Driving an aluminum star

[Bobosan]

Been a bit of hype about cutting 700 pounds off the weight of the new Ford F150 series trucks by going all aluminum. Check out this series of burn down photos and notice the explosion pic looks like a aluminum/magnesium star shell going off.

 

Using thin aluminum panels has always been risky. Look at the results of mobile/manufactured home fires. I don't think that kind of flammability in a vehicle is worth 700lbs. weight reduction.

Edited August 5, 2014 by Bobosan

[mabuse00]

A rather lurid article. I think this is bs.

 

I wonder if the aluminium even played a role as a fuel in that fire, or if most of it just melted down.

Even without the aluminium the car consists of a great quantity of combustible material.

And considering the "Explosions" - I'd rather call that popping airbags and boiling over oil and fuel. Any car could burn like that.

 

The aluminium has nothing to do with flammability. Even if it burns, it would take something else to burn first - and that is what should not happen with a well designed car, even after a crash. It seems it was a prototype after all.

 

 

Once you americans will have to pay european gas prices you'll learn to love efficient cars. I cant understand why there is no higher tax on such monsters anyway. Rather people poison their drinking water with this fracking shit, making a few guys rich and let the oil party continue for a few years longer, and leaving the little man with the troubles afterwards.

Edited August 5, 2014 by mabuse00

[taiwanluthiers]

700 pounds is actually pretty significant.. that's 700lb more you can carry in your vehicle without consuming more gas.

 

In a fire the last thing you're going to worry about is the flammability of aluminum. There's plenty of things inside a car that is more flammable. Aluminum is only flammable in powder form.

 

Just how much is 700lbs? That's enough to carry about 4 more people (unless you're talking about an average American, then 3 people)

[Bobosan]

Interesting that MotorTrend has taken the series of burn pics offline, probably at Ford's request or demand.

 

There was a pic at the front of the series that definitely looked like small pieces of ignited aluminum or al/mg went flying through the air from the explosion. The truck was still intact and the flames were confined to wheel well and hood at that time. I don't think air bags do that but the camoflage covering sure helped to feed the fire.

 

There was no hulk of a body left after the truck was completely consumed. Pics seem to have been taken 5-10 minutes apart in the series.

Edited August 5, 2014 by Bobosan

[taiwanluthiers]

I always wonder what's with Ford and explosions...

[BurritoBandito]

Mabuse00, IMO in the second picture it looks like aluminum is burning. Airbags contain NaN3, if it gets hot enough the decomposition would be violent enough that most people would consider it an explosion.

 

Edit: I just realized that the orientation of the images may not be the same for everyone. I visited the article from my phone. Bobosan is correct, the link he provides below is the image I was refering to.

Edited August 5, 2014 by BurritoBandito

[Bobosan]

^^ this

 

http://www.automobilemag.com/features/news/1408-2016-ford-f-series-super-duty-prototype-catches-fire-burns-in-desert/photo_14.html

 

 

[mabuse00]

OK, I see this the first time, on the other site it was invisible.

 

 

he second picture it looks like aluminum is burning. Airbags contain NaN3, if it gets hot enough the decomposition would be violent enough that most people would consider it an explosion.

 

Yeah, but any car today has airbags. Tires can pop to.

 

Seems like molten glowing aluminium was splattered around. If you light magnesium powder on a spatula it glows slowly. Once you flip the glowing stuff in the air you got a similar effect.

 

I still do not consider this to be a special hazard. It's a burning car after all.

[Shadowcat1969]

I still do not consider this to be a special hazard. It's a burning car after all.

 

I agree. I simply do not see the truck bed igniting on its own as you are driving down the road.

 

By the time a fire is hot enough to begin melting and igniting the aluminum panels you have a LOT more to worry about.

[BurritoBandito]

I'll just contunue trying to stay out of ANY car that is burning. The policy has served me well so far.

[Bobosan]

According to the article, the front end was completely consumed in 3 minutes, the entire truck in 21. In some places that's not even enough time for first responders to arrive and try to cut you out if trapped in a crash. True, it can happen with any vehicle. Given the nature of molten aluminum in contact with fluids, the explosions described are the probable result of other vehicle fluids spilling onto molten al puddles.

 

Not knocking the fact that 700 pounds were saved but people around here usually buy a truck to be a TRUCK!, not some stripped down gas saver whose pick up bed rarely sees a bale of hay or stick of lumber.

[nater]

Airbags do not sound like an explosion when they go off. During a car fire, the tires and struts frequently pop causing bystanders to mistake them as an explosion. Magnesium is often found in engine blocks, which would be my first guess for the burning white.

 

It is too hard to judge what is going on based on pictures and a written account from people who are not trained in fire behavior.

[MrB]

In modern car manufacturing today magnesium, or magnalium i used in a lot of components. Hell, GM use something like 20-25 kilos of the stuff in Savana & Express vans.Mercedes uses it to cast G7 gearboxes. (i'm sure it's used for more)

Ford then, do they use magnesium / magnalium? They sure do.

 

Airbags do not sound like an explosion when they go off.

Uh. I've blown airbags for fun, and heard em go of in fires. It sounds like an explosion, every time. No wonder, since it's what it is.

