Re: ANSI compliant?????
Or to put it another way, speculating on the risks of the technique described, the last thing a climber should worry about is a 22kN sling:
-A doubled ascender on a doubled line has no back up.
-A factor 1 fall will have a high force from poor energy absorption from a doubled line (ascenders are designed and tested for single kernmantle ropes).
-A doubled ascender is typically not securable to the doubled rope by clipping the top holes that it was originally designed to do.
-Ascenders are only rated to 4kN
-The line probably wasn't kernmantle, and so has an unknown quantity in a fall
- A speedy return to ground in the event of complications (e.g. bees).
The 22kN sling has a very large safety factor compared to the above points that were probably overlooked or ignored.
I suspect it was a succinct way of Frank trying to get us to 'think' about systems SECURITY over the dangerously limited reliance on STRENGTH?
The strength of something, MAY ensure a suitable margin for system security over time i.e. DURABLE SAFETY. But the CONSTRUCTION is just as important e.g. a single braid rope and kernmantle rope can be the same material and strength, but one is perfectly capable of retaining most of its breaking strength for 15 yrs whilst the other can lose half in 15 months.
Apply what we know about planning rigging systems to other areas of safety: Breaking strength divided by working load limit = the safety factor which implies a certain number of cycles before failure i.e. durable safety (or not as the case may be). The safety factor depends on the nature of the material e.g. a rope and karabiner both running at 5:1 certainly aren't going to have the same cycles to failure! So why have all components of a system (inc harness) rated the same strength? Makes for a very heavy harness that doesn't necessarily have durable safety, and an unknown quantity in a fall (especially if not tested for the possible fall).
Some food for thought.
