The Social Network & Community JUST for Firefighters
Car Engine Firey s
General question for those with more experience than I have:
If my station runs on a car engine fire, and the engine is off, would there be any way for the battery/ electrical equipment in the car to engage? Also is the best agent for an engine fire water or foam? Why?
Replies to This Discussion
-
Permalink Reply by Fireyladd - Retired Chief Sharp on
-
Yes, as the fire encounters electrical wires it can cause a short and thus the ignition can turn over and other electrical issues happen. I once saw a set fire with a car on a training drill with the State Fire Marshal where a car was set on fire and it actually started and jumped forward almost running out int the freeway. WOOPS!
Yes, a vehicle can attempt to start of fire up even if the key is off or not in the ignition. Best action is to remove the battery cables or cut them. Water would e the better of the two. Less issues with clean up.
-
Permalink Reply by Brian Mackie on
-
Absolutely agree with Chief Sharp. Secure the vehicle to avoid a runaway. Also, while I am thinking about that engine fire, there some vehicles that contain magnesium. Now I am unsure at this point if there are any engine blocks that contain magnesium, however, I know some car frames do. I was working a rollover that was fully involved. When I reached the front end/engine compartment, it "popped" quite violently and we knew by the WHITE flame and reaction to water, it was indeed magnesium. The lucky thing for me was it was not a direct hit with the stream, but splashover, which was certainly enough to cause a good enough pop for me to realize I was in too close. Lession learned! :) Now, I have a question. Does anyone know if there is anything available to responders telling us what vehicles contain magnesium? I think if we knew what we were dealing with right off the hop, it might better determine which agent ..water or foam or dry chem..etc.. to use. I don't want to hijack his thread but maybe someone can add to it? Thanks
-
-
The issue with Magnesium is to apply lots of water. Yes, you will know a magnesium fire by the accelerated fire when applying water and the white glow. But just keep applying water and a hard stream will put it out.
-
-
Chief, can you please post some links as to where this information is found? I tried to find anything that indicated that water would work, but can't find anything.
I found numerous sites to the contrary, but perhaps that's still old school, and there might be something new that I have missed. I would really like to see something supporting that statement about water on mag. fires.
http://www.lenntech.com/periodic/water/magnesium/magnesium-and-wate...
http://nuclearpowerradiation.tpub.com/hdbk1081/hdbk10810035.htm
http://www.youtube.com/watch?v=0av7h76OdIk
-
Permalink Reply by Eric Robinson on
-
I am a hot rod hobbyist and builder and to start many have mentioned that as long as power is supplied to car there is still a risk for starting and even electrical spark increasing the hazards. That is absolutely correct as the protective coating melts from the wire potential shorts can activate the starter. Cutting the battery is the best plan of attack, however if the vehicle is still running the alternator will supply power even in the instance the battery is cut.
For the magnesium in cars it is used as lighten the vehicle and in turn make better power. European manufacturers have been using it for years. Also, racecars, including street racers, have added aftermarket equipment that contains traces of magnesium in it. As part of your size up consider looking if the car contains aftermarket features and check the rims. The wheel manufacturers are using mag because it is lighter too.
I wanted to add I located this site http://www.magnesium-elektron.com/markets-applications.asp?ID=7
It is helpful with which cars contain it and the years the vehicle was in production. It is a company promoting magnesium, but it discusses what their customers use it in pertaining to the automotive sector. I thought it may be helpful for informational purposes.
-
Permalink Reply by Jack/dt on
-
We always flow with foam on fully involved. But using a CO2 does have some advantages if the fire is confined to the engine compartment: blasting CO2 up into the engine compartment (without first opening the hood) displaces the oxygen with CO2 - an inert atmosphere - works well if you're on scene quickly.
Also let's not forget about bumpers and their known propensity for firing off, knee height from the heat of the fire. Don't approach it head on, front or back. And if upon arrival it looks like it may be out, there is a (slim, but still a) possibility of a back draft explosion if you tap a window, might want to use something long handled (and maybe full PPE).
