A-1-1-31-2 Flashcards
What should be referred to prior to conducting EOD procedures?
60-series manuals on electromagnetic radiation hazards, electrical grounding procedures, EOD demolition materials, tools, and equipment, and EOD disposal procedures
Refer to A-1-1-12, A-1-1-13, A-1-1-31-1, and A-1-1-31 for detailed guidance.
What action should be taken during demolition operations if an immediately dangerous situation is encountered?
Shut down all operations in the vicinity and evacuate personnel to a safe location
Properly qualified personnel will then eliminate the hazard before resuming operations.
How long should one wait after the anticipated time of detonation to approach a misfired nonelectric blasting cap?
1 hour
This is due to the risk of burning energetic material causing delayed functioning.
How long should one wait to approach a misfired electric initiator?
30 minutes
A malfunctioned electric initiator may have burning energetic materials that could lead to delayed functioning.
What is the wait time to approach a misfired nonelectric blasting cap, detonator, or booster in a shock tube/MDI-initiated firing system?
30 minutes
This applies if the shock tube/MDI has functioned but the blasting cap, detonator, or booster has not.
What is the recommended wait time before approaching a misfired length of detonating cord?
30 minutes
This is necessary when the firing system has failed to fully initiate detonating cord or demolition charges.
What should personnel use for guidance on procedures like routine disposal and emergency destruction of munitions?
Specific service guidance
This includes guidance on transportation/handling of explosives and disposal range criteria.
What is the minimum number of personnel required for demolition operations?
Two
The number of personnel engaged should be kept to a minimum.
What must be used for techniques that require perfectly simultaneous detonation of multiple blasting caps or detonators?
Equal length of detonating cord or shock tube/MDI initiated from a single source
Electric or time fuse systems alone cannot provide the exacting initiation requirements.
What does the term ‘time fuse’ represent throughout the manual?
Safety fuse and other fusing of similar design
This term is used interchangeably in the context of EOD procedures.
What is the recommended distance to conduct a time fuse test burn from any explosives?
15.24 meters (50.00 feet)
This distance is necessary to ensure safety during testing.
What are the length requirements for time fuse testing for each military service?
- Air Force: 305.00 millimeters (1.00 foot)
- Army and Marine Corps: 914.00 millimeters (3.00 feet)
- Navy: 1.83 meters (6.00 feet)
Each service has distinct requirements for testing time fuses.
What is recommended for igniting a time fuse for greater accuracy?
An igniter
While a match can be used, an igniter provides better precision.
How should a time fuse be cut before inserting it into a blasting cap?
Smoothly and squarely
A clean cut prevents misfires.
What should be done with a length of time fuse before testing its burn rate?
Cut and discard approximately 152.00 millimeters (6.00 inches) from the free end
This prevents misfires due to moisture absorption.
What is the burn rate for older types of safety fuse?
30 to 45 seconds per foot
This rate is important for calculations in testing.
What is the burn rate for the time fuse (M700)?
36 to 44 seconds per foot
This defines the specific burning characteristics of M700.
How do you compute the burning rate per foot?
Burn rate per foot = (test burn time in seconds) / (length of tested fuse in feet)
This formula allows for accurate calculations of fuse lengths needed.
What is the minimum safe distance to reach before an explosion when using a time fuse?
1.83 meters (6.00 feet)
This distance is based on normal walking pace.
What is the first step in attaching a M60 or M81 igniter to a time fuse?
Unscrew fuse holder counterclockwise two or three turns
This prepares the holder for the fuse insertion.
What should be done if any foreign matter is present in a blasting cap?
Hold it with open end down and shake it gently
If foreign matter does not come out, reject the cap.
How should the blasting cap be seated on the time fuse?
Slip blasting cap gently down over it so that the ignition charge is in contact with the end of the fuse
Proper seating is critical for effective detonation.
What is the purpose of crimping the blasting cap to the time fuse?
To hold the time fuse in place on the blasting cap
This ensures a secure connection for ignition.
How should a non-electric blasting cap be waterproofed?
