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General Science / Re: Oxygen levels In A packed Train. Is There Always Enough ?
« on: Today at 12:27:08 »
Oxygen extraction is about 0.25 liter/minute for an adult.
The smallest London Underground rolling stock has about 0.6 m headroom above the standing passengers, maybe 1.5 m above the seated ones. Say average headroom about 1 m Assume each passenger occupies 0.4 square meters. So you have 0.4 cubic meters of available air, or 80 liters of available oxygen, per capita if the train is fully packed.
So the crude answer is about 5 hours. However as the oxygen concentration depletes, so does its partial pressure, and folk begin to suffer below 10% of atmospheric pressure, so expect some fainting and collapse after 2.5 hours.
Problem is, however, that as CO2 levels rise, people begin to hyperventilate and panic well before the level becomes toxic, so you are more likely to die in a crowd surge than from asphyxiation.
The smallest London Underground rolling stock has about 0.6 m headroom above the standing passengers, maybe 1.5 m above the seated ones. Say average headroom about 1 m Assume each passenger occupies 0.4 square meters. So you have 0.4 cubic meters of available air, or 80 liters of available oxygen, per capita if the train is fully packed.
So the crude answer is about 5 hours. However as the oxygen concentration depletes, so does its partial pressure, and folk begin to suffer below 10% of atmospheric pressure, so expect some fainting and collapse after 2.5 hours.
Problem is, however, that as CO2 levels rise, people begin to hyperventilate and panic well before the level becomes toxic, so you are more likely to die in a crowd surge than from asphyxiation.
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