Final Review Flashcards
What are Comp B and B4 primarily used for?
Filler in projectiles(mortars) and shaped charges.
Why is Ammonium Nitrate not suitable for cutting or breaching?
It has a low detonation velocity(RE Factor)
Ammonium Nitrate is extremely hygroscopic which means what?
It absorbs humidity
What block explosive is best suited for irregularly shaped targets that you wish to cut and why?
M112; High detonation velocity(RE Factor), Can be cut and molded
What is the main explosive material in M112 C4?
90% RDX
9% Non-explosive plasticizer
1% Taggant
How long is a roll of M186 sheet explosive and how much explosive does it provide per foot?
50 feet, .5 lb per ft
What are the main purposes for using a 15 lb M2A4 or 40 lb M3A1 shaped demolition charge?
Boring holes in earth, metal, masonry, concrete, paved and unpaved roads
Describe the packaging of M700 time fuse
Dark green plastic cover with a single yellow band every 12-18 inches and a double yellow band every 60-90 inches.
What is the average burn rate of one foot of time fuse?
Approximately 40 seconds per foot
What is the NEW of a roll of Det Cord?
12.8 lbs PETN per 1000 ft.
How many inches can penetrate Det Cord and what actions should be taken to prevent this from happening?
Moisture can penetrate up to six inches, so a six inch tail should be left when making connections priming charges.
How many volts do you need to initiate an M6 blasting cap?
3 Volts/1.5 Amps
What are the contents of an M7 non-electric blasting cap?
Ignition Charge: Lead Styphinate
Intermediate Charge: Lead Azide
Base Charge: RDX, PETN, or HMX
With what explosive can you use an M1A4 priming adapter? An M8 blasting cap holder?
M1A4 for securing blasting caps into explosives with threaded cap wells. M8 for securing blasting cap to sheet explosive.
Explain the characteristics of an M2 Crimper
Two Jaws: Top for crimping, bottom for cutting time fuse and det cord.
Two Legs: Pointed for making priming wells, Flat head screwdriver
What are the only authorized uses of a demolition multitool?
Knife to cut shock tube and C4 punch to prime cap wells.
Explain some the the differences between the M60 and M81 ignitors
M60: Initiates M700 in all weather conditions, cannot initiate shock tube.
M81: More energetic primer, has a shock tube reducer to accompany MDI
How many M6 caps can a CD-450J reliably fire in series?
70 M6 Caps
When using WD1/TT wire what should you consider?
Needs a greater power source if longer than 500ft. due to resistance. Reduces Cap number by 10 per 1000 ft.
Should you use blasting caps underground?
No
What is the first step you take when performing a continuity test?
Ground yourself
How far away from energized power lines should you keep electric blasting caps?
155 meters
When should you perform a 3 ft test burn on time fuse?
Every 24 hours
What is the minimum fragmentation hazard distance for a charge that has a NEW of less than 27 lbs
300m
For charges greater than 500 lbs, how is she distance computed
Cube Root of NEW x 100
How long should you wait to clear a nonelectric misfire, an electric misfire?
Nonelectric: 30 minutes
Electric: No wait time
Vehicles should be equipped with what type of fire extinguishes? How Many?
At least 2 B/C fire extinguishers
Where are blasting caps stored during transportation?
In a vehicle separate from explosives, or at least in an approved container in the cap.
What are the general rules of thumb for stacks in reference to earth flooring and cover of the magazine.
No less than 3 inches of dunnage between the bottom of the stack and earth flooring, no less than 18 inches between the top of the stack and the cover.
What are the rules of thumb for storage of explosives in a temporary magazine?
No more than 500 lbs per pile
No less than 140 ft apart
What items can be burned during construction procedures? Detonated?
Anything fully encase in metal must be detonated, if not it can be burned.
Where should you place initiating charges on piles of explosives you want to detonate during destruction procedures.
On top of the pile.
What are the 3 detonation effects? Explain them.
Deformation(earth), Spalling(metal), Radial Cracking(concrete)
Name the critical calculation factors
Type and Strength of Target Size, Shape, and Configuration of Target Desired Demolition Effect Explosive Type Charge Size and Placement Tamping Method Priming Direction
What are the charge thickness rules?
