|Comments on Learn the Basics of Rappelling||Add Comment|
By Old lady H
From: Boise, Idaho
Aug 24, 2015
|Assuming your ATC is hanging on your harness from a biner (mine always parks front right gear loop), load the rope strands into the ATC and biner first, then move the biner into your belay loop and lock. No dropped ATC or biner.|
From: Poughkeepsie, NY
Jul 19, 2016
The advice in the article is decades out of date.
First, the autoblock-on-legloop is a suboptimal method. There are at least two problems:
1. Prying open a legloop buckle. If the leg loop has buckles, then depending on where the autoblock is placed it might or might not pull open a buckle. See blog.alpineinstitute.com/2011/... for bad and good places to clip.
2. Autoblock failure. As alluded to in the article, the length of the autoblock sling has to be very carefully determined so as to keep the autoblock from colliding with the rappel device. But even with what seems like the proper proportions, the autoblock might collide (and so either release or fail to grab) if the rappeller takes a high step with the leg on whose loop the autoblock is installed. In any case, if the rappeller inverts for some unfortunate reason, the autoblock will collide and is likely to fail.
Here's a classic example from the internet advice mill of how to set things up to almost guarantee a catastrophe. Note the tiny distance between the tightened knot and the device. Raising the right leg an inch or two will release the autoblock.
These problems can be avoided by extending the rappel device on a sling or tether and placing the autoblock on the harness belay loop. This has been common knowledge for many years and should by now be the standard method.
Here's the right way to rig (from climbing.com/skills/5-steps-fo...
Second, the rigging sequence is suboptimal. The best way to rig is to first put the autoblock on the rope and attach to the harness belay loop. Then pull some rope through the autoblock and let it hold all the rope below, leaving an unloaded loop above that can be threaded through the rap device on the tether. This is far better than standing on the rope and more efficient than having a partner hold the rope for you.