Urban Fire

Question 1

What are the (5) classes of fire?

Name, definition & example

Answer 1

A - Fire involving solid carbonaceous materials e.g. wood, paper
B - Fire involving flammable liquids e.g. petrol, solvents, alcohol
C - Fire involving flammable gases e.g. LPG, acetylene
D - Fire involving combustible metals e.g. magnesium
(E) - Fire involving energised electrical equipment (electricty is not a fuel, its a hazard) e.g. switchboard
F - Fire involving cooking oils or fats e.g. deep fryer

Question 2

What is the application rate required to extingish a flammable liquid fire?

Answer 2

6.5 L/min/m²

Question 3

What are (5) advantages of using foam?

Answer 3

1. Requires less water to extinguish a fire.
2. Reduces the danger of re-ignition due to smothering and insulating effects.
3. Foam can be used to totally flood areas or compartments.
4. When used on shipboard fires, the foam’s lightness reduces the stability problems created by large volumes of water.
5. Foam can be used to extinguish fires where firefighters are unable to access the fire or to use water streams.
6. Foam is the only practical extinguishing agent for large Class ‘B’ fires.

Question 4

Give examples of what 3% & 6% foam are used for?

Answer 4

3% = petrol and hydrocarbons (e.g. propane)
6% = solvents (e.g. acetone)

Question 5

What do black top hydrants indicate?

Answer 5

• They may be very high pressure or dry
• Should NOT be used for firefighting purposes without permission of the appropriate water supplier

Question 6

What type of extingusihers are most effective for each class of fire?

Answer 6

A - Need cooling = Water (but all types may be used)
B - Need smothering or interupting = Foam (CO2 and Dry Chem may be used)
C - Needs interrupting or starving = Dry Chem (or starving fire by turning off fuel)
D - Need smothering = special smothering agents such as dry sand and powdered glass
E - Need inhibiting or smothering = Dry Chem (CO2 may be used)
F - Need smothering = Wet Chem (Foam may be used)

Water extinguishers can be dangerous on any class except A

Question 7

What are the (4) types of wall collapse?

Answer 7

1. Collapsing structural framework
2. Inward-outward collapse
3. Curtain-fall wall collapse
4. 90 degree angle wall collapse

Question 8

What does PENSPACE stand for?

Answer 8

PPE worn correctly
Evacuate if signs of impeding collapse
No go zones
Safety officer
Path of escape
Awareness of surroundings
Communication
Engineer