Very well explained. I would add (or emphasize) a double checking of the systems including squeeze checking the locking 'biners. I also like to weight the system before unclipping from the anchor.
From viewing several of his videos, Glen is really good at explaining these concepts clearly and concisely. Great job! For this specific video, I've used this technique for years to rap off of many mountains with my family (including small kids) with much more confidence (carefully avoiding the word "safe"). In response to a comment below: Yes, *ALWAYS* put knots on both strands, if for no other reason than habit. Technically the first rappeler is safe since the system is locked above, and the second has the benefit of the first fireman, but why make this situational. Easier to have the same habit in all cases.
Good good video, thank you. With pre-installed rappelling there is no way to check that the rope slides in the correct way so that it does not get stuck. If you are using two ropes it is even more necessary to check that they slide correctly.
Interesting technique, thanks for posting this! A question: I'm not sure I understand why you don't need a backup knot on both strands? My understanding: if you come off the right strand, that strand gets unweighted and your above climbers will no longer be on a fireman's belay, so the rope will start slipping through their devices. Eventually it will make it's way through their devices, at which point you and your followers fall.
I think a better question is to ask when do you need a knot in both ropes? (1) If you're doing a simultaneous counterweight rappel (one climber on each strand rappelling at the same time) you need to knot both ends. If one climber rappels off the end of the rope, then that climber falls, the counterweight is gone, and then second climber falls too with his/her strand of rope still in the device. This seems to be how Brad Gobright died. RIP. (2) If you are rappelling and no one is securing the rope above you with his/her rappel device above you (or if you are rappelling alone) you need to knot both ends. In this case, rapping off one end of the rope would cause you to fall and take the rope with you after the unknotted tail pulls through the rap rings. If there were other climbers above you tethered to the anchor, but not anchoring the rope with ATCs, they would be stranded at the anchor without a rope. I concede that the method in the video is 100% safe as described, but there are many ways to get this wrong and rappelling is a major cause of accidents. Personally, I just make a habit to close both ends of the rope when rappelling. I even do this if I am sure the rope will make it to the ground.
Thanks for posting this. This seems safer in that one climber isn't left setting up their rap device without a second set of eyes, which is especially nice when climbing with less experienced climbers or kids. My climbing buddies and I rap down with GriGris. We situate the middle of the rope between the chains as usual, fix one line with an overhand knot and krab so that it can't pull through the chains, then rap down on the other line. With that setup, is it acceptable to pre-rig multiple climbers' GriGris onto the non-fixed line?
