hammock help .

[crozbo]

Hi,can anybody tell me if it is best to hang your hammock as tight as you can or have so play in it to get get a good diagonal. thanks a lot Paul.

[russb]

You want some sag to it. How much? It depends on the hammock and the person. The only way out what is perfect for you is trial and error.

[KG4FAM]

I like to have mine tight so the tarp is not sitting way up in the air.

[JaxHiker]

I agree with the "some sag" concept. Especially if you have a ridgeline I don't think you want to get it too tight.

[take-a-knee]

I agree with the "some sag" concept. Especially if you have a ridgeline I don't think you want to get it too tight.

I stretch my Hennessy tight and get pretty flat on the diagonal.

[Bulldawg]

I leave enough sag for me to be happy. IT is all trial and error. I even have to rehang my sometimes after laying in it. But I get closer and closer to perfect with each hang.

[bobbyw]

How Much Stress?

When you tie off to a live tree, the stress generated is normally not enough to bother the tree too much because it has a good root system and generally you will be tying off to a tree 4" or more thick. But what if you want to tie off to a post in your yard or in a shelter. That big beam may look strong enough, but the forces acting on it and the few nails holding it in place are a lot greater than you may think.


Diagram from the Hammock Camping Yahoo Group
Force = ( occupants weight/2 ) / ( sin ( rope angle ref. to the horizon)).

There is a spreadsheet here with a diagram and the equations: all you are interested in is Force1, Angle1 and Weight.

Rope Angle Weight Multiplier
30˚ 1
15˚ 2
10˚ 3
7˚ 4
6˚ 5
3˚ 10
So the more slack your ropes are, the less stress you put on the support. A totally horizontal line (realistically impossible to have) would have infinite force.

Example: If I weigh 160, and I have a 2 pound hammock and about 5 pounds of gear in the hammock with me, then the total weight is 167 pounds. If I decide to set up using the roof support for the front of the shelter so I can be inside the shelter, and I put up the tightest pitch I can get, then the force I am putting at each point is 10 times the weight being supported, or 1,670 pounds of force. That might be enough to damage the shelter!

[bobbyw]

P.s. that's from http://hikinghq.net/hammock/hammock2.html#Storm Set Up
by SGT Rock

[RadioFreq]

I stretch my Hennessy tight and get pretty flat on the diagonal.

I stretch my HH as tight as I can get it initially. The straps will stretch a
bit once I'm in it to give it a slight bit of sag.

[RadioFreq]

How Much Stress?

When you tie off to a live tree, the stress generated is normally not enough to bother the tree too much because it has a good root system and generally you will be tying off to a tree 4" or more thick. But what if you want to tie off to a post in your yard or in a shelter. That big beam may look strong enough, but the forces acting on it and the few nails holding it in place are a lot greater than you may think.


Diagram from the Hammock Camping Yahoo Group
Force = ( occupants weight/2 ) / ( sin ( rope angle ref. to the horizon)).

There is a spreadsheet here with a diagram and the equations: all you are interested in is Force1, Angle1 and Weight.

Rope Angle Weight Multiplier
30˚ 1
15˚ 2
10˚ 3
7˚ 4
6˚ 5
3˚ 10
So the more slack your ropes are, the less stress you put on the support. A totally horizontal line (realistically impossible to have) would have infinite force.

Example: If I weigh 160, and I have a 2 pound hammock and about 5 pounds of gear in the hammock with me, then the total weight is 167 pounds. If I decide to set up using the roof support for the front of the shelter so I can be inside the shelter, and I put up the tightest pitch I can get, then the force I am putting at each point is 10 times the weight being supported, or 1,670 pounds of force. That might be enough to damage the shelter!

You are coming dangerously close to resurrecting the "Help With Math" thread.

[Manach]

The amount of sag will depend on the hammock used. Hennesseys have a structural ridgeline so the sag is preset. Not so with Clarks, Claytors, Speers, and others. ENO hammocks need a lot of sag, Claytors a little, Clarks take a lot of tweaking to get it right.

[SunnyWalker]

I stretch it up and tie it up. No fancy things needed, just use the roap/line it came with. Any extra is added weight. Then I get comfortable. It's great.

[Quoddy]

I use a 30 degree angle for my Speer, which is close to perfect for it's type. Any less and it squeezes and any more I become a banana.

[kayak karl]

I stretch my Hennessy tight and get pretty flat on the diagonal.

...ditto

[cmt]

Hi,can anybody tell me if it is best to hang your hammock as tight as you can or have so play in it to get get a good diagonal. thanks a lot Paul.

For a hammock without a ridgeline, I pick a tension that gives me the most comfortable amount of sag. "Just right" will vary with person and hammock.

For a hammock with a structural ridgeline, I shoot for a tension that results in an almost non-structural ridgeline. In other words, the ridgeline will be under tension when the hammock is loaded, but there won't be much tension. Because the hammock shape is largely fixed by the ridgeline, pulling things tighter doesn't offer me much benefit (assuming I can hang high enough to keep the hammock off the ground and don't mind swaying a bit more), but it does result in some bad things. Specifically...

As mentioned by others, tighter hanging increases stress throughout the system, increasing the chance of catastropic/embarassing malfunction. Additionally, although it may be counter-intuitive, tighter hanging also lets the hammock sink more when I climb into it. A slack hammock sinks less than a tight hammock because 1) less stress means less stretch and 2) a given amount of stretch has greater influence at shallow (tight) sag angles. I like to keep sink to a reasonable minimum because it's easier for me to get a happy storm pitch on the tarp without starting out uncomfortably low (if the tarp attached to the trees) or without excessive loosening of the tarp when I crawl in (if the tarp is attached to the support lines, like in a Hennessy hammock).

Below should be links to a spreadsheet I put together to help me make semi-educated hammock design decisions. (I've also attached a copy in xls format for posterity in case Google Docs ever craps out.) It's functional rather than pretty. Input includes tree separation, ridgeline length, hammock length, sag angle, load weight, and rope stretch. With that information it'll spit back support, ridgeline, and fabric tensions along with dynamic sag information and other sundry values.

to look:
http://spreadsheets.google.com/pub?k...u08KBaQ0eP2fLw
in OpenOffice format:
http://spreadsheets.google.com/pub?k...fLw&output=ods
in MS Excel format:
http://spreadsheets.google.com/pub?k...fLw&output=xls

Thank you to those who got me thinking about getting off the ground.

Cheers,
Craig

[StubbleJumper]

I tighten up my Hennessey about as much as I can....and then I lay in it for 5 minutes and it's all slack due to stretching in the treehuggers and the lines. I then cinch it up tight again and I'm good for the night.

It's one of the few things that I really dislike about my Hennessey....I'd really rather be able to set it and forget it.

[Manach]

I tighten up my Hennessey about as much as I can....and then I lay in it for 5 minutes and it's all slack due to stretching in the treehuggers and the lines. I then cinch it up tight again and I'm good for the night.

It's one of the few things that I really dislike about my Hennessey....I'd really rather be able to set it and forget it.

Have you tried using something adjustable like a ring buckle system? Makes adjustments a lot easier.