In reply to airborne:
> Petzl is launching its RAD (Rescue & Descent) System at ISPO, Jack. A similar rappel system with 6mm cord but with crevasse rescue kit as well. I'll show it to you guys next week...
I expect it to use a very special 6 mm cord.
In an alpine storm ( half frozen / wet ropes and climbers ) using standard 6mm acc cord tag line to retrieve 50m of 8.5mm rope, we could not believe the stretch involved to get sufficient tension to free the climbing rope.
When 6mm starts looking like 4mm and is screaming with the tension, it cannot take much scuffing on the rock to slash the sheath or even the full cord.
No wonder Spectra/Dynema 5.5 mm is the preferred tag line nowadays.