Rappelling on accessory cord

7mm is fine if you know how to add more friction

To see 5 ways to add more friction, see Section 6 of Chapter 10 in multipitchclimbing.com/

Make sure you test whatever you do somewhere safe - e.g. a tree in your garden

Will Copeland wrote:Personally, I'd do just about anything in "dire" circumstances. Even the thinnest of accessory cords is rated well above my body weight, so that isn't necessarily concern. As for the question at hand, I wouldn't want to do it on an ATC b/c of the diameter issue you've pointed out. Maybe an 8 would be better, or even a munter. Or maybe an ATC with a leg lock. On the other hand, I wouldn't do this for a variety of reasons which include but are not limited to strength, sheath durability, access to better tools/ropes, length (30ft rappel??). Don't know when/why you wouldn't have your regular rope. Would rather rap on a full rope even if it did have a core shot or sheath damage.

After reading this thread -- and having a solo-scrambling enthusiast suggest 6mm diameter --
I purchased some Sterling 6mm accessory cord.
First I tried indoors using a double strand of cord, hanging free off a pull-up bar ...

With Black Diamond ATC-XP in high-friction mode with a single carabiner a bit thicker designed for belay/rappel. Seemed to work fine for holding me hanging, lowering several inches / cm, then holding me again.

Next with Munter hitch (demi-cabestan / halbmastwurf) with the double strands around a single carabiner a bit thicker designed for belay/rappel. Hanging free off pull-up bar with the same test sequence. Worked fine (but trickier to get it set up because I don't practice that method hardly at all any more).

Then outdoors with a longer rappel like 60 feet / 17 meters on a not-quite-vertical cliff with double-strand 6mm -- also with a separate belay by a second person using a single full-thickness single rope.

Probably I'm not understanding something critical about how to test this sort of thing, but here's what I observed:

Black Diamond ATC-XP in high-friction mode with a single carabiner (extended by a sling to be around a foot away from my body), bare hands, no glove. Worked just fine for smooth descending and stopping as desired. I was impressed with how the design of the V-slot on the high-friction side worked for me.

Petzl Reverso 4 same test scenario -- worked fine (perhaps not quite as much friction as BD ATC-XP).

Munter hitch (demi-cabestan / halbmastwurf) with the double strands of 6mm around a single carabiner on my belay loop. Surprising to me: worked fine with bare hands. Felt trickier to get set up correctly (with spine of carabiner on safer side), and not as smooth as BD ATC-XP.

Also tried holding myself hanging "no hands" on Munter hitch (while on belay) - by wrapping the double-strand 6mm two or three times around one leg. That worked well, felt rather secure.

Of course there's lots of other complications (e.g. wind, getting rope caught) with using 6mm in real backcountry situations, but it was nice to see how the basic descending and stopping functions could work.

Ken

Reviving old thread...

I am specifically looking for a 30-35 meter static rope used for ski mountaineering. This rope will only be used for rappelling and an emergency line to tie in for things such as cornice cutting and ski cuts. I have a 8mm dynamic twin lines I use for short lead climbs on rock and ice when needed. This rope would only be used for a double rope rappel (or pull cord) or for short ski rappels. The idea is it will be small and light enough to live in the bottom of my ski pack. The less weight/bulk the better. I have a mini 8 rappel device for use with small diameter ropes. I like the Petzl 6.0mm Rad Line but it is far too expensive for something that will primarily live in my pack. Any recommendations for a 4mm-6mm emergency rap line? Also saw the 6mm pull cord thats used for canyoneering as an option. Imlay 6mm Pull cord or Mammut Rappel Cord Anything less bulky or is that a bad idea? Shouldn't really have to worry about getting the rope stuck as it will be pulled straight and over ice/snow for the most part.

A 30m RAD line can be had from Backcountry for $180 or Exxpozed for $158 shipped. I've got a 60m on the way from Exxpozed. But if I was you and I wasn't really planning on using it, I'd just buy 30m of Sterling or Bluewater 6mm cord and plan to replace it every couple years, depending on use. I spent about 15 years using 6mm accessory cord as a second rope on two rope rappels.
8.8kn:
sterlingrope.com/c/climbing…

Will Copeland wrote: Personally, I'd do just about anything in "dire" circumstances. Even the thinnest of accessory cords is rated well above my body weight, so that isn't necessarily concern. As for the question at hand, I wouldn't want to do it on an ATC b/c of the diameter issue you've pointed out. Maybe an 8 would be better, or even a munter. Or maybe an ATC with a leg lock. On the other hand, I wouldn't do this for a variety of reasons which include but are not limited to strength, sheath durability, access to better tools/ropes, length (30ft rappel??). Don't know when/why you wouldn't have your regular rope. Would rather rap on a full rope even if it did have a core shot or sheath damage.

Casey Lammers wrote:

Great first post and welcome to MP. :)

Peter Jackson wrote: I use 7 or 8mm cord for an emergency chairlift evacuation rap rope. o_O Are you serious? You actually carry a cord just in case you need to rap off a chairlift?

Officially commandeering this idea. So many good inaccessible lines under chair lifts  sometimes. THANKS!

Woodchuck ATC wrote: I use 7 or 8mm cord for an emergency chairlift evacuation rap rope. I have no trouble trusting a nice new piece of line that hasn't been dragged as a trail or haul line in any prior use. Clean and new, only saved for that last minute emergency rap off a chair when a breakdown leaves you hung up for an hour in a storm. Quick piece of 1 inch tubular web for a diaper sling, and a rap device of some sort and I'm set. Dont' think the local ski patrol would like me unweighting my chair and leaving on my own though.

