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Post by rmc on Nov 4, 2012 19:15:47 GMT
Posted by PAN VIRGO INTACTA on January 5, 2012, from DCI (Discovery Channel International) Mythbusters forums:
It must be possible to construct a Pogo-Stick that will absorb all the energy of a falling person. Fitting a latch to the device that clicks into place when the spring(?) is fully depressed, allowing the person to calmly step off and go dry clean their shorts, seems obvious?
It must be possible, it simply must.
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Post by trakmec on Nov 4, 2012 22:29:01 GMT
I do not think this one is particularly possible, Parachutes use drag and slow your rate of descent. The pogo wouldn’t.
So very quickly after leaving the AC you’d reach terminal velocity. Now could you build a shock absorber that could handle the impact? Yes, sure but it’d be bigger and heavier than a chute.
As you’d be riding it would have to slow you down from terminal V slowly so as not to splat you against its framework, again making it bigger and heavier.
Then there is the matter of landing this few hundred pound contraption upright with you on it, requiring a broader and again heavier base than the normal pogo.
Finally if you aren’t attached to this thing as it begins to slow down on impact you’re still going to be moving. There’s a really good chance you’d lose grip or balance and come off the thing.
What you’d end up with is something so large and heavy that you couldn’t maneuver it out of most normal Aircraft on your own, it would just be a really big shock absorber not a pogo of any sort as there’d be no practical way I can think of for you to jump up and down with this contraption.
Lord forbid that you landed safely and upright and the suggested safety catch failed. The stored energy in the springs would probably be enough to launch you over a house. Possible maybe, Practical no.
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Post by Cybermortis on Nov 4, 2012 23:44:37 GMT
One also has to wonder what happens if you were to fall on soft ground...by the time the spring started to compress you'd already be six feet under.
I guess the possibility would depend on how you would classify a pogo-stick in this context. If it is a single pole like structure you'd need a rather frightening spring to be capable of absorbing that much energy at a safe rate. But you might be able to create something that would work using several 'poles' around a platform.
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Post by freegan on Nov 5, 2012 2:02:52 GMT
It would make for some entertaining videos if you landed on a skateboard.
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Post by silverdragon on Nov 5, 2012 6:53:07 GMT
I think Tracmec has it with the "Bigger and heavier than a chute" estimate....
I know the RAF researched alternative ideas for dropping crates out of the back of a Herky-bird at one point (C130 in U$A), they tried the arrester hook idea you get on aircraft carriers to "catch" a dangled hook from the ground (Ok, it was a boat anchor dragged out the back of the plane on a long rope...)
But again, having that kind of equipment on the ground, its bigger and heavier than a cargo chute, and, how would you set it up anyway if you havnt got it?....
There is that guy with a "Wing suit" that swears he will eventually get it so that he can land safely without a HUGE pile of boxes, but, otherwise, the keep-it-simple approach, has anything yet been found thats better than a parachute....?...
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Post by memeengine on Nov 5, 2012 7:40:53 GMT
Another point that hasn't been mentioned is that if the fall has any horizontal velocity (i.e. you're not falling straight down) then landing safely on a single pogo-stick point would be tricky.
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Post by spork on Nov 8, 2012 4:24:52 GMT
There is that guy with a "Wing suit" that swears he will eventually get it so that he can land safely without a HUGE pile of boxes I think you're referring to Jebb Corliss. Jebb has been threatening to land a wingsuit without a pile of boxes, but I'm pretty sure his plan requires a $2 million custom landing ramp. So not all that practical either. I'm guessing rmc wasn't proposing a practical approach to jumping without a parachute, but yes, I'm pretty sure it could be done. And frankly, I'll be more than happy to build the rig to put Buster on to prove it. I just ran some quick numbers. If you wanted to experience 5 G's during deceleration - you'd decelerate for 1.7 seconds, and you'd need a telescoping pole on the pogo that could retract 187 feet. Not very practical, but like I said - it'd be fun to watch Buster do it. |
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ronbo6
Demi-Minion
Survivor: End of the World. 12/21/2012
Posts: 91
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Post by ronbo6 on Nov 22, 2012 18:46:09 GMT
The biggest problem I see with this concept is that your 'pogo stic'k would have to be capable of dealing with the largest possible weight/range of weights falling at, or below, terminal velocity and STILL give you a deceleration in EVERY case that would not destroy the payload/kill the rider.
A 100 pound person at terminal velocity would not 'challenge' the system as much as a 250 pounder, and the G loading experienced while using the same 'stick' would be hugely different for either one. Therer would be similar problems with non-terminal-velocity falls.
Combine the two issues, and you will have a real design nightmare.
Just Sayin'.
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