Pre-rigging rappel rope for ascending

[rcwild]

If someone rappels down on two strands of rope (set for retrieval) then realizes they need to go back up, how do you reset the rope to work with single rope ascenders?

One way is to tie the end of one strand of rope to an anchor at the bottom, then ascend the other strand. Keep in mind that you will be putting a 2:1 mechanical disadvantage on the anchor at the top, so it must be solid.

Another way is to create a loop at the end of one strand with a figure eight knot on a bight. Clip a carabiner into this loop and onto the other strand of rope. Pull on the strand without the loop. As you pull, the carabiner will slide up the rope until it comes to rest on the anchor above. Make sure it is not merely caught part way up, but resting against the anchor.

[skirocaileen]

I think both of these scenarios assume you have completed the rappel and need to go back up? What if you are in the middle of a double rope rappel and for what ever reason, need to stop, and ascend. I'm not sure what the scenario might be, but I've often wondered about this. Would a Shunt or prusik knot grip both ropes equally and allow you to ascend?

[rudy118]

A prusik works. I' ve done it.

[rcwild]

The most common scenario that involves rappelling on two strands, then needing to stop and ascend is when the first person down realizes the rope doesn't reach the ground. If you are not certain the rope reaches the ground, it is better to rig a single strand releasable system. If the first person down discovers the rope does not reach, someone on top can release the system and lower him until the end of the rope reaches.

The last person down can rappel on a block (releasable or static), single strand, or rappel double strand. Once he is down, the most common scenario that requires ascending back up is a stuck rope. My original post was meant to address this scenario when the last person came down on double strands.

Most friction hitches will work on two strands of rope. Shunt will work as long as the two strands of rope are identical diameter. If you tied two ropes together for the rappel and one is thicker than the other, the Shunt will grab the thick rope and slip on the thin one. You can also use two Tiblocs or two Ropemen together. Put one on each rope and clip through both with one HMS (pear-shaped) carabiner.

[skirocaileen]

How would two Tiblocs work? When you weight one, wouldn't the other side begin to pull?

[mountain man]

How would two Tiblocs work? When you weight one, wouldn't the other side begin to pull?

I believe the two Tiblocs or Ropeman will be moved in unison and another one (friction hitch with cord will work) will be need for a foot ascender. At least that’s how I envision the set up. Of coarse it will depend on the ascending system you set up.

[rcwild]

How would two Tiblocs work? When you weight one, wouldn't the other side begin to pull?

Put one on each rope and clip through both with one HMS (pear-shaped) carabiner.

One Tibloc on rope A. One Tibloc on rope B. Side-by-side. One carabiner clipped through both Tiblocs. They will move up in unison. If you only have two, the pair will serve as either your harness ascender or foot loop ascender.