Halon dumps: a data point

From: Douglas Quebbeman <dhquebbeman_at_theestopinalgroup.com>
Date: Thu Sep 14 09:49:05 2000

> The sudden pressure from the halon dump sent numerous ceiling
> tiles flying, as well as large stacks of paper that were blown off the
> consoles. Not everyone evacuated immediately - several folks
> in safety-critical roles stuck around for ten or fifteen minutes
> until the firefighters showed up with air packs that allowed others
> to relieve them. Some who did stick around eventually left
> in ambulances (I *hope* just to run some precautionary tests.)

Back in my Prime days, when we got our Halon system, the salesman
demonstrated it at their cost after installation. Triggering it
deliberately, the result was as you describe. Additionally, boxes
of greenbar that were open had the top layes of paper sucked out
of the box, without breaking the perfs, sending it flying.

He stood in there for 15 minutes, lighting matches which went
out immediately, so we could see how well it worked. He drove
away in his car, didn't crash or die. As it was explained to
me, Halon is safe, but under temperatures that would kill anything
organic, it can transform to a deadly gas.

The joke was that the gas didn't kill you, but the reason you
weren't supposed to be in the room if you had to trigger it
manually was to avoid the shrapnel when the spheres exploded.

> The good news: the computers didn't hiccup at all during all this.

Actually, I think one of the CDC disk drives went offline.
 
> Moderately good news: Halon dumps aren't instantly fatal.
> Seeing as how I spend a good fraction of my day within a couple
> of feet of some giant red Halon tanks in the concrete bunker -
> oops, officially it's called "computer room" - this is good to know.
> I'd been heavily trained that when the Halon dump alarm sounds, you
> *get out*. Now I know a little more, especially about the dead-man
> switch you can use to delay an electronically-triggered dump.

Again, we were told, given the choice of breathing air or Halon,
choose air everytime. But Halon was safe and we didn't need to worry.
 
> This Halon is Good Stuff. Other than some grit blasted from the
> ceiling tiles, there was zero debris left in the machinery.
> What's the "environmentally friendly" equivalent used today?
> Is there such an equivalent - something that will put out a fire,
> but at the same time not damage vital equipment?

You can buy small Halon extinguishers still, but only at your local
civil airport for your plane. I have recently heard, however, that
there is a replacment gas that does just as well, but can't recall
its name. Does seem that it starts with an "H", though.

regards,
-doug q
Received on Thu Sep 14 2000 - 09:49:05 BST

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