- Crimp 1/4 inch from open end
- Rotate and crimp again 1/8 inch from the first crimp
This method improves water tightness.
What should be done just prior to firing the igniter?
Shout out the warning ‘Fire-In-The-Hole’ three times
This is a safety protocol to alert personnel.
What is the first step to fire the M60 or M81 igniter?
Squeeze together the spread legs of the safety (cotter) pin
This action is necessary to prepare the igniter for activation.
What should be done if an igniter is not available?
Light the time fuse with a match
A match can be used as an alternative ignition method.
What should you do to reset the igniter?
Push the plunger all the way in and attempt to fire as before.
What is the procedure after three failed attempts to fire the igniter?
Remove the igniter, attach another igniter, and repeat the attempt to fire.
How long should you wait after the anticipated time of detonation before approaching a misfired nonelectric blasting cap?
1 hour.
What might cause a delayed functioning of the firing system in a time fuse firing system?
Deterioration or dampness of the time fuse or malfunctioned nonelectric blasting cap.
What is the first step to take after waiting 1 hour to approach a misfired nonelectric blasting cap?
Reprime charge if possible without disturbing the misfired blasting cap.
If you cannot reprim the charge without disturbing the misfired blasting cap, what should you do?
Counter charge the original charge by priming and placing a new charge next to the original.
What should be done if neither repriming nor counter charging is possible?
Carefully remove the misfired blasting cap and reprim the charge.
What should be avoided when handling shock tube/MDI?
Mechanical impact
Mechanical impact could initiate the energetic material located within the shock tube/MDI core.
What tool should be used to cut shock tube/MDI?
A sharp knife or other single blade
Using pliers, crimpers, or scissors will cause a narrowing of the small diameter hole in the shock tube/MDI.
What is the recommended length to cut and discard from the shock tube/MDI before use?
152.00 millimeters (6.00 inches)
This reduces the potential for misfires due to dampness.
What should be done with the shock tube/MDI before laying it out from the charge location?
Cut and insert any required branch lines into the mainline
This ensures proper setup of the shock tube/MDI.
What must be used to increase the outer diameter of the shock tube/MDI when priming a non-electric blasting cap?
Tygon tubing
It allows for a proper fit into the open end of the blasting cap.
What is the part number for the 0.118 in (3.00 millimeters) commercial shock tube?
AAB00006
This part number is for Tygon tubing tested and approved for use.
What is the minimum length for the Tygon tubing to be cut?
38.00 millimeters (1.50 inches)
Ensure that the shock tube/MDI is cut smoothly and squarely before insertion.
What should be checked when inspecting a blasting cap?
Look into the open end for foreign matter or dirt
If foreign matter is present, it should be removed or the cap should be disposed of.
What action should be taken if foreign matter does not come out of the blasting cap?
Dispose of the cap
It is important to ensure the cap is clean for safe use.
True or False: It is safe to use pliers to cut shock tube/MDI.
False
Pliers can cause a narrowing of the small diameter hole, leading to potential failure.
What is the first step when preparing to use a shock tube/MDI?
Hold shock tube/MDI with Tygon tubing adapter vertically with square cut end up
Ensure the blasting cap is seated correctly to avoid misfire.
What should be done after seating the blasting cap on the shock tube/MDI?
Hold cap firmly against shock tube/MDI and adapter by one or two methods
Refer to Figure 4 for the methods.
At what points should the blasting cap be precrimped?
Between 3.00 and 6.00 millimeters (0.12 and 0.24 inches) from open end
This is equivalent to 1/8 and 1/4 inch.
What should be done after precrimping the blasting cap?
Complete crimp using one of two methods shown in Figure 4
Ensure proper crimping is followed to secure the blasting cap.
What should be repeated for each blasting cap used in the system?
Repeat steps (2) through (9)
This ensures consistency and safety in the setup.
What is the warning associated with the M81 igniter?
Ensure it is only used with time fuse or shock tube/MDI
Incorrect usage may cause instantaneous detonation and result in personnel injury or loss of life.
