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Month Index: June, 1996


From:     Pete Neale <101720.2134@??????????.com>
Date:     19 Jun 96 15:04:47 EDT
Subject:  Re: Air consumption
>    This seemed a bit high, so I decided to pull out my HP48GX and do
>some math.
>
>    Now, each ton of a ship represents 100 cubic yards, which is 2700
>cubic feet.  So, a 60 ton ship is 162,000 cubic feet.
>    Going from the figures from the COAS, to find out the volume of a
>ships air envelop in wildspace simply multiply the ship's volume by 27
>(3^3).  Thus our ship would have an air envelope of 4,374,000 cubic feet.

I'll take your word on the x27 factor, I can't really be bothered to look it up.

>But not _all_ of this spaceis going to hold air.  Things like decks,
>weapons and masts take up space.  So we will assume only one half of the
>ship can be counted to hold air.  This drops volume to 4,293,000 cubic
>feet.

I think you have wildly overestimated the amount of space taken up by solid
objects.  A 10'x10' (outer dimensions) room with walls 1 foot think (a lot
thicker than on a ship) has a total volume of 1000 cubic feet but contains 729
cubic feet of air.  Thats only 27% of the volume lost.  As it's all such a drop
in the bucket compared to the whole volume, I'd be tempted to ignore this, but
for simplicity's sake I'llcarry on with your figures.

>    Not all of this air is going to be available for breathing, though.
>Some will be consumed in small fires (i.e.  cooking and lamp fires).
>Plus, at some point the breathable air will be spread through the rest of
>the air, and will be thin enough not to be usable.  So, I will assume
>only half of the volume is usable.  Thus the volume of breathable air is
>2,146,500 cubic feet.

Here I think you've underestimated.  Cooking fires will consume a vast quantity
of oxygen.  I don't really know how much, but I would be tempted to cut the
amount of air by a factor of 10, unless your sailors are going to eat hard tack
for 8 months.

>    According to Static's figures a person uses .5 cf of air while
>sleeping, 1.0 during an average non-exertive period, and 1.8 during light
>labor, per hour.  So, if a person spends 8 hours per day asleep (4 cf),
>eight hours at light labor (14.4 cf), and eight hours doing little but
>relaxing or very light work (8 cf), they will consume 26.4 cubic feet of
>air.  We will round this up to 30 for convenience.

With all due respect to Static, I have problem believing these figures.  If you
went to sleep for 8 hours in a box 1' x 1' x 6" (ignoring the physical
impossibility here), you would suffocate long before you woke up.

<SNIP>

>    I am not a mathemtician, so there may be some critical mistakes in my
>logic.  Which is why I am posting this to the list.  Any ideas?

With all the imponderables involved, i wouldn't really like to hazrd a guess,
and I am a mathematician.  My idea would be to say"Sod it, it's fantasy" and go
with the rules guidelines.

..Pete Hat
"De apibus semper dubiadum est"
101720.2134@??????????.com



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Month Index: June, 1996

SubjectFromDate (UTC)
Air consumption    phantom@????.????.???.edu    12 Jan 1996 17:57:02
Re: Air consumption    SJammer123@???.com    12 Jan 1996 19:25:06
Re: Air consumption    Eugene Shumu1insky    12 Jan 1996 20:37:42
Re: Air consumption    phantom@????.????.???.edu    17 Jan 1996 13:02:49
Air consumption    Eugene Shumu1insky    22 Mar 1996 07:54:39
Re: Air consumption    Pete Neale    19 Jun 1996 19:04:47

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