Force of a 250mm fall

[Mick Dempsey]

Thanks, that’s set my mind at ease.

[Puffingbilly413]

1 hour ago, Mick Dempsey said:

I could jump 10 inches off my sofa right now.

Don't do it Mick - just sit down.

[Khriss]

1 hour ago, Mick Dempsey said:

Am I going mad here?

Pointed out to me by my physio that pull starting yr saw several times is equivalent to dislocating yr shoulder - mind that coffee table when you jump.... 😉  K

[David Cropper]

1 minute ago, Khriss said:

Pointed out to me by my physio that pull starting yr saw several times is equivalent to dislocating yr shoulder - mind that coffee table when you jump.... 😉  K

Panic over Khriss. I rushed down to Chateau Dempsey. He's fine, I managed to talk him down off the sofa. I've made him hot cocoa and tucked him up in bed. 

[Khriss]

1 minute ago, David Cropper said:

Panic over Khriss. I rushed down to Chateau Dempsey. He's fine, I managed to talk him down off the sofa. I've made him hot cocoa and tucked him up in bed. 

...... Oh, but is that coffee table still ok thou, it was a good one  🙁 K

[David Cropper]

1 minute ago, Khriss said:

...... Oh, but is that coffee table still ok thou, it was a good one  🙁 K

Didn't look. I was more concerned about his mental state. Just got there in time, completely insane in my view.

[Paddy1000111]

Am I right in saying the furthest theoretical fall (assuming you stuck to all the rules) is 750mm? You can have 500mm of slack in your climbing equipment and you can climb 250mm above your anchor? If you fell you would fall 250mm to the anchor and then 500mm past that. 

 

Assuming a climber weighs 90kg and falls 750mm then the velocity at stop is 3.83 m/s. Which gives us a kenetic energy of 661.5J but that's not useful so as open space man says you need to know how far the climber falls once stopped or his deceleration. It's quite different depending on length:

 

50mm  = 13230N or 13.230kn

100mm= 6615N or 6.615kn

200mm= 3307N or 3.307kn

 

The distance you fall is all down to how springy your equipment is, how static your ropes are and how hard your anchor is. I would suggest maybe 50-75mm would be a good distance on 500mm of rope? 

Edited February 20, 2021 by Paddy1000111

[Doug Tait]

25 minutes ago, Paddy1000111 said:

Am I right in saying the furthest theoretical fall (assuming you stuck to all the rules) is 750mm? You can have 500mm of slack in your climbing equipment and you can climb 250mm above your anchor? If you fell you would fall 250mm to the anchor and then 500mm past that.

Is it not just 500mm max.

250mm above anchor, giving 500mm of slack to fall in to 

[Paddy1000111]

12 minutes ago, Doug Tait said:

Is it not just 500mm max.

250mm above anchor, giving 500mm of slack to fall in to 

So if you're climbing above your anchor then it's only 250mm of slack in the climb line? 

[Doug Tait]

1 minute ago, Paddy1000111 said:

So if you're climbing above your anchor then it's only 250mm of slack in the climb line? 

That's my understanding Paddy, if you fall while 250mm above anchor, you'll travel 500mm before system catches you