prusik cordage strength

[jeff_r]

I believe ASNI states that prusik cords have to meet the same strength requirements of climbing lines, which would require a 5400lb minimum breaking strength. How rigorously is this enforced? There are conflicting views on this within my circle of climbing colleagues, who are using various types of cordage for their knots.

 

[Tom Dunlap]

Since the climber is supported by two ends of a hitch cord the interpretation of the Z133 standard is that the cord needs to have a minimum breaking strength of 2,700#.

 

[Mahk_Adams]

ANSI Z133.1-2006:

"8.1.9 Prusik loops, split-tails, and work-positioning lanyards used in a climbing system shall
meet the minimum strength standards for arborist climbing lines."


My interpretation of this wording is that the 'Prusik loop', which is a doubled piece of cord, needs to be 5400 pounds. The cord for the split-tail, and the rope for the lanyard need to be 5400 pounds.


But that's my interpretation. This section of ANSI is often interpreted as Tom described. Hence the "...conflicting views on this within [your] circle of climbing colleagues..."


I should also add that tensile strength is not the only factor to consider. Some other important factors are abrasion resistance, heat resistance, susceptibility to UV degradation, and compatibilty with the climbing line.

 

[NickfromWI]

I look to maintain a 3,000 pound limit (I rounded up from the 2,700..for convenience) on prusik cordage.

With HRC, Beeline, Icetail, etc, maybe one day it'll be a moot point, as all these lines come in over that 5400 mark anyways (actually not sure on the ice tail...just guessing on that one!)

love
nick

 

[TLHamel]

I believe Ice Tail is 8500 lbs. avg tensile/ 7700 lbs. min tensile.