Hey Tech-Heads

Placing a cam? Slotting a nut? Slinging a tree?
marathonmedic
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Hey Tech-Heads

Post by marathonmedic »

Instead of studying I was poking around online and came across something confusing.
• Never catch and weight the nose of a biner on a sling, hanger, or cable. This can cause it to break under body weight, as there is a tremendous amount of leverage on the spine of the biner.

I'm interpreting this as meaning that the nose of the biner shouldn't be facing the gear. But I don't get it. How is the direction of the biner going to change the forces on the spine? Aren't you pulling in straight lines along the long axis of the biner (assuming you're not crossloaded or something)? What about quickdraws pulling on hangers? Please educate a poor fool who doesn't understand fisiks.
Ticking is gym climbing outdoors.
J-Rock
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Post by J-Rock »

Rick? Are you here?
"Those iron spikes you use have shortened the life expectancy of the Totem Pole by 50,000 years."

--A Navaho elder
Wes
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Post by Wes »

Sounds like they are trying to discribe the notch where the gate closes catching on something with the spine against the rock?

Wes
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kato
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Post by kato »

If you catch on the nose, you are not quite cross-loading it, but you are not loading along it's strongest axis either. It's a diagonal load. And obviously, if a sling or whatever is stuck on the nose, the gate will not be closed, so it loses that strength as well. I've seen a person snap a biner in half that way.

As for the leverage, the force is normally applied in the hook in the end, closer to the spine (on a D shaped biner) and resisted through the spine and the gate. This is only a tension load. Loaded like you've described, the load is applied at the nose and resisted only through the spine, so there is both a tension and a torque.
dhoyne
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Post by dhoyne »

I think they're pretty much talking about using a beaner as a hook. That's obviously a no-no.
Sarcasm is a tool the weak use to avoid confrontation. People with any balls just outright lie.

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marathonmedic
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Post by marathonmedic »

Hmm. Yep. Makes a lot more sense when you look at it that way.
Ticking is gym climbing outdoors.
batguano
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Joined: Wed Oct 09, 2002 4:24 pm

Post by batguano »

I couldn't resist.
I rigged the biner as illustrated here,

Image

then a very moderate bounce test yielded this,


Image
weather is occurring.
Alan Evil
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Post by Alan Evil »

note to self: don't do that.
[size=75]You are as bad as Alan, and even he hits the mark sometimes. -charlie

"Not all conservatives are stupid, but most stupid people are conservative." - John Stuart Mill[/size]
J-Rock
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Joined: Tue Apr 13, 2004 9:30 pm

Post by J-Rock »

Also, don't rappel from belt loops on your blue jeans. I did this while night climbing once. I thought it was my belay loop. I'm surprised it held me for the entire descent. I noticed my error after touching down on the ground. It ripped off easily with a sharp tug.
"Those iron spikes you use have shortened the life expectancy of the Totem Pole by 50,000 years."

--A Navaho elder
Alan Evil
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Joined: Fri Oct 10, 2003 1:08 pm

Post by Alan Evil »

note to self: don't do that either.
[size=75]You are as bad as Alan, and even he hits the mark sometimes. -charlie

"Not all conservatives are stupid, but most stupid people are conservative." - John Stuart Mill[/size]
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