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brunoschull
Dec 17, 2010, 11:14 PM
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Hi Folks,
I would like to try climbing with a single rope and a lightweight rap line. Some questions:
If I have a dynamic single rope, and a static rap line, should the rap line be longer to accommodate the dynamic rope stretch? If so, how much longer?
Are there any knots that are particularly well suited to joining two ropes with different characteristics/diameters? (Let the debate begin...)
Is it best to set up this kind of system like a standard two-rope rappel, with the joined ropes passed through the anchor, and the knot on the pull side, or is it best to use one of the techniques for rapping on a single strand, for example, the way you would rap with a Gri Gri or similar?
Ideas about lightweight tap line options, diameters, availability?
OK, that's all for now.
Thanks,
Bruno
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vinnie83
Dec 17, 2010, 11:40 PM
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Having a longer static line will give you the ability to do slightly longer rappels, but if you have a 60m static and you don't plan on rappelling longer than 60m it isn't needed. If you do want to go with a longer static rope figure out how much the dynamic rope you want to use will stretch under body weight.
I've never had any trouble with the EDK.
I much prefer to rap on both ropes as rappelling on a single 9mm rope doesn't provide a whole lot of friction and the other methods increase your chances of getting your rope stuck when you pull.
I used to use an 8mm static made by beal for this purpose, but when that rope was retired I got a dynamic twin rope, I think its 7.8mm. They both worked well, but I like the handling characteristics of the dynamic better.
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coastal_climber
Dec 17, 2010, 11:49 PM
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i use a 60m, 9.8mm tied to a 8mm 65m tag line with a flat overhand knot. (EDK)
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caughtinside
Dec 18, 2010, 12:24 AM
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brunoschull wrote: Is it best to set up this kind of system like a standard two-rope rappel, with the joined ropes passed through the anchor, and the knot on the pull side, or is it best to use one of the techniques for rapping on a single strand, for example, the way you would rap with a Gri Gri or similar?
Not sure if you have heard, but there was a fatality this summer in Yosemite from guys doing a single line rap with a skinny pull cord. They were counting on the knot to hold them, and the small knot pulled through the rap rings. If you do the thin pull cord, be sure to use a back up block to prevent this.
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sherpa79
Dec 18, 2010, 1:56 AM
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caughtinside wrote: Not sure if you have heard, but there was a fatality this summer in Yosemite from guys doing a single line rap with a skinny pull cord. They were counting on the knot to hold them, and the small knot pulled through the rap rings. If you do the thin pull cord, be sure to use a back up block to prevent this.
That's sad to hear but definitely worth paying attention to.
If I think I need 60m raps, I usually just grab my doubles.
However I have used lines as skinny as 1.75mm spectra lines for pull lines. But these are obviously not knotted and use a biner block or some other technique for keeping the lead line where it is which can have it's own potential problems. By far the lightest way to go with today's skinny singles, but I wouldn't suggest this as a technique to someone new to environments that put you more than 60 meters off the ground.
An 8mm static pull rope doesn't save that much weight, especially compared to a double or twin rope system, as I'm sure you are aware. Certainly not with my old fuzzy 10.5 anyway Save up and get some doubles or twins, you will be happy you did.
Skinny pull lines can save weight as well for solo climbing, but you wouldn't (or shouldn't) be asking about skinny pull lines if you're new to that arena either
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USnavy
Dec 20, 2010, 8:42 AM
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caughtinside wrote: brunoschull wrote: Is it best to set up this kind of system like a standard two-rope rappel, with the joined ropes passed through the anchor, and the knot on the pull side, or is it best to use one of the techniques for rapping on a single strand, for example, the way you would rap with a Gri Gri or similar? Not sure if you have heard, but there was a fatality this summer in Yosemite from guys doing a single line rap with a skinny pull cord. They were counting on the knot to hold them, and the small knot pulled through the rap rings. If you do the thin pull cord, be sure to use a back up block to prevent this.
Do you know any more details on the situation? Were they doing a single rope rap, or were they rapping on the pull line as well? I use a 10.5mm lead line and 6mm cordelette joined with an EDK to rap routes in Red Rocks however, I rap on both the 10.5 and the 6mm line. I also thread the anchor in a manner that requires the knot to pull through the anchor in order for the 6mm to slip, and I watch the rope carefully to make sure I don’t get a situation where I am only rapping on the 6mm cordelette and the 10.5mm is not moving through the belay device. With that I have had no problems, however it requires you pay close attention to how you thread the anchors.
(This post was edited by USnavy on Dec 20, 2010, 8:43 AM)
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bearbreeder
Dec 20, 2010, 10:04 AM
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the knot pulled through the rings ... there was no backup knot and biner ... it was a single line rap
a backup knot and biner would have saved the guy
the thread is on supertopo somewhere
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billl7
Dec 20, 2010, 1:36 PM
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I've done this with a 10+ mm dynamic and a 6 mm static. If you simply thread both in the belay device, the fat will still see more of the weight (more friction) which causes the rig to want to shift through the attachment at the anchor and so cause uneven rope ends at the bottom. Place the joining knot so it works against that shifting (i.e., would run up against the rap rings or chains). Still, there is some risk that in some situation the knot will pull through the attachment point at the anchor.