What should be done if using a percussion igniter for initiation?
Proceed to step m
This includes following specific instructions for the M81 igniter.
What is the first action when attaching a M81 igniter?
Unscrew fuse holder cap counterclockwise two or three turns, but do not remove
This step prepares the igniter for connection.
What should be removed from the shipping plug when preparing the M81 igniter?
Remove the weatherproofing plug from the shipping plug
Do not remove the shipping plug itself.
What should be done with the weatherproofing plug after removal?
Discard the weatherproofing plug
This is necessary for proper function of the igniter.
What is the recommended wait time before approaching a misfired nonelectric blasting cap?
30 minutes
This wait time is crucial to avoid potential delayed functioning of the shock tube/MDI firing system.
What should be done if a blasting cap has misfired?
Reprimed charge or counter-charge
Repriming can be done without disturbing the misfired blasting cap, or a new charge can be placed next to the original.
What should be done if neither repriming nor counter-charging is possible?
Carefully remove the misfired blasting cap and reprimed the charge
This should be done with caution to avoid any accidents.
Why should demolition circuits be shunted?
To prevent an electric charge from building up
This is essential unless testing, building, or firing.
What precautions should be taken before removing a shunt from an electric blasting cap?
Place blasting cap in a hole or behind a barricade
The cap should be positioned as far as possible from the operator and pointed away from him.
What is the importance of unrolling the legs of the blasting cap?
To position the cap as far as possible from the operator
This minimizes risk in case of an accidental discharge.
True or False: The blasting cap should be pointed towards other personnel when testing.
False
The cap should not point towards other personnel or explosives for safety.
How long should you wait to approach a misfired electric initiator?
30 minutes
What is a malfunctioned electric initiator also known as?
Electric blasting cap or electric match
What may a malfunctioned electric initiator have that can cause a delayed functioning of an electric firing system?
Burning energetic materials
True or False: You should approach a misfired electric initiator immediately.
False
Fill in the blank: A malfunctioned electric initiator may have _______ that can result in a delayed functioning.
burning energetic materials
What is the recommended length of bare wire to expose before splicing?
Approximately 38.10 millimeters (1.50 inches)
This length ensures adequate contact for a secure connection.
How should foreign matter, such as enamel, be removed from wire?
By carefully scraping wire with the back of a knife blade or other suitable tool
This method prevents damage to the wire while ensuring cleanliness.
What is a critical requirement when bared wires are prepared for splicing?
Wires should not be nicked, cut, or weakened
Maintaining the integrity of the wire is essential for effective connectivity.
What should be done to multiple strand wires after scraping?
Twisted lightly
This helps to ensure that all strands make good contact during splicing.
What condition must all wire ends meet before connection?
Must be bright and clean
Dirty connections can lead to circuit failure and misfires.
What can happen if connections are not clean?
Circuit failure and misfires
Ensuring cleanliness is vital to avoid operational issues.
What should be done to wires in extreme cold before twisting them together?
Warmed with bare hands
This helps to make the wires more pliable and easier to work with.
What is the most common splice used in general demolition?
The pigtail splice
The pigtail splice is easy and quick to employ, holding under moderate strain.
How do you tie a pigtail splice?
Join wires with several tight twists
This method is straightforward and effective.
What is the Eye Splice used for?
To connect cap lead wires to multiple strand firing wire
It facilitates the connection in multi-strand setups.
What is the purpose of the Hook Splice?
To connect cap lead wires to single strand firing wire
This splice is specifically designed for single strand applications.
What type of strain can the western union splice hold?
Moderate to heavy strain
The western union splice is versatile and commonly used for various splicing needs.
When is a western union splice commonly used?
When one pair of firing wires is spliced to another
This splice is suitable for connecting multiple wire pairs.
What is a common series circuit used for?
Connecting charges fired with blasting machines
Series circuits allow for a single path of current, making them suitable for applications like blasting where simultaneous activation is needed.
What is the maximum number of blasting caps that may be used in a parallel circuit for dual priming?
