Hammock Hanging Method Addendum - 8-4-2008
Here's my Birthday present, me to HF.
I've had some spare time to work on my hammock suspension some more and the method that had been gestating in my mind has been implemented, tested and combined with the above method.
NOTE: I have included 2 AWK programs for computing 2 tables. You can PMme and I will run the programs for you. I will post the results to the forums so that others can use the results if desired.
My wife's cousin told me about the Single Line Suspension that HeadChange4U developed.
Interesting that we both developed Single Line Suspensions at almost the same time. I'll bet that carrying all that webbing is what motivated HeadChange4U just like it did for me.
After reviewing his work, I realized that he has done something very brilliant that helped me to simplify my hang rope even more. He "marked"his suspension line. It is such a great idea. It has given me the meansto really simplify things even more.
First I eliminated the dyneema loop on one end to connect to a tree hugger, instead I now use a bowline loop on both ends. That means one less steel toggle.
Following HeadChange4U's lead with marking the rope, I have modified the hang rope as detailed below so that centering the hammock is now even easier. This allowed me to eliminate the measure cord and replace it with marks on the hang rope for accomplishing the same purpose. Simpler and 1 less piece to the system.
Also, I have dropped the hang knots and hang directly from the toggles in the Marlin Spike Hitch stopper knots. In essence the Marlin Spike Hitches have become combined hang knots and stopper knots, i.e., stopper/hang knots. That eliminates 2 hang knot loops and 2 toggles. Again less pieces to the system and simpler.
The evolution here is interesting: I started out concentrating on Prusic knots which morphed to Larks Head hang knots plus Marlin Spike Hitch stopper knots which morphed to combined Marlin Spike Hitch hang/stopper knots.
I have found that I tend to start out more complex than really necessary. It is then hard work to make myself give up those "gadgets" that work, but whose purpose can be accomplished with simpler, easier, and usually lighter, means. I found this to be true of the hang knots and the end loop. It took me a long time to convince myself that even though they did work, they just weren't necessary. I think I actually had "gear head" withdrawal symptoms.
As mentioned, I have adapted HeadChange4U's great idea and marked the hang rope. The marks serve more than one purpose:
- to mark the positions for the Marlin Spike Hitch stopper/hang knots thus setting the ridge line length, and
- to facilitate centering the hammock and setting the hang rope sag.
- to facilitate getting the right height of the hammock from the ground
First determine the desired hang rope length and mark the center. For example, for 20' maximum tree separation, I use a 25' hang rope and mark at 12.5'. Now tie a small bowline loop at one or both ends of the hang rope. These bowline loops will be left in place and their purpose will become evident later.
We need to mark the hang rope for the Marlin Spike Hitch stopper/hang knots and place them on the rope.
- determine your desired ridge line length or the approximate ridge
line length.- mark the hang rope at 1" increments over the intervals encompassing
the ends of the ridge line. For example, I use a 114" ridge line and so
I have marks at 55", 56", 57", 58", 59" and 60" on both sides of the
center mark. If you are using a Speer or Hennessy hammock, it is likely
your ridge line will be on the order of 100".- use the marks to place the Marlin Spike Hitches for the desired
ridge line length
As mentioned above, I have eliminated the separate hang knots and now hang the hammock directly from the toggles in the Marlin Spike Hitch stopper/hang knots.
I use a Lark's Head tied as follows:
First bring the hammock suspension bight close to the Marlin Spike Hitch
fold the end of the bight back on itself and on top of the bight
hook the loops over the "ears" of the toggle
pull tight
looking at the toggle and hitch from underneath
NOTE: Before continuing to mark the hang rope further, it is important that the Marlin Spike Hitch stopper/hang knots with toggles are tied. They do not have to be tied at the exact ends of the ridge line at this point, but they must be tied somewhat near the approximate ends of the desired ridge line length. Otherwise the hang rope marks made in the next step will not be accurate.
I leave the Marlin Spike stopper/hang knot positions unchanged, I now adjust the hang rope from the ends with slipped bowline knots. To accomplish this, I have marked the hang rope as follows:
Starting at a convenient distance on both sides of the center mark, say 6', mark the rope every 3" out to 1/2 of the maximum tree separation from the center. For example, I mark starting at 6' and then every 3" out to 10'.
