Urban Breaching (Chapter 14) Flashcards
Breaching is the method an assault force uses to ?
Gain access to a hostile stronghold
What are the three keys to making a successful positive entry ?
Speed, surprise, and violence of action
What are the three breaching techniques ?
Mechanical
Ballistic
Explosive
How many grains of PETN does DET cord have per foot?
54 grains per foot
DET cord has an RE factor of ?
1.66
Blasting Caps are equivalent to how many grains of TNT?
30.4 Grains of PETN
Blasting caps have how many grains of PETN? What is its RE factor ?
19 grains
1.60
What is the formula for Safe Blast Distances?
SBD = K factor x Cubed Rooted N.E.W.
*round to next foot *
K = 18 is constant for 4 PSI
what is the K factor?
K factor is constant, 18 for 4 PSI
Operations will be planned for what PSI ?
4.0 PSI
What are some examples of a mechanical breach?
Sledge hammer , bolt cutters, halligan, brocco torch, quickie saw
What is an example of a ballistic breach?
Shotgun
What are some examples of an explosive breach?
Charges fabricated out of Det cord and/or sheet explosive
What are the explosive effects?
Blast Pressure
Fragmentation
Thermal Effect
Chemical Poisoning
What are the two aspects of blast pressure?
Positive phase (shock front coming out) and negative phase (vacuum at point of detonation)
What are the four types of blast pressure?
Dynamic
Incidental
Reflective
Residual
What is dynamic blast pressure?
Impact of the shock front
What is incidental blast pressure?
Pressure 90 degrees to the blast front, i.e. behind cover
What is reflective blast pressure?
Pressure will reflect back at twice the strength at 90 degree angles, corners can quadruple pressure
What is residual blast pressure?
Overpressure built up in a confined place
What is the most important hazard mitigation factor?
Breacher fall back point
Types of urban breaching charges
18" strip Flex linear Rigid linear Water impulse Rubber strip Silhouette Uli knot sliding
How is the amount of explosives in det cord measured?
Grains
How is the amount of explosives in sheet explosives measured?
Grams
Grams to grains equation
Grains = grams x 15.4
Grains to pounds equation
Grains / 7000 = pounds