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The cold world of skimo & alpine climbing

The cold world of skimo & alpine climbing

Thursday, April 15, 2010

BD tests/warning on Umbilicals



Worth a look for all the guys new to the limitations of umbilicals.





More here:

http://www.blackdiamondequipment.com/en-us/blog/index/view/slug/qc-lab-how-strong-is-the-spinner-leash


Thursday, February 4, 2010 - posted by BD crew:


QC Lab: How strong is the Spinner Leash?

I don't usually write-up BD product specific tests and results, but I've just been getting so many of a similar type question on the Spinner Leash lately, that I felt I needed to. And to be honest, these questions are kinda freaking me out.

"I just bought the Spinner Leash, How strong is it?"
"Is the Spinner Leash strong enough for it to hold me if I get too
pumped?"
"Will the Spinner Leash hold a fall if I whip onto it?"
"I want to make my own ice climbing tether system, how strong do I need to
make it?"
"Is the BD Spinner Leash stronger than the Grivel Double Spring Leash?"

Why do these sort of questions freak me out? Because it shouldn't matter how strong these things are. Sure they're rated to 2kN—like most tethers—and you can hang on them if you wanted or needed to, but you must remember that the leash is only as good as the placement of the ice tool it's attached to. Think of bounce testing a Pecker with a daisy chain. If the Pecker blows, you have it zinging towards you—same as if you decide to weight your tools via your Spinner Leash, except the tool is further out of your reach and has way more mass, and now it has the potential to slingshot towards your head. Ouch.




Ultimately the real purpose of these leashes is to stop your tool from falling into oblivion should you drop it on a long ice or alpine route. They're not really designed as something that you should sit on if you get too pumped mid-pitch (they are too long, and then you will have to climb back up to the tools), and they're definitely not intended as a "just in case"
if you were to whip, or used as a personal anchor system at a belay. I could compare this potential misunderstanding of usage of a Spinner Leash similar to the common misunderstanding and mis-uses of a daisy chain. I've seen folks using daisy chains incorrectly when aid climbing (e.g., you should never use a daisy chain such that there is even a possibility of taking a fall directly ONTO it). And I've seen tons of folks at the cliffs
using daisy chains as personal anchor systems—do you know the pocket strength on most daisy chains is ~ 500 lbs, a load easily generated with a slip, small fall and jolt onto the anchor? Daisy chains aren't designed for that kind of loading scenario—and neither are Spinner Leashes.




Bottom Line
The Spinner Leash and most new-school leash/tethering systems are intended to stop your tool from falling, NOT intended to stop YOU from falling.

I apologize for the soap-box-type speak, but just wanted to spread the word about the tether systems and the fact that you shouldn't be anchoring into anything with them, whipping onto them, and strongly consider the risks of weighting them at all if you are pumped.

Be safe out there.

KP



Kolin Powick (KP) is a Mechanical Engineer hailing from Calgary, Canada. He has nearly 20 years of experience in the engineering field and has been Black Diamond's Director of Global Quality since 2002. Kolin oversees the testing of all of Black Diamond's gear from the prototype phase through continual final production random sample testing.

1 comment:

Oscar Fors said...

I have unintentionally fallen with one tool in the ice. The Leash caught me before my rope did and held me. The spiral was slighlty extended, so now one is about 2 inches longer then the other.