Re: On board fires

[VBra676539@aol.com]

In a message dated 4/30/99 5:32:38 PM, shawl@torchlake.com writes:

<<Hi Vance,
OK, I agree, no water extinguishers, I wasn't trying to say there would be no
shock hazard, I just meant It may not add to the short circuit problem. Just
thought I would bring it up for discussion. I'm still wondering what gas is 
used
in the dry chemical type extinguishers? I know it's NOT oxygen. What is the 
safe
% limit for CO2 in a sub?
Could you tell us what specifically what kind of problem caused the smoke and 
or
fire in the sub or subs you where in, you mentioned earlier? Bad design, 
faulty
parts, crimp on connectors, bad workmanship, human error, water shorting out
something, unforeseen problems??????
Jon>>

Jon,
	Won't matter about the CO2 (which is the propellant in some fire 
extinguishers) as the clever and forward thinking psubber will be on BIBBS 
until the crisis is over or the sub surfaced or whatever.
	The fires I had were a paper wrapped bayonet fuse for main propulsion 
in the old PC-8 which smoldered and sputtered for a few seconds while it was 
in the act of committing suicide.  The second was in PC-9 and was a light 
circuit overlapping a thruster wire.  Under heavy useage, the overlapped 120 
VDC wires got warm and melted/burned the insulation which made a nice little 
puff of smoke before the fuses snapped and then the whole thing went away on 
its own.
	One other thing I was mulling today after all that writing about 
fires was the psubber thinking of his/her vehicle as a UNIT.  I remember my 
first sub (Amersub 300) was really just one puzzle after another for  me.  I 
did not finish that one, but moved to the Florida submersible mecca of 
Riviera Beach to learn from the experts, and what I learned was that the 
vehicle(s) were subsystems making a system.  Yeah, yeah.  I know it's 
obvious, but I had been so focused on learning about the bits and pieces that 
I had not really gotten around to thinking of the INTERACTION of all those 
parts as a functioning whole.
	That's where all those pesky little details really start to pay off.
Vance