Rope stuff that is often misstated regarding single and half ropes and the
impact force etc.

"1. Half ropes likely do not offer significantly lower impact forces than single ropes in high fall-factor falls where one strand is clipped as is common.
2. Rope diameter alone is NOT a good indicator of impact force (some of the “fat” 11mm ropes offer lower impact force than the “skinny” single or half ropes).
3. The “published” impact numbers may not mean much (there’s a wide range between the published and actual in Jim’s data)."


http://willgadd.com/single-and-half-rope-impact-forces-data/