Joining two ropes

climbing friend,

you would be doing the dying

Nick Evans wrote:

It makes me wonder if there is any advantage at all to linking the rappel rope and the pull cord with a biner. Is there some advantage to having the biner slide down the whole length of the single rope when pulling the pull cord? 

The biner secures the fat rope back to itself so it is impossible for the whole rig to come undone when the knots slip through the hardware.

I suppose one could instead tie a loop of cord or rope around the long leg of the fat cord - may add some resistance to the pull.

jeremy long wrote:

A more streamlined way would be to use a stopper knot on the rap line with a 16" tail, then use an arborist throwball line to tie a pile hitch to the tail of the rap line. This eliminates large knots, loops and that damn biner. Probably safer to. I use something similar every day to get into the tree.

I'm gonna chime in here because (as well meaning as I am certain you are) I feel this is bad advice for a climbing application.

In your personal use you have (I presume) significant experience with the precise anchor "link" that your knot won't go through and know it is safe, but in climbing the link ring/chain etc is **highly** variable and judgment issues come in to play that in fact have resulted in deaths.  At some point people make a bad call thinking "the knot won't pull through" but it can and does. Brian Ellis was tragically killed rappelling Serenity Crack in Yosemite due to this exact error and failure to back it up with a carabiner as shown in the diagram.

In general, the climbing safety axiom is "backing up" any such judgment calls. We don't rap off of one bolt, we use 2, even though one looks fine and is theoretically more than strong enough. We don't place one piece for an anchor, we use two or more even though one is theoretically more than capable of handling any expected load etc etc...there are many such examples of this in climbing and it is "standard operating procedure" or "standard safety practice" ie the principal of redundancy....

It in large part is our own judgment and ability to assess the quality of such things properly and to protect us from what we cannot see that we are backing up. I think this is sound practice that keeps people alive. All of us eventually use bad judgment due to fatigue, familiarity, haste or laziness and always backing up our judgment is sound policy.

If rapping on a single line with a pull cord then only use the diagrammed method. That is all that anyone should be recommending, particularly to newbies. They simply don't have the judgment to safely do it with just a knot. They also get practice doing it the right way and familiarity breeds expertise.

In general, I prefer having 2 ropes along that can both function as lead lines if needed (ie, a 9mm tag line that can be pressed into service in an emergency), despite the extra weight due to the possibility of rope damage making the main lead line unsafe if 2 full ropes are strictly needed for rappels on a multipitch route. Others, will be happier with other systems based on their own experience. As well, the diagrammed method as several have observed has a lot of potential for getting stuck (it is designed to get stuck, after all) and would not be my first choice for rappelling.

^^^thanks Tut. Just what I was thinking. People seem to come into climbing from other backgrounds without realizing that you have such a varied set of circumstances to deal with that you have to use safety systems that won't fail because sometimes the hardware that you're connecting to will. You never know what you're going to get on a route. It could be 50 year old bolts on a rusty homemade hanger, or a brand new stainless steel glue in. No sense in risking your life to a system that can fail (knowing that other factors that you cannot control) can make it fail. Do it right, have fun and go home at the end of the day. 

Ryan Hamilton wrote:

^^^thanks Tut. Just what I was thinking. People seem to come into climbing from other backgrounds without realizing that you have such a varied set of circumstances to deal with that you have to use safety systems that won't fail because sometimes the hardware that you're connecting to will. You never know what you're going to get on a route. It could be 50 year old bolts on a rusty homemade hanger, or a brand new stainless steel glue in. No sense in risking your life to a system that can fail (knowing that other factors that you cannot control) can make it fail. Do it right, have fun and go home at the end of the day. 

Yes, every kind of hardware imaginable is still out there in use for a "rappel ring" and spending any effort deciding your knot won't pull through is a fool's errand. Back it up and remove all doubt.

Ropes/Knots are compressible and become smaller yet under load, not necessarily becoming a hard ball that won't fit through the ring. Very, very few climbers have any real knowledge (myself included) as to just what a given rope or knot might or might not squeeze through, particularly if there is a sudden unexpected load.

About the skinny-with-fat knot squeezing through ...

For a while I would rap on both strands and include some additional friction on the skinny line so that the forces on it and on the fat line were more balanced.  They do not need to be exactly balanced - just enough so the tendency for the rope to run through the anchor to be reduced below what the friction at them can resist. 

For that, I tried including various things on just the tag-line side:

• extra wrap around the main rap device's biner;
• munter above on a separate biner
• smaller rap device above (i.e., DMM Bug)

What this amounts to is depending on the tag line as much as on the fat rope during the rap.  And the knot against the tight constriction of chain links (much preferred) was a backup should the tag line somehow fail.

I've mostly retired such hair brain ideas for two reasons:

1. The rig shown in the OPs image has never failed to work well the times I've used it.
2. I can now afford to keep a pair of double ropes.

Bill Lawry wrote:

The biner secures the fat rope back to itself so it is impossible for the whole rig to come undone when the knots slip through the hardware.

Bingo, this will work if the anchor is big enough for the knot to pass. Any size ring or even a loop of cable or chain is still safe this way. The biner also will keep the pull line following the mainline. It actually might keep the rope(s) from slipping into a crack where they would get stuck. I've used this fairly often without issues. JB

Edit, It can be done without the biner. 

Tie the ropes together with a double-fisherman's knot, then tie one of the ropes to the anchor with a clove hitch.

Jackson Chambers wrote:

Tie the ropes together with a double-fisherman's knot, then tie one of the ropes to the anchor with a clove hitch.

Clove hitch one of the ropes to the anchor? That will work fine if you don't want your ropes back.

Ryan Bowen wrote:

Yes.