Chapter 13

Question 1

131

Fire triangle ends

Answer 1

oxygen, fuel, and heat

Question 2

131

What is the limiting factor that must be present for fires to grow in a residential house fire?

Answer 2

the limiting factor is the oxygen

Question 3

132

The fire tetrahedron

Answer 3

Oxygen, Heat, fuel and Chemical reaction

Question 4

132

What role does the chemical reaction have in fire

Answer 4

It’s feedback loop that propagates the fire. The chain reaction provides the heat and gaseous fuel generation necessary to maintain fire.

Question 5

133

Where are CO explosions or cockloft explosions mostly found?

Answer 5

in row homes with common cocklofts

Question 6

133

Every fire is impacted by ____ and the results can be either positive or negative?

Answer 6

ventilation

Question 7

135

What is rollover/flameover?

Answer 7

the condition where unburned fuel pyrolysate from the originating fire has accumulated in the ceiling layer to a sufficient concentration that it ignites and burns.

Question 8

135

Pyrolysate

Answer 8

unburned fuel

Question 9

135

What makes rollover so dangerous?

Answer 9

the increase in flame and heat production as well as the ability of the fire to hide.

Question 10

135

How does the adage of not passing fire apply to roll over?

Answer 10

it applies much the same, need to cool the environment (not that he actually come out and says this)

Question 11

136

flashover Dan Madrzykowski of NIST

Answer 11

Transition phase in the development of a contained fire in which surfaces exposed to thermal radiation, from fire gases in excess of 1100 degrees reach ignition temperature more or less simultaneously and fire spreads rapidly through the compartment.

Question 12

136

what ignites in flashover?

Answer 12

everything in the room, not just gases and temperatures soar past 1000 degrees.

Question 13

136

What is the difference between a room on fire and a flashover in a room

Answer 13

the difference is flashover room lights up all at once due to the radiated temperature of the room.

Question 14

136

What is a backdraft?

Answer 14

an explosion

Question 15

136

At what stage of fire does back draft occur?

Answer 15

during the decay phase, when the fire has consumed all the available oxygen, but fuel and heat are still present.

Question 16

136

What are the important aspects to remember about back drafts?

Answer 16

1. They are explosions
2. Introduction of oxygen will set off the explosion
3. recognizing fire is in decay, paired with unusual smoke smoke conditions, are signs of backdraft

Question 17

136

Four major issues affect the change we see in the rapid progression of fire in residential structures:

Answer 17

1. Construction methods
2. Fuel composition
3. Firefighter actions
4. Science

Question 18

137

What change in modern home has contributed the most to rapid fire spread?

Answer 18

Open stairs, which act as chimneys, allowing smoke and flame to travel vertically unimpeded.

Question 19

137

How fast did fire spread up the stairs at the Cherry Rd incident in DC?

Answer 19

18mph

Question 20

137

What are the tactics that can aid firefighters once fire does reach the stairwell?

Answer 20

1. when operating above grade, all windows must be laddered.
2. Coordinate ventilation and consideration for the actions that make that possible?? control doors
3. Identify and announce location of stairwell (to engine company).
4. Do not operate on the stairwell, get up or get down (its a chimney and escape route).

Question 21

138

What are the construction methods that aid in fire growth and spread?

Answer 21

1. Open Stairs

2. Age of home old or new construction.

Question 22

138

What are construction methods in older homes that contribute to fire spread?

Answer 22

1. Ballon frame construction, that allows fire to quickly travel from the basement to the attic, possibly hidden, through void spaces.
2. Knee walls, in older homes that create large void spaces for fire to travel in areas that are often full of fuel for the fire.

Question 23

138

What about newer construction homes what are the concerns?

Answer 23

Newer construction methods, outside of open stairs, restrict the movement of fire and smoke quickly. however the concern is with the materials that are engineered and not robust when subject to fire conditions, causing early failure.

Question 24

138

What do modern furnishing represent compared to legacy furnishings?

Answer 24

Modern furnishings have much more stored energy in comparison to legacy furnishing. This creates a dramatic uptick in the rate oaf heat release that can built to flashover much more quickly. This is a danger to everyone within the structure.

Question 25

139

What does uncoordinated ventilation amount to?

Answer 25

random, haphazard introduction of oxygen to an under ventilated fire, before means of suppression are in place.

Question 26

140

What is the first step understanding when to ventilate?

Answer 26

understanding fire behavior

Question 27

141
What do the National Institute of Standards ad Technology NIST, and the Underwriter’s Laboratory research in terms of fire science?

Answer 27

They identify the exact issues that are injuring and killing firefighters at residential fires.

Question 28

141
What four points were discussed related to the the UL study Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction.

Answer 28

1. It is common w/ today’s fire environment to have a decay period prior to flashover which emphasizes the importance of ventilation.
2. Coordination- If you add air to the fire and don’t apply water in the appropriate amount of time the fire gets larger and safety decreases. The time from vent to untenable conditions was 100s in one story and 200s in two story. In many cases the fire flashed after only 10s.
3. Smoke tunneling and rapid air movement through the front door. Rapid in rush of air could signal ventilation controlled fire
4. No smoke showing: common event during the experiments, once the fire became ventilation limited the smoke being forced out of the house greatly diminished or stopped all together. No smoke showing should = increased awareness of potential conditions inside.

Question 29

What points were learned from the NIST study Horizontal Fire Ventilation Experiments in Townhouses?

Answer 29

1. Even with a window is open, the fire can still be under ventilated, until we arrive and open the front door
2. Nothing showing is not indicative of no fire, the ventilation controlled fire decreases in heat creating a lower pressure inside and unable to overcome outside pressure, effectively containing all smoke. Introducing air can result in flashover in 80s.