FLETC Written Exam 4
1. Three Types of Explosions ans
Mechanical Chemical
Nuclear
2. High Explosive ans Explosive which normally requires a blasting cap for
initiation and once initiated produces a supersonic detonation with a shattering
or brisant effect
Detonate without confinement, doesn't need container
3. Low Explosive ans Explosive, which when unconfined, responds to
initiation by deflagration or burning and produces a pushing effect
Transitions from deflagration to detonation when confined
4. Incendiary Explosive ans Explosive designed to start fires or destroy
sensitive equipment
5. Detonation ans Supersonic combustion that propagates through shock
compression generating exothermic heat and an accompanying blast wave
6. Deflagration ans A subsonic combustion that propagates through thermal
conduc- tivity
7. Effects of an Explosion ans
Thermal Blast Pressure
Fragmentation
8. Thermal Effect ans Usually seen as a bright flash or fireball at the
moment of detonation
May cause localized ignition of highly combustible materials
Generally least damaging of the three effects
, FLETC Written Exam 4
9. Blast Pressure Effec tans Very hot gasses (between 3,000 and 7,000
degrees Fahrenheit) expand out from the point of detonation at supersonic
velocities (up to 20,000 mph)
The further the pressure wave travels, the less power it has
Most powerful and destructive/deadly of the effects
When taking place in a confined area, it can amplify the original blast wave
10. Two Phases of Blast Pressure ans Positive
Phase Negative Phase
, FLETC Written Exam 4
11. Positive Phase of Blast Pressure ans Pressure wave moving outward from
the point of detonation
12. Negative Phase of Blast Pressure ans Partial vacuum is created near the
epicen- ter due to the outward movement of air and the consumption of oxygen
from the combustion process
13. 4 Types of Injuries Sustained During a Blast ans Primary Blast
Injury Secondary Blast Injury
Tertiary Blast Injury
Quaternary Injury
14. Primary Blast Injury ans Caused by direct effects of blast
15. Secondary Blast Injury ans Caused by propelled fragmentation (most deadly)
16. Tertiary Blast Injury ans Occurs when a casualty's body is propelled by the
blast against the ground or stationary objects
17. Quaternary Injury ans Any other injuries (burns and crush injuries)
18. Three Mechanisms of Primary Blast Injury ans
Implosion Spalling
Inertial Effects
19. Implosion ans Occurs when blast impacts the human body by compressing
air-filled cavities in the body and causes tissue damage as compressed air stretches,
tears, and ruptures internal organs and tissues
20. Spalling ans Describes tissue injury caused when blast wave rapidly
changes velocity as it moves through tissues of different densities
21. Blast Lung ans Severe form of pulmonary contusion, crushed lung tissue fills
with blood and cannot exhange oxygen
22. Inertial Effects ans Injury occurring when connected tissues of different
, FLETC Written Exam 4
densities move at different velocities
23. Progressive Collapse ans Refers to the spread of an initial local failure
from element to element, eventually resulting in a disproportionate extent of
collapse relative to the area of initial blast damage
24. Two Types of Progressive Collapse ans
Pancaking Cascading
25. Pancaking ans Occurs when an explosion destroys a structural member or
mem- bers, causing floor directly above destroyed members to collapse and the floor
above that to collapse and so on
26. Cascading ans Collapsing of a series of bays from the destruction of one or
few bays
27. Fragmentation Effect ans When an encased explosive such as a pipe bomb
det- onates, the rapidly expanding gases produced by the explosion enlarge the
casing to about one and one-half times its original diameter before it ruptures
1. Three Types of Explosions ans
Mechanical Chemical
Nuclear
2. High Explosive ans Explosive which normally requires a blasting cap for
initiation and once initiated produces a supersonic detonation with a shattering
or brisant effect
Detonate without confinement, doesn't need container
3. Low Explosive ans Explosive, which when unconfined, responds to
initiation by deflagration or burning and produces a pushing effect
Transitions from deflagration to detonation when confined
4. Incendiary Explosive ans Explosive designed to start fires or destroy
sensitive equipment
5. Detonation ans Supersonic combustion that propagates through shock
compression generating exothermic heat and an accompanying blast wave
6. Deflagration ans A subsonic combustion that propagates through thermal
conduc- tivity
7. Effects of an Explosion ans
Thermal Blast Pressure
Fragmentation
8. Thermal Effect ans Usually seen as a bright flash or fireball at the
moment of detonation
May cause localized ignition of highly combustible materials
Generally least damaging of the three effects
, FLETC Written Exam 4
9. Blast Pressure Effec tans Very hot gasses (between 3,000 and 7,000
degrees Fahrenheit) expand out from the point of detonation at supersonic
velocities (up to 20,000 mph)
The further the pressure wave travels, the less power it has
Most powerful and destructive/deadly of the effects
When taking place in a confined area, it can amplify the original blast wave
10. Two Phases of Blast Pressure ans Positive
Phase Negative Phase
, FLETC Written Exam 4
11. Positive Phase of Blast Pressure ans Pressure wave moving outward from
the point of detonation
12. Negative Phase of Blast Pressure ans Partial vacuum is created near the
epicen- ter due to the outward movement of air and the consumption of oxygen
from the combustion process
13. 4 Types of Injuries Sustained During a Blast ans Primary Blast
Injury Secondary Blast Injury
Tertiary Blast Injury
Quaternary Injury
14. Primary Blast Injury ans Caused by direct effects of blast
15. Secondary Blast Injury ans Caused by propelled fragmentation (most deadly)
16. Tertiary Blast Injury ans Occurs when a casualty's body is propelled by the
blast against the ground or stationary objects
17. Quaternary Injury ans Any other injuries (burns and crush injuries)
18. Three Mechanisms of Primary Blast Injury ans
Implosion Spalling
Inertial Effects
19. Implosion ans Occurs when blast impacts the human body by compressing
air-filled cavities in the body and causes tissue damage as compressed air stretches,
tears, and ruptures internal organs and tissues
20. Spalling ans Describes tissue injury caused when blast wave rapidly
changes velocity as it moves through tissues of different densities
21. Blast Lung ans Severe form of pulmonary contusion, crushed lung tissue fills
with blood and cannot exhange oxygen
22. Inertial Effects ans Injury occurring when connected tissues of different
, FLETC Written Exam 4
densities move at different velocities
23. Progressive Collapse ans Refers to the spread of an initial local failure
from element to element, eventually resulting in a disproportionate extent of
collapse relative to the area of initial blast damage
24. Two Types of Progressive Collapse ans
Pancaking Cascading
25. Pancaking ans Occurs when an explosion destroys a structural member or
mem- bers, causing floor directly above destroyed members to collapse and the floor
above that to collapse and so on
26. Cascading ans Collapsing of a series of bays from the destruction of one or
few bays
27. Fragmentation Effect ans When an encased explosive such as a pipe bomb
det- onates, the rapidly expanding gases produced by the explosion enlarge the
casing to about one and one-half times its original diameter before it ruptures
