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loyota
May 12, 2009, 9:51 PM
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Since we know that most, if any falls don't produce the kind of KN force generated by the x2 lab drop test, and 10KN+ gear isn't exaclty breaking left and right... etc etc
Are there any studies or data out there regarding what range of KNs are typically generated in more real world falls (not necessarily factor 2).
John Long cites scientist Craig Connally in his book who throws out a 5.5-8.5 KN max figure. JL also mentions that in an eight year period QA at Black Diamond hadn't seen any stopper over 10KN fail and only a few 10KN carabiners fail in closed gate mode.
I guess if some yates screamers kick in at 2KN, we know we can get into that range probably without trying too hard :-D
I can't recall of hearing of any 5KN type gear breaking, I hear of Micros breaking but I don't know how low they were rated.
Anyway, just curious, be nice to know what's a little more based in the real world when you're forced / choose to start placing pro that's dropping into the lower KNs
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hafilax
May 12, 2009, 10:41 PM
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Micros are typically rated at around 2-5kN.
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rocknice2
May 13, 2009, 12:24 AM
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Worst real world fall???
Not counting FF2.
I'm starting P2 and it's hard right off the bat. I climb up a bit [feet level with belay device] and plug a cam and clip it. Now the cam is 7ft above belay device and 10ft above ledge.
I struggle up until the cam is at my feet and plug a nut. I'm so pumped fiddling with the nut and can't stabilize for the clip. I bitch, scream and cry in that order. Finally I peel off.
I take a 6 footer on 10 feet of rope = 6kn
Even more realistic the belayer worries I might deck and manages to take in an arm length of rope in.
A 6 footer on 8 feet of rope = 7.5kn
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angry
May 13, 2009, 12:32 AM
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I'm not sure that's how it works.
I could be wrong but I've never heard of being able to calculate fall forces in KN based on the distance of the fall vs. the amount of rope out. Maybe it's some sort of approximation based on fall factors.
1KN = 224 lbs or so. It's a real weight applied to your gear, not a fall factor applied to your rope.
Please correct me if I'm wrong, but I think you've got to be mistaken.
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majid_sabet
May 13, 2009, 12:46 AM
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rocknice2 wrote: Worst real world fall??? Not counting FF2. I'm starting P2 and it's hard right off the bat. I climb up a bit [feet level with belay device] and plug a cam and clip it. Now the cam is 7ft above belay device and 10ft above ledge. I struggle up until the cam is at my feet and plug a nut. I'm so pumped fiddling with the nut and can't stabilize for the clip. I bitch, scream and cry in that order. Finally I peel off. I take a 6 footer on 10 feet of rope = 6kn Even more realistic the belayer worries I might deck and manages to take in an arm length of rope in. A 6 footer on 8 feet of rope = 7.5kn
there is no such thing as FF2 in climbing. the best you may get is like FF1.75 or so.
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majid_sabet
May 13, 2009, 12:49 AM
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angry wrote: I'm not sure that's how it works. I could be wrong but I've never heard of being able to calculate fall forces in KN based on the distance of the fall vs. the amount of rope out. Maybe it's some sort of approximation based on fall factors. 1KN = 224 lbs or so. It's a real weight applied to your gear, not a fall factor applied to your rope. Please correct me if I'm wrong, but I think you've got to be mistaken.
wrong girl
1 KILO mean 1000 chingon
you sould say 1N =100 kg or @ 224 lbs
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shockabuku
May 13, 2009, 12:54 AM
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majid_sabet wrote: angry wrote: I'm not sure that's how it works. I could be wrong but I've never heard of being able to calculate fall forces in KN based on the distance of the fall vs. the amount of rope out. Maybe it's some sort of approximation based on fall factors. 1KN = 224 lbs or so. It's a real weight applied to your gear, not a fall factor applied to your rope. Please correct me if I'm wrong, but I think you've got to be mistaken. wrong girl 1 KILO mean 1000 chingon you sould say 1N =100 kg or @ 224 lbs
Dumbass.
1 KN = 1000 N = 1000 kg m/s^2
divide 1000 kg m/s^2 by 9.8 m/s^2 to get an equivalent mass = 102.04 kg = 224.49 lbs.