Not too thick(wasted explosive potential)
Not too thin(charge too weak to achieve desired effect)
Explain the explosive firing train.
Detonator-Booster(if needed)-Main Charge
What is the six step problem solving process?
- Critical Data
- Solve for P(pounds TNT)
- Divide by RE Factor
- Divide by package weight and Round Up
- Number of Targets of Charges
- Multiply 4. and 5.
What are the three main components of a nonelectric initiating set?
Fuse ignitor: M60 or M81
M700 Time Fuse or equivalent
M7 Nonelectric Blasting Cap
What is the final step when constructing a nonelectric time system?
Mark with DTG, name, and system time.
What is the first step when crimping a blasting cap?
Inspect the blasting cap
What are the main components of an electric firing system?
Power Source: CD-450J
Firing Wire: AWG 18 or equivalent
M6 Electric Blasting Cap
What must you always do before unshunting an M6 electric cap?
Ground yourself
What are two Det Cord priming methods on a line or ring main?
Gregory knot, square knot, girth hitch w/ extra turn, scanman(sapper) knot.
What are the priming methods for each type of charge?
8 wrap uli(m112), 4 wrap uli(TNT), spiral(urban breaching), wiseman(several applications), detcord lace(M1)
What are the contents of MDI?
- 5% HMX
10. 5% Aluminum Powder
What are the contents of the low strength det cord on the M151/M152 booster?
M151: 10’ 5-7.5 grain mini det cord
M152: 30’ 5-7.5 grain mini det cord
How many shock tubes can an M9 bunch block hold?
Up to 5 shock tubes
Explain the splicing process of MDI?
- Cut 6 inch piece from both side of damaged MDI
- Perform blow test to ensure powder exits both sides
- tie overhand knot with loose ends
- Push open ends of MDI into splicing tube, ensure at most 1/4 inch apart.
When must you wait 30 minutes before investigating if you have a shock tube misfire?
If shock tube flashes and charges do not detonate
What are the 3 main components to a M152 RAMS system?
M26 Transmitter
M16 Receiver
M6 Relay/Power Supply
What are the operating distances for nominal line of site(LOS) of the 152?
Low Power: Nominal: 2km, 1.2mi Nominally Expected: 5km, 3mi
High Power: Nominal: 5km, 3mi Nominally Expected: 8km, 5mi
How many caps can an M16 simultaneously detonate?
4 M6 caps connected to 100 ft of WD1/tt or similar type wire. Can do more with multiple M16s in series
Both the M26 and M16 are designed with what codes?
Common Codes: A, B, C
Unique Codes: 1, 2, 3, 4
What are the misfire procedures for the M26 transmitter?
- Rotate F-Switch to “Hole Off” position then back to X and fire again.
- Move 50 meters left or right and closer if practical and repeat above steps
What is the exception to the misfire procedures for the m17 reciever?
Combination electric and nonelectric initiating so there is a 30 minute wait time before approaching.
What is the max time allotted for the M153 TD-SYDET in Time Delay Mode?
30 Days
For the M153 TD-SYDET what is the time allotted and distance between each device?
120 hours and no more than 30 meters apart
What capability does the the M156 MI-Rams allow that the M152 does not?
Can penetrate areas that the M152 cannot(caves, bunkers, tunnels, soil, rock, water)
What are the ranges for the M156 MI-RAMS?
Low Power: 150 meters
High Power: 200 meters
For optimal range, loop antenna must be as circular as possible
For greater distances, use M152 in relay mode
What are the three considerations when targeting timber?
Wind, lean, and least dimension
What formula do you use for a ring charge?
External Formula
Which direction should abatis fells be facing?
45 degrees toward the enemy direction of travel.
What should be the width and thickness of a ring charge on a tree that is 12’’ thick? 26’’ thick?
at least 1/2’’ for trees up to and including 15’’
1’’ for trees up to 30’’ in diameter
Which direction should abatis fells be facing?
45 degrees toward the enemy direction of travel.
What are the three most important factors in conventional steel cutting?
Type, Size, Placement
When considering placement, what is the most important factor?
Placement: Charge to Target Contact
For railroads less than 5’’ how many pounds explosive?
5’’ or more?
Switches and Crossovers?
Frogs?