The marks give a measure of tree separation. Each mark is 6" of tree separation. For example, the first marks on each side of the center mark are 12' tree separation, then 12' 6", 13', 13' 6", etc.
To set-up the hang rope with the hammock centered, I have found the following simple procedure works well for me. I tried various procedures. Some worked and some didn't. This procedure worked the best for me and is the simplest, but may not work for others.
Before explaining the full procedure, I first want to explain how I set the hang rope sag angle.
Note that this is the hang rope sag angle, NOT the hammock sag angle. The hammock sag angle is determined by the length of the ridge line between the Marlin Spike Hitch stopper/hang knots.
I want to set a hang rope sag angle for 2 important reasons:
- with a sag angle close to 30 degrees, I lessen the forces on the trees and the hang rope, and
- by controlling the hang rope sag angle, I control the height I need to hang on the trees. If the hang rope sag angle is too great, the height is also too great.
To adjust and set the hang rope sag, I have found the easiest way for me is to simply allow a measured amount of slack.
I have constructed a table for the amount of slack for a desired hangrope sag angle and tree separation. It is based on my ridge line length of 114". A different table would be necessary for your desired ridge line length.
For a 30 degree sag angle and for my desired ridge line length of 114" (the highlighted line), it is very simple to judge the amount of slack by following this simple rule: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
2" for a 12' separation and add 1" of slack for each extra foot of tree separation.
Thus, for example, for a tree separation of 16', I would allow 2 + 4 = 6" of slack to get a 30 degree sag angle.
I have included the AWK program to compute the table at the end of this addendum and output for various ridge line lengths for a 30 degree sag angle. It turns out that for a 30 degree sag angle, the slack amount rule has to be changed slighty for different ridge line lengths, but only slightly.
For example, for a 100" ridge line like the Hennessey ULBA has, the rule would be: 3" for a 12' separation and add 1" of slack for each extra foot of tree separation.
In explaining the procedure for setting up the hang rope, I will assume that the hang rope is marked on either side of the center mark at 6' and at 3" intervals out to 10'. Adjust if you use something different.
- First put the tree huggers on the trees at the desired height and tie the attachment hitches using a Marlin Spike Hitch or Pile Hitch.
- pass one end of the hang rope around the attachment hitch on one tree hugger centering the first or last mark on the attachment hitch and tie a snug slipped half hitch.
If the tree separation is less than 16', center the first mark, i.e., the 6' mark
If the tree separation is greater than 16', use the last mark, i.e., the 10' mark.- Walk to the second tree and wrap the hang rope around the attachment hitch and pull the rope taut.
- Not counting the first, 6', mark, count the marks to the attachment hitch and multiply by 3 to get the total inches. I count to the mark that is closest to the attachment hitch even if it is a little past.
- If using the 6' mark in step 2, add 12' to the above result.
If using the 10' mark add 16'.
That will give you an accurate distance measurement from attachment hitch to attachment hitch.
For example, if I am using the 6' mark on the first tree and I count 7 marks past the 6' mark at the second tree, then I have 21" + 12' or 13'9" from attachment hitch to attachment hitch.- Now add the distance of the attachment hitches from the respective trees to obtain the measured tree separation.
For me, the attachment hitches are always 5" to 6" from the trees. Just seems to always work out to that for me.
So I add 1' and I have 14' 9" tree separation.
Round to the nearest foot.- Once I have measured the tree separation, I can set up the hang rope to hang from the tree huggers with the correct sag angle.
With an accurate distance measurement, I use my 2" at 12' + 1" for each foot over rule to get the slack needed for my 30 degree sag angle. That is the slack to be allowed at each end of the hang rope.
In my example, I have 14' 9" separation, so I round to 15' and I want 5" of slack each end of the hang rope.
Since the hang rope is actually hung from the tree hugger attachment hitches, I use the attachment hitch to attachment hitch distance in the following.
