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guangzhou
Oct 14, 2010, 12:32 AM
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kachoong wrote: guangzhou wrote: kachoong wrote: roy_hinkley_jr wrote: dingus wrote: I just tie in with the rope. DMT Sometimes a good solution. But smart climbers have many options. And that includes using daisy's, at times and carefully. Dumb climbers call daisy's the devil. Unless I'm climbing aid I don't even take a daisy to the crag. How much aid do you do in Texas. With that said, when I climbed at Enchanted rocks, I didn't take a rope, my partner and I soloed most of the slab routes there. Why would I aid climb in Texas? You soloed most of the routes on the backside? There's at least 20 routes up to .12-
An Austin climber showed me around. We manged 14 routes. The next days, we did a couple of crack routes, with gear. Two stand out, one was an easy 5.10, the other a 5.12. Both had similar names. Top Gun, Maybe People's Choice, something like that.
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TarHeelEMT
Oct 20, 2010, 10:16 PM
Post #77 of 84
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spikeddem wrote: Doesn't FF get thrown out the window when one is only looking at a purely static connection to the anchor? Assuming negligble stretch, isn't falling four feet on two feet of material the same as falling four feet on four feet of material?
It is the same. It's not meaningful to talk about fall factors when you're talking about a purely static connection to the anchor.
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SnowLurk
Oct 22, 2010, 3:42 PM
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After watching the video, the point is more about how you clip-in than the breaking strength of the daisy. Single biner (bad) vs. Double (good).
If you are clipped into the end of the daisy with a single biner and to shorten the daisy, you connect one of the stitch loops to the same biner, you have a 50/50 chance of unclipping from the end up the loop, if the stitches fail and unzip. Adding the twist will remedy, but it's subtle on the eyes and easy to miss.
Take a look at the video. BD suggests simply using a second biner on the stitch loops and clipping that to the fist biner on the end of the daisy (biner on biner), to eliminated the risk.
I don't think everyone gets this. The single biner method: If you have it clipped without the twist, you are relying on the stitches only. If the stitches break, you will plummet. I'd rather be clipped into the main loop than the stitches regardless of their breaking strength. Two biners better. This is basic and I would want to understand this before aiding.
I just looked at my aiders. The aider loop itself is connected by seven stitches. The stitch loops are held by only three. Also consider the biner force stresses the stitch loops to peel open as opposed to shearing on the main loop. The stitch loops are obviously much weaker.
(This post was edited by SnowLurk on Oct 22, 2010, 7:16 PM)
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kenr
Nov 29, 2010, 12:28 PM
Post #79 of 84
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SnowLurk wrote: If you are clipped into the end of the daisy with a single biner and to shorten the daisy, you connect one of the stitch loops to the same biner, you have a 50/50 chance of unclipping from the end up the loop, if the stitches fail and unzip. BD suggests simply using a second biner on the stitch loops and clipping that to the fist biner on the end of the daisy (biner on biner), to eliminated the risk.
Tie an overhand knot in the daisy between the two carabiner-attachment points.
Big problem then is that tying a knot significantly weakens the whole runner -- rather substantially for materials like Dyneema + Spectra -- so I can see why the BD video didn't mention this possibility.
Ken
(This post was edited by kenr on Dec 5, 2010, 1:34 PM)
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kenr
Nov 29, 2010, 12:44 PM
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majid_sabet wrote: based on drop test, only industrial grade 1" daisy ( used in some rescue operations) Purcell prussic and or tying via dynamic rope will survive the fall factor above 1.25. Everything else could FAIL and you may DIE.
Here's three other possible solutions to falling from short above the anchor (which I haven't tested):
(a) Petzl Absorbica leash
http://www.petzl.com/...nergie/absorbica-i-y
(b1) Sterling Chain Reaction PAS, but girth-hitched to a short prusik loop (not full Purcell prusik) which is wrapped around the climbing rope in a section where there is space for the prusik knot to slip on impact. (I carry a short prusik loop with me climbing anyway).
Hopefully when the fall impact comes on the prusik knot, it will slip on the rope, and dissipate the impact energy as heat. Which might melt the sheath of the rope, so afterward might need to replace it. When I learned about using prusiks from an expert who lived there in the Purcell mountains, he showed me climbing ropes where he had tested this with different colored ropes so you could see the melted substance from the prusik smeared on the climbing: but without breaking.
(b2) Even when using the climbing rope as "tether", tie a knot loop in the rope, wrap a short prusik loop (not full Purcell) around the rope between knot loop and anchor, then clip prusik by carabiner to knot loop.
(c) Insert a Screamer between the leash and my harness tie-in.
