Retrievable Screw Anchor

This is more on the topic of Alpine climbing, but I came across this on Reddit and wanted to bring the discussion here. I’ve never seen this techniques mentioned in any books, but it seems like it has a good few advantages over threading, even if quite situational. There is also a German video on it here 

i would be surprised if this worked in real life... the stretch of the rope, angle, edge friction etc.  seems like you would need a perfect scenario for this to actually work as advertised.

Yeah, I have a hard time believing the screw would actually reliably unscrew once the release-cord is pulled. It seems more likely that the screw would bind up pretty badly with such a strong shear-force applied. But maybe if conditions are just right....

The purpose of which, anyways, is.... what?

A retrievable cam anchor for rock would be useful. But given V-threads..... what's the point of this one?

I'm an old man but I remember reading about this sort of thing in even older books.  Seems like the invention of the v-thread let techniques like this go extinct. 

I remember Bela Valdez (alpine skills institute) having a video on this years ago.

Bela died a few years back; heart condition.

Good man super strong skier, I believe his wife Mimi, is still running the show

Andy Kirkpatrick's book " Down" page 179@

The Reddit thread erroneously suggests that this would be a "safe alternative for V-threads, in certain circumstances - such as deteriorating alpine ice". This makes no sense. Ice screws are metal and therefore conduct heat better than ice, which means they melt out faster and lose strength faster than a v-thread in any sort of warming or aerated ice. If the ice is too aerated to v-thread a screw is no safer. If the ice is melting, the v thread will stay solid much longer than a screw. Use a v-thread and get out of there before the ice gets worse instead of wasting your time with complicated tricks that might not pull anyway. The only situation I can think of for which this might make sense is if you have a narrow vein of nice ice, say in a crack in the rock, and it is not big enough to place a v thread (in width or height), but it just happens to be big enough that a screw can go in and out unimpeded AND the pull is going to be clean enough to allow you to execute this unscrewing method... pretty rare scenario. 

It’s an old idea from way back in the dusty corners of ice climbing.  It stayed there for good reason.  It’s not practical or even remotely better than alternative methods.  It would only be suggested today by people who are inexperienced. 

This technique was widely used in Europe before the V Thread was developed, and it works just fine in the "real world" . Today it is not practicle given the strength, and the speed at which a naked V Thread can now be developed.

Man, I'm having a hard time getting excited about this one.