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curt
May 13, 2009, 12:54 AM
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majid_sabet wrote: angry wrote: I'm not sure that's how it works. I could be wrong but I've never heard of being able to calculate fall forces in KN based on the distance of the fall vs. the amount of rope out. Maybe it's some sort of approximation based on fall factors. 1KN = 224 lbs or so. It's a real weight applied to your gear, not a fall factor applied to your rope. Please correct me if I'm wrong, but I think you've got to be mistaken. wrong girl 1 KILO mean 1000 chingon you sould say 1N =100 kg or @ 224 lbs
Isn't your thumb healed yet? for God's sake back off on the meds.
Curt
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rocknice2
May 13, 2009, 1:00 AM
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Sorry
Your right I mixed it up a bit.
Corrected below for 175lbs climber
rocknice2 wrote: Worst real world fall??? Not counting FF2. I'm starting P2 and it's hard right off the bat. I climb up a bit [feet level with belay device] and plug a cam and clip it. Now the cam is 7ft above belay device and 10ft above ledge. I struggle up until the cam is at my feet and plug a nut. I'm so pumped fiddling with the nut and can't stabilize for the clip. I bitch, scream and cry in that order. Finally I peel off. I take a 6 footer on 10 feet of rope = FF0.6 = 5.8kn Even more realistic the belayer worries I might deck and manages to take in an arm length of rope in. A 6 footer on 8 feet of rope = FF0.75 = 6.2kn 20ft fall on 10ft of rope = FF2 = 8.9kn
Ignore the FF on the calculator
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colatownkid
May 13, 2009, 1:28 AM
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loyota wrote: Since we know that most, if any falls don't produce the kind of KN force generated by the x2 lab drop test, and 10KN+ gear isn't exaclty breaking left and right... etc etc Are there any studies or data out there regarding what range of KNs are typically generated in more real world falls (not necessarily factor 2). John Long cites scientist Craig Connally in his book who throws out a 5.5-8.5 KN max figure. JL also mentions that in an eight year period QA at Black Diamond hadn't seen any stopper over 10KN fail and only a few 10KN carabiners fail in closed gate mode. I guess if some yates screamers kick in at 2KN, we know we can get into that range probably without trying too hard :-D I can't recall of hearing of any 5KN type gear breaking, I hear of Micros breaking but I don't know how low they were rated. Anyway, just curious, be nice to know what's a little more based in the real world when you're forced / choose to start placing pro that's dropping into the lower KNs
Real world the greatest force is not necessarily a factor-2 fall. this situation actually produces a greater force:
hanging belay on a multipitch climb, the leader clips the top piece of the anchor or places a piece shortly after the anchor. the leader then continues for some distance without placing any gear and then falls. this results in a high-factor fall (though not factor 2). however, the pulley effect on the top piece results in a greater total force than a simple factor-2 fall. depending on how far the leader climbed, this force could be theoretically massive.
the max force from a factor-2 is somewhere around 9kN by my calculations. this assumes the belay is static, the belayer is about 1 meter from the anchor, and the leader is the standard 80kg climber. i don't remember the rope impact force i used in the calculations, but it was a decent median of single ropes currently on the market. these calculations were largely based on a paper rgold put together a while ago that i can't find the link to right now.
of course, assuming a static belay is not entirely realistic as the belayer will move and rope may slip, so forces could conceivably be even lower.
hope that helps.
edited to add: as fishclimb pointed out, this calculation also assumes the rope is an ideal spring and is not critically dampened (as it is in real life).
(This post was edited by colatownkid on May 13, 2009, 2:19 AM)
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adatesman
May 13, 2009, 1:45 AM
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spikeddem
May 13, 2009, 1:49 AM
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adatesman wrote: In case there's any willing guinea pigs at the NRR this weekend, I just put all the test equipment needed to test this into the car.... All we need is someone willing to take a couple FF1.5+ falls and we can finally put this to rest. If you're interested I'll most likely be in the NRAC tent and fairly easy to find.... Not too many people showing up with a pull tester. Oh, and we're not using my rope.  -aric.
The volunteer can borrow my static rope. 
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fishclimb
May 13, 2009, 1:52 AM
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The key factor in calculating the Falling Force is the time it takes to decelerate. F=ma. Shorter deceleration times increase the force in a fall. But I don't know the elongation rate of the rope for certain distances as this is the key to determining the time in deceleration.
