2024 Version
What are the effects of an explosion? - ✔✔
Thermal Effect
Blast Pressure Effect
Fragmentation Effect
T/F: Thermal effecs are generally the most damaging of the three primary effects? - ✔✔False;
Fragmentation is usually the most damaging.
What is important to know about thermal effect high explosives? - ✔✔They produce higher temperature
thermal effects but for a shorter duration.
What is important to know about thermal effect low explosives? - ✔✔They produce lower temperature
thermal effects but for a longer duration.
What is the blast pressure effect? - ✔✔When very hot gases are formed in approximately 1/10,000 of a
second expand out from the point of detonation at supersonic velocities, up to 20,000 mph.
What are the two distinct phases of the blast pressure effect? - ✔✔The Positive Phase and Negative
Phase.
T/F: The negative phase is typically three times longer than the positive phase but less intense. -
✔✔True.
The four types of injuries sustained during a blast are: - ✔✔Primary Blast Injury: Direct effects of blast
upon the body
Secondary Blast Injury: Propelled fragmentation
, Tertiary Blast Injury: Casualty's body is propelled against a stationary object
Qauternary Blast Injury: Being crushed or burns.
___________ blast injury is the most common cause of death in explosions. - ✔✔Secondary Blast Injury
(Fragmentation)
IED's may have precut/preformed objects (ie ball bearings, hexagonal nuts, nails, etc) placed within or
along the device to serve what purpose? - ✔✔To form fragmentation when the IED detonates.
What is primary fragmentation? - ✔✔Fragments produced by the IED or explosive container.
What is secondary fragmentation? - ✔✔Object propelled from around the detonation point, and
fractured pieces of the intended target that become lethal missiles.
IED's generally consist of what four components? - ✔✔Power source
Initiator
Explosive
Switch
(PIES)
Also may be a fifth - the container.
Examples of power source for an IED? - ✔✔Batteries (electric)
Coiled Spring(mechanical)
Flame(Heat).
Examples of initiators for an IED? - ✔✔Blasting Caps
Spark Plug