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loyota


May 12, 2009, 2:51 PM
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Common KNs in real world falls
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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


hafilax


May 12, 2009, 3:41 PM
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Re: [loyota] Common KNs in real world falls [In reply to]
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Micros are typically rated at around 2-5kN.


rocknice2


May 12, 2009, 5:24 PM
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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


Partner angry


May 12, 2009, 5:32 PM
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Re: [rocknice2] Common KNs in real world falls [In reply to]
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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.


majid_sabet


May 12, 2009, 5:46 PM
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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.


majid_sabet


May 12, 2009, 5:49 PM
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Re: [angry] Common KNs in real world falls [In reply to]
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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


shockabuku


May 12, 2009, 5:54 PM
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Re: [majid_sabet] Common KNs in real world falls [In reply to]
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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.


curt


May 12, 2009, 5:54 PM
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Re: [majid_sabet] Common KNs in real world falls [In reply to]
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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


rocknice2


May 12, 2009, 6:00 PM
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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
http://www.myoan.net/...t/climbforcecal.html
Ignore the FF on the calculator


colatownkid


May 12, 2009, 6:28 PM
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Re: [loyota] Common KNs in real world falls [In reply to]
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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 12, 2009, 7:19 PM)


adatesman


May 12, 2009, 6:45 PM
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spikeddem


May 12, 2009, 6:49 PM
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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. Angelic

-aric.

The volunteer can borrow my static rope. Laugh


fishclimb


May 12, 2009, 6:52 PM
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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.


bill413


May 12, 2009, 7:01 PM
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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. Angelic

-aric.
Oh, well, in that case count me out!

(Not that I'd make the event anyway, much as I'd like.)


taydude


May 12, 2009, 8:07 PM
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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!


theguy


May 12, 2009, 8:08 PM
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majid_sabet wrote:
there is no such thing as FF2 in climbing. the best you may get is like FF1.75 or so.

Wong again, wabbit: UIAA Article: Beware of Quickdraws for Self-Belay

For a useful answer to the OP's question see the UIAA Technical Committee Note: How strong does your climbing gear need to be?


Partner angry


May 12, 2009, 8:11 PM
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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!!


jt512


May 12, 2009, 8:18 PM
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Re: [majid_sabet] Common KNs in real world falls [In reply to]
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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!


pfwein


May 12, 2009, 8:21 PM
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loyota wrote:
. . . and only a few 10KN carabiners fail in closed gate mode.
What kind of a carabiner is only good to 10kN?--all I've seen are good to over twice that.
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


adatesman


May 12, 2009, 8:23 PM
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Partner angry


May 12, 2009, 8:34 PM
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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.


adatesman


May 12, 2009, 8:37 PM
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Terry2124


May 12, 2009, 8:50 PM
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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.

Frown

Your looking for some excitement.

None here Frown


Partner angry


May 12, 2009, 8:57 PM
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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.

Frown

Your looking for some excitement.

None here Frown

You're


jt512


May 12, 2009, 9:10 PM
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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.

Frown

Your looking for some excitement.

None here Frown

You're

Angry, 5 stars.

Terry, I've actually killfiled your proflile pic.

Jay

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