Structural Firefighting

Question 1

What are the (4) sides of the fire tetrahedron?

Answer 1

1. Heat
2. Oxygen
3. Fuel
4. Chemical Reaction

Question 2

Define flashover?

Answer 2

• Flashover may occur where a large amount of combustible gas is produced, in an environment with adequate oxygen supply
• These gases are subsequently heated to their ignition temperature
• This results in all combustible material in the compartment catching fire.

Goes from ‘a fire in a room’ to ‘a room on fire’

Question 3

What is B-SAHF and what does it stand for?

B(2) - S(5)A(4)H(3)F(1)

Answer 3

Its used for reading a structural fire.
Building (style and materials)
Smoke (volume, velocity, density, colour & neutral plane)
Air Track (inlets/outlets, velocity, direction & pulsations)
Heat (blackening, blistering & sudden heat build-up)
Flame (colour)

Question 4

What are the (3) structural methods of attack?

Answer 4

1. Direct
2. Indirect
3. Gas cooling

*Transitional may be a 4th

Question 5

Define Auto Ignition Temperature (AIT)?

Answer 5

The minimum temperature required to cause self-sustained combustion in any substance, in the absence of a spark or flame.

Question 6

What are the (3) extreme fire behaviours?

Answer 6

1. Flashover
2. Backdraught
3. Fire Gas Ignition

Question 7

Define backdraught?

Answer 7

• Occurs when oxygen is introduced to a room containing a severly under ventilated fire (depleted of adequate air) and large volumes of unignited super-heated gas.
• The oxygen combines with the superheated gases causing it to enter its flammability range and explode

Question 8

Define Fire Gas Ignition?

Answer 8

When flammable fire gases already in their flammability range travel to other areas of a structure and are ignited by an ignition source (such as travelling embers).