Courage cannot be approached with caution

Thursday, July 26, 2012

Tag Lines

I find that there are numerous discussions on internet forums and at the crags regarding techniques or recommendations for retrieval ropes in a rappelling application.  The following are some tips and guidelines I use for selecting the appropriate system. 

Typically a “tag line” or “pull cord” is an auxiliary rope intended as a retrieval rope for double rope rappels.  When deciding what type of tag line to use, I will ask myself two questions.  First, do I intend to rappel the route?  And second, am I using this rope as an emergency retrieval cord because I need to descend due to extenuating circumstances?

If my intent is to rappel, I will bring a tag line that I would still be able to lead on if my ropes became stuck.  A simple solution is to bring an 8mm-ish half rope.  If you are concerned with weight savings there are a few ropes rated as half and twin ropes that are smaller diameter.  Sterling Ropes makes the “Fusion Photon” at 7.8mm.  This now allows you to thread either your initial lead line or your retrieval rope in the rappel anchor.  In addition, if your lead line is damaged, you have the ability to still lead on your tag line.

If I am climbing a route where my intent is not to rappel, but I still want the added security of a secondary rappel rope, I will use 6-7mm on nylon accessory cord. This allows you to have a small, compact, and lightweight emergency rappel rope.  I will also use this system if I am climbing something difficult where it is necessary to haul a small bag on the crux pitches.  There are a few limitations to this system.  First, if your lead rope becomes damaged or stuck, leading on the 7mm cord is not advisable.  Also, the smaller diameter cord can become extremely difficult to pull on long rappels.  In addition, the small knot where the ropes are tied together can become stuck in the rappel anchor, or worse, pull through the rappel anchor.  Furthermore, you must always thread your lead line through the rappel anchor, not the 7mm cord. 

Flat Overhand/Patagonia Knot
Whichever system I use, I tie my rappel ropes together with a flat overhand or Patagonia Knot, not to be confused with the European Death Knot.  Make sure your knot is adequately dressed, tightened by pulling all strands, and has at least 15 inches of tail.  I choose this method because the knot will roll over edges decreasing the likelihood of stuck rappel lines as opposed to using a double fishermans or Flemish Bend that will get caught on edges.
European Death Knot: Improperly tied Flat Overhand- loose, not tightened, and without adequate tail.

A Flat Overhand/Patagonia Knot is still used when tying ropes of various diameter together.  I will add a small overhand knot in the smaller diameter cord on the tail side of the Flat Overhand.  This keeps the knot from “slipping” at all. 
Flat Overhand with 7mm Cord.  Notice the additional overhand backup on the tail side of the knot.

When rappelling on large rings or carabiners as in an emergency rappelling scenario;  add a “backup” in the tag line so the Flat Overhand will not get pulled through the rings.  Keep in mind this will add friction in the system and make pulling your ropes more difficult.     
Tag line with backup on the rappel rope.