Ch. 2b Fire Development, Enclosure Fires, and Flashover

Question 1

Define fire signature.

Answer 1

Fire development curve of time versus heat release rate

Question 2

What are the 4 phases of a fire signature?

Answer 2

1) Incipient
2) Growth
3) Fully-developed
4) Decay

Question 3

Define flashover.

Answer 3

Transition phase in which surfaces exposed to thermal radiation reach ignition temp more or less simultaneously, causing fire to spread rapidly, resulting in full-room involvement

Question 4

How hot must upper-layer gases be for flashover to occur?

Answer 4

600 degrees Celsius

Question 5

What is a lean flashover?

Answer 5

Result of ignition after incomplete combustion

Question 6

How would you describe the gases that result from a lean flashover?

Answer 6

Fuel-rich

Question 7

When does a delayed flashover occur?

Answer 7

After fuel-rich gases interact with oxygen

Question 8

What is the most effective strategy with handling a flashover?

Answer 8

Attacking the smoke with water

Question 9

What are two key common signs of a flashover?

Answer 9

Sudden temperature changes and heavy smoke concentration

Question 10

On Valentine’s Day of 1981, this Irish nightclub experienced a flashover originating from a small chair fire…

Answer 10

Stardust

Question 11

How many people died in the Stardust nightclub fire?

Answer 11

48

Question 12

How is positive-pressure ventilation used to prevent flashover and backdraft?

Answer 12

Big fans send enough air in to push heat, smoke, and flame back into the affected area