So on the end I'm at, I find the mark for 13' 6" separation, halfway to the next mark would be another 3" of separation for 13' 9" separation, add 5" for the slack. Form a bight with that position at the end of the bight and tie a slipped bowline with the bight forming the bowline loop. Since that loop will not reach to the tree hugger, I place the bowline loop at the end of the hang rope over the tree hugger attachment hitch to keep the hang rope off the ground.
Walk to the other end of the hang rope, pull the slipped half hitch, find the 13' 9" separation position as done on the other end, add in the 5" slack amount, form a bight and tie another slipped bowline loop with that position at the end of the bowline loop and place the bowline loop over the attachment hitch.
Then return to the other tree and place the correct slipped bowline loop over the attachment hitch.- Done.
With a little practice, this method is quick, easy and the best method for hanging a hammock I have used and I have used a lot of them. No finagling, no fussing, no adjusting end-to-end. I use the hang rope to measure the separation and tie 2 slipped bowlines - done.
For all practical purposes, the above method gives me the same sag angle at the tree every time. I have measured the sag angle at the tree and this procedure consistently gives me close to the proverbial 30 degree sag angle, between 26 degrees and 32 degrees.
Experiment to find the correct amount of slack for the hang rope sag you like for your ridge line length. You can use the tables or the AWK program at the end of this addendum to experiment.
There is one other aspect to using the hang rope system: tree separation and how high I have to place the tree huggers. Here again, having measured the tree separation, I can accurately place the tree huggers.
Note that I measure ridge line height instead of hammock height. Since the two are intimately related, if you set one the other is also set. However, measuring the ridge line height is easy while measuring hammock height isn't and is largely a matter of where on the hammock you measure it.
Fortunately, with the hang rope system it is easy to set the hang rope sag angle and determine the tree hugger height necessary for a desired hammock height.
The following table lists the necessary tree hugger height above the desired ridge line height for varying hang rope sag angles and tree separations for my ridge line length.
I have printed the height of the tree huggers above the desired ridge line height since the ridge line height can vary depending on weather conditions.
The table is in 6' increments and, in my experience, is accurate enough for obtaining the proper hammock height, For example, for a 30 degree hang rope sag angle and 15' tree separation, the table indicates 3 6" increments == 18" == 1.5' above the desired ridge line height. If necessary, I can raise or lower the tree huggers up to 3" to raise or lower the hammock. I find moving the tree huggers is usually fairly easy.
Also note that a value is printed only if it is different from the previous value, otherwise "--" is printed.
In good conditions, I set my ridge line almost mid-chest high. I lower it to waist high in really, really terrible conditions. I don't like the ridge line that low, since I have to literally crawl into and out of the hammock. With the ridge line, mid-chest high, my Bridge Hammocks are chair high and it is very easy to just sit down or stand up.Code:Tree Hugger height above ridge line, 6" increments Ridge Line Length: 114 Tree Separation -> 12 13 14 15 16 17 18 19 20 20 -- 1 -- 2 -- -- 3 -- -- 4 22 -- 1 -- 2 -- 3 -- -- 4 -- 24 -- 1 2 -- -- 3 -- 4 -- 5 26 -- 1 2 -- 3 -- 4 -- 5 -- 28 -- 1 2 -- 3 -- 4 5 -- 6 Sag 30 -- 1 2 3 -- 4 -- 5 -- 6 Angle 32 -- 2 -- 3 -- 4 5 -- 6 7 34 -- 2 -- 3 4 -- 5 6 -- 7 36 -- 2 3 -- 4 5 -- 6 7 8 38 -- 2 3 4 -- 5 6 7 -- 8 40 -- 2 3 4 5 -- 6 7 8 9
Thus, once I know how high I want my ridge line and how far apart the trees are, I can determine how high to place my tree huggers or if I need to modify my desired hang rope sag angle.
If I maintain the 30 degree sag angle of the hang rope, then, for my ridge line length, I must place the tree huggers 3', above my ridge line when the trees are 20' apart. For me that is a little over 7' which is usually doable, but totally impossible sometimes. If, however, I reduce the hang rope sag angle from 30 degrees to 26 degrees or 24 degrees, then I need to place the tree huggers only 2.5' above the desired ridge line height. I only need consult my previous table for sag angle and note that for a 24 degree sag angle at 20' separation, I need 6" of slack instead of the 10" of slack needed for a 30 degree hang rope sag angle.
