RSS
In MAKE 07 the creator of MacGyver (Lee D. Zlotoff) challenged you to save a man stuck in a fissure filled with toxic gas, the winners have been selected!
"My apologies for not posting the winners of the Makeshift Volume 07 challenge sooner. There was an exceptionally high number of entries, most of them fairly lengthy, quite detailed, and all over the map in terms of creative thought and relative kindness toward a fellow human being in a difficult situation. Hence the judging was both time-consuming and difficult.
The Scenario:
You set off on a solo backpacking jaunt one blissfully free weekend, in search of a legendary mountain hot spring that has remained pristine thanks to the 12-plus-hour climb it takes to reach it. A well-earned sweat topped off with nothing but silence, solitude, and hot water - what's not to like?
Just as your topo map indicates that you're within minutes of the spring, you hear an agonized shouting from somewhere off the rocky trail. You quickly discover a large, cylindrical fissure in the ground, about 15 feet in diameter and about 20 feet deep, at the bottom of which lies a rather large example of humanity, with his leg bent at such an unnatural angle that there's no doubt it's badly broken. You yell down to the man - who is easily twice your weight - to say help has arrived. He acknowledges you with a wave, but he seems to be fading fast from shock, pain, or whatever. the walls of thet fissure are nearly vertical and full of jagged rocks, but your experience tells you they're scalable. Still, there's no way you'll be able to climb those rocks with this guy on your back. You'll have to come up with another way to get him out of this whole.
And then it hits you:
A noxious, sulfuric smell that says that this fissure is a vent for the same gases that make the hot springs so warm and bubbly. If you don't quickly find a way to get fresh air to this guy, he's not going to survive long enough for you to rescue him.
The Challenge:
Devise a way to keep this guy breathing while you come up with and execute a plan to safely extract him from the fissure. Then get him stabilized long enough that you can either get him off the mountain yourself, or hike back out to summon more help." - Link.
Winners:
You may want to reconsider the science behind the winning solutions.
I had considered the idea of using the tent poles as an air-transfer system but discarded it after some quick calculations and went on to provide a rescue method using the air mattress as his air supply.
The problem with the tent-pole, air-supply solution is that the victim wouldn't be able to displace enough of the CO2 in the tube during each exhalation, to be able to inhale any fresh air from outside the fissure.
The tidal volume for a "normal" human breath is about a 0.5 liter (let alone an overweight human under stress and pain, which causes one to take smaller, faster breaths). The volume of air to be displaced in a 20' long 0.5" pipe is about 0.75 liter. i.e., the volume of the pipe is greater then the volume of his breath.
What would happen is that the victim would be able to take in his first breath of fresh air just fine, but when he went to exhale his first breath through the pipe, his breath wouldn't completely fill the pipe. Consequently, his next inhaled breath would consist entirely of his previously exhaled breath, being mostly CO2 (along with a small amount of exhaled oxygen).
If the tube was significantly shorter (which unfortunately wouldn't be long enough to reach the rim) or narrower (which would be all but useless as a tent pole), the pipes volume would decrease and each exhaled breath might be able to expel more CO2 then the tube would hold, allowing each indrawn breath to contain a small amount of fresh air along with the pipe's full volume of CO2. Still, the majority of the indrawn air would be CO2, which would cause the victim an increased sense of anxiety, likely resulting in even shallower more rapid breaths.
A single sized air mattress, on the other hand, filled with fresh air would provide an adequate supply of fresh air for both the victim and his rescuer for the time it took to pull him out of the hole. A 72" x 20" x 4" air mattress would provide almost 95 liters of air.
Reply to this comment
Starboy-- The idea wasn't to exhale through the tent poles, only inhale. You inhale through the pole, then just exhale into the air, and repeat going back and forth with the pole like that.
>> but when he went to exhale his first breath through the pipe, his breath wouldn't completely fill the pipe.
Reply to this comment
I would have serious misgivings about breathing thru these tentpoles. The half inch (12.5 mm) diameter given in the above post is significantly lower : my tent poles have a outer diameter of 9 mm. Most ICU workers have one relevant formula at hand : reducing the diameter by a factor of two increases the flow resistance by a factor of eight. I just tried breathing thru infant ventilator tubing , with a effective diameter of 10 mm , and I gave it up after making it ten feet long.
So sorry , Mr. Large Humanity seemed like a nice guy.
Reply to this comment