22 Marines Exposed to Halon Fire Retardant in Training Accident | Military.com

TWENTYNINE PALMS, Calif. — Nearly two dozen Marines were treated for exposure to a fire retardant gas Thursday after an extinguishing system accidentally went off in an assault vehicle during a training exercise, but there were no serious injuries, officials said.

An equipment malfunction caused the fire suppression system to go off inside a tank-like amphibious assault vehicle during an afternoon exercise at the Marine Corps Air Ground Combat Center in Twentynine Palms, base spokesman Dave Marks said.

There was no fire or explosion but 22 Marines were exposed to halon, Marks said.

All of them were taken to the base hospital. Three were kept overnight for observation and the rest were released to resume training, Marks said.

via 22 Marines Exposed to Halon Fire Retardant in Training Accident | Military.com.

Halon discharges are fairly common, usually the result of some dumbassery on the part of a junior troop (face reddens a bit here).

We’ve noted before that armored vehicles tend to be filled with a lot of very flammable things, such as fuel, ammunition and people. It only makes sense to provide a robust fire suppression system. Older systems used CO2. The problem with CO2 was that a sufficient concentration of it was enough to not only extinguish the fire, but also rapidly extinguish the crew. Halon works better at suppressing a fire while also allowing the crew enough oxygen to breath long enough to abandon the vehicle.

The primary goal of the fire suppression system is to save the crew. If it also saves the vehicle, that’s a bonus.

In peacetime, the fire suppression system is (usually) manually initiated. There are internal and external “T” handles that are pulled to discharge the Halon.

In combat, there an automatic system. Sensors inside the vehicle detect an explosion and almost instantly unload the Halon. It’s… loud. It doesn’t take long at all for the bottles to empty. More of a “boom!” than a “whoosh.”

Ships use similar fire suppression systems in their engineering spaces, though I have no idea what the current agent used is.

6 thoughts on “22 Marines Exposed to Halon Fire Retardant in Training Accident | Military.com”

  1. Having worked for 21 years in a “Fortune 100” computer center with a Halon fire-suppression system, I was subject to a few “Halon Dumps”.
    LOUD noise, ceiling-tiles flying around, immediate fog to where you could not see six-feet, temperature-drop, and you talk funny, kinda like helium.
    The Mainframes were powered-down automatically.

    Everyone just filed out the door, waited for the Fire Department to come.
    No side-effects, some screaming during the event, no injuries or hospitalization.
    Much ado about nothing…

    1. having been around many vehicles that blew Halon bottles, i am going to comment that I suspect there is a significant difference between being in an open office and a buttoned up tracked vehicle when the halon goes off. Even when the track is not buttoned up, there is still enough action to impact the crew. Over and above the sudden disruption of oxygen to your ability to breathe, it can cause other things. For example, my own tank driver popped the halon in the driver’s station once. I was standing out front of the tank. I looked up at the loud pop and saw him coming from the hatch like a Polaris missile (from fear,not the Halon…) He landed on the front slope, then rolled off and fell to the ground, hurting his back or neck. I can’t comment on the circumstance in the article, but the fact that most Marines quickly returned to duty does not make it, or any other Halon incident “nothing.” While not happening every time, evacuation is often prudent.

      On a separate note, when a Halon bottle pops, the vehicle is deadlined until it is replaced. Lastly, barely a year ago, I can assure you that the three tank platoon leaders that I inspected which were unaware of the location of any of the fire sensors in the turret or engine compartment of their tanks or that they were so muddy as to be inoperative have a new found appreciation for the importance of Halon systems.

  2. Esli,
    Not “open offices” but a secure buttoned-up computer room. LOTS of Halon tanks above the ceiling and below the raised floor. As I said, there was enough dumped for a marked temperature drop, ceiling-tiles blown off, and a roar like a 747 running-up. and instant fog. You needed to know where you were and get the fuck out. It was not a “casual” experience. When the fire alarm tripped, the AC shut-down, so as not to remove the Halon from the fire-zone.
    Nobody was going to just ‘hang around’. It did not hurt us, but we did not hang around breathing it to see what would happen.
    Just sayin’…

    1. Trust me, there is a low probability that the confines of an armored fighting vehicle compare to even a buttoned-up computer room.

      Due to the need to tell a story and show action, most films that depict the interior of a tank show about 4x the space there really is. To get an appreciation for how tight confines we’re really talking about, check out one of these videos:

      https://www.youtube.com/watch?v=_gONk5PS4zM

      Keep in mind that in these videos this is one man operating in a space filled by three in operating conditions, plus a basic combat load of ammunition.

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