Dirt Cratering (Chapter 12) Flashcards Preview

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1

34. What is explosive requirement for Dead stumps?

1lb of explosive is used per 1’ of diameter

2

13. What is the spacing between deliberate crater boreholes?

5 feet between boreholes, center to center
Same as hasty crater

3

32. An expedient cratering charge should be primed with what?

Prime with 1lb of TNT (dual priming is recommended)

4

27. What is formula to calculate number of boreholes for a relieved face crater?

N_fr = ((L-10) / 7) + 1

Calculates number of charges for friendly row of boreholes.

Round any fractional numbers to next higher number

N_er = N_fr - 1

5

14. What is characteristics of deliberate crater?

V shaped
7-8 feet deep
25-30 wide
37 degree slope

6

17. What is measurement requirement for boreholes at the end of a deliberate crater?

End boreholes are 7’ deep

7

35. What is explosive requirement for live stumps?

2bls of explosive is used per 1’ of diameter

8

21. What is measurement and explosive requirement for an enemy row in a relieved face crater?

4’ deep
30 lbs explosive

9

33. How do you measure for stump removal?

Stumps are measured 12-18” above ground level then diameter is rounded to next higher ½ foot

10

6. What is the spacing between hasty crater boreholes?

From center to center 5’ between boreholes

11

2. An effective craters takes _______ allowing time to employ anti-tank weapons

4 or more passes

12

3. How do you improve craters?

Digging face vertically on friendly side
Mining
Filling with water
Any other means to further delay the enemy

13

9. What are the geometric characteristics of hasty crater?

V shaped
6-7 feet deep
20-25 wide
25-35 degree side slope

14

31. What is the fuel oil requirement to mix with fertilizer?

1 quart per 25lbs of fertilizer

15

5. What is minimum weight of explosive per borehole used in hasty craters?

At minimum 50 lbs of explosive per borehole

***DOES NOT MATTER WHICH EXPLOSIVE***
Do not convert using RE factor, only divide by pounds per unit

16

22. To construct relieved face crater, which row will be fired first?

Enemy row

1/2 to 1 1/2 second delay

17

29. For breaching hard surface pavement, how many pounds of explosives should be used?

1 pound for every 2 inches of pavement

Tamp charge twice the breaching radius (thickness of the pavement) (2 x Br)

18

15. What is depth of deliberate crater boreholes?

A combination of 5’ and 7’ deep

19

24. What is the placement/spacing between friendly and enemy rows when constructing a relieved face crater?

On Dirt or Gravel roads: 8 feet apart
On Hard surface road: 12 feet apart

20

36. What is explosive requirement for complete tree?

3lbs of explosive is used per 1’ of diameter

21

30. How much nitrogen must be contained in Ammonium nitrate fertilizer?

33 1/3% of nitrogen

22

8. What is hasty crater blowout distance?

Approximately 8 feet beyond the end boreholes

23

39. What are the three methods of boulder removal?

Snake-hole, mudcapping, and block-hole method

24

26. What is the shape/characteristics of a relieved face crater?

Trapezoidal shape
7-8 deep
25-30 feet wide
Unequal side slopes

25

7. For hasty crater, what is average traverse attempts of modern tanks?

Average of 4 attempts

26

37. What is taproot hole depth equivalent to?

Equal to stump diameter

27

20. What is measurement and explosive requirement are a friendly row in a relieved face crater?

5’ deep
40 lbs explosive

28

25. For relieved face crater, where would you place first borehole?

5 feet in from the desired edge of the crater

29

23. What is the spacing between relieved face crater boreholes?

7 feet between boreholes, center to center

30

38. What is lateral hole depth equivalent to?

Equal to stump radius