Structural Firefighting

Question 1

Stages of fire progression

Answer 1

Phase 1: Developing Fire Phase 2: Flashover
Phase 3: Fully Developed Phase 4: Decay

Question 2

What is the neutral plane?

Answer 2

The area between over pressure (hot fire gases) and under pressure (fresh air)

Question 3

Hot fire gasses could pose a risk of becoming?

Answer 3

Fire gas ignition

Question 4

7 Signs of Flashover

Answer 4

1. Ventilation controlled, vented fire2. Painful radiant heat3. Hot surfaces 4. Fingers of flame through smoke 5. Increased rate of pyrolysis 6. Low turbulent neutral plane 7. Increased turbulence of neutral plane

Question 5

Signs of backdraught

Answer 5

1. Ventilation controlled, non vented fire2. Lack of visible flame3. Dirty smoke4. Smoke pulsating through small gaps and openings5. Air drawn in (whistling noises)6. Indicators of extreme heat e.g. blistering of paintwork, crazing of glass in windows

Question 6

Flammability range is the ratio of

Answer 6

Fuel to air Too low concentration and things cant burn Too high concentration and things cant burn

Question 7

The decomposition of a substance is

Answer 7

Pyrolysis caused by heat

Question 8

Direct attack - what is the correct branch setting

Answer 8

Jet, flow rate 115 to 475 lpm

Question 9

What is the branch setting when gas cooling

Answer 9

30-60degreecone angle, 115 lpm at 700kpa

Question 10

What is gas cooling, when is it used

Answer 10

Used to control the fire environment when advancing during fire attack, to perform search & rescue and for protection.The water droplets are converted to steam, the flammable gases are cooled and diluted below their Auto ignition temperature. The steam expands by absorbing the thermal energy/heat of the fire gases, and displacing the oxygen away from the fire

Question 11

What are the Gas laws

Answer 11

Thornton’s rule - As oxygen increase, the heat rate increasesCharles’s law - Gases expand when heated. Gases become less dense and will rise when heated Gay-Lussac’s law - when gases are confined and heated, pressure increases. Increased pressure, higher temperatures.

Question 12

Definition of a fire gas ignition?

Answer 12

Fire gas explosion ignited in another compartment e.g. second floor, adjacent room

Question 13

When do we use door entry

Answer 13

Always

Question 14

Ventilation vs fuel control signs - scenarios will be given in exam, list which one it is e.g. bush fire

Answer 14

Fuel Controlled signs- Developing fire- high neutral plane- better visibility- bright yellow flame- fire in decay stageVentilation - fully developed fire- low neutral plane- poor visibility- air being drawn back in to fire- smoke pulsations- smouldering fire- whistling sounds

Question 15

Intent of an indirect fire extinguish attack and what is it most suited for?

Answer 15

To extinguish a fire by creating large amounts of steam. This has a smothering effect on the fire by displacing the oxygen. This method is generally used when the fire is fully involved or to suppress a suspected backdraught risk.

Question 16

List the extinguisher colours and what they are most suited for

Answer 16

Red - Water - AWhite - Dry powder - A,B, C & EBlue - Foam - A & BBlack - CO2 - B & EA - Wood, Paper, PlasticsB - Flammable LiquidsC - Flammable gasesE - Electrical

Question 17

What is meant by overhaul

Answer 17

Overhaul involves the systematic checking, turning over and wetting down of structural materials and contents to ensure that no pockets of fire still exist

Question 18

What are 5 signs of structural collapse

Answer 18

1. Falling plaster, mortar, bricks or from walls or ceilings 2. Cancerous concrete spalling3. walls leaning or bulging4. ceilings sagging5. floors spongey or springy6. gaps appearing in between walls, beams or ceilings, or walls and floors7. cracked or sagging arches over door or window openings8. displacement of supporting pillars, joists or beams

Question 19

What is salvage operations

Answer 19

Salvage describes the actions taken during and immediately after the fire to minimise the damage caused by fire and by the water used to extinguish it.

Question 20

What are some assisted evacuation producers for high rises?

Answer 20

Smoke curtains, pressurised stairs, pressurised zones and sprinkler systems