By accurately measuring the tree separation with the hang rope itself, I can use the marks on the hang rope and easily adjust the tree hugger height and sag angle to maintain my desired hammock height and do that all at the same time. Also, I can accurately judge if I need to find another set of trees with a more favorable separation or, if the present set is the best choice due to location (weather protection or view or something else entirely). then I can accurately change hang rope sag angle and tree hugger placement so that the the current trees are usable. Also, I can do so easily and quickly without any experimentation, just by measuring the tree separation.
I have printed both the slack and hugger height tables on a single 1/2 sheet of all-weather paper and now carry the tables with me for ready reference when necessary. I only really need the tables when the tree separation exceeds 16' to 17', but the paper weight is negligible so it it is easy to carry and use when needed. By using the All-Weather paper, I don't even need to laminate it.
I have included the AWK program to compute the tree hugger height at the end of this addendum and a sample table for a 100" ridge line length.
So the new hang rope system allows me to easily and efficiently hang my hammock at the desired height by varying the sag angle and tree hugger height for varying tree separations.
The whole process of attaching the hammock to the Marlin Spike Hitch stopper/hang knot toggles only takes a few seconds.
Since hanging the hammock on the hang rope is so easy, I prefer to detach the hammock from the hang rope on take-down and re-attach when I hang the hammock. This also means that I don't have the weight of the hammock, however slight it is, to deal with in setting up the hang rope. It just makes it even easier.
I simply fold the hammock and wrap with the suspension triangle cords. It takes less than 1 minute. The hammock suspension line could be used for the same purpose to bundle a Speer/Hennessey type hammock. I don't need a stuff sack since a bundled Bridge Hammock is not much bigger than my open hand. I find folding and wrapping my Bridge Hammocks much easier than stuff sacks or snake skins and I have fewer pieces of gear.
I like to undo the slipped bowlines on the hang rope placed over the tree hugger attachment hitches when I take down the hammock and hang rope. It makes it easier to coil the hang rope for storage and the hang rope is then ready for the next hang spot.
The tree huggers are stowed in their own stuff sack to prevent contaminating anything else with whatever they might have picked up from the tree.
In the simplifications, I have subtracted one end loop and associated toggle and 2 hang knots with associated toggles, leaving me with the 2 toggles of the Marlin Spike Hitch stopper/hang knots on the hang rope instead of the previous 5 toggles. I don't count the toggles used in the tree hugger Marlin Spike Hitches since I pick those up from the ground and don't carry them. I have attached the toggles in the Marlin Spike Hitch stopper knots to the hang rope using lanyards. This keeps the toggles from getting lost. Since the Marlin Spike Hitch stopper knots are not moved or moved very seldom and only when it is desired to change the ridge line length, it is unlikely they would be lost anyway.
There are times that I use rope for tree huggers instead of webbing. There are several reasons for this:
- no other hangers/campers/hikers/rangers/people - no other people means that I can hang once and the tree can recover from any small scrapes very easily.
- trees are hardy enough - I know that the trees are not going to be damaged, only minor scrapes.
- big trees - finding trees between 2' to 2.5' diameter can be done fairly easily, but smaller than about 2' is just about impossible. A tree diameter of 2.5', requires a tree hugger at least 9' long and 10' is better.
- bulk - webbing is just plain bulky, especially 9' or more
- weight - webbing is heavy, especially 9' or more. Even the lightest webbing is 3 times heavier than 3 mm diameter hi tech rope, so long lengths of tree hugger webbing is very heavy in comparison.
For these purposes, I sometimes use rope tree huggers. I use either 42" or 10' of 3 mm dyneema rope, a bowline on one end and a 1.5", 1/4" OD stainless steel toggle. These tree huggers weigh 0.2 oz for the 42" and 0.65 oz for the 10'. The steel toggle is attached to the bowline with a guy line lanyard. Because of the compression exerted by the small diameter rope, wood toggles are not appropriate here. Wood picked up from the ground could be used if necessary, but be prepared to have an epic struggle removing the wood toggle after a night hanging.