But I've heard or read the numbers 3-5 kn.
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bill413
May 13, 2009, 2:01 AM
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adatesman wrote: In case there's any willing guinea pigs at the NRR this weekend, I just put all the test equipment needed to test this into the car.... All we need is someone willing to take a couple FF1.5+ falls and we can finally put this to rest. If you're interested I'll most likely be in the NRAC tent and fairly easy to find.... Not too many people showing up with a pull tester. Oh, and we're not using my rope. -aric.
(Not that I'd make the event anyway, much as I'd like.)
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taydude
May 13, 2009, 3:07 AM
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shockabuku wrote: majid_sabet wrote: angry wrote: I'm not sure that's how it works. I could be wrong but I've never heard of being able to calculate fall forces in KN based on the distance of the fall vs. the amount of rope out. Maybe it's some sort of approximation based on fall factors. 1KN = 224 lbs or so. It's a real weight applied to your gear, not a fall factor applied to your rope. Please correct me if I'm wrong, but I think you've got to be mistaken. wrong girl 1 KILO mean 1000 chingon you sould say 1N =100 kg or @ 224 lbs Dumbass. 1 KN = 1000 N = 1000 kg m/s^2 divide 1000 kg m/s^2 by 9.8 m/s^2 to get an equivalent mass = 102.04 kg = 224.49 lbs.
Owned by Physics!
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angry
May 13, 2009, 3:11 AM
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shockabuku wrote: majid_sabet wrote: angry wrote: I'm not sure that's how it works. I could be wrong but I've never heard of being able to calculate fall forces in KN based on the distance of the fall vs. the amount of rope out. Maybe it's some sort of approximation based on fall factors. 1KN = 224 lbs or so. It's a real weight applied to your gear, not a fall factor applied to your rope. Please correct me if I'm wrong, but I think you've got to be mistaken. wrong girl 1 KILO mean 1000 chingon you sould say 1N =100 kg or @ 224 lbs Dumbass. 1 KN = 1000 N = 1000 kg m/s^2 divide 1000 kg m/s^2 by 9.8 m/s^2 to get an equivalent mass = 102.04 kg = 224.49 lbs.
That's got to sting!!
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jt512
May 13, 2009, 3:18 AM
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majid_sabet wrote: rocknice2 wrote: Worst real world fall??? Not counting FF2. I'm starting P2 and it's hard right off the bat. I climb up a bit [feet level with belay device] and plug a cam and clip it. Now the cam is 7ft above belay device and 10ft above ledge. I struggle up until the cam is at my feet and plug a nut. I'm so pumped fiddling with the nut and can't stabilize for the clip. I bitch, scream and cry in that order. Finally I peel off. I take a 6 footer on 10 feet of rope = 6kn Even more realistic the belayer worries I might deck and manages to take in an arm length of rope in. A 6 footer on 8 feet of rope = 7.5kn there is no such thing as FF2 in climbing. the best you may get is like FF1.75 or so.
*bzzzzt* Thanks for playing!
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pfwein
May 13, 2009, 3:21 AM
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loyota wrote: . . . and only a few 10KN carabiners fail in closed gate mode.
And please excuse my ignorance , but can someone explain the pulley effect mentioned in this thread. In something like a FF2 situation, (i.e., at hanging belay, climber goes up and then falls without any other pro, except clipping the anchor), why would clipping the anchor cause more force? Isn't it just a function of how much rope is out, and it's slightly better to clip the anchor cuz slightly lower fall factor
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adatesman
May 13, 2009, 3:23 AM
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angry
May 13, 2009, 3:34 AM
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No battle today, just more misinformation. It wasn't as bad as normal, he was only off by a factor of 10.
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adatesman
May 13, 2009, 3:37 AM
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angry
May 13, 2009, 3:57 AM
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Terry2124 wrote: adatesman wrote: angry wrote: No battle today, just more misinformation. It wasn't as bad as normal, he was only off by a factor of 10.  Your looking for some excitement. None here
You're
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jt512
May 13, 2009, 4:10 AM
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angry wrote: Terry2124 wrote: adatesman wrote: angry wrote: No battle today, just more misinformation. It wasn't as bad as normal, he was only off by a factor of 10. Your looking for some excitement. None here You're
Angry, 5 stars.
Terry, I've actually killfiled your proflile pic.
Jay
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