Not more than two caps
Initiated by a 10-cap or more powerful blasting machine.
What type of electric sources are normally used for initiating parallel circuits?
DC electric sources, such as batteries
Instead of blasting machines.
What is a dual priming system?
Two electric blasting caps with one firing lead connected to one power source.
What is the only method of dual priming?
A simple parallel circuit.
What dictates the method used for dual priming?
The available power source.
What is a simple parallel in the context of dual priming?
A system where two blasting caps connect in parallel across a double conductor firing lead.
What does a dual electric firing system consist of?
Two independent electric circuits, each with an electric blasting cap.
What is the primary purpose of a dual electric firing system?
To provide a backup firing circuit.
What can cause a fault in the first firing circuit of a dual electric firing system?
Short/ground circuit, poor electric connections, or faulty blasting cap.
What should be ensured regarding the blasting cap/nonelectric detonator when the adapter is screwed in?
It will not be subject to pressure
Ensuring the blasting cap is not under pressure prevents accidental detonation.
What should you do if a cap cannot be easily forced into an activator well?
Remove cap; enlarge hole
Forcing a cap can damage the components and lead to unsafe conditions.
What may cover the activator well of TNT charges?
A paper seal
The seal ensures the integrity of the charge until ready for use.
How should the paper seal of the threaded activator well be broken?
By inserting a suitable tool through the hole in the charge cover
A blasting cap must not be used to break the seal to avoid accidental ignition.
What should be checked after the seal is broken?
Examine the activator well for foreign matter
Ensuring cleanliness is crucial for safe and effective detonation.
After breaking the seal, how is the charge prepared?
Ready to be primed similar to a standard demolition block fitted with a threaded activator well
This ensures compatibility and safety during the priming process.
What is the first step in placing the blasting cap/nonelectric detonator?
Fully seat it in the activator well
Proper seating is essential for effective detonation.
What should be done with the adapter after placing the blasting cap?
Slide it down the shock tube/MDI/time fuse/detonating cord and screw it finger-tight into the well
Care must be taken not to apply pressure to the detonator during this step.
What is the length of the detonating cord used in the common method?
4-foot
How is the detonating cord positioned across the explosive?
At an angle
How many wraps does the running end of the detonating cord make around the block?
Three wraps
What is done on the fourth wrap of the detonating cord?
Slip the running end under all wraps parallel to the other end and draw tight
What is the purpose of the whipping method?
To give an extra boost for priming charges with detonating cord
Whipping is a technique used in explosive priming to enhance the effectiveness of the detonating cord.
How many wraps of detonating cord are used for charges 567 grams or less?
Eight wraps
This applies specifically when using lightweight detonating cord.
What is the wrapping method for charges over 567 grams?
Pyramid seven wraps on top of nine wraps
This method is applied to ensure proper priming for heavier charges.
What types of explosives are the priming knots inserted into?
Malleable explosives such as C-4
This indicates the compatibility of the priming methods with specific explosive materials.
Describe the Over Hand Knot method.
Loop the end of the detonating cord, tie an overhand knot in the double section, mold explosive around the knot
Ensure at least 1/2 inch of explosive around the knot and 1 inch over the end.
What is the minimum explosive coverage around the Over Hand Knot?
At least 1/2 inch around all sides and 1 inch over the end
This is crucial for ensuring the knot is adequately primed.
What are the measurements for placing an overhand knot in a charge?
What is the first step in creating a Uli Knot?
Loop the end of the detonating cord so that approximately 10 inches are double.
How many wraps are made with the bitter end around the loop in a Uli Knot?
Four wraps.
In which direction should the wraps be made around the loop when tying a Uli Knot?
Working away from the running end.
What should be done with the bitter end after wrapping it around the loop?
Pull the bitter end through the eye of the loop and tighten.
What is done with the excess bitter end after tying a Uli Knot?
Cut off excess bitter end.
Uli Knot
Priming sheet explosive
What is the first method for priming sheet explosives?
