Discussion Topic |
|
This thread has been locked |
| Messages 1 - 14 of total 14 in this topic |
D Fred
Trad climber
san francisco, ca
|
|
|
Topic Author's Original Post - Jan 27, 2015 - 10:37am PT
|
I thought I'd throw this out to the ST sharks to chew on...
We all know the bunny ear figure 8 as a quick option for setting an anchor, but it does take some time adjusting to get the loop lengths right and even then I feel like it never does a perfect job equalizing the load between two points.
It occurred to me that I could just use a slip knot in order to dynamically equalize the two points. Tell me what you think? It's super quick, but is it safe, or ridiculously dangerous? Penny for your thoughts.
 Doug
here is a photo with the slip knot (left anchor point with clove, harness at bottom representing the climber)
for comparison, here is a photo of the traditional bunny ear figure 8 set up (again harness at bottom representing the climber)
|
|
guyman
Social climber
Moorpark, CA.
|
|
|
Jan 27, 2015 - 10:46am PT
|
What are you trying to equalize???
|
|
Rock!...oopsie.
Trad climber
the pitch above you
|
|
|
Jan 27, 2015 - 11:01am PT
|
What are you trying to equalize???
The odds of total failure (left failure) vs. large shock load due to elongation (right failure) based on the looks of it.
|
|
wallyvirginia
Trad climber
Stockholm, Sweden
|
|
|
Jan 27, 2015 - 11:15am PT
|
I don't know but the slipknot might be a bitch to untie after putting weight on it? Why not use an Alpine butterfly knot like Mark Hudon does?
|
|
D Fred
Trad climber
san francisco, ca
|
|
|
Topic Author's Reply - Jan 27, 2015 - 11:42am PT
|
not a troll... but i'll guess which way you're leaning.
i know at first glance it seems ridiculous, but we do a similar thing with sliding X's all the time for equalization, and even with an extension-limiting knot, there's always some extension... and at least with this set-up the extension is on a dynamic rope instead of a static nylon sling.
i hear you about the shock loading and it's always a risk... and it takes us back to the unfinished eternal debate of either (1) perfect dynamic equalization with risk of a shock loading extension versus (2) zero extension but not great equalization.
in largo's book, he talks about the two camps
"most climbers in the no-extension camp avoid the sliding X unless the primary placements are bomber... and equalize using overhand knots on a sling, a method that testing has shown to yield little, if any, equalization between pieces. For those less concerned about extension, it's better to dynamically equalize the load using the sliding X in an effort to prevent failure rather than anticipate failure and mitigate the consequences"
i agree that i'd favor building an anchor for perfect equalization and risk extension since it focuses on preventing failure rather than expecting failure
still... i know... a slip knot? for real? ...it's not confidence inspiring, that's why i thought i'd post to hear others' thoughts
doug
|
|
D Fred
Trad climber
san francisco, ca
|
|
|
Topic Author's Reply - Jan 27, 2015 - 11:45am PT
|
I don't know but the slipknot might be a bitch to untie after putting weight on it? Why not use an Alpine butterfly knot like Mark Hudon does?
because i've met mark hudon... and i'm no mark hudon. we met him after climbing the nose last year and the man is truly inspiring... climbed the phoenix on friggin hexes! climbed the nose in 15hrs in his 50's. snap
|
|
wallyvirginia
Trad climber
Stockholm, Sweden
|
|
|
Jan 27, 2015 - 12:00pm PT
|
Yeah, Hudon is definitely tough as rocks but he's got a method of tying a belay with the ropes quite similar to yours (it's on here somewhere) only the slipknot is a butterfly, like Cosmic said.. Quite easy to make it fairly equalized by adjusting the Alpine butterfly.
|
|
RyanD
climber
Squamish
|
|
|
Jan 27, 2015 - 12:01pm PT
|
If u can't tie a butterfly like Hudon maybe just get one of these?
|
|
Pajamas
climber
Wilderness, Home
|
|
|
Jan 27, 2015 - 12:18pm PT
|
Just stupid.
Melted, fused rope in the making.
Tie and clip a butterfly first, equalize by snugging up the clove to second bolt.
The bowline on a bight works great with two bolts as well. Easy to untie after loading, and a shelf for belaying and additional peoples.
|
|
D Fred
Trad climber
san francisco, ca
|
|
|
Topic Author's Reply - Jan 27, 2015 - 12:18pm PT
|
If going for static equalization (i.e. fixing lines), I usually go for the bunny ears figure 8 over the alpine butterfly, but for no apparent reason.
Regardless, neither the alpine butterfly or the bunny ears offer any dynamic equalization if the direction shifts.
Regarding the PAS/daisy shown... I'd just prefer two shoulder length slings for the anchor (unless rappelling), again just offer static equalization. (don't get me wrong, this is usually what i do on two bolts, but on gear, i usually prefer a dynamic equalization set-up... i.e. sliding-X combos
this is the hudon alpine butterfly set-up you mentioned, right?
|
|
WBraun
climber
|
|
|
Jan 27, 2015 - 12:30pm PT
|
Can't Americans even do a simple thing?
|
|
brett
climber
oregon
|
|
|
Jan 27, 2015 - 04:10pm PT
|
I think the wire pegs will bend and drop the biners but the pressboard might blow first. Either way, definitely no good for an upward pull.
|
|
nature
climber
Boulder, CO
|
|
|
Jan 27, 2015 - 04:14pm PT
|
yup. Sharks.
|
|
| Messages 1 - 14 of total 14 in this topic |
|
SuperTopo on the Web
|
Let us know!