There is a problem with the rope tree huggers though. The Marlin Spike Hitch cannot be used to form an attachment point for the hang rope as I do with webbing tree huggers. The suspension forces pull a Marlin Spike Hitch in small diameter suspension rope closed and very tight. With the 3 mm dyneema rope I use, it is impossible to untie the hitch after the toggle has been pulled out. It must be firmly anchored on one end and the hitch pulled through. This puts more wear on the rope. The Marlin Spike Hitch is really designed for situations where there is tension on both ends of the rope such as for the stopper/hang knots.
I found another knot that works much better for the rope tree huggers to replace the Marlin Spike Hitch, the Pile Hitch (Ashley #1194):
In small diameter rope, tying the Pile Hitch is as easy as tying the Marlin Spike Hitch and it falls out when the toggle is pulled no matter how tight the rope has been pulled. Since, technically, it is a crossing knot, the harder it is pulled the tighter it holds.
For both the Marlin Spike Hitch stopper/hang knot toggles and the Pile Hitch toggles, I have used Type 304 stainless steel tubing, 1/4" OD, 0.049" wall thickness. I cut the toggles to a 1.5" length, drill a hole on one end, thread guy line cord through the hole and out the end and tie a double overhand knot to retain the cord. Either smooth bore, seamless or welded and drawn work fine. I obtained the tubing from McMaster-Carr, the source of all materials hard to find locally. I have found the 0.049" wall thickness adequate to hold the hammock in the Marlin Spike stopper/hang knots and the Pile Hitch suspension line knots.
Make sure that whatever toggle you use is polished to a very smooth surface so that the toggle may be extracted from the Hitches, both Marlin Spike Hitch and Pile Hitch. I put the toggles in a drill chuck, spun the toggle and used the finest emory cloth I could find to polish the toggle surfaces and ends.
I considered the Pile Hitch to replace the ridge line Marlin Spike Hitch stopper/hang knots, but in the Pile Hitch, both ends of the rope exit the knot on the same side whereas on the Marlin Spike Hitch they exit on opposite sides. This gives the Marlin Spike Hitch a decided advantage for the ridge line stopper/hang knot.
The Pile Hitch could replace the Marlin Spike Hitch with a webbing tree hugger, but I find the Marlin Spike Hitch much easier to tie in webbing and the Marlin Spike Hitch doesn't suffer the same problem in webbing.
For those interested in the weight, the new hang rope system as I now use it weighs as follows:
- 3 mm dyneema hang rope and 42" x 1.5" strapworks seatbelt webbing
tree huggers
- 25' hang rope: 1.40 oz
- 2 steel toggles: 0.20 oz
- 2 42" tree huggers w/6" loop one end: 2.00 oz
- Total: 3.60 oz
- 3 mm dyneema hang rope and 10' x 1.5" strapworks seat belt webbing
tree huggers
- 25' hang rope: 1.40 oz
- 2 steel toggles: 0.20 oz
- 2 10' tree huggers w/6" loop one end: 5.60 oz
- Total: 7.20 oz
- 3 mm dyneema hang rope and 42" 3 mm dyneema tree huggers
- 25' hang rope: 1.40 oz
- 2 steel toggles: 0.20 oz
- 2 42" tree huggers w/stainless steel toggle: 0.40 oz
- Total: 2.00 oz
- 3 mm dyneema hang rope and 10' 3 mm dyneema tree huggers
- 25' hang rope: 1.40 oz
- 2 steel toggles: 0.20 oz
- 2 10' tree huggers w/stainless steel toggle: 1.30 oz
- Total: 2.90 oz
There is a very significant weight penalty for the webbing tree huggers when I must use them instead of the rope tree huggers.
For me, this new system is really easier to use than my previous Carabiner Hitch system. Also for me, it is much, much easier to use than the ring buckle or CC buckle systems which are more than twice the weight !!
I'm just happy that I no longer carry all that webbing. It's just too heavy and too bulky.
Simplifying the system has reduced the weight even more and I have a system that is the lightest and easiest to use of any system I have used to hang a hammock, any hammock.