Ken
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MS1
Nov 29, 2010, 2:14 PM
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kenr wrote: majid_sabet wrote: based on drop test, only industrial grade 1" daisy ( used in some rescue operations) Purcell prussic and or tying via dynamic rope will survive the fall factor above 1.25. Everything else could FAIL and you may DIE. Here's three other possible solutions to falling from short above the anchor (which I haven't tested): (a) Petzl Absorbica leash http://www.petzl.com/...nergie/absorbica-i-y (b1) Sterling Chain Reaction PAS, but girth-hitched to a short prusik loop (not full Purcell prusik) which is wrapped around the climbing rope in a section where there is space for the prusik knot to slip on impact. (I carry a short prusik loop with me climbing anyway). Hopefully when the fall impact comes on the prusik knot, it will slip on the rope, and dissipate the impact energy as heat. Which might melt the sheath of the rope, so afterward might need to replace it. When I learned about using prusiks from an expert who lived there in the Purcell mountains, he showed me climbing ropes where he had tested this with different colored ropes so you could see the melted substance from the prusik smeared on the climbing: but without breaking. (b2) Even when using the climbing rope as "tether", tie a knot loop in the rope, wrap a short prusik loop (not full Purcell) around the rope between knot loop and anchor, then clip prusik by carabiner to knot loop. (c) Insert a Screamer between the leash and my harness tie-in. Ken
If you have rope available to incorporate as a tie-in, then the (b) options are pointless because the rope is a sufficiently dynamic and adjustable tie-in by itself.
If you don't, only (a) or (c) will work. Both use more gear and are more expensive than using a purcell prusik. And (a) is non-adjustable as well.
If for some reason a PP is out of the question for you and you can't use the rope, you could look into suprasoup's set-up, which involves a short length of spare dynamic rope rigged up with a metal shock-absorbing plate (basically a prusik made out of hardware - I think he uses a Kong Kisa?).
Why are you working so hard to reinvent the wheel?
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kenr
Nov 29, 2010, 7:10 PM
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MS1 wrote: If you have rope available to incorporate as a tie-in, then the (b) options are pointless because the rope is a sufficiently dynamic and adjustable tie-in by itself.
I'm very sure I'd rather take a 2 meter fall tied into the climbing rope in configuration (b2), than with the rope just simply connected to the anchor.
And just because the rope is within reach doesn't mean it's convenient to stay tied or clipped to it statically for performing some tasks. Like if both ends of the rope are already hanging down thru a ring or sling prepared for rappelling, and you decide you need to place (or remove) some backup protection above it, seems to me it's more convenient to just wrap a prusik around both ropes, clip it to my personal anchor system or leash and get up and take care of it -- than to spend time rigging some system of knots to allow me to do it while clipped to the hanging rappel rope (and dragging the weight of half the rope up with me).
I can think of belaying situations where it's convenient to untie from the rope and move away from the anchor connection with a prusik attached to a free section of the climbing rope (e.g. to get into a position for better communication with the climber following).
MS1 wrote: a short length of spare dynamic rope rigged up with a metal shock-absorbing plate (basically a prusik made out of hardware
But an actual prusik made out of flexible cord has lots of other uses. Like ascending the rope. Like as an autoblock backup when rappeling. Like for belay escape in self-rescue. Like in Z-pulley systems.
MS1 wrote: Why are you working so hard to reinvent the wheel?
Ken
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MS1
Nov 29, 2010, 7:20 PM
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kenr wrote: MS1 wrote: If you have rope available to incorporate as a tie-in, then the (b) options are pointless because the rope is a sufficiently dynamic and adjustable tie-in by itself. "Sufficiently dynamic" for what? Sufficient for avoiding spinal injury from a short high-factor fall, injuries which might take months or years to recover from? I'm very sure I'd rather take a 2 meter fall tied into the climbing rope in configuration (b2), than with the rope just simply connected to the anchor. And just because the rope is within reach doesn't mean it's convenient to stay tied or clipped to it statically for performing some tasks. Like if both ends of the rope are already hanging down thru a ring or sling prepared for rappelling, and you decide you need to place (or remove) some backup protection above it, seems to me it's more convenient to just wrap a prusik around both ropes, clip it to my personal anchor system or leash and get up and take care of it -- than to spend time rigging some system of knots to allow me to do it while clipped to the hanging rappel rope (and dragging the weight of half the rope up with me). I can think of belaying situations where it's convenient to untie from the rope and move away from the anchor connection with a prusik attached to a free section of the climbing rope (e.g. to get into a position for better communication with the climber following). MS1 wrote: a short length of spare dynamic rope rigged up with a metal shock-absorbing plate (basically a prusik made out of hardware But an actual prusik made out of flexible cord has lots of other uses. Like ascending the rope. Like as an autoblock backup when rappeling. Like for belay escape in self-rescue. Like in Z-pulley systems. MS1 wrote: Why are you working so hard to reinvent the wheel? Because I'm suspecting that for this particular (infrequent) situation, the Purcell prusik ("new invented wheel") adds bulk and weight without much additional benefit -- compared with the century-old climber's method of using a simple prusik loop. Ken
You are either trolling or you have no idea what people use tethers for in ordinary rock climbing situations. Hint: If the rope is available to use as an attachment, you don't need a tether.
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chadnsc
Nov 29, 2010, 7:25 PM
Post #84 of 84
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dingus wrote: I just tie in with the rope. DMT
Yup.
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