Thinnest line you'd rap off of?

Clickbait title.

I've been toying with the idea of doing full length raps using a carabiner block and a throwline (2-3ish mm cord) as a pull line. I've heard about the woes of using smaller pull cord; it twists, gets knotted, is hard to pull, ect. But I've got a ct roll n lock to haul the line down, and then it'll stuffed into a chalk bag. 

I'm most afraid of having the climb line get stuck, especially when it's got a carabiner attached. I've also never had a problem with stuck lines in the past, and I've reefed wayyy harder on a throwline than any rap line, so I feel pretty confident it'd work.

Given the terrifying situation of slowly dying of dehydration or soloing at my onsight limit, I'm only thinking about using this setup when I either have cell service or there are other parties on the wall.

So my question is: am I gonna die?

Zach Baerwrote:

Clickbait title.

I've been toying with the idea of doing full length raps using a carabiner block and a throwline (2-3ish mm cord) as a pull line. I've heard about the woes of using smaller pull cord; it twists, gets knotted, is hard to pull, ect. But I've got a ct roll n lock to haul the line down, and then it'll stuffed into a chalk bag. 

I'm most afraid of having the climb line get stuck, especially when it's got a carabiner attached. I've also never had a problem with stuck lines in the past, and I've reefed wayyy harder on a throwline than any rap line, so I feel pretty confident it'd work.

Given the terrifying situation of slowly dying of dehydration or soloing at my onsight limit, I'm only thinking about using this setup when I either have cell service or there are other parties on the wall.

So my question is: am I gonna die?

Probably not but someone may die trying to save/recover you if that matters.

Zach Baerwrote:

I'm only thinking about using this setup when I either have cell service or there are other parties on the wall.

i can't tell if you're joking or this is just your inner millennial coming out.

either way, don't try it where i climb

Your title doesn’t seem to match your question, as you’d almost certainly have the climbing rope to rap off, Then a pull cord to pull it down. I would definitely not trust 2-3mm cord... not abrasion resistant enough. Try to find some thin dyneema cord maybe. Biggest concerns would be abrasion/cut resistance which isn’t too terrible as you just weight it once, making sure the ropes stay tied together and the knots/bends don’t come undone (which would be another concern with 2mm cord) and that it is very hard to pull... even 6mm can be hard to pull on long raps when it’s not totally vertical. To those saying YGD, I don’t see the concern, ascending a single line blocked off is way easier than a standard double rap assuming you have Prusiks. Most likely outcome of an issue is, you have to ascend the blocked off rope, do double the raps and leave gear, I most things that have double rope raps someone screwed up and there’ll be some kind of sketchy intermediate station around

There’s better ways to save 5 oz.

Zachary Zwickwrote:

Your title doesn’t seem to match your question, as you’d almost certainly have the climbing rope to rap off, Then a pull cord to pull it down. I would definitely not trust 2-3mm cord... not abrasion resistant enough. Try to find some thin dyneema, or I know some people use Amsteel. Biggest concerns would be abrasion/cut resistance which isn’t too terrible as you just weight it once, making sure the ropes stay tied together and the knots/bends don’t come undone (which would be another concern with 2mm cord) and that it is very hard to pull... even 6mm can be hard to pull on long raps when it’s not totally vertical. To those saying YGD, I don’t see the concern, ascending a single line blocked off is way easier than a standard double rap assuming you have Prusiks. Most likely outcome of an issue is, you have to ascend the blocked off rope, do double the raps and leave gear, I most things that have double rope raps someone screwed up and there’ll be some kind of sketchy intermediate station around

I have some tiny Amsteel on my sailboat, and would not recommend it for anything like this. A 60m piece of 7/64" Amsteel would be an absolute rat nest clusterfuck nightmare. 

3mm cord has a breaking strength of 250kg half that with a knot, 125kg if you weigh 70kg and the rope gets stuck or abraded at all you could easily break it. This and 3mm cord is dead weight outside of this pure tagline, at least 5mm can be left as tat when abseiling.

Dyneema shares the same issues as being useless as tat and being of questionable strength as far as knots go.

Even if all of these were a non-issue, the tangled cluster fuck you would still make it not worth it.

I remember reading in Ueli Steck's book that he would use a rappel setup of a 5mm rap cord with a 2mm as the pull cord. Seems like it would be a tangled rat's nest when you pull it.

Zachary Zwickwrote:

To those saying YGD, I don’t see the concern, ascending a single line blocked off is way easier than a standard double rap assuming you have Prusiks. Most likely outcome of an issue is, you have to ascend the blocked off rope, do double the raps and leave gear, I most things that have double rope raps someone screwed up and there’ll be some kind of sketchy intermediate station around

On a 1-2 pitch climb where you are getting down in one double length rap, the only potential risk is losing a rope. On a route with multiple double rope raps, your risk is that you pull the thin pull-cord and the climbing rope, thin cord, or carabiner block snags. Worst case scenario is you are left with a few dozen feet pull cord and a climbing rope that is well out of reach. With a 2-3mm pull cord, you can't safely ascend it and are stranded. Properly fucked.

