SABT 5 D FIRE SCENE INV

Question 0

-Three basic elements of fire = Heat, Fuel, Oxygen

Answer 0

FIRE TRIANGLE

Question 1

1 -
A rapid oxidation process, which is a chemical reaction resulting in the evolution of light and heat in varying intensities.

Answer 1

FIRE

Question 2

• Expanded upon the fire triangle to include the uninhibited (Chemical) chain reaction to a four side solid geometric form called a ______
• continue as long as all three are there Heat, oxygen, fuel

Answer 2

FIRE tetrahedron

Question 3

2 Explain fire growth as it relates to the

• three methods of heat transfer and the
• three types of fuel.

Answer 3

• 1 Conduction-heat transfer to another body or within a body by direct contact (needs a body to get thru)
• 2 Convection- Heat transfer by circulation within a medium, such as a gas or liquid (side of flame is Radiation/ top is heat) Go thru air heat rays
• 3 Radiation- Heat transfer by way of electromagnetic waves.

-1 Solid
-2 Liquid
-3 Gaseous
Convection and Radiation are the primary source of the fire

Question 4

Types of Combustion

Answer 4

Spontaneous
Smoldering
Premixed
Diffusion

Question 5

Extremely slow oxidation of a fuel due o the limited exposure to air

• Temperature rise in the fuel in inversely proportional to its ability to dissipate heat
• Insufficient heat loss may lead to a thermal runaway
• Process from inception to ignition may range from hours to days

Answer 5

Spontaneous Combustion

Question 6

Combustion with flame, usually with incandescence and smoke

Answer 6

Smoldering combustion

Question 7

Any flame in which the fuel and oxidizer are initially mixed and ignited

Answer 7

Pre-Mixed Flame

Question 8

A flame in which fuel and air mix or diffuse together at the region of combustion

Answer 8

Diffusion Flame

Question 9

The movement of molecules from an area of high concentration to an ara of low concentration

Answer 9

Fick’s law of diffusion

Question 15

Two major types of fuel air explosive that are encountered most commonly by fire investigator s

Answer 15

1 Mechanical explosions

2 Chemical Explosion

Question 16

as explosion in which a high pressure gas creates internal pressure within a confining container and produces a purely physical reaction

Answer 16

Mechanical Explosive

Question 17

the most common explosion related to fires is a chemical explosion that is also referred to as gas/ vapor explosion, a fuel air explosion, or a combustion explosion.
-high pressure gas is the result of exothermic reaction wherein
A- combustion reaction
B- decomposition reaction
C- rapid exothermic reaction

Answer 17

chemical explosion

Question 19

3 Explain fire behavior as it relates to the four phases of fire growth, flashover, fire spread and fuel load.

Answer 19

1 Ignition Phase
2 Growth Phase,
3 Fully Developed,
4 Decay phase-fire begins to decline in intensity due to lack of fuel oxygen or heat (Fire suppressions Efforts)

Question 20

-The transition stage in fire development when all combustible in the room reach ignition temperatures simultaneously. BC a room on fire

Answer 20

-Flashover

Question 21

The amount of energy impacting a solid fuel surface necessary to gasify a unit mass of fuel
-referred to as (PYROLYSIS)
Breaking down fuels until they decompose and gasify. The gas ignite and burns

Answer 21

Heat of Gasification

Question 22

• Fire will spread at the heat is transferred by methods of convection, conduction and radiation.

Answer 22

-Fire spread

Question 23

-The consideration of fuel loads will answer the question of what is burning?

Answer 23

-Fuel Load

Question 26

have a flash point of less than 100F

Answer 26

Flammable Liquid

Question 27

Have a flash point of 100F or greater (additional energy required)

Answer 27

Combustible Liquid

Question 28

Heat of combustion x area will tell u

Answer 28

Mass burn rate

Question 30

Turbulent Flame
-Fame heights approaching approaching 1 foot less stable due to velocity of air entrainment
-Large eddies develop from air entrainment
Radiant heat transfer can account for up to ___ heat tranfer

Answer 30

50%

Question 31

4 List and define two major types of fuel air explosion and the properties/ behaviors of common combustible gases.

Answer 31

1 Mechanical explosions

2 Chemical Explosion

Question 33

Relatively uniform pushing

• Window frames tend to stay intact and are projected away from structure
• Greater damage away from point of initiation
• Subsonic blast wave

