Date: Fri, 17 Feb 2006 11:08:59 -0800
Reply-To: Robert Fisher <refisher@MCHSI.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Robert Fisher <refisher@MCHSI.COM>
Subject: Re: Firewood
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The firefighting training I went through in the Navy had a intensive section
on magnesium fires, largely because the aircraft have so much magnesium in
them. Add that to the fact that many of those aircraft will also have
ordnance attached to them and it makes a pretty problem.
The way they explained it to us was that magnesium has a high enough oxygen
content in of itself that it will burn solely on its own oxygen once
ignited. I don't know any more about it than what I was told, although some
googling brought up some information that confirmed that information. I also
saw some information that supports what John said as well, particularly the
CO2.
The Navy used a training video that showed a loaded fighter on fire, at
night. Basically the technique in fighting those fires is to push the thing
overboard. They had a few shots from different cameras showing the burning
plane going into the water and then sinking. You could very clearly see the
bright light from the fire as the plane sank, and the narration said that
the fire was still visible at an estimated 200 feet- which is kind of
astounding if you think about it. They don't even bother trying to fight the
fire because if they lose control of the situation the plane (or rather, the
burning magnesium mass) could melt its way down through the ship. They know
this because it has happened.
I saw this played out once on the Midway. It's a long story how the entire
situation came to pass, but it wound up with the burning plane going over
the side. I was thinking 'wow, 50 million right down the pisser...' They
didn't even bother trying to get near the plane, nevermind trying to do
anything about the fire. One lone guy (how'd you like to have this job?)
caught it on his tractor on the side away from the fire, pushed it to the
side of the forecastle and jumped just before the whole thing went over.
Those of you that are doing these case fires might want to reconsider, or at
least do some reading before you continue. The simple fact that it can't be
put out readily is a problem in of itself, but there are other dangers- eye
damage from the intensity of the flames, the fumes can be poisonous, etc.
Didn't sit down to do a thesis paper but a quick scan gave a pretty clear
picture.
Additionally, the magnesium is highly reactive to acids (think of this when
you're choosing an engine cleaner) and in the presence of those and even
plain water can make it give off hydrogen gas- there were lots of 'flash
fire' hazard warnings.
Finally, I think all this lends even more weight to the fuel line issue. I'm
thinking those burnt out hulks we've all seen pictures of may have more to
do with the engine catching fire after the fuel fire than 'just' the fuel
fire itself.
Just some food for thought-
Cya,
Robert
----- Original Message -----
From: "John Rodgers" <inua@CHARTER.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, February 17, 2006 7:49 AM
Subject: Re: Firewood
> Magnesium - once lit - will burn under water. Heat is so intense and
> chemical reaction so fierce that it splits the oxygen from the water
> molecule for it's own use in combustion. Tough to fight a fire like that
> with water. CO2 extinguishers don't work very well either. The intensity
> of the chemical reaction in the magnesium is such that it also splits
> off the oxygen from the carbon in the CO2 and consumes it. Carbon is the
> leftover byproduct of magnesium combustion and it makes a heck of a
> carbon soot mess. The intensity of the cold of a discharging CO2
> extinguisher might chill the magnesium sufficiently to reduce and then
> snuff the flame, but I would not count on it. I can't say I have ever
> seen a magnesium fire extinguished successfully- it only went out when
> it burned itself out.
>
> Regards,
>
> John Rodgers
> 88 GL Driver
>
>
> ROBERT DONALDS wrote:
>
>> I machine the bug cases so I have magnesium flakes that collect over time
>> one night I took a large hand full out into the ally and lit it on
>> fire not
>> very impressive until I kicked it with my boot it then lighted up the
>> ally
>> like daylight and then some funny what a little sturring will do
>> water will not put this out
>> Bob
>>
>>
>> ----- Original Message -----
>> From: "Bill Collins" <wb6otg@INTREX.NET>
>> To: <vanagon@GERRY.VANAGON.COM>
>> Sent: Friday, February 17, 2006 9:00 AM
>> Subject: Re: Firewood
>>
>>
>>> >Wood is nice, but I highly recommend burning an engine case (ala
>>>
>>>> Burning Van 06).
>>>
>>>
>>> Just make sure no one throws water on it! Someone did that the last
>>> time
>>> they burned one at Everybus. (I think that's part of the reason it
>>> was the
>>> LAST time)
>>>
>>> Bill
>>>
>>
>>