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stoutclimb1
Oct 8, 2002, 3:44 AM
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I know that it transfers to pounds but cant find anything about it, im computer ilitirate. But ive got a biner that says its kn is 24 how many pounds is that.
PS. if its less than 100 just lie to me and say a 10000
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andy_lemon
Oct 8, 2002, 4:10 AM
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kN = Kilonewton
One kiloNewton (kN) is the force required to change the inertia of a mass of a little over 220 pounds
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andy_lemon
Oct 8, 2002, 4:12 AM
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I came up with 5280lbs... did it in my head though.
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jetace
Oct 8, 2002, 4:13 AM
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I'm not sure on the weight, I think that would be a force rated up to 2400pds, but I do know it stands for kilonewton, I have no idea how its spelled, but thats what kn stands for
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matt
Oct 8, 2002, 4:16 AM
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Check this thread out...I think this is what you're looking for http://www.rockclimbing.com/forums/viewtopic.php?topic=13515&forum=40
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droche
Oct 8, 2002, 4:20 AM
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Newtons and pounds are just different units of force (like centimeters and inches are for length). 1Kn=1000N=225 lbs.
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stoutclimb1
Oct 8, 2002, 4:20 AM
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yup that helps thanks everyone be back tomorow
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fixxervi6
Oct 8, 2002, 4:24 AM
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Pounds is MASS
KN is FORCE
You convert by using excelartion, example, gravity, 32.2 feet per second on earth.
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coldclimb
Oct 8, 2002, 4:30 AM
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a newton is acceleration of 1 gram per meter per second per second. So a kilonewton is 1000 grams, which is, like they said, 225 pounds.
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apollodorus
Oct 8, 2002, 4:38 AM
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The Newton is the unit of force in the S.I. (metric) system of measurement. A kiloNewton (kN) is 1000 Newtons. The kilogram is the unit of mass in the S.I. system.
The unit of pound refers to both pound-mass and pound-force in the S.E. (stupid English) system of measurement. The usual thing, though, is to use pounds for force and slugs (HUH?) for mass. Or if you use pound-mass for mass, you need a conversion factor of 32.2 (lb-force * ft)/(second^2 * lb-mass). Not surprisingly, a mass of one slug has a weight (gravitational force on earth) of 32.2 pound-force. Like I said, the old English system of units is stupid.
So, 4.45 Newtons equals one pound-force; 224.7xxx pounds equals one kiloNewton.
And 2.204 pounds-mass equals one kilogram. Or, 0.4537 kilogram equals on pound-mass. If you multiply 0.4537 by 9.81 m/s^2 (earth's gravitational acceleration) you get 4.45 Newtons per pound-force. Guffigure.
Remember when those rocket scientists crashed a probe into Mars a couple of years ago? It was because they got their lb-f, lb-m and N and kgs all mixed up. I'm not making that up. They fired the control rocket wrong and crashed a zillion dollar probe.
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wlderdude
Oct 8, 2002, 11:37 AM
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Anyone who says that the English system is stupid needs to go work on their car and beat their hands up on those idiotic metric bolts!
I think they are designed to strip out!
Man, standard is the only way to go with bolts sizes!
But, yeah, for number crunching, you can't beat metric!
I mass 4.3 slugs.
How many slugs do you mass?
[ This Message was edited by: wlderdude on 2002-10-08 04:39 ]
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burz
Oct 8, 2002, 1:20 PM
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Not sure what happened to the long version of this post, but...
kN stand for kilo newtons which is a unit of force. The units of a newton are kilogram meter per second squared. Since gravity on earth is constant if you do the conversion, the caribiner can hold approximately 5400 pounds (mass).
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jamison
Oct 9, 2002, 5:29 PM
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There is no simple answer to this (unless your an engineer or a physicist).
My advise is forget pounds and think in metric. Know that on earth a person who weighs 180 pounds exerts about .8kN when just hanging on the rope.
But it really doesn't matter, because I imagine you are more concerned what happens when you fall and load the equipment. That .8kN is out the window at that point.
The good news is that from what I know about rope dynamics is, about the maximum fall that can be created in "normal" climbing is 10kN. I imagine that requires a pretty high fall factor (ie. 1.78 or higher).
But to answer the question... 1kN = 225 pounds (force).
Jamison
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jamison
Oct 9, 2002, 5:33 PM
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Just to clarify...that 10kN is "in line with the rope". Since the person falling is exerting 10kN down and the belayer is exerting 10kN down to resist, the biner feels 20kN. So on a top rope, the force on the biner has to resist double ----> 20kN. Thus a 24 kN biner.
Jamison
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vicum
Oct 9, 2002, 5:42 PM
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So if the binew feels 20 kn in a 10 kn fall( I understand the physics of that) what good does it do to have nut/hex/cam/ that only withstands 10-14 kn? Doesn't really make sense to me. Thanks ~Arnold
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mountainmonkey
Oct 9, 2002, 5:57 PM
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Well...
A fall that produces 20 kN on a piece is the worst case scenario for normal climbing falls (factor 2) - no matter the length of the fall. This doesn't take into account simul-climbing falls or when the belayer jumps/falls too. To answer your question, as if you haven't guessed it yet, that is the worst fall and most falls are much less than that. Check out Petzl's website and find the fall simulator.
casey
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stoutclimb1
Oct 9, 2002, 6:37 PM
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thanks you all i understand
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jamison
Oct 9, 2002, 7:00 PM
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V,
That is a question I have not figured out yet.
