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Rapping with tag line - which strand to pull to retrieve ropes?

Eric Engberg · · Unknown Hometown · Joined Apr 2009 · Points: 0
will ar wrote: Actually saw some guys in Europe with this setup. It was rated as a half rope and one climber has to tie in to the middle of the rope. Seemed a lot less versatile than using a set of twins or doubles.
In the good old days (1960/70's) having a 100m bi-color 9mm rope and using it as doubles was considered THE hot set for alpine.
Patrick Mulligan · · Reno, NV · Joined Oct 2011 · Points: 995

For the long rappels in a place like Red Rock (or any other place with featured rock) your scenario of pulling the lead rope only to have the tag line snag is a very real issue. I've rarely had any problems with lines over 8.5mm, but have run into endless issues with ropes of less than 8mm widths. My primary partner down there even sold a pair of 7.7mm twins after we had issues on every pull getting down from Unimpeachable Groping. I guess after my trip down there he ran into the same issue with every other rappel on which he used the ropes. Given this potential one could argue that you're safe pulling the tag line, however, I would want to ensure that I could lead safely if necessary.

I know lots of folks who prefer the lead tag method, but honestly feel like learning how to efficiently use doubles is the better deal. I've had a set of 8.2mm doubles for years now and would choose this set up every time. They're small enough that I've even used one of the doubles as a tag when a partner has no interest in climbing using double ropes.

Eliot Augusto · · Lafayette, CO · Joined Dec 2013 · Points: 60
rocknice2 wrote: With 100m+ of rope out, the static elongation is about 10m. So you didn't whip but just sat on the rope.
Lol. That makes me wonder though. I am under the impression that the average rope stretch is ~10%. But I thought you had to create a large force to cause the rope to stretch that much.

Does sitting cause the same amount of rope stretch as falling? It would be counter intuitive if it does.
rocknice2 · · Montreal, QC · Joined Nov 2006 · Points: 3,847
Eliot Augusto wrote: Lol. That makes me wonder though. I am under the impression that the average rope stretch is ~10%. But I thought you had to create a large force to cause the rope to stretch that much. Does sitting cause the same amount of rope stretch as falling? It would be counter intuitive if it does.
Static elongation around 7-10%
Dynamic elongation between 27-37%

That's why on super long topropes the climber can deck from even 20ft up.
Healyje · · PDX · Joined Jan 2006 · Points: 422

If the intent is to use this in RR then it'll be a disaster all the time. As said, just use twins or doubles and save yourself a boatload of hassle and pain.

20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,346
rocknice2 wrote: Static elongation around 7-10% Dynamic elongation between 27-37% That's why on super long topropes the climber can deck from even 20ft up.
Dynamic elongation is the peak elongation value with tested with an 80kg steel mass and a factor 1.78 fall. Static elongation is the difference between a static weight of 5kg and 80kg. Static elongation is far more relevant to a TR fall. The maximum UIAA values for dynamic and static elongation are 40% and 10% on the first drop, respectively. I would not buy a rope with a static elongation over 8% or dynamic over 35% as they stretch like wet noodles, which is really annoying. Further, ropes with that much elongation pose a serious risk to climbers in conditions in which they really need to limit the fall distance (e.g. climbing over a ledge). The flip side is theoretically the reduced impact force increases the chance of a marginal piece holding, although it's difficult to say how this translates to the real world in terms of pieces pulled vs pieces held.
Healyje · · PDX · Joined Jan 2006 · Points: 422
20 kN wrote:The flip side is theoretically the reduced impact force increases the chance of a marginal piece holding, although it's difficult to say how this translates to the real world in terms of pieces pulled vs pieces held.
Probably not much in my experience. I think maybe it's better spending time really honing and optimizing the minutiae of marginal placements, equalization where possible, and slinging them intelligently than worrying too much about % of rope elongation (even if you could somehow translate that variable into the mix of all the other variables involved with marginal pro). Pretty much if you're climbing above these sorts of 'as-good-as-its-going-to-get' placements on anything hard then the elongation characteristics of your rope is likely to be the least of your worries.