Cut a notch approximately 38 millimeters long and 6.00 millimeters wide in sheet explosive, insert blasting cap to limit of notch, and secure it with string, tape, or strip of sheet explosive.
What is the second method for priming sheet explosives?
Place blasting cap on top of sheet explosive and secure it with a strip of sheet explosive at least 76.00 by 76.00 millimeters.
Describe the third method for priming sheet explosives.
Insert end of blasting cap approximately 38 millimeters between two sheets of explosive.
What is the fourth method for priming sheet explosives?
Attach an M8 blasting cap holder to the end or side of the sheet explosive and insert an electric or a nonelectric blasting cap into the holder.
Fill in the blank: In Method 1, the notch cut in sheet explosive is approximately _______ long and _______ wide.
38 millimeters; 6.00 millimeters
True or False: Method 2 requires the blasting cap to be placed underneath the sheet explosive.
False
What dimensions should the strip used to secure the blasting cap in Method 2 be?
At least 76.00 by 76.00 millimeters.
Fill in the blank: In Method 4, the end of the blasting cap must press against the _______.
sheet explosive
How are electric blasting caps usually connected in smaller demolition projects?
In series and fired by a blasting machine.
What must be done if a project requires a voltage higher than the rated capacity of the blasting machine?
The circuit must be fired by some other power source.
What is a series circuit?
A circuit that provides one path for electrical current to flow through each blasting cap.
What is the risk of connecting an overload of caps in a series circuit?
Increases the hazard of cutoffs in the firing line or cap leads prior to initiation.
What defines a parallel circuit?
A circuit with a pair of main wires and firing wires, with each blasting cap connected across the pair.
What type of circuits should be used in blasting?
Only balanced parallel circuits.
What is a balanced circuit?
A circuit where each branch is electrically identical to every other branch.
Describe a series-parallel circuit.
A circuit consisting of separate series-connected groups of blasting caps joined in parallel.
What must be ensured when using series-parallel circuits?
Only balanced series-parallel circuits should be used.
What precautions should be taken in parallel or series-parallel circuits?
Connect no more than one type of cap, limit caps in series branches, and ensure balance.
What should be checked when wiring has been accomplished in several stages?
Ensure there are no more caps in the entire series-connected branch than the equipment will handle.
In series-parallel circuits, what should be done with lead wires?
Use identical lead wires of approximately the same length.
What is Ohm’s Law?
E = IR, where E is voltage, I is current, and R is resistance.
What does the electrical power formula state?
W = I^2R, where W is electrical power, I is current, and R is resistance.
What is the minimum current needed to fire military electric blasting caps in series?
At least 1.5 amperes.
What is the minimum current needed per blasting cap in a parallel circuit?
At least 0.60 ampere.
What is the resistance of a military blasting cap?
2 ohms.
What contributes to the total resistance of a circuit?
Both the blasting caps and wire.
What factors affect the resistance of the wire in a circuit?
The size and length of the wire.
What are the most common gauge wires EOD uses?
16 and 18
What is the formula for calculating voltage?
E = IR
Where E is voltage, I is current, and R is resistance.
How is power calculated in an electrical circuit?
W = I^2R
Where W is power, I is current, and R is resistance.
What is the required current for detonating the blasting caps?
1.5 amperes
What is the total resistance of the system with 20 blasting caps and 18-gauge wire?
46.4 ohms
Total resistance includes 40 ohms from the blasting caps and 6.4 ohms from the wire.
How do you calculate the voltage needed for the circuit?
E = 1.5 x 46.4 = 69.6 volts
What is the total power requirement for the circuit?
104.4 watts
Fill in the blank: The current required for the circuit is _______.
1.5 amperes
True or False: The total resistance is based on a 305 meter (1,000 foot) length of firing wire.
True
What is the resistance of 20 blasting caps?
40 ohms
Each blasting cap contributes 2 ohms.
What is the resistance of 305 meters of No. 18 wire?
6.4 ohms
Fill in the blank: The formula for power can also be expressed as W = _______.
I^2R
