[PSUBS-MAILIST] life support test

Sun Mar 18 19:59:31 EDT 2018

Hi Alan,
Agreed the martini test probably is easier although I think that model is
going to deviate the further you go.

I had a friend (very experienced deep air diver) who was pushed to
60m/180ft by a current and he literally didn't have the mental faculty to
save himself (he was fortunately holding a rope which I pulled up).

If you're even still conscious breathing air at 100m/300ft you're doing
pretty well. High oxygen seizures start to become a real risk beyond 70m on
air, quite apart from how debilitating the narcosis will be.

Cheers,
Steve

On 19 Mar 2018 10:23 am, "Alan via Personal_Submersibles" <
personal_submersibles at psubs.org> wrote:

> Steve,
> you are advocating a nitrogen narcosis experience as a training for escape.
> Nitrogen narcosis is known as the Martini effect & is equivalent to
> drinking
> 1 martini on an empty stomach for every 10 metres you descend.
> I think a standard Martini is 3 oz, (some of the alcoholics in the group
> might
> confirm  this). It would be much easier to see how many Martini's you could
> drink & still get out of your sub, than try & do a real simulation with
> nitrogen.
> For those with K250s that's about 5 Martini's & K350's 8 at maximum depth.
> I am shooting for 500ft so that's 12. (36oz)
> How deep is Scott going?
> Cheers Alan
>
> Sent from my iPad
>
> On 19/03/2018, at 11:02 AM, Stephen Fordyce via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
> Hi Brian and all,
> I'm just going through commissioning a new/modified rebreather which is a
> bit relevant to this. I believe (sort of at odds with conventional training
> manuals) that it's valuable to experience the physiological signs and
> symptoms of the various gases at incorrect levels. Your other systems
> should of course protect you and be highly conservative, but you never know.
>
> To that end, after a recent long dive I continued to breather the scrubber
> at home on the couch (for several hours) until the high CO2 effects were
> noticeable. I've also had a controlled low oxygen experience that I
> consider valuable. Both worth doing, maybe even regularly - I'd like to do
> high oxygen one but that's been a bit tricky so far.
>
> If anyone has plans to be exiting a partially flooded sub at depths below
> 30m/100ft then a nitrogen narcosis experience would be extremely valuable.
> Especially with quick compression, your mental faculties deteriorate
> rapidly. Even at that depth, and it gets worse as you go deeper. I don't
> dive below 50m on air because I barely know what I'm doing.
>
> Cheers,
> Steve Fordyce
>
> On 18 Mar 2018 2:04 pm, "Cliff Redus via Personal_Submersibles" <
> personal_submersibles at psubs.org> wrote:
>
>> See
>>
>> *DESIGN GUIDELINES *FOR
>>
>> CARBON DIOXIDE SCRUBBERS
>>
>> I
>>
>> MAY *1983*
>>
>> REVISED *JULY 1985*
>>
>> Prepared by
>> M. L. NUCKOLS, A. PURER, G. A. DEASON
>>
>> for the philological affects of high CO2 level but if you abort the test
>> if you ever exceed 5000 ppm, you should be safe.  In addition to the CO2
>> issues, you should also familrrize yourself with both *Hypoxia* which
>> describes levels lower than Normoxia, or percentages lower than 21% and
>> *hyperoxic* breathing gas when levels rise above 22% of oxygen. Hypoxia
>> would come from running out of makeup O2 or leaving the O2 supply valve
>> closed by accident and hyperoic state would most likely be caused by a high
>> pressure leak of O2 into the cabin caused by a loose fitting.  I would
>> recommend you abort the test if O2 concentration falls outside the
>> acceptable range as defined by ABS.
>>
>> When you go back and analyze the test, it is helpful to have data logged
>> cabin atmosphere parameters including, CO2 and O2 concentrations, cabin
>> pressure and temperature and relative humidity.
>>
>> Cliff
>>
>> On Sat, Mar 17, 2018 at 5:37 PM, Brian Cox via Personal_Submersibles <
>> personal_submersibles at psubs.org> wrote:
>>
>>> Hi All,
>>>               Thinking about testing my life support.  Will obviously
>>> have some people outside the sub watching me, and talking via radio.  But I
>>> was wondering if there would be a point at which I should abort the test
>>> when the CO2  gets to a certain point .   If it levels off and stays at a
>>> constant but is some what elevated would it be ok to monitor that situation
>>> ?   Like say it levels off at 2000 ppm and assuming my oxygen is at a
>>> constant 20.8 %    ?
>>>
>>> Brian
>>>
>>>
>>>
>>> _______________________________________________
>>> Personal_Submersibles mailing list
>>> Personal_Submersibles at psubs.org
>>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>>
>>>
>>
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>
>> _______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
> _______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20180319/112f00c9/attachment.html>