Multi directional placement with two opposing stoppers
Rigging two opposed stoppers/nuts in a vertical crack it's kind of an old-school trick, which dates back to the Paleolithic era before cams were invented. But even today, it can be a good tool for those times when you need a multi directional placement and are low on cams, or want to preserve them for further up the pitch.
Basically, it can make one good placement out of two lousy ones!
When might rigging opposed stoppers be helpful?
The first piece when leading a trad pitch, to prevent an upward pull from zippering out your gear.
Setting up a belay anchor that needs to take a potential upward pull, such as a fixed point lead belay
Top rope soloing, where you need to set an anchor to take an upward pull
Clipping a Micro Traxion or Tibloc for simulclimbing
This “opposing two stoppers” trick is typically done with a clove hitch. However, many people find the clove to be tricky to tie and snug down, and that the clove doesn’t maintain tension very well between the placements.
Here's an alternative. The #CraftyRopeTrick here is to pass the sling TWICE around the top carabiner, with the second pass going BETWEEN the strands of the first pass. Then pull down to tension the sling. This double wrap maintains sling tension, making it much easier to tie a final half hitch to secure the whole thing.
Caveats . . .
You need a good stance and probably both hands to do this.
Although you’re using two pieces, because there's only one downward piece, this essentially counts as one placement. (In other words, this is NOT a two piece anchor.)
As shown here, this technique uses two stoppers, three carabiners, and a sling. (You can save one carabiner by girth hitching the bottom stopper, yes it's strong enough.) Often simple placing a solid cam can serve as a multi directional placement, plus it's faster and uses less gear. This is simply one more trick in the toolbox for more advanced climbers.
Questions, concerns, grumbles . . .
“Does this create a 2:1 ‘pulley affect’, doubling the load on the top piece of gear?” No. Because of the half hitch at the end, it doesn't. It’s a bit hard to describe, but give it a try and see for yourself.
“Does this create a vector/outward load on the gear which greatly increases the force on the placements?” It doesn't. The only force on the gear is going upwards or downwards.
“What if you did this in a horizontal crack?” Then you would have some odd vector angles on this anchor and it would probably not be so strong. But, if that's your only placement option, then you might have to do it.
“Good luck doing this on lead.” Yes, this does take a good stance and probably two hands to rig, so you're probably not gonna do it in the middle of some hard pitch. But as part of the anchor when you're hopefully on a ledge, usually not a problem.
Like most climbing techniques, it’s a better show than a tell. Check the video below to see how it works.