Anybody?
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blazesod
Oct 9, 2002, 7:35 PM
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V,
I am not a scientist but I will take a SWAG (scientific wild ass guess) at this one. I believe types of protection rated less than 20kN may be safely used in a conjunction with other pro or for supporting body weight, gear etc on long routes.
Example a) equalize 3 (9kN pieces)
Example b) use a 9kn cam to aid up a route
Another thing to consider is the strength and quality of the rock itself. If you have very little outward force on pour quality sand stone the rock may not support 20kN. In an extreme case your 8kN nut may be in good shape after it rips out of a crumby rock face.
Just a good reason to always have a backup.
Take Care,
Dave
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pir8penguin
Oct 10, 2002, 2:03 AM
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As already mentioned, the newton is a measure of force, so it can't be converted to pounds, or vice versa since pounds are a measurement of weight. however, to CLARIFY this 225lbs = 1kN (1000 newtons), what that REALLY means is that a 225lb person NOT moving or falling exerts a force of 1kN i believe. that same person falling obviously exerts more of a force. for that, i don't have an equation.
don't think of as how much WEIGHT your gear can hold, rather how much FORCE...it should seem obvious that a massive object can fall a short distance and cause an equal force to a much less massive object falling a long distance.
physics 101 lesson:
Force = mass * acceleration
Force unit: Newtons
Mass unit: kilograms
Acceleration unit: meters/second/second (m/s^2)
since we're on earth, gravity is our acceleration, it's value being 9.8 m/s^2. consider a mass of 100kg...
F = 100 * 9.8
F = 980N (.98 kN)
now, consider 200kg
F = 200 * 9.8
F = 1960N (1.96 kN)
greater mass, harder fall.
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petsfed
Oct 10, 2002, 2:27 AM
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Pardon me while I step in and flash my genuine "physics major" badge. Do to the fact that when the idea of a pound was created, the people had no idea that mass was seperate from weight, it's often confused as such. In any event, when you apply the force of gravity to an object of mass=1kg, the object will "weigh" 9.8 newtons or 2.2 pounds. Therefore to get an object of mass=1kg to have a constant acceleration of 1 meter per second per second, you would have to push it with a force of 1 newton. We named this in honor of Sir Isaac Newton and his three laws of motion, of which one is Force = Mass x Acceleration. We certainly didn't immortalize him for his people skills. Based on that, 1 kN, that is 1000 newtons, acting on a carabiner would be equivalent to hanging a weight on that carabiner of approximately 225 pounds. That's why the biners are rated at least 22 kN, and I've seen as far as 36 kN on a carabiner that must've had a mass of at least half a kilo.
As for the protection/carabiner rating inequality, keep in mind that force on that biner comes from 3 sources: the falling climber, the belayer, and the rock keeping the pro in. The pro need only be equivalent to the downward force of the belayer and the climber. On top of that, the rope dissapates some energy, as well as the sling inbetween. So realistically, the only pro that would be sketchy to fall on would be that which is rated to 2-3 kN.
[ This Message was edited by: petsfed on 2002-10-09 19:30 ]
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curt
Oct 10, 2002, 2:37 AM
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Boy, there is enough scientific information (and disinformation) in this thread to make this topic seem complicated--and this is simple. I'm glad we're not talking about something difficult.
The pound (lb.) is a traditional unit of force--just like a Newton! A force of one pound is simply the gravitational force experienced at the Earth's surface by a mass of one pound. To compute this force, we multiply the mass by the acceleration of gravity, following Newton's law F = ma. Since one pound of mass is 0.454 kilograms and the acceleration of gravity averages 9.8 meters per second per second at the surface of the Earth, one pound force equals the product of these two numbers, 4.4492 newtons.
So, the use of weight = force is perfectly correct. Unless you climb somewhere other than Earth where F = mA will differ, due to A being not equal to "G", the acceleration due to the Earth's gravitational attraction.
Curt
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apollodorus
Oct 10, 2002, 4:13 AM
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The reason you need 20 kN biners on 10 kN pro is because there has to be a safety margin. A biner that gets tweaked in an odd placement will not hold its full 20 kN rating. Also, the biner crab is a link that often takes more than one load. We can all thank Yvon Chouinard for essentially setting the standard for carabiner strength. Lord knows he worked long and hard to optimize the common crab in terms of weight and strength. His final analysis is what most companies depend on today. BD bought his climbing gear company, and thus still brings us the best of the best.
Also, when you "rip the pitch", every piece that blows out will take some of the energy of the fall with it, so the last piece that finally grabs you (the belay???) doesn't take the full force of the fall. Well, that's for aid or really scary trad.
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pir8penguin
Oct 10, 2002, 2:20 PM
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hey curt, you can't define a unit of measurement with itself. try again.
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jamison
Oct 10, 2002, 2:59 PM
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Burren (and somebody with a physics degree),
OK, I'm confused. Firstly, I'm american, but I learned metric, and I like metric. Secondly, I don't remember my pounds/slugs/etc. very well.
But.....What I remember is that 1 pound(mass) is directly proportional to 1 pound(weight)
No, they are not the same! They vary by the coefficient of gravity. But contray to what Burren said, you can't just multiply pounds(mass) by gravity to get pounds(force).
Don't you have to convert pounds(mass) to slugs first?
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