THis is why I wanted an expert. I just saw the tanks and apparently
repeated an untruth. We were always told to hit the button as we left. As
to what the percentage would be when the halon discharged I have no idea.

--
R. Scott Carroll
"Steve Barlow" wrote in message
...
On Thu, 19 May 2005 20:20:08 -0600, "sailct41" wrote:

Halon displaces oxygen. When we used to use it at work we had to
evacuate
the room and then hit the Halon on the way out. If you were in there
they
always told us we would die. Might want to think about that. In the
Navy
we use AFFF and I was amazed how well that foam worked on oil fires.
Maybe
a firefighting boat builder can help with advice.


Not quite correct see http://www.halonmarketing.com/mall/prod01.htm

As for you loosing your life in a halon flooded compartment, I know from
personal experience this is incorrect.
However if Halon is exposed to surfaces at high temperature, Phosgene type
gases
are produced, which will kill you.
If you are in a space where CO2 has been released , it will kill you.
CO2 is flooded at about 35% into a space and it displaces the oxygen,
Halon flooding is about 5.5% of the volume and sufficient oxygen remains
to
live.


If you use CO2 to flood a space you must ventilate it properly before
re-entry
the same as with Halon but for different reasons.
At sea IMO it is always good to have an automatic system with manual
override.


--
Steve Barlow