# Thread: Mathletes: Dare ye enter?

1. A 23kN load is a measure of force. If that force is static (not moving, just a dead weight hanging) then we can convert that force to a weight of 2300 kg, which for you 'mericans means 5070.63 lbs, or a small car. Climbing rated carabiners are amazingly strong for their size and weight.

Now if take into account the fact that the object being measured for force is moving, then that's when things get interesting. Say you're getting into your hammock and simply flop yourself in. Not really a fall, but flop yourself in a top entry hammock. If you ignore the fact that your feet are on the ground slowing your decent, then the centre of gravity for your mass falls, say at most 2 ft? Given that F=ma, and the example above of someone being around 200 lbs...

F=ma
F=90.71kg*(9.8m/s2*0.61m)
F=90.71*5.98
F=542.45N

Just dropping into your hammock from 2 ft up will exert a force of 1195.9 lbs.

Just some more wood for the fire.

Dave

(man I hope my math is right on this one, I can't remember how to do this stuff anymore)

2. Another log on the fire, or at least adding some more math to the back of the napkin.

25kN/9.8= 2.55 tons of force.

I'm not concerned with my biners breaking. All the math does make a great case for using climbing biners.

3. I just realized what I wrote above. No wonder falling on my a\$\$ hurts so much.

4. I think everyone can agree that there are LOTS of forces being applied in different directions at different times. It's amazing as to just what those forces are!

Therein lies the rub: exactly when will a 22-23kN carabiner fail? Has there ever been an instance of one failing while using it in the hammocking world?

The simple carabiners I got with my TL Double hammock are listed as 500KGS, or roughly 1100lbf along its long axis. If Doftya's math is correct when he says "Just dropping into your hammock from 2 ft up will exert a force of 1195.9 lbs", then it stands to reason that one could exert enough force upon entry to overwhelm the TL carabiners. I just might replace them with 23kN climbing carabiners just to be safe!

5. Originally Posted by Alan
I think everyone can agree that there are LOTS of forces being applied in different directions at different times. It's amazing as to just what those forces are!

Therein lies the rub: exactly when will a 22-23kN carabiner fail? Has there ever been an instance of one failing while using it in the hammocking world?

The simple carabiners I got with my TL Double hammock are listed as 500KGS, or roughly 1100lbf along its long axis. If Doftya's math is correct when he says "Just dropping into your hammock from 2 ft up will exert a force of 1195.9 lbs", then it stands to reason that one could exert enough force upon entry to overwhelm the TL carabiners. I just might replace them with 23kN climbing carabiners just to be safe!
I have well over 100 hangs on the same biners. No signs of wear. Including twice when the webbing failed on one end. I think my backside and the ground account for the forces with those falls.

I would be very surprised to see something rated to 23 kN fail due to normal hammocking.

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