Path: utzoo!news-server.csri.toronto.edu!rutgers!att!cbnews!cbnews!military
From: fed!m1phm02@uunet.UU.NET (Patrick H. McAllister)
Newsgroups: sci.military
Subject: Re: using AFMs to exginguish oil fires
Message-ID: <1991Mar13.004413.8473@cbnews.att.com>
Date: 13 Mar 91 00:44:13 GMT
References: <1991Mar1.052316.28686@cbnews.att.com>
Sender: military@cbnews.att.com (william.b.thacker)
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From: fed!m1phm02@uunet.UU.NET (Patrick H. McAllister)

I minute of thought will suffice to show that FAMs would be useless for 
extinguishing oil well fires. A FAM works by carefully distributing a
flamable substance in the air and then, when it has reached the optimal
distribution, igniting the mixture. As a side effect, most of the oxygen
in the air is burned away, until normal air circulation replaces it, and
the folks here seem to think that that effect would extinguish an
existing fire at that location. Unfortunately, the effect of the existing
fire would be to ignite the fuel from the bomb as quickly as it was
release, preventing the bomb from achieving the near-instantaneous
combustion that would be needed in order to deplete all the oxygen. 
Furthermore, these fires are BIG and must be generating an enormous
convective flow of air in order to keep themselve fed in the first place,
so the depleting-the-oxygen effect would be moot. All you would achieve
is making the fire burn a little better for a minute. The point of using
an explosive like dynamite to put out the fires is not that it uses up
oxygen from the atmosphere -- the oxidizer is part of the dynamite, it
would explode just as effectively in a vacuum -- but rather, that the
shock wave and the combustion products from the explosion displace all
the air for a brief while, leaving the fire with nothing to breathe.

Pat