Twin rope contingency with Smooth Operator?

[Triggerfish]

I was wanting a way to get all the following in one setup:
1. Twin ropes
2. Simple, quick system
3. Ability to convert to lower without needing a LIFT step or pulling the entire free end of rope through

So I rigged this up in a tree.
1. Attach biner to anchor webbing
2. Attach rope midpoint to anchor biner with Munter
3. Stone both strands just below Munter with Smooth Operator
4. Lock Operator on both sides (if I really use this, I'll get a proper dogbone instead of the Amsteel pictured here)
5a. If all goes well, LAMAR converts Stone to standard block of choice before rappelling
5b. IF STUCK RAPPELLER:
6. Add VT Valdotain to Stuck strand, push down strand as far as possible
7. Basket hitch a short sling through the anchor biner
8. Clip the VT biner to the basket sling (***For how I tie the Stone, the sling must pass over the top of the unweighted strand to keep from creating a twist when the Stone is released***)
10. Warn Stuckman of upcoming short drop
11. Remove a biner from the Operator and pop it from the other side
12. Using both the Munter and the Valdotain, perform controlled lower

I tested it with my own weight. I had to stand up a bit (partly unweighing the rope) to properly pull the toggle. I expect with a big stuck rappeller, the pull will be hard but not impossible.

I was pleasantly surprised with how little the rope moved with the Valdotain in place during toggle pull. My first try, without the Valdotain, revealed that the simplest, tightest Stone still uses 8 or more inches of rope (each strand). 8ish inches of drop on the Stuck side +8ish of instant slack on the free side that even a quick belayer can likely only partially reduce = a likely unpleasant amount of sudden drop to Stuckman. Maybe ok to ditch the Valdotain in a very time-sensitive situation?

I know there are other ways to do twin contingency, and certainly other ways to help stuck novice rappellers, but I often need to stay up top and be LAMAR to make sure everyone else rigs right, and recently had a kid with stuck hair who was unable to free herself despite a step-up lowered to her.

Or, maybe this was just a fun exercise, but the probable need : added rigging time ratio doesn't justify using it over the beautifully simple approach of clipping the biner block to the anchor, and LAMAR unclips it, then rappels, and just deal with the rare stuck hair episodes with old lift and lower.

Thoughts?

[oldno7]

Love innovative thinkers.

So you wanted to have a system to speed up a rappel stage by being able to utilize both strands?

And also be a contingency for only one of those strands?

I guess I don't see how the VT is helping you out.

Can you release your smooth operator under load?

Do you have a good understanding of fall factors and shock loading a system and/or victim?

[Triggerfish]

This is contingency to either strand.
-The Munter can go either way.
- The VT can be placed on whichever strand someone is stuck on.

The point of the VT is to minimize shock loading. Dressed right and fully extended down the weighted strand, it allowed only an inch or two of jump in my tests when releasing the stone.

The Smooth Operator under load question I’m not sure on. I pulled it with maybe 100lbs load. Hard, but not incredible. With a big guy on high angle, could be a deal breaker.

Has anyone tested how hard it is to pull in Operator/Fiddlestick at some real-life loads? I’d love to know, for those moments when I’m hanging from one, curious about how hard it would likely be to pull free while I’m on rope. And it would decide that part of the practicality of this rig.

In real life, I doubt I’ll ever rig this. The complexity and time penalty seem to nullify the usefulness compared with a biner block clipped to anchor, and using a z or pig or balancier to lift and re-rig for lower in the rare event of a stuck rappeller. But hey, fun backyard experiment!

[vanyoneer]

I ran with your idea Triggerfish and improved it. This is a very nice technique to add to the quiver. The trick is to place the munter (or the figure 8 contingency) *below* the stone knot.

Before performing the lower, you must back the unweighted side clear of the munter biner, which means unthreading the munter, (or unthreading the figure 8.) This is easy to accomplish because you are not worrying about a brake hand yet.

When you are ready to release the toggle, the brake hand grasps the strand in the space between the stone knot and the munter biner. There should be no drop or pop at all. As you lower, you can pull a bunch of slack through the quicklink to clear the rope from potentially abrading the sling.

[moab mark]

When you pop your round fiddlestick how are you going to catch the slack from the stone knot? Interested in how your round stick has worked for you as a fiddlestick?

[moab mark]

Not that hard to pull straight out. When we first started screwing around with this concept we tried every possible way to figure out how it could go south.

[vanyoneer]

When you pop your round fiddlestick how are you going to catch the slack from the stone knot? Interested in how your round stick has worked for you as a fiddlestick?

You can get a hand between the stone knot and the device/munter. When you pop the stone knot, the rope is taut between your hand and the device, with the slack above your hand.

FYI After testing specifically with the 8, there isn't enough friction (with a 180lbs rappeller on the rope). The better option is to "double-up", pass the bight around the figure 8 tail and then back through the big hole and around the tail a 2nd time. Even with both strands doubled up it is pretty easy to back out the unweighted strand to perform the lower.

Re: the round stick, I would not recommend it unless you want to experiment. It cannot be safetied with a quickdraw like a fiddlestick. I think it pulls smoother with soft rope and would probably be good for sterling c-lux rope. This is 5/8" diameter rod.

[moab mark]

Yeah I was just wondering if you use the rod. When we started playing around with the fiddle stick concept we were using some wood dowels and they would create a loop in the rope and the stone knot wouldn't release.

Sent from my SM-G996U using Tapatalk