4.0 Flashcards
The base explosive HMX is found in what explosive most commonly used in breaching?
Shocktube detonators.
Which types of explosives will be most commonly utilized for main charges during tactical breaching operations by law enforcement.
Det Cord
ECT
FLSC
Explosive Sheet
What is the flexible linear charge designed to produce?
A linear cutting action in various applications where remote, fast, reliable, cutting of materials is required.
What is the purpose of sealing ends of det cord after cutting?
To seal the explosives / keep moisture out.
How should lead sheathed flexible linear shaped charge be cut?
With a fixed or locking blade knife on a non-sparking surface.
What are some of the safety considerations in the use of a lead sheathed linear shaped charge, and what can be done to minimize these hazard to the entry team?
- Fragmentation, toxic gases, lead vapors.
2. Breathing apparatus and ballistic shields.
Under what conditions will wet det cord propagate?
At least 6” of det cord that is dry at initiation point.
What is the most common cause of “cut offs” when initiating a charge using det cord?
- Sharp bends
2. Overlapping 90 degree turns.
List 5 characteristics of flexible explosives (Ex. Explosive sheet)
- Flexible
- Waterproof
- Insensitive
- Easy to cut
- Easy to apply
What is the most hazardous activity associated with explosive charges?
handling misfires.
What is the intended use of sheet explosive and the work effects that are achieved in explosive breaching applications?
Used in general demolition as a cutting or breaching charge.
What are two base explosives used in producing explosive sheet?
PETN and RDX
What is the intended use of det cord?
A detonating agent, a priming agent, or alone as an explosive charge.
What is the primary means to insure proper detonation of a breaching charge using det cord?
Dual primed
Describe the features and characteristics of shock tube detonators.
It has a non electric detonator crimped to a hollow polyethlene-surlyn plastic tube filled with HMX with opposite end sealed with factory crimp. The detonator has an ignition charge, intermediate charge, and main charge (HMX).
The terms “detonator” and “blasting cap”, when used in explosive breaching, refer to the same thing (T or F)
True
Why should spray adhesives or electrical tape be avoided when constructing charges with explosive sheet?
They react with the plastisers causing a low order detonation.
Which of the following items are NOT considered to be mission essential to conduct explosive breaching operations.
A)Reliable dual shock tube initiator
B)Commercial wall entry frames
C) Hearing / Eye Protection
D) Gas mask / respiratory protection
E) All of the above.
B) Commercial wall entry frames
What is the type and quantity of explosive material used in shock tube?
0.1 gr/ft HMX with aluminum powder.
When initiated, what is the speed of propagation in the shock tube?
6,500 FPS
The shock tube is constructed of non-fragmenting, co-extruded polyethylene-surlyn plastic (T or F)
True
One advantage of a non-electric shock tube detonator is its resistance to impact (T or F)
False
name a disadvantage of utilizing a slant charge over a hinge charge when attacking a wood door.
Portion of door remains intact. Attacking against the wood grain of the door.
What conditions permit the cutting of explosives with scissors or shear-type cutters?
NEVER
When constructing breaching charges, what problems can be associated with operator error?
- Low order detonations.
- Charge failure
- Misfires.
In preparing the initiator assembly, what is the purpose served by the duct tape sheath?
To remove the “memory” from the shocktube.
Hides the flash/prevents tangle.
Fire hazard concerns are significantly reduced utilizing a fluid impulse charge (T or F)
true
Describe the proper placement of the door lock strip charge.
Placed on the lock side of the door, priming end down, centered over locking mechanisms and B/T door knob and frame.
Explain versatility of the door hing charge.
The charge can be constructed with 3 or more charge assemblies and placed at will around selected points of a door, gate or window.
What are two acceptable methods of connecting the detonating cord of the firing assembly to the main charge?
A square knot
Plastic det cord connector.
Describe the major factors that could prevent success with a fracture charge.
Inaccurate information of the wall’s construction that could lead to construction of a charge of inadequate strength and not having knowledge of the objectives inside or on the other side of the wall that could prevent success.
Describe the condition the mechanical shock tube initiating device must be in before attaching the shock tube firing head/block.
Ensure the trigger mechanism is locked and all safety features are engaged.
What is the waiting period for a misfire with shocktube before inspecting the conditions down range during training?
30 mins
When documenting an explosive shot, why are photos and video taken before and after?
This documents exactly the conditions of the intended breach point and the charge placement and the actual results. These photos and video compliment written documents.
Which of the following statements are parts of a range safety brief?
A) Explanation of the evolution’s objectives.
B) The sequence for priming charges.
C). Documentation assignments
D) Misfire procedures
E) All of the above
E) All of the above.
List the components of a tactical firing assembly.
- Mechanical / Dual shock tube initiating device
- Shock tube leads X2
- Detonators X2
- one foot of 50gr/ft det cord.
An explosive charge consists of 12” of 50gr/ft det cord, two 20 gram boosters, and 9 feet of 125 gr/ft lead flexible linear shaped charges.
A) What is the NEW?
B) What is the maximum distance of the frag hazard zone?
C) What is the MSD for team personnel?
A) 0.43
B) 246 feet
C) 14 feet
An explosive charge consists of 32 feet of 50gr/ft det cord and 16 squares of C-3 explosive sheet 3” x 3”.
A) What is the NEW?
B) What is the MSD for team personnel?
A) 1.96
B) 23 feet