Answer 33

Fuel/ Air Signatures

Question 34

Why Inv Fire scene

Answer 34

Need to bring to the Courtroom - Never miss an opportunity to walk where a bad guy walked - scene polygraph

Question 35

what is the Scientific Method of a fire ( A systematic Approach)

Answer 35

``` Recognize the need Define the problem Collect Data Analyze Data Develop Hypotheses Test Hypotheses Select Final Hypothesis Make a determination ```

Question 36

Scene Investigation steps

Answer 36

Arrival at scene use-determine legal authority Security of fire scene= CS, limit access, overnight security safety at the fire scene Documentation Origin and cause determination

Question 37

Finish Sketches are

Answer 37

NOT TO SCALE

Question 38

What is Examine the scene from the outside to inside | -Examine the scene from the area of least damage to the area of most damage

Answer 38

Systematic Approach Origin to inside

Question 39

Why are fires investigated

Answer 39

To determine if a criminal act has occurred (arson) To determine liability or responsibility (Civil) To determine fire prevention (Public Safety)

Question 40

Fuels are lighter than air (natural gas) will result in explosion damage in the upper portions of the structure: fuels that are heavier that air (LP) will result in damage that is in the lower portions of the structure= T or F

Answer 40

note

Question 41

``` Artifacts left by the fire FP of the fire Noted and Documented Part of Data collection process Studied and tested ```

Answer 41

Fire Patterns

Question 42

What are the two type of fire patterns

Answer 42

Fire Movements Patterns Fire intensity patterns

Question 43

``` Multiple origins -trailers -Pour patterns, Ignitable Liquids -Disabling fire protection system -Tampering with utilities -Unusual fuel loads or fuel configurations -Incendiary devices -crime concealment - ```

Answer 43

Incendiary Fire indicators

Question 44

Accidental causes of fire

Answer 44

``` Electrical Heating equipment mechanical Cooking smoking candles Spontaneous heating Children ```

Question 45

The intentional or unintentional destruction of evidence which would prohibit the interested parties from a fair examination of evidence

Answer 45

Spoliation

Question 46

Common Fire causes

Answer 46

``` 1 Improper careless use of smoking materials 2 Electrical causes 3 Cooking/ kitchen fire 4 Industrial 5 mechanical Failures 6 Natural 7 Open Flame 8 Negative corpus ```

Question 47

What is intentionally ignited fore under circumstance in which the person knowns that the fire should not be ignited

Answer 47

Incendiary

Question 48

- Accidental - cause that does not involve an intentional human act to ignite - Incendiary - Cause that involves an intentional human act to ignite - Undetermined- A proven cause that cannot be determined

Answer 48

Three fire cause determinations

Question 49

- suspicious is a fire call - fire burned too hot and fast - this hole means something was poured low burn - most damage always equal area of origin - multiple origins means incendiary - inverted v pattern means accelerant - Depth of Char

Answer 49

Myths, Legends and pitfalls

Question 50

-

Answer 50

Cause investigation

Question 60

10 ID and explain the origin and cause of a fire in a burn cell during the fire scene practical Exercise (PE) by following the step of the systematic approach and by using team concept

Answer 60

-

Question 62

``` 9 - Spalling of concrete Crazing of glass Area of greatest damage= area of origin Rate of char analysis Alligatoring of wood Hot and fast fire Pour Pattern vs post flashover damage Melting of aluminum thresholds ```

Answer 62

Common Myths and Legends (False)

Question 63

8 Accidental- cause that does not involve an intentional human act to ignite Incendiary- A cause that involves an intentional human act to ignite Undetermined- a proven cause that cannot be determined

Answer 63

-

Question 64

7 what is

Answer 64

Common incendiary fire indicators

Question 66

5 List and define the steps of the systematic approach to the origin and cause investigations of a fire and how it applies to the team approach at fire scene investigations.

Answer 66

``` Recognize the need Define the problem Collect Data Analyze Data Develop Hypotheses Test Hypotheses Select Final Hypothesis Make a determination ```

Question 67

6 List and define common terms pertaining to direction and intensity of burn and fire patters such "V" patterns, lines of demarcation, char, protected areas, clean burn, calcination, pour patterns, and spalling

Answer 67

- V Patterns= up and out - Hourglass=narrow down low then spread out at top - Lines of Demarcation=soot and heat damage line around the building - Char (Depth of Char) - Pour Patterns vs Floor patterns - Protected Areas - Clean Burn - Calcination of Gypsum