CO2 levels
 

At what levels does it become a problem, and what is the effect on the crew? Eventual death?
I'm trying to determine how long I can stay submerged before having to surface and vent the sub.

Re: C02...
 

Myself, have submerged, early on in the morning, before the sun was even up... sky had just started to begin to lighten up, indicating that sunrise was not far off... & stayed submerged, until I could see that it was... as totally dark as it could be, by that point... the C02 levels were, I believe (irc) by that time, in the 50-60% range... I could be off a bit... I really wouldn't push it much past 60.

:Kaleun_Salute:

M. M.

The real subs did manage to stay down for upwards of 48 hours. They did experience CO2 poisoning, of course, but I do not remember the figures of percentage of atmosphere. It does not take much though. Lethargy is the first sign, as well as a bunch of yawning, as your body tries to bring in more oxygen. For whatever reason, some of the crew tried to smoke a cigarette - nic fit!!! - and their smokes would not stay lit... which was a good thing, because the smoke would have further polluted their atmosphere. Being a former smoker and suffering the effects of my youthful ways the last few years, I wish I would never have started - but that's for a different discussion.

Anyway, you can stay down from first light until after dark in the game, and the effect on your crew is minimal. Much beyond that though, and the game is a bit over-the-top. First signs with the crew, since the 3D world does not change, is a slow response to orders, especially the helm and depth control. You might have to tell the crew several times to come to a given heading, or a set depth. Then they still might "drift" away from that. But that is after a good while of being down. The CO2 meter will light up after maybe six hours? Probably sooner. It does change colors from blue to yellow to red though, to warn you. At yellow is where they really get strange in following "orders". When you hit the red, the crew starts dropping like flies. You won't see them "stagger" at their stations - they just "disappear", and turn "injured" on the crew page. Then they die shortly after. No warning, other than the red icon. Turn on a light switch, and you have it. We had this all timed in FotRSU a few years ago, but have since misplaced the info... I'll see if I can dig that up. Most of the mods don't try to change that from Stock.

Did we have the same type of personal filters like the Germans?

i do not understand your question. can you re-state it, please? to what personal filters are you referring?
:Kaleun_Salute:

The German U-Boats had a CO2 "eater", or absorbent canister (paint can sized??), but the material was apparently rather difficult and expensive to make, since there were only like four on a boat, and "For Emergency Use Only" kind of thang (one of the movies shows that - ??). The US had the Momsen lung, which was a "re-breather", and functioned in a similar manner, but was for use in the water. Seems to me the US had something close to ready for release by the time the end of the war came - but I am not certain of that. The problem is that you can "absorb" the CO2, but that does not replace the oxygen content of the atmosphere, unless you use the pressurized air... which was known to cause ear and nose bleeds...

Believe that what they were asking after, is with regards to a "C02" scrubber... which, the Uboats did have on board.

On which, propbeanie, covered quite well, on that point:

:Kaleun_Salute:

M. M.

i missed that but then it happened before PB cleared up my confusion.:haha:

Perhaps it will be interesting to someone.

Under normal conditions, the reduction in O2 is never critical before the increase in CO2 becomes critical.
Atmospheric air contains 21% O2 and 0.03% CO2 by volume.
At normal atmospheric pressure in the compartments:
- a noticeable decrease in the efficiency of the crew due to CO2 appears when its volumetric concentration rises to a level of 1 - 2% and above;
- signs of oxygen starvation appear when O2 drops to 16% and below;
- loss of consciousness and death due to high CO2 content occurs when its volumetric content is at the level of 9 - 10%;
- Loss of consciousness and death due to low content of O2 occurs at its concentration at the level of 10 - 11%.

Oxygen consumption by one person:
25 ... 67 liters of O2 per hour
(depending on the state: rest ... hard physical work, respectively)

Excretion of carbon dioxide by one person:
22 ... 60 liters of CO2 per hour
(depending on the state: rest ... hard physical work, respectively)

Let us assume that the average respiration values ​​for the crew serving at battle stations are 28 liters of O2 per hour and 25 liters of CO2 per hour per person.

For these values, I will give a calculation of how the composition of the air in the compartments changes over time after the submarine has gone submerged and isolated from the atmosphere under the condition of normal air pressure inside the pressure hull and provided that the air purification and air renewal systems are inactive.

Let's say we have a U-Boat VIIC with its free space inside a pressure hull of about 400 cubic meters and a crew of 44 people. After complete ventilation with atmospheric air and sealing, the compartments contain 84,000 liters of O2 (21% of 400 cubic meters of air) and 120 liters of CO2 (0.03% of 400 cubic meters of air).
In order for the O2 and CO2 content to require intervention to normalize the situation (16% O2 and 2% CO2), the amount of O2 must decrease to 64,000 liters, and the amount of CO2 must increase to 8,000 liters.

44 people consume oxygen at a rate of 28 * 44 = 1232 liters per hour and emit carbon dioxide in the amount of 25 * 44 = 1100 liters per hour.
Before the situation deteriorates in oxygen from 21 to 16%, it will pass (84,000 - 64,000) / 1232 = 16.2 hours.
Before the situation deteriorates in carbon dioxide from 0.03 to 2%, it will take (8,000 - 120) / 1100 = 7.2 hours.

Nicely done. I like details... unfortunately, the game doesn't seem to play that way... lol

Thank you Kaleuns!