Quote:
Originally Posted by thinwater
No. Not correct. I'm guessing you are a recreational climber without exposure to industrial climbing.
Dynamic lines are for taking falls. Lead climbing. I have several and have climbed rock and ice for 40 years. Still do.
For rope access, hanging, and ascending, static lines, or at least semi-dynamic are preferred. In fact, jugging up s a dynamic rope is far less efficient, because you bounce more. You will not find dynamic ropes in use in industrial settings, for ascending and work at height. You won't find an arborist using a dynamic climbing rope. Check Westspur and similar sources. A typical example of a rope used for this type of climbing, which is very different from recreational rock lead climbing. https://www.wesspur.com/ROP1AFM-arbo...-climbing-rope
Double braid yacht ropes can meet OSHA and ANSI standards for this application if properly sized.
By the way, there is no reason not to use static or semi-static line for top roping. In fact, it has many advantages, including less stretch near the ground, where ankle sprains can be an issue. It's just habit that most climbiners use lead ropes for top roping. Mostly, it's because they only own one rope. And because they might want to lead something.
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Thank you for fact checking me. It sounds like your
depth of knowledge is better than mine on this subject. I find that refreshing. I don't like being the smartest guy in the room when I consider my knowledge base on a given subject to be only fair to middle quality.
I do have a small amount of experience using this
gear in an OSHA
environment, mostly at a Fortune 100 company that has rather strict standards. That represents probably less than 2% of my time at that location, so I don't consider myself a frequent flier in that
environment. I have much more time in with this
equipment, going up masts. My information was mostly gathered from rock climbers & tree guys. Here too, I am no expert, just a guy who pieced it together from a bunch of different sources that have managed not to hospitalize themselves over the years. I try not to be stupid, but I may still be a little ignorant on the finer points. I do like to share what I have learned & figured out so far.
I have noticed the difficulties of bouncing when jugging up a line. I have gone up a bouncy line before. It was an athletic event. Getting started was a little tough. It's good to hear that pulling yourself up a static line while using the dynamic for fall
safety is a condoned practice. It makes sense. It's the way that I would rather do it.
In the OSHA environment I was required to use what a rock climber would call a "screamer" attached to the top back of my full body harness, so that in the event of the fall, that sacrificial screamer would come unstitched as it absorbed the momentum of the fall. It was a one-shot device that would need to be replaced after a fall. It was used with 2" wide
safety straps that had basically ZERO stretch and much overkill for load capacity. In rock climbing, I only see the screamers used in "Via Ferrata" rigs when climbing attached to the
steel cables that the Italian army left in the Alps after their sneak attack during WWII. The guys that were frequent fliers in those rigs at the OSHA site had centrifugal breaking devices that were reusable, rather than the disposable screamers. I remember those things being pricey.
I'd be interested in
learning more about how yacht braid can meet the OSHA specs. My concern there is not with load rating, but rather with how stiff the line is, the coefficient of friction of the jacket, the jacket's wear resistance & the minimum bend radius of the line. I honestly don't know what the OSHA specs are. I just know that one client's standards & they may be more stringent than OSHA requirements.
I have noticed that a soft yacht braid can twist in an ATC & slip, when a stiff rope of the same diameter would not. That is my primary concern with using double braid in a climbing device. I've had that happen. My secondary system kept me out of trouble. That is why I previously said that the stated ranges on climbing devices is for climbing ropes & if you use yacht braid, a little trial & error may be needed.