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Last edited by TeeDee; 08-07-2007 at 10:41.
I use Air Core Plus from BPL now. I've also used Spectra from a kite-surfing store. 550 cord stretches way too much.
Check the files section at the yahoo hammockcamping group - Youngblood posted an Excel spreadsheet with the forces on supports and ridgelines.
“Republics are created by the virtue, public spirit, and intelligence of the citizens. They fall when the wise are banished from the public councils because they dare to be honest, and the profligate are rewarded because they flatter the people, in order to betray them.” ~Judge Joseph Story
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IMPOSSIBLE JUST TAKES LONGER
I just added a ridgeline to my hammock. I use the 1/16 Spectra stuff Speer sells.
I see why Hennessy patented it. I'm amazed at the difference it makes.
1 - I use 3/32" (1.8mm) Spyderline from Annapolis Performance Sailing. It's really light and rated to 350 lbs. It's also listed as "low-stretch", which testing bears out.
2 - I've measured less than 3/4" stretch, under my weight (165 lbs.), in my ~ 10' ridgeline. I can remeasure for accuracy if anyone's interested. I've tried 550 cord, and I'd estimate that it stretches WAY more than just 10%. Just an eyeball judgment, though.
3 - I'm not really sure how you're measuring stretch using a plumb bob. I measured the line with no load, then hung, got in, and measured again.
I've run through the force diagram for a ridgeline before, but I don't have it handy right now. If you want, I'll sketch it out again really quick and post it. I do remember that, under 'normal' conditions, I came up with ~ 250 lbs. breaking strength as being save for both ridgeline and ridge biners. By 'normal' conditions, I mean my weight and a sag angle of about 20* (I think). That being said, I've been using unrated biners on the ridgelines of both my homemade Speer-type and my HH ULB with no visible stress to the biners.
The HH ridgeline is probably a lot stronger than you think. I'm assuming they source it from wherever they get their support Spectra (who knows where that is...). I know the ridge is Spectra, and going from the pretty impressive strength (through testing) of the support lines, I'd bet the stuff on the ridge is pretty strong, too. I have no idea where they get either cord, though, so it's kinda hard to say.
"Physics is the only true science. All else is stamp collecting." - J. J. Thompson
Biners? How do you use/place a ridgeline biner?
On both my HH and my homemade, I use a biner to attach one end of the ridgeline. That way I can remove the ridgeline quickly and easily if I want - it makes lounging, cooking, etc. much nicer. I actually haven't needed to remove the ridge on my homemade yet because I somehow managed to attach it higher in the first place - I have enough clearance so it doesn't bother me. It's MUCH nicer to remove it for lounging in my HH though.
"Physics is the only true science. All else is stamp collecting." - J. J. Thompson
Ahh, that makes sense. Right now my ridgeline is really high, But I was wondering if there was a way to set it lower and remove it when needed.
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