This is a bad idea. At least if you are using 6mm+ cord, you have a chance to ascend it (or at least use it as a TRS while you climb or aid to the end of your climbing rope) to save your life if you had to.

curt86irocwrote:

i can't tell if you're joking or this is just your inner millennial coming out.

either way, don't try it where i climb

You're also a millennial, but don't worry, you won't catch me in colorado. My tiny, old van wouldn't make it that far. I'd have to rent a uhaul to bring my half ropes, and that's far too expensive!

Ueli Steck's setup sounds insane. Definitely wouldn't want to use that for more than a rap.

Abrasion is a good point, but this cord is designed to be pulled across rough bark for thousands of feet so it should be okay?

I guess to refine my question more; how often are y'all getting your ropes stuck on 60m raps?

Zach Baerwrote:

Ueli Steck's setup sounds insane. Definitely wouldn't want to use that for more than a rap.

Ueli was probably using this system in a dramatically different environment than you are. 

Abrasion is a good point, but this cord is designed to be pulled across rough bark for thousands of feet so it should be okay?

Bark is absolutely nothing compared to rock, you'll damage the tree before you damage the cord. 

I guess to refine my question more; how often are y'all getting your ropes stuck on 60m raps?

It depends on you and the terrain, more than you'd want though and it always ends up with me absolutely yarding on it. 

Zach Baerwrote:

You're also a millennial

barely. but i just spoke to my inner millennial and he is a little more self sufficient than you...

..and he also doesn't rap with dental floss...

I would think that the knot for your biner block on that small of cord would constantly get jammed up in the anchor.

Chad Elliottwrote:

I would think that the knot for your biner block on that small of cord would constantly get jammed up in the anchor.

You would DEFINITELY put the biner block on the full rope, otherwise you’d be weighting and trusting your life to the strength of the small cord

8 mm

Uli is dead.

ALWAYS carry two prussic loops on your harness to reverse any rappel.  So to better answer your question, what is the the thinnest line you want to ascend with your prussiks?

Zach Baerwrote:

You're also a millennial, but don't worry, you won't catch me in colorado. My tiny, old van wouldn't make it that far. I'd have to rent a uhaul to bring my half ropes, and that's far too expensive!

Ueli Steck's setup sounds insane. Definitely wouldn't want to use that for more than a rap.

Abrasion is a good point, but this cord is designed to be pulled across rough bark for thousands of feet so it should be okay?

I guess to refine my question more; how often are y'all getting your ropes stuck on 60m raps?

On a recent trip to City, with winds? Rope got stuck several times when it was pulled. This, just on easy peasy single pitch cragging, not even the full rope out, let alone a tagline. 

It sure makes sense to keep the option open to have that second line something you could use, in a pinch. If you're hauling a second line, you've already upped the odds of type two fun, so stack the deck on your side, not the rock's. 

Yeah, just a noob opinion, but some shenanigans ensued even on the easy stuff. On harder stuff? Up the odds in your favor.

What's the rock you usually climb on? My ropes are purchased with the assumption they will be taking a beating, with COR being my main crag. May or may not matter, in your case, but a consideration for skinny lines, as many pointed out.

Best, Helen

rapping on an 8mil beal rando with an atc guide feels pretty good

I think I’d look into using a Beal Escaper before I tried to mess with a 2mm pull cord...  or just bring 2 ropes. 

I’ve made many rappels on doubled 6mm & 7mm accessory cords, anything smaller would be difficult to control in terms of feeding through a rappel device. My last solo using a 7mm to descend I said “never again”, now I have a 120 meter 8mm static line. A savings of weight is irrelevant if some hapless rescuers have to lug your twisted broken body out of the backcountry then call your next of kin to say yer dead.

I used to rappel twin 8mm back in the 1990's (especially on alpine climbs.

I have rappelled 5mm tech cord. (5000 lbs breaking strength)

New England Ropes, originally developed Tech Cord for Military Special Forces to rappel in 3mm (3000 lbs. breaking strength) and they had a specialized device. 

SMC makes an escape "8" and Rock Exotica makes a small 8 with side tie off ears for rappelling "Small Cords"

If you have to rappel smaller diameter cords, thread it through the small hole of your figure eight for tighter bend and more friction.

Advantage to Tech cord is melting point is over 900 degrees! Nylon just over 500 and Dynema / Spectra is just over 400 degrees!

Consider Strength, Melting Point and your ability to hold and control the rope. 

+1 beal escaper