Simplify, Simplify ---- beginning to sound like a Zen Buddhist, which really isn't bad at all. Maybe they were the original hammockers. Hmmmmm, multi-purpose garment - robe and hammock all in one.
With my new hang rope suspension, my Bridge Hammock Weight is now as follows. I have a lot of option to choose from depending on which tree huggers I decide to use. I have listed the weight with the tree hugger options in the same order as above (42" webbing, 10' webbing, 42" dyneema, 10' dyneema)
Bridge Hammock with DWR polyester ripstop and Spyderline
- Bridge Hammock: 8.95 oz
- Suspension: 3.60 -- 7.20 -- 2.00 -- 2.90 oz
- Subtotal: 12.55 -- 16.15 -- 10.95 -- 11.85 oz
- Bug netting: 7.45 oz
- Subtotal: 20.00 -- 23.60 -- 18.40 -- 19.30 oz
- Draft stoppers: 2.65 oz
- Overcover: 5.65 oz
- Subtotal: 28.30 --31.90 -- 26.70 -- 27.60 oz
- Tarp, 10'x9.5': 18.35 oz
- Total: 46.65 -- 50.25 -- 45.05 -- 45.95 oz
Slack Tables:
Slack tables for tree separations from 12' to 20' and ridge lines from 90" to 120". This table lists only those slack values for a 30 degree sag angle. Also, only the ridge line lengths for which for which the slack amount changes from the previous values. For example, the slack amount is the same for ridge line lengths from 99" to 105". The AWK program for computing the slack values for various sag angles is given after the tables.
The following AWK program computes the necessary height above the ridge line for the tree huggers. The table is the output for a 100" ridge line length.Code:Ridge Line Length: 90 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 4 5 6 7 8 9 10 11 12 Ridge Line Length: 92 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 4 5 6 7 8 9 10 11 11 Ridge Line Length: 94 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 4 5 6 7 8 9 9 10 11 Ridge Line Length: 95 Max Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 4 5 6 7 8 8 9 10 11 Ridge Line Length: 96 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 4 5 6 6 7 8 9 10 11 Ridge Line Length: 97 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 4 5 5 6 7 8 9 10 11 Ridge Line Length: 98 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 4 4 5 6 7 8 9 10 11 Ridge Line Length: 99 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 3 4 5 6 7 8 9 10 11 Ridge Line Length: 106 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 3 4 5 6 7 8 9 9 10 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 3 4 5 6 7 8 8 9 10 Ridge Line Length: 108 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 3 4 5 6 6 7 8 9 10 Ridge Line Length: 109 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 3 4 5 5 6 7 8 9 10 Ridge Line Length: 110 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 3 4 4 5 6 7 8 9 10 Ridge Line Length: 111 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 3 3 4 5 6 7 8 9 10 Ridge Line Length: 112 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 2 3 4 5 6 7 8 9 10 Ridge Line Length: 118 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 2 3 4 5 6 7 8 9 9 Ridge Line Length: 119 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 2 3 4 5 6 7 8 8 9 Ridge Line Length: 120 Tree Separation -> 12 13 14 15 16 17 18 19 20 30 -- 2 3 4 5 6 6 7 8 9 #--------------------------------- # slack computation # AWK program to print slack table, slack output in inches BEGIN { # start and stop table sag angles in degrees start_angle = 