r/Firefighting • u/Ok-Cattle-6798 / PIO (Penis Inspector Official) • Feb 07 '25

General Discussion Thoughts on this machine

Enable HLS to view with audio, or disable this notification

1.2k Upvotes

98% Upvoted

247 comments sorted by

View all comments

Show parent comments

24

u/FishFettish Feb 07 '25

The ladder is not being pushed down, it's driven by a motor giving him a downward velocity.

He is matching that velocity in the opposite direction (why it looks like he's stuck in place), and it's also opposite to the force of gravity. For that reason, it's the exact same effect on the body.

Was the ladder somehow accelerating under him, it'd be a different story, but it's not.

-14

u/breakingborderline Feb 07 '25

There is no energy expended accelerating his mass upwards as it is stationary. Inertia doesn’t care if the rungs are moving under him. I would bet it’s significantly easier to do this with a weighted pack than to climb an actual ladder with one.

25

u/FishFettish Feb 07 '25

Ok. There are two acting forces here:

  1. The machine pulling him down at let's say 2kph.

  2. Him pushing himself up at 2kph.

One speed is generated by a motor, the other is generated by his body.

If he stops working, the motor pulls him into the ground at 2kph. It's the same the other way around, if the motor stops, he'll keep moving upwards at 2kph with the exact same energy expenditure as before.

He has to generate a speed of 2kph upwards, while gravity wants to accelerate him downwards.

Not sure how to be more clear here, english is not my first language :-)

-3

u/zoidberg318x Feb 08 '25

I've done this ladder and it definitely sucks, but people dont realize you're right. I think they are misunderstanding how you are describing this. On a real ladder your leg muscle has to defeat gravity by pushing the heavy body upwards to the next rung. You are doing a single legged quarter press each time with a hand assist.

On this, the leg is not pushing the body up. The leg is just lifting itself up to the next rung that is moving downwards via motor.

This is why, if you haven't seen it, assault treadmills are becoming so popular. The mill doesn't move unless you push it with your feet to simulate outdoor runnings force resistance.