 

Not knocking the fact that 700 pounds were saved but people around here usually buy a truck to be a TRUCK!, not some stripped down gas saver whose pick up bed rarely sees a bale of hay or stick of lumber.

Weird complaint to have. The load capacity increases when saving weight, it's not like they make the car out of cardboard, that falls apart when it rains. An all aluminum vehicle has one huge advantage. It wont rust. Unlike "regular" cars. It doesn't really matter how careful you are, a workhorse gets dented, and dents allow rust. Going with an all aluminum body-shell is a huge improvement. Just design it right, with the appropriate reinforcements in place, and you'll never have any issues... Well, until you light it on fire. Much less left to recycle at that point.

B!

[taiwanluthiers]

Not to mention you save that much more fuel when you aren't carrying that capacity, or at least you're carrying more stuff for the same amount of fuel. With gas prices the way they are it makes me wonder why American manufacturers won't design more efficient vehicles.

 

By the way the only reason iron/steel is traditionally used is because when the industrial revolution started, aluminum was worth more than gold! The right alloy of aluminum has nearly the same strength of steel but only half the weight! There's a reason why they don't use cast iron engines in airplanes.

 

Oh and by the way at the right temperature, iron is also flammable...

Edited August 6, 2014 by taiwanluthiers

[Bobosan]

 

 

Weird complaint to have. The load capacity increases when saving weight, it's not like they make the car out of cardboard, that falls apart when it rains. An all aluminum vehicle has one huge advantage. It wont rust. Unlike "regular" cars. It doesn't really matter how careful you are, a workhorse gets dented, and dents allow rust. Going with an all aluminum body-shell is a huge improvement. Just design it right, with the appropriate reinforcements in place, and you'll never have any issues... Well, until you light it on fire. Much less left to recycle at that point.

B!

 

I was hoping Nater or some other first responder/ firefighter could chime in as to how/what hazards they deal with fires in aluminum bodied vehicles. I know there are plenty out there besides Ford's new truck. I think the Audi's use a lot of al and there may be others.

 

I fully understand the weight saving benefits of the new pickup and in fairness, the fire was in a prototype Super Duty rather than the new all aluminum standard F150. Time will tell and for the record, I own a F150 and a Lincoln so you might say I'm sort of a FoMoCo fan.

Edited August 6, 2014 by Bobosan

[taiwanluthiers]

I don't have any particular brand loyalty when it comes to vehicles... whatever is reliable, fuel efficient, and relatively maintenance free gets my vote. I realize that the kind of vehicle you want depends largely on what you want to do with it, but given that, the above 3 still applies.

[nater]

We have not had any special training considering aluminum framed vehicles. Many ambulances and fire trucks have a significant amount of extruded aluminum components to save on weight. I do not believe the fire hazard is significantly higher than steel. These days, I am mostly on the medical side and do not fight fires as much.

 

Back to the airbags, while they are deployed with a small explosive charge, I would not consider the sound to be confused with an exposion at all more like a pop.

[gregh]

This is off the current topic, but isn't it ironic that if you look at the pictures, the truck was pulling a trailer with a tank of water.

[dagabu]

"After 21 minutes, the prototype was completely destroyed, leaving behind charred remnants of the frame and piles of molten aluminum."

 

I am somewhat confused with this posting, are we saying that aluminum is being burnt in this still frame montage? That the new trucks can somehow be more hazardous than steel because the aluminum catches fire? Aluminum melts at 1220° F, it immediately slumps and forms globs with enormous thermal capacity. Conventional fuels such as upholstery, gasoline, rubber tires etc. do not have anywhere close to the therms it takes to ignite sheet aluminum little alone a glob of the stuff.

 

The GTAW arc is around 4000° F and MIG is around 3600° F, the *ignition temp is 4478° F so even welding cannot produce the heat that is needed to burn the aluminum before it becomes a liquid and falls away. Once on the ground, it accumulates in "globs" and the temperature is greatly reduced on contact causing the mass to harden once again.

 

There is no special risk or hazard using aluminum sheet, this is not a powder, it is not aerosol and is of no concern to firefighters.

 

...Yes, I do have a metallurgy background and am a certified welder.

 

*Aluminum does not ignite or burn, it actually vaporizes and a rapid oxidation takes place causing heat and light... Laymans explanation.

Edited August 6, 2014 by dagabu

[Bobosan]

Now that you mention these welding temps Dag, it was sort of a "duh!" moment for me. So what may be burning in those pics? Possibly a lower combustible composite of some type to simulate the future aluminum body panels? That would make more sense but then it negates the weight saving factor of this desert test unless it was only the drive train they were putting under stress.

[nater]

I speculate the white burning to be magnesium in the engine. Everything else burning in the car would be fuel, oil, plastics, upholstery, etc... Car fires are more hazardous to firefighters than a lot of people think due to the toxins released during combustion.

[dagabu]

For sure! Aluminum sure isn't one of the toxic metals.

[MrB]

I speculate the white burning to be magnesium in the engine.

Consoles to hold the dashboard and other interior, gearbox, and so on. A lot of things are made from magnesium aloy these days, all in an effort to save weight. As the link states in my other post, Ford is among the top consumers of magnesium in the vehicle industry.

B!