C&P Conventional Breaching

Question 1

Critical factors

Charge thickness

Answer 1

Intent is to create spalling

Charges will not cut rebar ( use bulk explosives p=d

0 LB - 5 LB = 1”

5 LB - 40 LB = 2”

40 LB - 300 LB = 4”

300 LB + = 8”

Question 2

Formula for breaching

Answer 2

P= R3 x K x C

Question 3

Internal breaching radius rules of thumb

External breaching radius rules of thumb

Answer 3

Ext: = thickness of target
Round breaching radius up to nearest 1/2 ft

Int= 1/2 the breaching radius of target for charges center mass

= remaining thickness of target not drilled if not placed center mass

Round breaching radius up to nearest 1/4 ft

Question 4

Material factors

Answer 4

Assume target consists of strongest material if not specified

Always assume reinforced concrete if unknown, and masonry is first class unless exact construction is known.

Question 5

Tamping factors

Answer 5

Efficient = internal center mass

Quickly = ground placed untamped

Charge not fully tamped unless tamp depth is equal or greater than breaching radius

Question 6

of charges formula & rules of thumb

Answer 6

N= W/ 2 x R

If N is less than 1.25 use 1 charge

If N is equal to 1.25 but less than 2.5 use 2 charges

If N is equal to or greater than 2.5 round off to nearest whole # ex: 3.1=3 or 4.5 = 5

Question 7

Counterforce rules of thumb and formula

Answer 7

Effective against rectangular masonry or concrete columns up to 4” thick

Must have 3 free faces or free standing

Relies on shockwave collision

Round measurements up to next 1/2 ft

Only works on non reinforced concrete

S2: f fewP= 1.5 x breaching radius

Question 8

CDAT rules

Answer 8

Uses shockwave collision

Placed knee high 15” center to center

Equal distance between shots create maximum shock wave