Hanging from the Ridgeline

[SuperTroll]

This has GOT to have been discussed here before, but I come and go and missed it I'm sure...I searched for it and missed there too...

SO...

One long rope or heavy spectra cord with two prussik loops attached...(allows for nearly all types of hammock ends to be used)...the rope allows for hanging from two anchor points WAY apart, the hammock is tensioned on the loops attached to the rope......as the hammock sags, the rope serves double duty as the Tarp ridgeline.....(weight will be an issue for the ultralighters / I understand that - maybe...How heavy would 25 to 30 feet of Spectra cord capable of safely supporting a hammock be?)

a link or two to prior discussions would be appreciated....

[NCPatrick]

It may take a day or so for the Mathletes and/or "Quants" here to fully collect themselves for an in depth answer. I am not one of them, but I think it's a very (seemingly) simple and interesting concept though.

Good question.

[adkpiper]

I'll start in advance of the heavyweight mathletes.

It's an interesting idea, but I don't think your idea of Spectra/Dyneema load-bearing line with Prusiks is going to work. Most of those slide-and-grip hitches work based on a difference in diameter between the load line and the gripping line. Spectra's going to be thin, so I'm not sure you could get a Prusik to hold.

This part's just speculation: I wonder whether an integral Spectra ridgeline would have problems with shock-loading due to its extremely low stretch. Impact forces on a lot of hammocks are pretty small in part because their nylon supports stretch to minimize the peak load. At least in rock climbing, you don't ever want to fall onto a Spectra/Dyneema runner without some rope in the equation because it won't give at all, and will rip out.

The lack of stretch might be a good thing for the tarp, though, as it might correct some of the issues Hennessy hammocks have with getting a taut pitch. If it were possible to hang the hammock from the Prusiks using a higher-stretch material, that might take care of the shock-loading problem.

It's an interesting idea. Try it!

[miisterwright]

I'm not sure of the weight , but 25 to 30 feet of rope isn't going to span a great distance. obviously < 30ft. and I think I can span that with my Claytor JH (about 9 ft) and 12 ft straps on each side. So I guess I'm missing the point. What's the benefit??? Plus, the greater the span, either you have to climb the tree to attach the straps, or tighten the rope extremely tight to keep it from sagging. ( probably WAY unsafe IMO)

[Ramblinrev]

I am anything but a quant. But this sounds like the Single Line Suspension (SLS) which has been widely talked about and "peer reviewed" so to speak. Am I missing something?

[NCPatrick]

I am anything but a quant. But this sounds like the Single Line Suspension (SLS) which has been widely talked about and "peer reviewed" so to speak. Am I missing something?

I didn't go look. Have you got a link to it?

[Ramblinrev]

http://www.hammockforums.net/forum/s...ine+Suspension

As I looked at it again... the attachment is different in that there are no prussics used. I am not interested in trying this suspension so I don't know whether the same result is accomplished or not.

[miisterwright]

Again, I'm no mathlete or anything like that, but I don't think shock load comes in to play all that much. Dynamic ropes absorb/reduce the shock of a falling climber, but unless you are leaping into you hammock, I don't think dynamic lines are needed. I sit down nice and slow especially the first time..!!

[Ramblinrev]

Dynamic ropes absorb shock but they do so by stretching. In a static load system the weight will cause a dynmic line to stretch. If you have ever tried to haul a climber _up_ by climbing rope it is next to impossible because t=of the stretch factor. When I worked high ropes courses we could only let climbers _down_ on their ropes.

[GrizzlyAdams]

Quant? Did someone here call for a quant???

adkpiper is right, for the idea as stated to work you need to have a single line from tree to tree whose diameter is at least 50% more than that of the line going from hammock to this cord. Waste of a lot of big diameter cord.

RamblinRev is right, this is the so-called Single Line Suspension. You can search on that and look for postings by headchange4u, and TeeDee.

If I understand TeeDee's method correctly, you replace the prussiks in the method you propose with Marlinspike hitches that hold a toggle in place, then hang the hammock lines from the toggles. I do Marlinspike hitches at the trees all the time, takes all of about 3 seconds.

This way you can use a thin strong line between trees, which makes much more sense than a fat one.

dang, no equations. Well, maybe next time...

Grizz