-
-
That's a good point Jack about the possibility of a backdraft once the passenger compartment has lost it's oxygen, and being air tight enough, particularly when new, the possibility might be more real than people would expect. Thanks for that thought. What about your experience with magnesium? any thoughts on that part? Really interested in finding out what is what now, and admittingly I don't have a whole lot of experience with it..just the once time in fact. IS water the best agen despite what the websites say?
-
Permalink Reply by Marc Hansen on
-
for mag fires use a class d ext or dry sand (make sure it is good and dry). If all else fails copious amounts of water!
Magnesium burns in water because it is hot enough to separate water into hydrogen and oxygen. While it burns brighter and hotter than most things, the process of splitting atoms is energy intensive so the fire burns much less efficiently. Using copious amounts of water works because all of the energy gets used up splitting atoms to get fuel, you in effect are making the "engine" run too rich to support combustion while at the same time the rest of the water is effectively cooling off the unburned magnesium below its ignition point. All that being said engine and tanker/tender for the small amounts of magnesium used in vehicles (road/air) and lots and lots of dry sand for large quantities found being transported by semi or stored in industrial settings.
For training purposes look around at the industries in your area, if they use magnesium they might allow you to use their scrap to conduct training with it. You dont really need much to get the point: gather a pile of shavings and light it with a flare then try to put it out with a spray bottle then a garden hose. Please do so with an overabundance of safety and you will learn a lot.
-
-
Marc, that is awesome information. I thank you much for that insight. I indeed will look for some and play with it. Yes, safety is the key.
I did not know that using water would be effective. Great info. Thanks. Also to Chief Sharp for bringing that point up.
-
-
Marc,
Good information, and not to put too fine a point on it but, when magnesium burns it's a chemical reaction, not a process of splitting atoms; that falls into the category of nuclear fission.
As for using copious amounts of water, the reaction between burning (molten) magnesium and oxygen releases hydrogen which further increases the reaction. Given that once ignited, magnesium can burn under water (certainly a definition of 'copious amounts of...') the only way to extinguish a magnesium fire is to remove oxygen from it. Sand appears to be the single best way to accomplish that. Let me repeat it, water will not put out a magnesium fire.
-
-
hmmm just when I thought I knew something new.. It appears I don't know anything new, because that's what my initial thoughts were right from the outset.
so, stay tuned folks for another dramatic episode of... "when Magnesium burns!" right here on NBC!
-
-
Jack,
sorry what i meant to say was it burning magnesium uses heat to break water down to its component atoms. Sorry fingers got lazy and the eyes were to tired to notice.
However...."Water is not generally accepted as an effective extinguishing agent for metal fires. When applied to hot burning metal, water will break down into its basic atoms of oxygen and hydrogen. This chemical breakdown contributes to the combustion of the metal. However, water is also a good universal coolant and can be used on some combustible metals, but only under proper conditions and application, to reduce the temperature of the burning metal below the ignition point. For example, automatic deluge systems in magnesium plants can discharge such large quantities of water on burning magnesium that the fire will be extinguished." ...OSHA 1910.157 (4) . Again not the best agent but can be used for small amounts of magnesium found in vehicles with a great water supply. Just as another aside large amounts of table salt (NaCL) is supposed to be effective in metal fires but I have not had a chance to play with it. One last question: Since magnesium is used extensively in aerospace wouldn't the water used to make foam in aircraft response vehicles mean that the FAA allows every airport FD to pour gasoline on a fire involving aircraft?
Brian Mackie,
Another source of magnesium would be bicycle frames from high end bicycles, scrap late model cars, certain styles of racing hubs. Again use small piles of shavings since they are easier to light, don't look directly at the fire, and don't breathe the smoke or eat the ashes(don't do it in the kitchen)
© 2024 Created by Firefighter Nation WebChief.
Powered by
