russian sub

You're correct it wouldn't be Freon. Halon most probably, or the Russian equivalent if you're referring to the recent fire.

Aren't they fairly close- both carbon-halide compounds?

Don, That is WAYYYYY beyond me. lol IIRC from when I was in the navy, the big issue with using Halon (other than long-term environmental effects) is that it basically sucks the oxygen out of the local atmosphere. So, if you're in a enclosed space and those Halon bottles go off, if you don't have some sort of O2 breathing device you are very likely to suffocate.

That is one of the reasons why our cranes have dry powder in our fire supression systems (which makes for a huge mess and looong, tedious clean-up when activated); of course, it could be because the engine room is not air tight - but then that implies logic and good planning, does it not?

Sort of answered my own question - if you read the bit about the demo down the page about half way

you can find some references to using freon in extinguishers on google / yahoo.

the interesting thing is that freon + fire = phosgene, which can't be good.

It's fairly bloody awful if you breathe the gas itself in too... your lungs classify as an 'enclosed space'...

"> the interesting thing is that freon + fire = phosgene, which can't be

Back in the 50s they marketed small aerosol cans of Freon as kitchen fire extinguishers - as I remember they had a picture of a fire dog on it and the break off cap looked like a fire helmet. In the TV commercial something on the stove catches fire and the house wife grabs the can and sprays it out. Then the phosgene issue was brought up in a news article. Although I think they were still sold after that.

Another favorite was the housewife who would pour ammonia and Chlorox in the toilet to get ut really clean and made chlorine gas instead.

Val Kraut

Our computer lab used to have a Halon system. We were assured that the gas was inert, and the volume available in the system was not enough to dilute the oxygen far enough to kill you. I suppose the exact amount of Halon and the volume it is discharged into are the key numbers. I don't remember how far down you can dilute the oxygen. I learned that in aviation physiology class in terms of partial pressure. I don't think you can cut it in half, though. Although you suffer from symptoms at ten thousand feet, you can stay alive for some restricted period up to nearly thirty thousand, like the folks who suffer from altitude sickness climbing Everest.

There was a small article in our local paper today (Tues) from a USN spokesman stating that there is no fire suppression system on subs. He said it is all done with portable extinguishers and sailors; I wonder if the "phosgene" issue is why? Was not there some issue with some sort of gas ruining lungs on the K-19 incident?

Basically, if it'll put a fire out, it'll put YOU out...

We also had Halon gas in our computer room (I work in local government IT). We had 2 computer rooms, one only used on dayshift, with nightshift data access, with the Halon system. Working at the other site, we detected a problem, and our shift leader went over to check it. Thinking she'd only be a minute to refill the paper on a printer or something, she left the Halon system switched on... Next to the computer room was a set of mains transformers to feed the whole 15 storey building, one of which chose that moment to blow (it was already affecting the power supply, thus the problem) - releasing a cloud of vapourised oil, which the fire system detected as smoke, releasing the Halon...

Our shift leader got out VERY sharpish! It took a week to clear the residue of Halon and oil off every surface...

Wulf

reminds me; in the old days when subs ran on batteries, if they sprung a leak and sea water got into the batteries, chlorine got produced. a major plot point in most of the submarine books i devoured as a kid.

well, carbon-halogen, to be exact. halide is the salt produced from reacting with a halogen.

but yeah, they're all pretty closely related. i'm still amazed at this day why freon (which actually covers quite a few compounds of different boiling points) would eat the ozone and other halons like the freon replacements for car ACs, not. but not enough to look up the explanation.

basically the same as CO2; it's a heavy inert gas that displaces the oxygen from a fire that's relatively low in the room. or a person. i assume that it's more popular than CO2 extinguishers these days because you can package larger volumes in compressed cylinders, but i've never bothered to check.

Bear with me as I try to remember some old technology.

First: "Freon" is Du Pont's brand name for its line of Halon products.

Second: The Halons are large molecules containing Chlorine, Bromine, Fluorine, methane, etc...

Third: In the USA, Halon 1301 was used in large room-flooding fire suppression systems. (I think that's Tribromofluromethane, but I may be forgetting something.)

Fourth: Other Halons were also used in hand-held fire extinguishers (Halon

1202?) But it's probably 1301 that we're interested in.

Fifth: Halons extinguish fires by decomposing in heat and interfering with the "flame-chain reaction". Basically like a reverse catalyst, it keeps the fuel and air from combining.

Sixth: There is one great advantage to using Halon as a fire suppressant; that is that concentrations as low as 4% by volume will extinguish a fire. CO2 requires much higher concentrations.

Seventh: You can breathe 4% Halon 1301 without harm. (At about 8 - 12% you'll get high, but will probably survive) CO2 (in firefighting concentrations) will do you in - in a couple of breaths.

Eighth: In a PROPERLY DESIGNED SYSTEM, occupants will survive an accidental release of Halon. In a properly designed CO2 system, you'll need a bunch of body bags.

Nine: If you're around a fire when Halon is released, there will be a few irritating gasses (HBr, HF, HCl) that will rapidly persuade you to leave the area.

Tenth: Though they are heavier than air, Halons are suspected of getting into the upper atmosphere and destroying ozone. Thus they were banned about

15? years ago.

My questions are: Since it was banned, why is a Halon gas being used in a relatively new ship?

And: Since it is important to exhaust the gas after a fire (HCl, HF, HBr are kinda hard on metals as well as people), why would the Russians use Halon on a sub?

I'm guessing that there is a mistake in the report, and the actual gas was CO2.

And finally,

Thanks to all the people who post and share their thoughts in this amazingly civil group.

Chuck

A key point in the story was that construction was started in 1992 (or so) then put on hold due to messed up economy. And this is Russia we are talking about, so they figure "banned what banned"? Just like other countries....

I think, just like rumours of the fuel on the Kursk torpedo blast (which if true, was a fuel that was not used by British/US boats in decades), that the Russians like to go their own way. Even if it makes others scratch the heads.

Thank you for the info - one reason why many still like this group.