26.0; stop_angle = 40.0; angle_increment = 2.0; min_sep = 12.0; # minimum tree separation in feet max_sep = 20.0; # maximum tree separation in feet sep_increment = 1.0; ridge_line = 114.0; # ridge line length in inches degrees_to_radians = 3.141592653589793/180.0; print("Slack Amount - sag angle vs. tree separation"); print("Ridge Line Length:",ridge_line); print("Tree\nSeparation -> 12 13 14 15 16 17 18 19 20"); for ( angle = start_angle ; angle <= stop_angle ; angle += angle_increment ) { printf("%10d --",angle); for ( len = min_sep ; len <= max_sep ; len += sep_increment ) { base_len = ((len * 12) - ridge_line) / 2.0; slack = (base_len / cos(angle * degrees_to_radians)) - base_len; printf("% 3.0f ",slack); } print(""); } }
Complete weight listing with various ropes for the hang rope and various webbings and ropes for the tree huggers. I have included multiple configurations below to make comparison with my previous hammock suspension thread easier since that analysis uses 2.8 mm Spyderline and 1" Harbor Freight webbing tree huggers - the Harbor Freight webbing tree huggers yield the lightest webbing system, but I still like the black of the strapworks seatbelt webbing. I have also included the new 3 mm Amsteel Blue and AS-78 that I have been experimenting with:Code:Tree Hugger height above ridge line, 6" increments Ridge Line Length: 100 Tree Separation -> 12 13 14 15 16 17 18 19 20 20 -- 1 2 -- -- 3 -- 4 -- -- 22 -- 1 2 -- 3 -- 4 -- -- 5 24 -- 2 -- 3 -- -- 4 -- 5 -- 26 -- 2 -- 3 -- 4 -- 5 -- 6 28 -- 2 -- 3 4 -- 5 -- 6 -- 30 -- 2 3 -- 4 -- 5 6 -- 7 32 -- 2 3 4 -- 5 -- 6 7 -- 34 -- 2 3 4 -- 5 6 7 -- 8 36 -- 3 -- 4 5 6 -- 7 8 -- 38 -- 3 4 -- 5 6 7 8 -- 9 40 -- 3 4 5 6 -- 7 8 9 10 # Tree Hugger Height computation # AWK program to print tree hugger height BEGIN { # start and stop table sag angles in degrees start_angle = 14.0; stop_angle = 40.0; angle_increment = 2.0; min_sep = 12.0; # minimum tree separation in feet max_sep = 20.0; # maximum tree separation in feet sep_increment = 1.0; ridge_line = 100.0; # ridge line length in inches degrees_to_radians = 3.141592653589793/180.0; print("Tree Hugger height above ridge line, 6\" increments"); print("Ridge Line Length:",ridge_line); print("Tree\nSeparation -> 12 13 14 15 16 17 18 19 20"); for ( angle = start_angle ; angle <= stop_angle ; angle += angle_increment ) { printf("%10d --",angle); for ( len = min_sep ; len <= max_sep ; len += sep_increment ) { d = ((len * 12) - ridge_line) / 2.0; h2 = d * tan(angle * degrees_to_radians); h3 = sprintf("%3.0f",h2 / 6) + 0; if ( h4 == h3 ) printf(" -- "); else printf("% 3.0f ",h2 / 6); h4 = h3; } print(""); } } function tan(x) { return sin(x)/cos(x); }
- 3 mm dyneema hang rope and webbing tree huggers
- with 42" x 1" Harbor Freight webbing tree huggers
- 25' hang rope: 1.40 oz
- 2 steel toggles: 0.20 oz
- 2 42" tree huggers w/6" loop one end: 1.55 oz
- Total: 3.15 oz
- 42" x 1.5" strapworks seatbelt webbing tree huggers
- 25' hang rope: 1.40 oz
- 2 steel toggles: 0.20 oz
- 2 42" tree huggers w/6" loop one end: 2.00 oz
- Total: 3.60 oz
- w/10' x 1" Harbor Freight webbing tree huggers
- 25' hang rope: 1.40 oz
- 2 steel toggles: 0.20 oz
- 2 10' tree huggers w/6" loop one end: 4.00 oz
- Total: 5.60 oz
- w/10' x 1.5" seat belt webbing tree huggers
- 25' hang rope: 1.40 oz
- 2 steel toggles: 0.20 oz
- 2 10' tree huggers w/6" loop one end: 5.60 oz
- Total: 7.20 oz
