Conventional Breaching (Chapter 11) Flashcards
(36 cards)
- What are Opposed Counter Force charges effective against?
Effective against rectangular masonry or concrete columns 4’ thick or less
- What is the rounding rule of breaching radius for External Charge?
Round breaching radius UP to the nearest ½ foot
If the amount of charge explosive is from 0 to less than 5 pounds, how thick would your charge be?
1 inches
- If N is equal to 2.5 or greater, how many charges should be use?
Round OFF to nearest whole number
- If concrete block with uncertain material factor, how would you identified it as?
Always assume as reinforced concrete
- For External Charges, Breaching Radius is equal to ____
The thickness of target
- If N is less than 1.25, how many charges should be used?
One charge
- How would determine if target material cannot be identified?
Assume target consists of strongest material in each specified groups
- The size of tamping should be…
Equal to or greater than Breaching Radius
- What is purpose of conventional breaching?
Used to destroy bridges, piers, abutements, and compound walls
- What is the formula to find the number of charges?
N = W / (2R)
Number of charges = Width / (2 x Radius)
N = number of charges W = width of pier, slab, or wall R = breaching radius in feet
Use this formula in Step 5
- What is the rounding rule of breaching radius for Internal Charge?
Round breaching radius UP to the nearest ¼ foot
- If you required to destroy a mason building with uncertain material, what will be the K (constant material factor)?
Assume it as first class masonry
- How much build up require to prime counter force charge?
Blasting cap required ½” build up
- What are the considerations of counterforce charges?
Charges should be diametrically opposed (explosive divided into 2 equal parts)
Obstacle must have at least 3 free faces or be freestanding
Relies on shockwave collision
Round measurements UP to next 1/2 foot (External charge)
- What are the critical factors in conventional breaching? Which are most important?
Size, shape, placement, and tamping
Size and confinement are most critical factors
(charges will not cut rebar reinforcement)
- What is the formula for breaching charges?
P = R^3 KC (Pound = route 3 to Kansas City)
(Pound = Breaching Radius^3 x Constant for material factor x Tamping factor
- If the amount of charge explosive is 40 pounds to less than 300 pounds, how thick would your charge be?
4 inches
- What is the formula for a counterforce charge?
Pounds = 1.5 x Breaching Radius
- If the amount of charge explosive is 5 pounds to less than 40 pounds, how thick would your charge be?
2 inches
- If N is greater than or equal to 1.25 and less than 2.5, how many charges should be used?
Two charges
- For Internal Charges, Breaching Radius is equal to ____
½ the thickness of the target (for charges placed at center mass)
Remaining thickness of the target not drilled if not placed at center of mass
- If the amount of charge explosive is greater than 300 pounds, how thick would your charge be?
8 inches
- A counterforce charge relies on what?
Shockwave collision
