Surface Flashcards
List all applicable K factors
K3.5 = Critical Cover Thickness
K9 = Interline Barricaded Distance, possibility of sympathetic detonation
K18 = Interline Un-Barricaded charge, external breaching
K24 = Public Travel Road Distance
L-1-1-1-1 states the P2 should be close enough to maintain visual and verbal communication with P1.
K36 = Internal breaching
K40 = Inhabited Building Distance
K50 = Essential Personell
K100 = All glass will break
K328 = Non-Essential Personell
K625 = Maximum Flyrock Distance
A consideration for cave openings/portholes is a minimum distance of 1800ft away from them in a 10 degree arc either side of the centerline.
Define Detonate
A decomposition reaction in which the zone of chemical reaction (blast wave) propagates at supersonic velocity.
Define Deflagrate
An intense, burning reaction in an explosive that consumes much explosive material. (Can disperse fragmentation up to 200 meters)
Define DDT
‘Deflagration to Detonation” is when a decomposition reaction changes from a slow process to a supersonic one. This occurs when an explosive in confinement burns so rapidly, a pressure wave of sufficient magnitude to detonate the explosive/propellant is achieved. Can occur in cracked propellant grains.
Define Sensitivity
The susceptibility of an energetic substance to heat, shock, and friction.
Define Stability
The property of an explosive to resist detonation or deterioration under normal storage conditions.
Define Brisance
The shattering effect of an explosive.
Define Sympathetic detonation
An explosion caused by the transmission of a detonation wave through any medium from another explosion. (Can also be caused by flying fragments impacting shock sensitive explosives)
Define Low Order
A detonation in which the reaction is less than total and/or the reaction is less than maximum velocity.
Define High Order
A detonation in which total reaction occurs at maximum velocity.
Define Low Explosive
An explosive which, when used in its normal manner, deflagrates or burns rather than detonates. The velocity of the detonation wave is less than the speed of sound of the unreacted material.
Define High Explosive
An explosive which, when used in its normal manner, detonates rather than burning or deflagrating. The velocity of the detonation wave is greater than the speed of sound of the unreacted material.
Define Primary Explosive
Substances, which upon being subjected to flame, heat, impact, friction, or electric spark, generate a detonation wave
Generally used to detonate larger, main charges.
Define Secondary Explosive
A material that is less sensitive than primary explosives, requiring a booster to initiate, and is generally used as the final charge in any explosive application.
Where do we draw the line between primary and secondary explosive?
PETN
Define Stable Detonation Velocity
The reaction velocity that occurs in an explosive under normal circumstances and results in a high-order explosion.
Define the Mach Stem effect
The resulting ‘3rd’ wave that is created from two explosive waves that meet and then fuse into one. The resulting wave is called the Mach Stem and is twice as powerful than the initial waves.
Define Primary Frag
Fragments associated with the munition’s primary casing whereby the inner case is in intimate contact or directly coupled with explosive material.
Define Secondary Frag
Fragments associated with materials in contact with, or in close proximity to the detonating explosive charge. These are generally produced by the shockwave of the original explosion but can also be made by impacting primary frag.
Define Glazing
High-velocity window glass fragments.
How does tempered glass react to breaking vs annealed glass?
Tempered glass breaks into small, smooth fragments
Annealed glass breaks into large, razor sharp fragments
Define Firebrand
A projected hot fragment, burning energetic material, or burning debris whose thermal energy is transferred to the surroundings.
Define NEW
“Net Explosive Weight” Total weight of explosives contained in an item based on its TNT equivalent weight.
Define Flyrock
Rock and large chunks of soil projected from a cave demolition site by force of the explosion.
What does NEWQD stand for?
“Net Explosive Weight Quantity Distance”
Define Spalling
Fragments torn from either surface of an armor plate or interior cave wall with adjacent chambers.
Define CCT
“Critical Cover Thickness” - Thickness required to prevent spalling on the other side of cave walls.
Define BOD
“Blast Over Pressure Distance” is the distance at which peak over pressure from an explosion will be experienced.