1/2 lb TNT
1 lb TNT
1 lb TNT
2 lb TNT
For railroads less than 5’’ how many pounds explosive?
5’’ or more?
Switches and Crossovers?
Frogs?
1/2 lb TNT
1 lb TNT
1 lb TNT
2 lb TNT
What are the 3 types of advance steel charges?
Ribbon, Saddle, Diamond
Where do you prime a ribbon charge?
Single prime at either end or in the middle
Where do you prime the C-Shaped Charge?
In the center of the C and at the ends of the dog legs
Where do you prime a Saddle Charge?
Apex of the long axis
Where do you prime the Diamond Charge?
Both ends of the short axis
What destructive effect does the saddle charge use?
Cross Fracture
What destructive effect does the diamond charge?
Stress Wave
The diamond charge is used on what type of target?
High carbon or alloy steel up to 8’’ in diameter
What explosive effect do concrete breaching charges create?
Spalling
What formula do you use on rebar reinforcement?
P=D
What are the rounding rules for breaching radius?
External: Thickness of target rounded up to nearest 1/2 ft
Internal: If placed center mass, 1/2 target thickness rounded up to nearest 1/4 ft. If not center mass, the length of undrilled target rounded up to nearest 1/4 ft
What kind of target is a counter force charge effective against?
- Rectangular masonry or concrete columns 4’ or less in diameter
- Must have 3 exposed faces
1 lb of explosives is used per how many inches of hard surface/pavement IOT breach for manual digging? What is the tamping rule?
1 lb per 2 inches
tamp 2x Breaching Radius
For a hasty crater, how many pounds per borehole and what is the spacing between borehole?
50 lbs per borehole
5 ft between boreholes
How many pounds of explosive are in the 5’ and 7’ boreholes in a deliberate crater?
5’: 40 lbs
7’: 80 lbs
For a relived face crater, what are the depths of the boreholes and how many pounds per borehole?
Friendly: 5’ 40lbs
Enemy: 4’ 30 lbs
What is the ratio of fuel mix for an expedient cratering charge?
1 qt per 25 lbs ammonium nitrate fertilizer
What is the optimum percentage of nitrogen in Ammonium Nitrate to use for expedient cratering charge?
33 1/3% Nitrogen
What are the rules for lbs of explosive for removal of each type of stump of tree?
dead stump: 1 lb per ft diameter
live stump: 2 lbs per ft diameter
full tree: 3 lbs per ft diameter
Round to next higher 1/2 ft
What are the three types of boulder removal?
Snake hole, Mudcapping, Block Hole
What are the optimism characteristics for a shape charge?
Cavity Liner: Copper, Tin, Zinc, Glass Cavity Angle: 30-60 degrees Explosive Height: 2 times cone height Standoff Distance: 1.5 Cone Diameter Detonation Point: Top Center of Charge
What are the principle differences between the Munroe and Miznay-Chardin effect?
Munroe: Shape Charge, greater depth/concavity in explosive
Miznay-Chardin: Platter Charge, powerful blunt-nose projectile
What are the explosive and plate weights of an expedient platter charge?
2-6 lb plates, explosive weight equals plate weight
What is you cover size for a dust initiator charge?
Partially Enclosed: 5 lbs
Fully Enclosed: 3 lbs
No more than 40 lbs of cover per charge
What are the time increments on an M2 crimper?
Top of Jaws to Nut: 4 seconds
Nut: 1 second
Base of leg to top of Jaws: 25 seconds
For directional napalm, what are the ratios?
3 oz M4 thickener per gallon fuel
What size M112 blocks should you use to prime mortar and artillery rounds?
60mm: 1/4 block
81mm: 1/3 block
4. 2in: 1/2 block
105mm: 1/2 block
120mm: 1 block
What are the types of breaching techniques?
Mechanical, Ballistic, Explosive
Define positive and negative blast pressure phases.
Positive Phase: Layer of compressed air known as shock front that moves outward
Negative Phase: Vacuum created by positive phase causes atmosphere to rush inward
What are the different types of blast pressure?
Dynamic: Impact of shock front.
Incidental: Pressure measured at 90 degrees to blast front.
Reflective: Reflected shock front builds up, corners can quadruple
Residual: Overpressure built up in a confined space
