California Fire And Life

11

"Prometheus," the little man in the tweed suit says.

Jack's like, Pro-who? And what the hell does it have to do with fire?

The lecturer acknowledges the blank stares of the class.

"Read your Aeschylus," he says, adding to the general puzzlement. "When Prometheus gave fire to mankind, the other gods chained him to a boulder and sent eagles to pick at his liver for all eternity. If you consider what man has done with fire, Prometheus got off easy."

Jack had expected fire school to be taught by a fireman – instead he has this tweed-jacket professor named Fuller from the chemistry department of Chapman mumbling about gods and eternity and telling the students in a thick Irish accent that if they don't understand the chemistry of fire, they can never understand the behavior of fire.

First thing Jack learns in fire school is, What is fire?

Nothing like starting with the basics.

So…

"Fire is the active stage of combustion," the professor tells Jack's class. "Combustion is the oxidation of fuel that creates flame, heat, and light."

"So combustion is flame, heat, and light?" Jack says.

The professor agrees, then asks, "But what is flame?"

The class's reaction is basically, Duhh.

It's easy to describe flame – it's red, yellow, orange, occasionally blue – but defining it is something else. Fuller lets the class sit with this for a minute, then he asks a very un-professor like question: "Are you telling me that no silly bastard in this room has ever lighted a fart?"

Ahhh, says the class.

Ahhh, thinks Jack. Flame is burning gas.

"Burning gases," Fuller says. "So combustion is the oxidation of fuel that creates burning gases, heat, and light. Which begs what question?"

"What is oxidation?" Jack asks,

"Full marks for the surfer dude," Fuller says. "What's your name?"

"Jack Wade."

"Well, Master Jack," Fuller says, "oxidation is a series of chemical reactions that occur when an atom – that is, matter – forms a chemical bond with a molecule of oxygen. Now don't you all wish you'd paid more attention in Chemistry 101?"

Yes, thinks Jack. Definitely. Because Fuller starts drawing chemical equations on the board. While the chalk is screeching, Fuller's saying, "In order for oxidation to occur, a combustible fuel – we'll talk about fuel in a few minutes – and oxygen must come together. This is called an exothermic – that is, heat-producing – reaction."

He draws an equation: 2H2 + 02 = 2H20 + heat.

"A basic oxidation reaction," Fuller says. "When you combine hydrogen and oxygen, you get two molecules of water, and heat. Heat is measured in BTUs – British thermal units. One BTU is the amount of heat that it takes to raise the temperature of one pound of water by 1 degree Fahrenheit. So the more heat you have, the greater the temperature you're going to get. Put simply, the more BTUs, the hotter the fire."

Fuller continues, "Look, gentlemen, to sustain a fire you need to have three things working together: oxygen, fuel, and heat. If you have no oxygen, oxidation obviously can't take place – no fire. If you have no fuel, there is nothing to oxidize – no fire. If the fuel doesn't contain enough mass of heat, then the fire dies out."

He strikes a match.

"Observe," he says. "We have oxygen, we have fuel, we have heat."

The match burns for a few seconds, then goes out.

"What happened?" Fuller asks. "We had plenty of oxygen, but not a lot of fuel and not a lot of heat."

He strikes another match.

"I will now attempt to burn down the classroom."

He holds the match to the metal desk.

The flame makes a slight scorch on the metal, then burns out.

"What happened?" Fuller asks. "We have oxygen, we have heat, it's a big desk – plenty of fuel – where is our sustained fire?"

"Most metals don't burn easily," Jack says.

"Most metals don't burn easily," Fuller repeats. "Which is the lay person's way of talking about flammability. Some substances burn more easily than others. Witness…"

He rips a page from a legal pad, strikes another match and holds the match to the paper.

"It ignites immediately," he says. He drops the burning paper into a metal trash can and puts a lid on it.

"Thereby depriving it of oxygen," he notes. "Look, paper has a lower flash point than the metal of the desk. Flash point is the temperature at which a fuel ignites. A simple match will ignite paper but doesn't have nearly the BTUs to create enough temperature to reach the flash point of the metal in this desk. It simply can't sustain the oxidation reaction needed to set the desk on fire and keep it on fire.

"Now, were we to add more fuel to the fire, and developed enough BTUs to raise the temperature, there is a point at which we could indeed melt the desk.

"It's a chain reaction, gentlemen – a chemical chain reaction. Difficult to break down into a description because it is a never-ending cycle of chain reactions, which are really quite fascinating in detail. But for practical purposes it's all about fuel. The amount of fuel, the flash points of that fuel, and the conductivity of that fuel.

"So, the amount of fuel – in proper terminology the fuel load, or the fuel mass. Why is it important to establish a fuel load for a structure that has suffered a fire? If, for instance, you find a melted metal desk in a burned structure where the pre-fire fuel load could not have produced sufficient BTUs to melt that metal, you have an anomaly that you need to resolve.

"You'll want to be taking notes on this because you'll need this terminology to pass the bloody test."

Jack takes notes.

He doesn't want to pass the bloody test.

He wants to ace it.