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sandbag
Nov 15, 2004, 10:15 PM
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Is it just me, or does anyone else think that instead of placing a hangar rated at 20+Kn on a 10Kn ice screw, Id rather see a 20Kn ice screw period.
Call me crazy....
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johnson6102002
Nov 15, 2004, 10:45 PM
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seems liek a good idea to me but how many ice screws have u broken?
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sandbag
Nov 16, 2004, 8:47 AM
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if you ever go re read Craig Lubbens article on Ice gear that he was paid to destroy inthe name of better equip, youd understand you dont ever want to have to worry about breaking an ice screw.... :x
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maculated
Nov 16, 2004, 8:50 AM
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Not only are you crazy, but . . . well . . . tough luck. Your biggest problem ice climbing isn't just the screw, but the ice around it.
What's the rating of ice?
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jamescuth
Nov 16, 2004, 9:47 AM
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i would've thought that if you put 20kn on the screw, the ice is (far) more likely to go before the screw does....
at least your hangar will be ok though...
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overlord
Nov 16, 2004, 12:27 PM
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^^^^ ditto that. dont worry about it. if you fall chances are youll pull the scre out. or, even worse, youll pull the whoe waterfall :shock:
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johnson6102002
Nov 16, 2004, 7:08 PM
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In reply to: if you ever go re read Craig Lubbens article on Ice gear that he was paid to destroy inthe name of better equip, youd understand you dont ever want to have to worry about breaking an ice screw.... :x
ohh please the ice will break far before the screw :twisted:
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sarcat
Nov 16, 2004, 8:06 PM
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I'm sure you can find whatever you'd like depicted in a movie. That means it's gotta exist and work to boot.
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sandbag
Nov 16, 2004, 8:09 PM
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In reply to: In reply to: if you ever go re read Craig Lubbens article on Ice gear that he was paid to destroy inthe name of better equip, youd understand you dont ever want to have to worry about breaking an ice screw.... :x ohh please the ice will break far before the screw :twisted:
Well, im digging fromthe recesses of my lil pea brain, but im remembering that you only need about 3 inch(~7cm) of ice to safely support and drive a 2500lb car onto it. so, ice is much stronger than you think. And again, go read Lubbens tests on ice gear. Im suggesting that if the screw is rated at 10Kn why put a 20Kn hangar on it?
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pulldownfrenzy
Nov 17, 2004, 7:42 AM
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just to let you know...
I just finished several hours of engineering homeworkand I have a pretty good idea of what 20 kN is. Do you know how much weight 20 kN of force is?
Like others said, you'd pull down half of your water fall and be lying on the ground with your ice srew still firmly embedded into the chunk you broke off.
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cantbuymefriends
Nov 17, 2004, 9:38 AM
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In reply to: Well, im digging fromthe recesses of my lil pea brain, but im remembering that you only need about 3 inch(~7cm) of ice to safely support and drive a 2500lb car onto it. so, ice is much stronger than you think. And again, go read Lubbens tests on ice gear. Im suggesting that if the screw is rated at 10Kn why put a 20Kn hangar on it?
Yes. But the load is distributed over a much larger area. And a (big) part of the load is also transferred to the water that the ice is "floating" on. Ice with air bubbles under it breaks much easier than solid black ice, right?
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jt512
Nov 17, 2004, 5:33 PM
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jt512 has locked this thread.
Reason: Title of thread is meaningless. Original poster: Edit the title, PM me and I'll unlock the thread.
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jt512
Nov 17, 2004, 9:04 PM
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jt512 has unlocked this thread.
Reason: Unlocked at user's request.
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jt512
Nov 17, 2004, 9:12 PM
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jt512 moved this thread from General to Gear Heads.
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chriss
Nov 17, 2004, 9:51 PM
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As everyone has said the strength of a screw placement is all about the quality of the ice.
Screw hangers are where all the weird loading angles are going to exist. The hanger will probably never be in the "perfect" positon, with the load applied in the "intended" direction.
chris
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sandbag
Nov 17, 2004, 9:56 PM
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In reply to: As everyone has said the strength of a screw placement is all about the quality of the ice. Screw hangers are where all the weird loading angles are going to exist. The hanger will probably never be in the "perfect" positon, with the load applied in the "intended" direction. chris
EXACTLY!
so why put a hangar, rated in excess of the piece, that will allow the 'wierd' loading cause the shearing of the screw????? Make the screw 20Kn and Id be happier.
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chriss
Nov 17, 2004, 10:34 PM
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In reply to: In reply to: As everyone has said the strength of a screw placement is all about the quality of the ice. Screw hangers are where all the weird loading angles are going to exist. The hanger will probably never be in the "perfect" positon, with the load applied in the "intended" direction. chris EXACTLY! so why put a hangar, rated in excess of the piece, that will allow the 'wierd' loading cause the shearing of the screw????? Make the screw 20Kn and Id be happier.
NOT Exactly.
The weird loading only exists in the hanger. The irregularity of the surface and the direction of the load cause the hanger to be loaded at odd angles. And any bending forces only effect the hanger.
The screw is round, it only sees shear (perpendicular) and tensile (along length) loading. This is transmitted to the ice.
If the screw is not in the ice all the way to the hanger. Well that's when you want a 50kn screw.
chris
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washufinku
Nov 17, 2004, 10:41 PM
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Uh, going to go out on a limb here. But, I'm guessing that in order to make a screw hold more than it does now, you would have to make it thicker. If it was thicker, it would displace more ice and result in a weaker placement overall, thus negating the purpose of having a 20kn screw..eh?
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gunkiemike
Nov 18, 2004, 12:12 AM
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Question to the original poster - is all your rock gear rated to 20 kN? All the cams? Wired nuts? Lowe Tricams?
Didn't think so.
What pro DO you have that's rated to 20 kN???
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sandbag
Nov 18, 2004, 12:29 AM
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In reply to: Question to the original poster - is all your rock gear rated to 20 kN? All the cams? Wired nuts? Lowe Tricams? Didn't think so. What pro DO you have that's rated to 20 kN???
Lets see:
biners 18-26Kn Check
Runners/webbing/slings 15-25Kn Check
Tricams 10-22Kn Check
Trango Big Bro 15Kn check
Nuts are limited to 10Kn because of the cable swage, Check
Camming devices 4-18Kn check
My point isnt the 10Kn, its the question on why they use the 20Kn Hangar why not a 10Kn, or why not make the screw 20Kn.......
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