Hummer fire

Oberon said:

In my WIP I have an abandoned Hummer in a forest fire. I assume the fire would touch off the gas tank and take out the tires, but I don't know how much damage an exploding gas tank would do. Any ideas? I seem to be unintentionally involved in a lot of explosions, about which I know so little.

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Which year model is it? Gas or diesel? Military or civilian version.

That being said, the military versions do differ from civilian ones............unless you buy an early H1 which is closet. Also, some hummers have two gas tanks, some have one. Most older ones are diesel, new ones can be gas. Are gas tank/s full, or partially filled. Gas tanks for diesel hold on average of 25 gals. Regular gas versions hold about 23 gal.

What kind of damage are you looking for? Heck, the forest fire alone should be enough.

How full is the tank?

Hollywood loves to show cars blowing up. The reality is that it very rarely happens.

What would probably happen for a car in a forest fire situation is that as the forest fire approaches closer, the heat buildup would cause the gas to start venting. Eventually, this flare would probably catch on fire, but you won't really get an explosion. The car would be totaled, but by fire damage. The gas burns, the tires burn, all the plastic and rubber burn, the seats burn, et cetera.

The only car fire I was at that produced some explosions was a police cruiser where there was live ammo stored in the trunk. I was glad I was running the pumper, but other than producing some pops, the trunk pretty much kept the bullets contained.

If you look at a car that's been in a fire, you'll see that it is pretty much structurally intact, although the metal will have been softened from the heat. Parts that do come off a car with explosive force are the bumpers and the rear hatch. This is caused by the compression cylinders used. Other than that, a car fire is pretty boring, just very dirty smoke.

There's no difference between car and truck fires, other than volume.

Best of luck,

Jim Clark-Dawe

How quickly do you need it towed? Any tow driver worth his salt will be very leary of loading a hot car onto the back of his truck. Where is it located? If you drove it where only Hummers can go then you'll be SOL with tow trucks. Every rural county has a couple of 4x4 wreckers but 4x4 flatbeds are rare. The only one I know of in central California is too small to load a Hummer especially after a fire department gets done loading it full of water. My guess is that most states don't have any. If the route isn't too bad I might consider dragging the beast out on its rims. My point is that you burn a Hummer in the middle of a forest its liable to stay there a while and definately not a case of holding AAA to a half an hour arrival time.

Kentuk's reply on towing jogged a couple of thoughts in my mind.

If this is out in the wilderness, I'm probably only going to be able to bring in a brush truck. I'll probably only have about 200 gallons of water to play around with (at most), which isn't enough to put out a car fire.

I'd set up a perimeter and let the car burn itself out. Much more efficient use of water. We had a small hunting lodge that went up. By the time I got there (first on scene -- I had a Jeep at the time), structure was somewhat still standing. By the time the brush truck got there (an hour after call was received -- ya, it was that far back in the woods and the trail wasn't too good), no walls standing.

We used the brush truck to put out the extensions, but ignored the structure. We just let it burn itself out.

So, for your scenario, it's probable that the fire department wouldn't actually put the car out, just let it burn. Remember, water is a pain in the butt to transport, and 1,000 gallons (normal for a rural pumper) weighs 8,000 pounds, meaning an engine weighs about 30,000 to 40,000 pounds and needs a road that can support it.

If the car burned itself out, by the time it cooled enough to be handled, you're looking at several hours. Probably the fire department would put it out on Monday and it would get towed on Tuesday type of situation.

I will say I never saw a reporter that really went into the woods. Usually they just put a few trees behind themselves and call it quits.

Best of luck,

Jim Clark-Dawe

Oberon said:

In my WIP I have an abandoned Hummer in a forest fire. I assume the fire would touch off the gas tank and take out the tires, but I don't know how much damage an exploding gas tank would do. Any ideas? I seem to be unintentionally involved in a lot of explosions, about which I know so little.

Click to expand...

What happens in a vehicle fire is that the gas in the tank heats up and expands to the point that it ruptures the tank or the filler cap and gasoline comes spurting out of the breach with a "whump" sound and catches fire as it spews. It's not explosive, more of a flamethrower effect. After the fire passes he'll have a torched shell, no tires, no interior, probably all the fluids burned out, glass melted or shattered, maybe even metal melted.

His problem is going to be access to the burned area without getting caught, because they are tightly controlled, with road blocks and closures for days to years after the fire. There are places burned over by the Rodeo-Chediski fire that are still closed to the public because of the danger of falling trees. The press tour will be in an escorted caravan, and residents will have to show proof of residence to get in. There will be teams doing "overhaul" in the burned out areas, checking for smoldering spots and literally raking the coals. There will be forestry teams out evaluating the reseeding possibilities, starting erosion control, and clearing the roads of fallen trees. There will be arson specialists if there is any hint of man-made. And there will be news copters taking shots for the 6PM news. They looooooove burnt vehicles.

Unless the fire was in a true wilderness (no roads, no effort to fight the fire), the vehicle has been seen by guys on the ground. And the wilderness fires are still monitored and photographed, and may even get data collection equipment and teams dropped near them.

It might have been back woods when he left the vehicle there, but if he was on a road, multiple wildfire teams were bringing equipment along that road to the fire front. They will stop to get the VIN and check the registration ... because they will be looking to make sure the owner got out OK. It's SOP to report all the vehicles you find, possibly occupied campsites, etc. in case the owner turns up missing. It's common for a vehicle that is leaving to tow out an abandoned vehicle if they can safely do it - just to get it out of the way of the fighters - so maybe his Hummer is in the custody of the Forest Service.

Here's another thought: wildland teams carry cameras for taking bragging rights photos, and making a record of what they did. Also fire fighting planes often have video cameras so they can see what their runs hit, and they take high-resolution stills to map the fire's progress. He's on film!