- Dave, I'm familiar with the Hennessey - it's one of the ones I

own. You said:

>but my guess is worse case would be 3 times as much, but I would

Remember the guy who did the cutting of the hennessy ridgeline and

>certainly plan on at least twice as much.

inserted the carabiner? If you did that, you could easily insert

something like a fish weight hanging scale and determine the strain

in the ridgeline. Testing the strain in the ridgeline I can't see

that it holds a significant portion of the force vector that is on

the hanging ropes, especially not to the point that you need to

consider that load in your hanging rope calculations. - Greg,

I was talking about selecting a rope for the hammock suspension line,

or the line you attach to the tree. It is different than the

ridgeline. I was also concerned about the hammock suspension line being

more than strong enough for a range of conditions and my feeling is

that a structural ridgeline can greatly add to that range of conditions-

- especially if one initially sets the hammock suspension lines taut,

stretches the hammock system out by getting in or on it and then

retensions the hammock suspension lines.

It you look at this diagram, http://tinyurl.com/b8jl8 , it is one I put

together in an attempt to show what is going on. I hope I got it

right, it uses vectors and when I went to school it was how one went

about defining forces in complex structures. It is based on Neutons

laws of motion, which have stood the test of time for hundreds of years

without exception. Hammocks have a degree of complexity as far as

force calculations go and a structural ridgeline certainly adds to

that. It is customary to use vectors to help simplify the mathematic

models.

But, like you mention one can set up simple physics experiments to

either prove or disprove the results and I think that is great thing to

do if one is so inclinded, I did myself to convince myself of the

charts I found in an article I read that was written by cave rescuers.

That article described the forces on the suspension lines but I don't

recall it describing the forces on a structural ridgeline itself. This

is a link to a pdf file for part 3 of that article:

http://www.draftlight.net/cgi-bin/download.pl?file=3 , the load

analysis starts of page 6 of 61.

Dave

--- In hammockcamping@yahoogroups.com, Greg Welker <gdwelker@v...>

wrote:>

> Dave, I'm familiar with the Hennessey - it's one of the ones I

> own. You said:

>

> >but my guess is worse case would be 3 times as much, but I would

> >certainly plan on at least twice as much.

>

> Remember the guy who did the cutting of the hennessy ridgeline and

> inserted the carabiner? If you did that, you could easily insert

> something like a fish weight hanging scale and determine the strain

> in the ridgeline. Testing the strain in the ridgeline I can't see

> that it holds a significant portion of the force vector that is on

> the hanging ropes, especially not to the point that you need to

> consider that load in your hanging rope calculations.

> - Take a look at Dave's work. It will make sense. The ridgeline really

can have a lot of tension in it. Or try the scale experiment. Sounds

interesting.

Bill in Houston

--- In hammockcamping@yahoogroups.com, Greg Welker <gdwelker@v...>

wrote:>

> Dave, I'm familiar with the Hennessey - it's one of the ones I

> own. You said:

>

> >but my guess is worse case would be 3 times as much, but I would

> >certainly plan on at least twice as much.

>

> Remember the guy who did the cutting of the hennessy ridgeline and

> inserted the carabiner? If you did that, you could easily insert

> something like a fish weight hanging scale and determine the strain

> in the ridgeline. Testing the strain in the ridgeline I can't see

> that it holds a significant portion of the force vector that is on

> the hanging ropes, especially not to the point that you need to

> consider that load in your hanging rope calculations.

>