Yes, I was thinking about that added length after I wrote the above. Also, if you're counting on the loose hanging end of the adjustable bury for a dripline, it may be pushed out from under the tarp by the added length. I'll stick with the bowline method...Originally Posted by SlowBro
SloBro - one thing I have done is shorten the buries when a problem such as this pops up.
I think it was nacr533 that pointed out that the recommended buries in the splicing guides are designed for critical loads and loads approaching the rope rating limits.
With the hammock suspension, for most of the ropes I see being used, the loads are not close to the limits of the ropes. Thus, I decided that for me shortening the buries wasn't going to be a safety factor.
In places where the length of the buries was preventing me from using the splices and having to revert to a knot, I simply used 2 fid lengths where 3 fid lengths was recommended in the splicing guide. I don't know if the strength of the splice is linearly related to the length of the bury or exponentially like Frawg thinks may be the case. I strongly suspect that Frawg is right. Either way, I am still better than using a knot.
Doing this has let me use buried eye splices where previously I needed a knot and to date I haven't detected any problems.
One other point, with the recommendations in the guides I have seen, the finished Whoopie bury length for 1/8" diameter rope will be 8.25", the same as for the buried eye splice. So if your's are ending up 10", you can safely shorten the buries
Those who sacrifice freedom for safety, have neither.
Do not dig your grave with your teeth. (Unknown)
I love the end bury for finishing a rope. Besides looking really great and professional, I can easily finish off the end of a cut rope in the field now using my splicing needle. Before, it was time consuming with whipping thread or just looked cruddy by melting the ends. With vectran, melting the ends wasn't an option even. Now I can quickly and nicely bury the end on vectran and get a great looking and functional terminus for the rope. Plus if I'm careful in pulling the end bury, it is super easy to pull out when needed.
Those who sacrifice freedom for safety, have neither.
Do not dig your grave with your teeth. (Unknown)
So's y'all can rest easy, it's not just my opinion*...
It's equation 9.4 in this lecture on "Rope Friction". Technically, it's the ratio of forces at each end of the bury (for a UCR, not a whoopie sling) that's exponential in the length of the bury. For a whoopie sling it's a bit different, but essentially exponential. (actually a displaced hyperbolic cosine, which is exponential in the limit.)
FWIW, I often cheat on bury lengths for exactly the reasons TeeDee cites.
* late note: Here's a nice write-up titled "The Mechanics of Friction in Rope Rescue". It's a bit easier to read.
Last edited by Frawg; 07-26-2009 at 19:58.
- Frawg
{generic tagline}
You are right, I just measured and my finished Whoopie bury length is actually 8.5". I keep forgetting that the bury shortens the rope a little.
As to using a shorter bury for the loop tied to the hammock, I have have no problem with that, I would assume, as you do, that there would be sufficient holding power with 2 fids. Still that would be about 5.5" per end or about 11" longer than a knot. If it weren't for the two trees in my back yard I would probably go with an eye splice. Unfortunately the folks that planted them 70 years ago didn't know what I needed.
Last edited by SlowBro; 07-26-2009 at 17:33.
-SlowBro
"Do what you can, with what you have, where you are."-Theodore Roosevelt
At the risk of seeming inconsistent, I actually do incorporate a whoopie sling in my UCR suspension.
The grey UCR to the tree goes off to the left; the blue part is a mini whoopie. When trees are too close together for the UCR, I can use the mini whoopie alone.
Side note -- the toggle is always under the tarp, so that blue eye will work as a last line of drip defense.
The picture is notional, though, so don't hold me to the dimensions you see there.
- Frawg
{generic tagline}
Frawg,At the risk of seeming inconsistent, I actually do incorporate a whoopie sling in my UCR suspension.
The grey UCR to the tree goes off to the left; the blue part is a mini whoopie. When trees are too close together for the UCR, I can use the mini whoopie alone.
Side note -- the toggle is always under the tarp, so that blue eye will work as a last line of drip defense.
The picture is notional, though, so don't hold me to the dimensions you see there.
Quick question: is that white(grey) loop on the right an endless loop? i.e. one end just buried into the other?
Last edited by SlowBro; 07-26-2009 at 17:33.
-SlowBro
"Do what you can, with what you have, where you are."-Theodore Roosevelt
Yes, it's an endless loop, but each end is buried into the other -- I basically followed Samson's instructions for the 12 strand class 2 end for end splice.
Last edited by Frawg; 07-26-2009 at 19:23. Reason: clarification
- Frawg
{generic tagline}
dang, this splicing business just gets cooler and cooler. It's a pain with 3 ply twisted rope, ask me how I know, but dead easy with this single 12 strand braid.
Grizz
Ok, I agree with Grizz- That is Cool
-SlowBro
"Do what you can, with what you have, where you are."-Theodore Roosevelt
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