6 ms·

I was looking into the ventilation rate of things and not sure if it was a misprint but submarines apparently have 8000ppm of CO2 when submerged, which to me so

by alliao 5y ago

I was looking into the ventilation rate of things and not sure if it was a misprint but submarines apparently have 8000ppm of CO2 when submerged, which to me sounds insane as we know for sure 1000ppm is when it starts affecting your mood, judgements, and decision making capability..

jedc 5y ago
There are CO2 scrubbers on board, the crew turns them on/off to control concentrations. It's one of the things I checked before I went on every watch as OOD (officer of the deck): the CO2/O2 concentrations. (One of our weapons officers was really sensitive to CO2 concentrations and would s*t all over any OOD who let them get too high.)
- solveit 5y ago
  I'm led to believe that the CO2 concentrations still routinely go above 2000 ppm though. Is that right?
- CharlesW 5y ago
  I really enjoyed this Smarter Every Day episode that talks about maintaining air quality on a submarine: https://www.youtube.com/watch?v=g3Ud6mHdhlQ https://www.youtube.com/watch?v=g3Ud6mHdhlQ
  - alliao 5y ago
    that is pretty darn cool, not sure how to convert that torr to ppm though, in they video they mentioned it's partial pressure? so sounds like one is able to work out percentages therefore ppm by the reading?
    - crmd 5y ago
      To convert a partial pressure in torr (mmHg) to ppm, you divide the partial pressure by the total atmospheric pressure (both in torr) and multiply by 1 million.
- dmitriid 5y ago
  Is there a "dad with a thermostat" joke in there somewhere, only applied to CO2? :)
solveit 5y ago
I'm also interested in the cognitive effects of CO2, and I have a great deal of skepticism in the studies that say small amounts cause noticeable deficits precisely because we know people can carry out complex tasks for months on end inside a submarine. I know other people have also remarked on this (absurd!) inconsistency but haven't seen it satisfactorily resolved. I will say that it's much easier to believe that the studies are somehow flawed and people don't get seriously impaired by 8000 ppm than it is to believe that we've gone nearly seventy years without noticing that the people who are supposed to launch nuclear strikes in the event of WW3 have been retarded all this time.
- deleted 5y ago
  [deleted]
- idontwantthis 5y ago
  I've also wondered about this, but its also true that they work on an 18 hour day, which is also clearly terrible. Submariner above says that they are always "semi-fatigued". I don't think it's unbelievable that they are operating impaired.
deleted 5y ago
[deleted]
sarchertech 5y ago
The military has done numerous studies showing that CO2 concentrations far higher than 1000ppm don’t have any cognitive impacts. That combined with the real world examples of submarine crews working in high CO2 concentration, means that the most likely explanation is a flaw in the studies showing severe cognitive impact at 1000ppm. Here’s a good summary of some of the data from a hacker news comment a while back https://news.ycombinator.com/item?id=19863319 https://news.ycombinator.com/item?id=19863319

by alliao 5y ago

jedc 5y ago

There are CO2 scrubbers on board, the crew turns them on/off to control concentrations. It's one of the things I checked before I went on every watch as OOD (officer of the deck): the CO2/O2 concentrations. (One of our weapons officers was really sensitive to CO2 concentrations and would s*t all over any OOD who let them get too high.)

solveit 5y ago
I'm led to believe that the CO2 concentrations still routinely go above 2000 ppm though. Is that right?
CharlesW 5y ago
I really enjoyed this Smarter Every Day episode that talks about maintaining air quality on a submarine: https://www.youtube.com/watch?v=g3Ud6mHdhlQ https://www.youtube.com/watch?v=g3Ud6mHdhlQ
- alliao 5y ago
  that is pretty darn cool, not sure how to convert that torr to ppm though, in they video they mentioned it's partial pressure? so sounds like one is able to work out percentages therefore ppm by the reading?
  - crmd 5y ago
    To convert a partial pressure in torr (mmHg) to ppm, you divide the partial pressure by the total atmospheric pressure (both in torr) and multiply by 1 million.
dmitriid 5y ago
Is there a "dad with a thermostat" joke in there somewhere, only applied to CO2? :)

solveit 5y ago

I'm also interested in the cognitive effects of CO2, and I have a great deal of skepticism in the studies that say small amounts cause noticeable deficits precisely because we know people can carry out complex tasks for months on end inside a submarine. I know other people have also remarked on this (absurd!) inconsistency but haven't seen it satisfactorily resolved. I will say that it's much easier to believe that the studies are somehow flawed and people don't get seriously impaired by 8000 ppm than it is to believe that we've gone nearly seventy years without noticing that the people who are supposed to launch nuclear strikes in the event of WW3 have been retarded all this time.

deleted 5y ago
[deleted]
idontwantthis 5y ago
I've also wondered about this, but its also true that they work on an 18 hour day, which is also clearly terrible. Submariner above says that they are always "semi-fatigued". I don't think it's unbelievable that they are operating impaired.

deleted 5y ago

[deleted]

sarchertech 5y ago

The military has done numerous studies showing that CO2 concentrations far higher than 1000ppm don’t have any cognitive impacts. That combined with the real world examples of submarine crews working in high CO2 concentration, means that the most likely explanation is a flaw in the studies showing severe cognitive impact at 1000ppm. Here’s a good summary of some of the data from a hacker news comment a while back https://news.ycombinator.com/item?id=19863319 https://news.ycombinator.com/item?id=19863319