Technology and Operations
This forum is for discussing technological & operational matters pertaining to U-boats.
RE: Achilles heel outside of pressure hull?
Posted by:
Ken Dunn
()
Date: April 18, 2001 09:32PM
Hi All,
At 10 atmospheres, the partial pressure of the oxygen in the compressed air divers use (which is roughly 20% oxygen and 80 % nitrogen – the same mixture we breath normally at the surface) causes the oxygen in the mixture to become toxic to humans. The condition is called oxygen poisoning or oxygen toxicity. The safe oxygen exposure depth for breathing air is 297 feet (9 atmospheres plus the 1 atmosphere at the surface) of seawater for 30 minutes. Exceed that a host of problems including death can result.
However, the crew would start feeling the effects of Nitrogen Narcosis at around 3 atmospheres (roughly like being high or a little drunk) and by 10 atmospheres they would probably have already become incapacitated by Nitrogen Narcosis.
Nitrogen Narcosis was a contributing factor in the deaths of at least two of the divers that died diving the U-Who. They were diving too deep on compressed air and the narcosis caused them to make some life threatening mistakes. They were so disoriented that they couldn’t find the spare air they left on the way down and they had to surface without decompressing which caused a massive case of the bends. Imagine what a U-boat full of people that disoriented would be like. In the case of the two divers, (In my opion) the plan to dive to that depth on compressed air was the major cause of their deaths. They were experienced divers and knew better.
The solution would be to breath another mixture of gasses and that has its own set of life threatening problems.
There are all sorts of other problems associated with pressurizing and de pressurizing a human being. None are pleasant, most are very painful and some are also life threatening.
Regards,
Ken Dunn
At 10 atmospheres, the partial pressure of the oxygen in the compressed air divers use (which is roughly 20% oxygen and 80 % nitrogen – the same mixture we breath normally at the surface) causes the oxygen in the mixture to become toxic to humans. The condition is called oxygen poisoning or oxygen toxicity. The safe oxygen exposure depth for breathing air is 297 feet (9 atmospheres plus the 1 atmosphere at the surface) of seawater for 30 minutes. Exceed that a host of problems including death can result.
However, the crew would start feeling the effects of Nitrogen Narcosis at around 3 atmospheres (roughly like being high or a little drunk) and by 10 atmospheres they would probably have already become incapacitated by Nitrogen Narcosis.
Nitrogen Narcosis was a contributing factor in the deaths of at least two of the divers that died diving the U-Who. They were diving too deep on compressed air and the narcosis caused them to make some life threatening mistakes. They were so disoriented that they couldn’t find the spare air they left on the way down and they had to surface without decompressing which caused a massive case of the bends. Imagine what a U-boat full of people that disoriented would be like. In the case of the two divers, (In my opion) the plan to dive to that depth on compressed air was the major cause of their deaths. They were experienced divers and knew better.
The solution would be to breath another mixture of gasses and that has its own set of life threatening problems.
There are all sorts of other problems associated with pressurizing and de pressurizing a human being. None are pleasant, most are very painful and some are also life threatening.
Regards,
Ken Dunn