The person who got hurt seconding on a long thin rope run for several connected pitches is a brilliant and experienced climber, but the whole notion of a second being at risk in this new and wonderful way just never entered their mind prior to getting hurt. I mean, on one hand it's a 'who knew?' sort of deal and on the other a [painful] 'duh!'.
20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,346
Healyje wrote: Probably not much in my experience. I think maybe it's better spending time really honing and optimizing the minutiae of marginal placements, equalization where possible, and slinging them intelligently than worrying too much about % of rope elongation (even if you could somehow translate that variable into the mix of all the other variables involved with marginal pro). Pretty much if you're climbing above these sorts of 'as-good-as-its-going-to-get' placements on anything hard then the elongation characteristics of your rope is likely to be the least of your worries.
I agree, in my experience, the pieces I have pulled likely would have pulled regardless of what rope I used. I can only think of one conflicting experience. I fell on a piece and nearly completely stopped before the piece pulled. In that exact scenario the piece may have held with a higher stretch rope, but that's only one instance in 12 years of climbing that I can think of. That said, I dont exactly pull pieces left and right though.
Brian C. · · Longmont, CO · Joined Feb 2010 · Points: 1,100

Here was on setup on the Petit a few years ago with a tagline that was REALLY skinny. Worked well but was hard on your hands to pull.

petitgreponraps

Marc801 C · · Sandy, Utah · Joined Feb 2014 · Points: 65
Healyje wrote:The person who got hurt seconding on a long thin rope run for several connected pitches is a brilliant and experienced climber, but the whole notion of a second being at risk in this new and wonderful way just never entered their mind prior to getting hurt. I mean, on one hand it's a 'who knew?' sort of deal and on the other a [painful] 'duh!'.
I once assisted in the evac of a broken ankle at the Gunks on Drunkard's Delight (tricky 5.8 crux about 12' off the deck) when the leader ran the first two pitches together and was belaying about 200' up and the second hit the ground.
bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065

Folks,

its impact force rating of the rope that matters to the force on the last runner ... not the stretch

BMC Technical Conference 2006

now there is a correlation between the stretch of the rope and impact force ... but its not perfectly linear

as to stretchiness, the main advantage of a stretchy rope is to prevent "hard catches" (swinging in) when your belayer cant give you a dynamic catch ...

personally ive been spiked into the wall on such a situation on a older lower stretch rope and gotten injured ... so i prefer to climb on stretchy lower impact ropes ... ive also pulled marginal gear on higher impact force ropes and taken the same fall on the same gear on lower impact ones which held

of course the disadvantage as mentioned is that the stretch can lead to a bigger fall and for the second they simply cant fall in the first so many feet off the belay/ledge

also as a rope tends to loose stretchiness/dynamism as it gets more used ... that 9.5 KN maxim rope after about 3 years of use might easily be significantly higher ...

ill do a proper full post about these things sometime latter ... im breeding a particularly KAIJU bear at the moment

;)

Paul Hutton · · Nephi, UT · Joined Mar 2012 · Points: 740

If I wanna rappel slowly, it helps to have more friction to help me brake--use both strands. If I wanna go quickly because I'm feeling the need for speed or I'm extremely hot or cold, less rope means less friction. Also, I just successfully executed a thigh rap last weekend (for those who don't know, rap the rope 2 or three times around your thigh, then lay a strand or two over the coils so the rope bites on itself). It was awesome! I was able to unclip a quickdraw from a hanger that had a weighted carabiner on top of it.

John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 392
Bob Johnson wrote:Hello Everyone, I just got a 75m 7mm tag line yesterday and have been thinking about how to set up rappels with it. Do you typically set up the rappel so that you are pulling on the lead rope (fatter rope) to retrieve the lines or the tag line (skinny rope)? ...deleted...
There always was, and always will be dissension on this topic. I published an article on this in Climbing Magazine about 20 years ago that, of course, sparked a bunch of "discussion".

IMHO you did it right. You got it 5m longer than your lead rope. A static rope shouldn't whip around as much as a dynamic 7mm.

I agree with George Bell: alternate which one you pull and feed the free end into the next anchor, as usual. Re-tying knots in the dark, rain, wind and when you're in a hurry never appealed to me.

If you have to lead back up on the static, remember that a dynamic belay with an ATC-like device and a 7mm rope is almost a given. Hopefully your belayer has a (tape) glove, and anchor him with long slings (2 x 2) so you'll lift him if you fall.

Although many will disagree, I've always used a double-fisherman's to join ropes of different diameter; with today's skinny ropes, the knot is a lot smaller than it used to be. It also has an advantage when going over a lip/roof/crack right below the anchor, which is often the case...

...thread the ropes to pull the lead rope, then get set-up on rappel as usual. With brake-hand in place, grab the knot with your free hand and pull up to unweight your device. Allow the thin rope only to slide through your brake-hand and device. Since the lead rope has more friction, this is easy to control and you'll move down as this happens. Repeat until the knot will be below the lip/roof/crack for easy pulling. Just make sure it's not more than 5m below the anchor ;-)
Guideline #1: Don't be a jerk.

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