Re: [PSUBS-MAILIST] PSUB Fatalities...

[Phil Nuytten <72020.572@compuserve.com>]

Dear Sean:
        Noted your response to Carsten: > Sorry to have to call you on
this, Carsten, but it's garbage . . .etc.<  Wow! don't you think that's a
little . .uh . .harsh?    'Garbage' ?? You'd think that there would a way
of making your personal opinion known without  the risk of offending
some-one who is, after all, just giving you and the rest of us the benefit
of his opinion. Just dismissing it as 'garbage is like me saying that your
opinion that  >> Helium is a much friendlier gas than nitrogen, from a
decompression perspective - it ongasses  quickly but also offgasses quickly
. . .etc.<< is 'Stupid' or ' Misses the whole decompression dynamic point .
. .etc.' Not real polite!
        You might want to consider that, if helium is given off at the same
rate that it is taken up, then Heo2 tables would be very simple; since the
required decompression could never exceed the bottom time. Alas, the
gas-driving pressure differentials are entirely different on descent and
ascent - but then, hell, you know all that . . . just like the rate of
saturation at a given pressure differential being a significant function of
the oil-water solubility ratio of the gas, rather than simply the molecular
mass - but, hey, Overton and Mayer showed that before the turn of the last
century . . so it's hard to overlook!
        Heo2 would be the last mix I personally would choose as a submarine
 escape gas. I'd opt for good ol' 02N2 every time . .with a nitrogen
equivalent air depth of about ten ats relative (330 feet) and a relative
oxygen depth of about 90 feet - balance composed of  dat debbil helium.(
You mentioned Albert Buhlman . .you probably remember his description of
his colleague Hannes Keller diving to 360 feet on an 02N2 mix with with an
oxygen concentration so low it gave a nitrogen equivalent air depth well in
excess of 400 feet - all with no sysmptoms of narcosis.) 
        I personally would have no hesitation about free escape up to about
one thousand feet. At depths up to about 750 feet, with low He levels,
there is a high chance of no clinical manifestations of bends - at least 
according to bubble growth dynamicist
Mike Gernhardt who ran the math for us when we were doing extensive studies
on free escape from the Newtsuit at depths up to one thousand feet -  (
Mike has been in the NASA astronaut program for years and has completed two
space shuttle flights - not bad for a former saturation-diving
physiologist!)
        So, I guess Carsten may have been pretty conservative in his
estimates of escape depths and times, after all !

        It's all pretty interesting stuff - I spent a lot of time on table
formulation and testing  before deciding that one atmosphere was the way to
go.     
        Anyhow, my point was that it's probably not politic to dump cold
urine on some-one else's opinion - in my opinion, of course!
Phil Nuytten