Define HFD
“Hazardous Fragment Distance’’ is the distance at which no more than one hazardous fragment (defined as a fragment having an impact energy of 58 ft-lbs or more) will impact in a 600ft^2 area.
Define MFD
“Maximum Fragment Distance” is the distance at which fragments are not expected to travel beyond. This does NOT account for primary fragments that bounce, ricochet, or roll, nor does it account for rouge frag.
Define VFD
Vertical Fragment Distance
Define HERO
“Hazards of Electromagnetic Radiation to Ordnance”
Susceptibility of an ordnance item to EMR
Define CREW
“Counter Radio-Controlled IED Electronic Warfare”
A-2-1-109
A-2-1-119
What are rogue fragments and how far do they travel?
Fragments that have a greater mass and can be projected very large distances. Associated components are bomb noses, nose plugs, suspension lugs, strongbacks, baseplates, and guidance and control systems.
10,000ft
How can you mitigate rogue frag?
Use of open pit or tamped disposals, use of natural barriers, and positioning items such that known rogue fragments are pointed away from areas of concern.
When do you increase frag distance on a demo shot?
When the item is not being detonated as designed. (+33%)
When intentionally detonating items with engineered fragmenting warheads.
When stacking items as opposed to detonating them side-by-side.
What exception exists to the added 33% when stacking ordnance or non-design initiation?
Exceptions can be made when engineered fragment control methods and PPE measures are employed.
What is K-Factor and how is it calculated?
A scaling factor based on risk assumed or permitted.
It can be thought of overpressure PSI at a given distance from a given weight of explosives.
K factor can be calculated with the following equation where BOD is blast overpressure distance and N.E.W is net explosive weight.
K=BOD * (N.E.W)^-3
What does K factor protect against?
Blast Overpressure
What are some personal protective measures you can take to mitigate blast and frag?
Observing safety standards
Frontal and overhead protection
Achieve minimum separation
PPE such as plates, helmets, glasses
What is frag orientation as a mitigation technique?
Orienting known rogue frag components away from safe area
What are Non-Engineered Stacked and Non-Design Modes of Initiation Mitigation
For stacks of Ammo/explosives or detonation of ordnance in a non-design mode of initiation +33% to MFD-H
What constitutes the use of Natural or Artificial Structures as a mitigation technique?
Use of land topography or robust existing structures for protection
What is Barricading and what are the barricade specifications?
Protects against high velocity, low angle fragments
Implement as close to the explosion site as possible
Height: Barricade will be one foot higher than the “line of sight line” created by drawing a line from the top of the AE stack to the top of the area needing protection
Length: The top of the barricade will be at least 36 inches wider than the AE stack or exposure site
Inspect barricade after each detonation
If the barricade is within two heights of the protected area, at least as high as and twice as wide as the protected area, the blast overpressure at the exposure site is reduced by approx. 50%
What are the Open Pit demolition specifications?
Pit should be 4x the stack height in depth
At the very least, no AE should be peeking over the top of the pit
Describe the sandbag mitigation technique
Used with ordnance sized 155mm and below (tested using the
Double layer minimum
6 inch standoff between ordnance and inside walls
Prepare a roof with a minimum ¾ in. thick piece of plywood that extends so that at least 6 inches rest on the sandbag walls
Ceiling height should be equal to wall thickness
Applicable to single item detonation
Describe the water frag mitigation technique
Similar to sandbag mitigation but with water
Requires ordnance to be in a pit 1 foot deep as a minimum
Using ¾ in. thick plywood or greater, stack plastic jugs or a kiddy pool on top
55 gallons of water are required for items < 0.42 lbs
155 gallons are required for items larger than 0.42 lbs but less than 2 lbs.
Describe the deep water control technique
Detonate the item under water if possible to catch frag and mitigate blast
What are the trenching specifications?
A trench dug between an item and a structure to interrupt ground shock from a buried munition
Must be 24 inches deeper than the foundation of the structure
At least 18 inches wide
What is venting?
Where a shaft is dug above UXO in order to cause blast pressure to travel upwards instead of through the ground