I've never heard of anyone doing that on a chair lift, but could be a legit out if shit happens. What would ski patrol do to you? Tell you to stay warm? Tell your baby sitter to stay later? 

Where I'm only going to use it for occasional rappels I use 8mm industrial polypropylene twisted rope. I looked into this quite carefully and actually started climbing with my school bottom roping on thicker polypropylene ropes in the 1960s. Tested it with various techniques including classic, krab and sling, and plate rappel as well as prusiking. Would use it as toprope in emergency. 8mm has great friction advantages over narrower cords. Mine is 23g/m, breaking strength given as over 900kg and absorbs minimal water.  The lower melting point isn't a problem if used sensibly.
But people should also check for themselves before using it for their intended purpose.

Three years has been way too long to let this important thread rest!  (Just kidding)

But great coffee sipping topic...
As a ski patroller I keep a 6mm rap line in my pack for sure.   Depending on the weather, you risk some serious misery should The lift go down. 

My personal opinion would be “hell yeah” if I saw someone rapping from their chair.   Probably against “official policy” but in such cases it falls under “ask forgiveness, not permission”
Chair Evacs suck and are time consuming.  
The obvious rule is “don’t fuk it up”.   Only do it if you know exactly what you’re doing, and only in an emergency. 

People die of sitting on the ledge because their rope 5 meter short to safety. If it is life and death situation you can take the strand off the rope core and make a long cord by tying strands together. People already rap of 6 mm cord so what is big deal of rap 1/2 10mm rope?

I've rapped down a 7mm cordellete off a tree as single strand with a munter when I wanted to check out a little cave thing and be able to get back up without fully trusting the kitty litter looking rock.

Are modern twin ropes e.g. Beal Gully at 7.3 mm or Edelrid Skimmer Pro at 7.1mm, that much different from what you're asking about?

Peter Jackson wrote: I use 7 or 8mm cord for an emergency chairlift evacuation rap rope. o_O Are you serious? You actually carry a cord just in case you need to rap off a chairlift?

Well if you are a Ski Patroller and you are on the ski lift and it breaks down and you are one of the people who are supposed to evacuate it (or just have something else you need to help with) you kinda need to be able to get off the lift.  Lift maintenance types will also carry that kind of gear.  Both have radios.

Shit, I followed my partner on a single 6.9mm last winter. This topic is making me feel like that was unsafe

Forrest Carver wrote: Shit, I followed my partner on a single 6.9mm last winter. This topic is making me feel like that was unsafe

Just lots of stretch to keep in mind, so don't fall!  Plus I bet you would shit yourself if you put a pick through it.

As for OP's original question.....

Sure you can.  There are other possibilities too.  I once fixed a cordelette that I rigged to rappel down as a backup as the scrambling was tricky, I was in boots, it was cold and the wind was blowing 70mph ish.  I was coming back that way shortly so it was a nice to have coming back up.  I didn't weight it.  A slip would have been 100% fatal.

I have used 6mm cordelette as a hand line to get myself or a client down tricky sections on glaciers or alpine rock.  You can wrap it around your arm a few times for friction or tie a few overhand loops.  Or use a Munter to lower somebody or rap.  
So there are situations shy of full on rappel where a cordelette can be pretty handy.  Keep that in mind.

As for actually using it to rappel, uh I'd keep in mind that 7mm cord isn't particularly strong or more importantly cut resistant.  Being more static in natue it could potentially transmit a lot of force to your anchor.  Breaking strength is affected by whether you are using one strand or two, any knots you are using, sharp edges, etc.  You would probably need to tie a more considerable knot on the end if you wanted that protection.

I have also read that accessory cord (and to a lesser degree non-dry dynamic rope) loses a great deal of its strength when wet.  

I'd place a premium on stopping and thinking whether doing that was a good idea.   Folks use accessory cord in their rappelling systems, but almost always only as a pull cord.

But two 30' sections of 7mm cord is way more than most anyone would ever take on a multi pitch or alpine climb (or glacier travel).  Too much weight and especially bulk.  Most cordelettes are no more than 18' long so it kinda limits the practical applications to building anchors or cutting up for bailing or prussiks.  I can see having that much 7mm (60' total) for cragging where there aren't bolted top anchors but not much else.  

I used a 30m 8mm static rope for speeding down some scrambles in the Canadian Rockies when the down climb gets technical or I just plainly want to skip over sections. throw it around a tree, body Rap the milder pitches, ATC the more vertical stuff. that short section gets dragged through sharp rocks, tree branches, around abrasive bark. its cheap, plenty strong for the purpose and has become an integral part of my kit for that and other uses.

if you take care of the abrasion by leveling out your rope before the rappel, preventing any flossing against the rock, and keep your rap smooth to prevent shock loading, that 8 mm is strong enough, even maybe too much. I've used 6-7mm recently for the same purposes and have no reservations doing it despite all warnings. If I fall, that's on  me. Being able to ascend in descend quicker thanks to the weight difference from carrying a full dynamic rope (10.2mm) to the static 7-8mm and still having that ability to bugger off when I've had enough excitement for the day is worth it to me.

depending on how much safety margin i want, I may choose to tie the rappel rope off mid rope at the top anchor, giving me two independent half lengths of rope instead of a looped full length rope. you do this, it stays behind, but you double your chances of getting home.