Repelling using a pull cord

People,

I found this video of Brette Harrington explaining how to use a pull cord when rapelling on a single line (use of Grigri, etc).  I was surprised to hear that she uses it on 90% of her rapelling in the mountains.  Has anyone ever used this system?  I am just curious how people like the system or if there are any real downfalls.  Thanks!

starts at 5:20

https://www.youtube.com/watch?v=90F5-4WO1No  

To start, it's "rappeling."  People would use a pull cord when a rappel is more than a single-length of rope. It will allow you to rappel further. A "pull cord" (or "tag line") is a thinner diameter rope than the one you climb on. You are rappeling on only the fatter climbing rope, as shown in the video. 

The downside is that you have less margin of safety with the skinnier pull cord. For example. if the main climbing rope gets stuck when you pull it, but before the end reaches you, all you have to ascend is the skinnier pull cord/tag line.

A pair of double or twin ropes is a better option, in my opinion. Or two skinny ropes, each rated as singles. I bought a 6mm tag line years ago and haven't used it in many years. Note that pulling on a 6mm tag line is hard on your hands, too.

FrankPS wrote:

To start, it's "rappeling."  People would use a pull cord when a rappel is more than a single-length of rope. It will allow you to rappel further. A "pull cord" (or "tag line") is a thinner diameter rope than the one you climb on. You are rappeling on only the fatter climbing rope, as shown in the video. 

The downside is that you have less margin of safety with the skinnier pull cord. For example. if the main climbing rope gets stuck when you pull it, but before the end reaches you, all you have to ascend is the skinnier pull cord/tag line.

A pair of double or twin ropes is a better option, in my opinion. Or two skinny ropes, each rated as singles. I bought a 6mm tag line years ago and haven't used it in many years. Note that pulling on a 6mm tag line is hard on your hands, too.

Thanks for the spell check!  I use twins on alpine/multi that need long rappels but I thought this might save some weight/rope management hassle in the long run.  Good point on the stuck rope situation. 

I use this trick to extend my raps.  Say for example you need an extra 30 feet of rope to reach the ground.  If you have 30' of cord/slings/etc you could thread to the middle then pay out the extra = to the length of your tech cord on your rap side.  Then use a biner/knot block and rap down the single line. When you get to the where your pull side ends EDK your cord to the end of your line to give you the extra pull length you need.  There are multiple ways to set this up, just google biner block rappell.  I have used it once in an attempt to save weight and found that it made getting down slower because you have to completely pull and then rethread at ever station instead of threading as you pull each time.  I wouldn't use the technique again in an attempt to save weight/time only to get some extra length out of a rap if needed.  

https://www.climbing.com/skills/long-rappel-short-rope/

Edit to add: If the ropes are a mess it can be nice to set a fixed single line and send the first person down with a gri gri to fix and straighten the lines and then the second remove the biner/knot block and does the normal double line rap.  Another issue is that pulling with an extra knot or biner gives more opportunity for the rope to get hung up which can create a cluster.  There are a lot of things to consider and it would be good for certain things but could turn out to really spoil your day in others. 

Yes, when using a pull cord, it is probably in a pack or a coil carried by the follower, so you're only dealing with clipping one rope when leading and only one rope at the belays. So those could be viewed as advantages of the pull cord system.

With twins, you don't need to use a carabiner block ("Reepschnur") to rappel.

Modern badasses use this technique, along with a few other tricks, e.g., hauling shoes, water and puffies in a pack, using the tag line, on every vertical pitch, while the second micro traxions up (rope solo style), all to speed up the pace and lower the weight on both climbers throughout the climb. 

I've done a lot of research on this topic recently, there's an area near me that I bought a static rap/tag line for. The dome is about 900 ft in some spots and super ran out, I wanted to option to bail fast because you climb here in the winter for the most part. Here's my conclusions, sorry about grammar errors I'm on my phone.

There is no one size fits all for using a tag line. If you can bail and rap the route with one rope only take your one rope. If you might need to have the option to bail because you are in the alpine take a static tag line or climb on doubles or twins. If you are really worried about your rope getting stuck on the raps after the climb use twins or doubles. If you are just using it as insurance you can use static line but you could get screwed if your rope gets stuck, consider a skinny 7ish mm rope you can lead on. If you are using a 7mm tag line you can tie the tag line to your lead rope and rap like normal with a proper edk, it doesn't matter what side the knot is on in respect to the anchor, but skinny rope will feed faster. Get a tag line that is 5 meters longer than your lead rope, tie knots in the end and be aware. If you are using a 6mm or smaller tag line use a binder block, if you do this consider getting the expensive special rope (I think it's an edelrid rope) that will take a lead fall. Binner blocks have a high chance at getting stuck. Binder blocks are a good trick to have in your tool bucket especially if you rope gets damaged, but you can also isolate the damage and pass the knot during the rap. If you're going to be doing a bunch of raps it's best not to rely on a binner block all the time, if using it for emergencies it's ok, or just rap like normal with a  7mm tag line or climb on twins. 

Just my 2 cents. There's lots of info on the subject on google and MP.