good enough. The 3" increments enable me to set the hang rope length to within 1". If the length of the hang rope is off by more than that, then the length must be adjusted once the hang rope is set-up and eliminating the adjusting is what using the hang rope is all about.
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