Although not quite the same set up as the above, the yose rap accident is sobering. Keep your wits about you at all times.
Once, I put an addtional munter above the belay device in only the static to help balance the load between the two strands. Seemed to work okay but haven't done it enough to feel for certain it gave a good balance. And if one had to stop the rap and ascend the rope, that extra munter might make for a bit of a hassel.
vinnie83 wrote: I've never had any trouble with the EDK.
I also use the EDK. Since the failure mode of the EDK in this use is to roll or capsize towards the tails, I tie the EDK such that the skinny has to roll over the fat strand for it to do the first roll.
If this rig is set up to pull the skinny first (see part of using knot to work against the shifting), be watchful of anything that causes friction during the pull and try to prevent it (edit: extra extra watchful). Pulling the skinny can be rather easy with a straight drop from fat rap rings to the pull point. Or it can be very very hard if, say, there is a low angle slap below the anchor that transitions to vertical terrain. The drag from a fat rope running over such a transition gets amplified when pulling on a skinny tag line. Bring gloves?
Bill L
(This post was edited by billl7 on Dec 20, 2010, 1:41 PM)
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billl7
Dec 20, 2010, 1:40 PM
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Looks like a repeated much of what you said.
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nh_ranger
Dec 20, 2010, 3:15 PM
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If you're having super trouble pulling a rope and can finagle a tree or ground anchor just build a z-drag system onto the rope. It's saved me from a few stuck or frozen ropes.
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ensonik
Dec 20, 2010, 4:21 PM
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caughtinside wrote: brunoschull wrote: Is it best to set up this kind of system like a standard two-rope rappel, with the joined ropes passed through the anchor, and the knot on the pull side, or is it best to use one of the techniques for rapping on a single strand, for example, the way you would rap with a Gri Gri or similar? Not sure if you have heard, but there was a fatality this summer in Yosemite from guys doing a single line rap with a skinny pull cord. They were counting on the knot to hold them, and the small knot pulled through the rap rings. If you do the thin pull cord, be sure to use a back up block to prevent this.
Here is all the info I had gathered when it happened:
ST thread: http://www.supertopo.com/...e-above-the-Awahanee
Carabiner block: http://www.canyonwiki.com/...dex.php/'biner_block
More block techniques: http://www.canyoneeringusa.com/utah/tech/blocks.php
Rappel knots strength tests: http://web3.bdel.com/...p_archive.php#123008
Account of the second guy involved in the accident: http://www.supertopo.com/...g=1165822#msg1165822
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healyje
Dec 20, 2010, 11:28 PM
Post #12 of 15
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brunoschull wrote: I would like to try climbing with a single rope and a lightweight rap line.
There are really no good reasons for doing this. Use twins if there is really an issue with weight in the face of 60m rappels.
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ptlong2
Dec 20, 2010, 11:51 PM
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healyje wrote: brunoschull wrote: I would like to try climbing with a single rope and a lightweight rap line. There are really no good reasons for doing this. Use twins if there is really an issue with weight in the face of 60m rappels.
What about pack hauling?
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healyje
Dec 20, 2010, 11:59 PM
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ptlong2 wrote: What about pack hauling?
Either really haul or don't bring a pack. Don't compromise rappeling for hauling - they are separate concerns. Take twins AND a thin cord if you really want to haul a light pack, though it stills sounds like more hassle than it's worth. Don't bring a pack is the better solution - eat and hydrate before leaving the ground and take a liter of water in a bladder and a snack bar in something like a Metolius 'big wall' gear sling instead. That should be good for a dozen pitches of free climbing if you're competent at the grade and moving at a reasonable speed.
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majid_sabet
Dec 21, 2010, 1:00 AM
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USnavy wrote: caughtinside wrote: brunoschull wrote: Is it best to set up this kind of system like a standard two-rope rappel, with the joined ropes passed through the anchor, and the knot on the pull side, or is it best to use one of the techniques for rapping on a single strand, for example, the way you would rap with a Gri Gri or similar? Not sure if you have heard, but there was a fatality this summer in Yosemite from guys doing a single line rap with a skinny pull cord. They were counting on the knot to hold them, and the small knot pulled through the rap rings. If you do the thin pull cord, be sure to use a back up block to prevent this. Do you know any more details on the situation? Were they doing a single rope rap, or were they rapping on the pull line as well? I use a 10.5mm lead line and 6mm cordelette joined with an EDK to rap routes in Red Rocks however, I rap on both the 10.5 and the 6mm line. I also thread the anchor in a manner that requires the knot to pull through the anchor in order for the 6mm to slip, and I watch the rope carefully to make sure I don’t get a situation where I am only rapping on the 6mm cordelette and the 10.5mm is not moving through the belay device. With that I have had no problems, however it requires you pay close attention to how you thread the anchors.
i think the rap rig was larger dia than a typical size.
(This post was edited by majid_sabet on Dec 21, 2010, 1:08 AM)
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