Originally Posted By: clearwater
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/


The main difference of stated impact force on the rope is the test weight:
Values required by the Standard:
• Single rope: Impact force lower than 12kN holding the first factor 1.77 fall with a mass of 80kg.
• Double rope: Impact force lower than 8kn holding the first factor 1.77 fall with a mass of 55kg.
• Twin rope: Impact force lower than 12kN holding the first factor 1.77 fall with a mass of 80kg,
(source: http://bealplanet.com/sport/anglais/savoir.php)

This effect can be seen on triple rates ropes like the Beal Joker. Not sure why you would weight less when falling from a double rope using a double rope technique.
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