- 2.8 mm diameter Spyderline hang rope and webbing tree huggers
- with 42" x 1" Harbor Freight webbing tree huggers
- 25' hang rope: 1.80 oz
- 2 steel toggles: 0.20 oz
- 2 42" tree huggers w/6" loop one end: 1.55 oz
- Total: 3.55 oz
- with 42" x 1.5" strapworks seatbelt webbing tree huggers
- 25' hang rope: 1.80 oz
- 2 steel toggles: 0.20 oz
- 2 42" tree huggers w/6" loop one end: 2.00 oz
- Total: 4.00 oz
- w/10' x 1" Harbor Freight webbing tree huggers
- 25' hang rope: 1.80 oz
- 2 steel toggles: 0.20 oz
- 2 10' tree huggers w/6" loop one end: 4.00 oz
- Total: 6.00 oz
- w/10' x 1.5" seat belt webbing tree huggers
- 25' hang rope: 1.80 oz
- 2 steel toggles: 0.20 oz
- 2 10' tree huggers w/6" loop one end: 5.60 oz
- Total: 7.60 oz
- 3 mm dyneema hang rope and 3 mm dyneema tree huggers
- w/42" 3 mm dyneema tree huggers
- 25' hang rope: 1.40 oz
- 2 steel toggles: 0.20 oz
- 2 42" tree huggers w/stainless steel toggle: 0.40
- Total: 2.00 oz
- w/10' 3 mm dyneema tree huggers
- 25' hang rope: 1.40 oz
- 2 steel toggles: 0.20 oz
- 2 10' tree huggers w/stainless steel toggle: 1.30 oz
- Total: 2.90 oz
- 2.8 mm diameter Spyderline hang rope and Spyderline tree huggers
- w/42" 2.8 mm Spyderline tree huggers
- 25' hang rope: 1.80 oz
- 2 steel toggles: 0.20 oz
- 2 42" tree huggers w/stainless steel toggle: 0.50 oz
- Total: 2.50 oz
- w/10' 2.8 mm Spyderline tree huggers
- 25' hang rope: 1.80 oz
- 2 steel toggles: 0.20 oz
- 2 10' tree huggers w/stainless steel toggle: 1.60 oz
- Total: 3.60 oz
- 3 mm Amsteel Blue or AS-78 hang rope and webbing tree huggers
- with 42" x 1" Harbor Freight webbing tree huggers
- 25' hang rope: 2.00 oz
- 2 steel toggles: 0.20 oz
- 2 42" tree huggers w/6" loop one end: 1.55 oz
- Total: 3.75 oz
- with 42" x 1.5" strapworks seatbelt webbing tree huggers
- 25' hang rope: 2.00 oz
- 2 steel toggles: 0.20 oz
- 2 42" tree huggers w/6" loop one end: 2.00 oz
- Total: 4.20 oz
- w/10' x 1" Harbor Freight webbing tree huggers
- 25' hang rope: 2.00 oz
- 2 steel toggles: 0.20 oz
- 2 10' tree huggers w/6" loop one end: 4.00 oz
- Total: 6.20 oz
- w/10' x 1.5" seat belt webbing tree huggers
- 25' hang rope: 2.00 oz
- 2 steel toggles: 0.20 oz
- 2 10' tree huggers w/6" loop one end: 5.60 oz
- Total: 7.80 oz
- 3 mm amsteel blue or AS-78 hang rope and 3 mm amsteel blue or AS-78
tree huggers
- w/42" 3 mm amsteel blue or AS-78 tree huggers
- 25' hang rope: 2.00 oz
- 2 steel toggles: 0.20 oz
- 2 42" tree huggers w/stainless steel ring & steel toggle: 0.75 oz
- Total: 2.95 oz
- w/10' 3 mm amsteel blue or AS-78 tree huggers
- 25' hang rope: 2.00 oz
- 2 steel toggles: 0.20 oz
- 2 10' tree huggers w/stainless steel toggle: 1.80 oz
- Total: 4.00 oz
If you compare the weights to the weights in my previous analysis, you will see that this system with 2.8 mm Spyderline and the Harbor Freight webbing is only 0.55 oz more than the system in that analysis using a plain knot. This is deceptive though since this system includes the weight of the ridge line, whereas the ridge line weight wasn't included in the previous analysis.
-----
The above article was submitted via email by TeeDee to me, angrysparrow. It was intended as an addendum to a previous thread, but I thought it might work best as a standalone article. If there are any formatting problems, assume they are my fault, not TeeDee's. All content is authored by TeeDee.
-----
Discuss this article HERE
Bookmarks