Re: On board fires

[VBra676539@aol.com]

Ray,

	I would like to add a few thoughts about fire protection and strong 
fire defenses to what I wrote this morning.  Some is obvious, and the 
operational psubbers will have sussed most of this out already no doubt, but 
folks still designing may see something they hadn't thought of.  Most is 
common sense--some good practices from my favorite E.T.s at work--and one or 
two things that made a difference for me when the smoke started leaking out.
	Here goes:

	1.  DO NOT use crimp fittings in your electrical system!  They 
corrode, arc and become hot spots over time.  Time bombs, one and all.  
Solder ALL connections, including the lugs you use to connect stuff.  Don't 
let the salesmen of the world talk you into crimping ANYTHING.  Get rid of 
the crimping pliers you now have and buy a good soldering iron.  Learn to use 
it.  Then use it.  Every time.  And always use shrink tubing, shrink wrap or 
shrink tape over the solder joints and then the black sealant goop they sell 
to paint over the shrink (shrunk?) wrapped joint.

	2.  DO NOT splice wire unnecessarily.  Use the correct length to 
start with, and plan it so that the wiring harness is neat and tidily 
bundled.  Ty Merritt used to tell me that if it LOOKS good, then it will work 
better.  It might be an emotional response but tangles and knots of wire look 
like hell and are ripe for shorts and crossover hot spots.

	3.  Size your wire according to load, and use pre-tinned, flexible 
wire, not drawn copper or aluminum.

	4.  Use spade or blade or ring lugs for all connections (and solder 
every one and shrink wrap it and goop it).  Yeah, I said that already.  It's 
important.  

	5.  Use explosive-atmosphere grade switches (sealed from the 
atmosphere).  Breakers, fuses and fuse links should be sealed so that arcing 
occurs WITHIN the unit, not in the psub's potentially oxygen rich environment.

	6.  Arrange your power distribution in a box of some sort (preferably 
sealed) so that insulation fires or hot wires will starve out as soon as the 
electricity goes away.

	7.  Fuse or breaker your battery bank(s) so that a short circuit in 
the bank itself will be self-isolating (one hopes!).

	8.  Pay strict attention to the materials going into the crew 
compartment of your psub.  Fire proof and fire retardant materials should be 
used whenever possible, including your paint.  The question to ask of each 
material is:  Will this give off particulate irritants, organic poisons, 
plastic toxins .... ?  Query the manufacturer for potential toxins and 
irritants of their products and then try to imagine sitting in there dealing 
with it.  (This can be very instructive, as imaginary fires can be pretty 
damned scary, too!).

	9.  Design a BIBBS (Built-In-Breathing-System) into your air 
distribution system (not the oxygen system, this will be isolated immediately 
a fire is suspected).

	10. Be sure your built in cabin pressure/vacuum relief is above the 
waterline but easily reached and readily available so that you can equalize 
as you surface and have no pesky delays in getting the hell out of there.

	11. Be vigilant.  Once you go operational and start diving, it is 
very easy to accumulate bits and pieces of this and that in the sub.  Rags, 
paper products, plastic cups and the like.  Watch out for flammables creeping 
in.  Add this kind of thing to your check sheets.  Keep your oxygen content 
at or slightly below 21%.  Keep your boat clean and clean up those hydraulic 
dribs and drabs that seem to accumulate no matter how careful you try to be.

	12. Always carry a fire extinguisher of the dry chemical type, 
securely mounted and immediately available.


	You may figure that planning all this stuff and practicing with the 
equipment and maintaining all the components is too much of a good thing.  
Until that first whiff of smoke, that is.  That's when it pays off.
	Remember, be a good Scout and BE PREPARED.  Like the man said, there 
is simply no use at all in carrying a knife to a gun fight.  The right tools 
are required and when the gunfight happens there is never time to think about 
it.  You have to be ready to fight.  And just as importantly, you have to be 
PREPARED to fight, which isn't quite the same thing.

Hope this helps,
Vance