Flashcards in Dirt Cratering (Chapter 12) Deck (55)
34. What is explosive requirement for Dead stumps?
1lb of explosive is used per 1’ of diameter
13. What is the spacing between deliberate crater boreholes?
5 feet between boreholes, center to center
Same as hasty crater
32. An expedient cratering charge should be primed with what?
Prime with 1lb of TNT (dual priming is recommended)
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
14. What is characteristics of deliberate crater?
7-8 feet deep
37 degree slope
17. What is measurement requirement for boreholes at the end of a deliberate crater?
End boreholes are 7’ deep
35. What is explosive requirement for live stumps?
2bls of explosive is used per 1’ of diameter
21. What is measurement and explosive requirement for an enemy row in a relieved face crater?
30 lbs explosive
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
6. What is the spacing between hasty crater boreholes?
From center to center 5’ between boreholes
2. An effective craters takes _______ allowing time to employ anti-tank weapons
4 or more passes
3. How do you improve craters?
Digging face vertically on friendly side
Filling with water
Any other means to further delay the enemy
9. What are the geometric characteristics of hasty crater?
6-7 feet deep
25-35 degree side slope
31. What is the fuel oil requirement to mix with fertilizer?
1 quart per 25lbs of fertilizer
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
22. To construct relieved face crater, which row will be fired first?
1/2 to 1 1/2 second delay
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)
15. What is depth of deliberate crater boreholes?
A combination of 5’ and 7’ deep
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
36. What is explosive requirement for complete tree?
3lbs of explosive is used per 1’ of diameter
30. How much nitrogen must be contained in Ammonium nitrate fertilizer?
33 1/3% of nitrogen
8. What is hasty crater blowout distance?
Approximately 8 feet beyond the end boreholes
39. What are the three methods of boulder removal?
Snake-hole, mudcapping, and block-hole method
26. What is the shape/characteristics of a relieved face crater?
25-30 feet wide
Unequal side slopes
7. For hasty crater, what is average traverse attempts of modern tanks?
Average of 4 attempts
37. What is taproot hole depth equivalent to?
Equal to stump diameter
20. What is measurement and explosive requirement are a friendly row in a relieved face crater?
40 lbs explosive
25. For relieved face crater, where would you place first borehole?
5 feet in from the desired edge of the crater
23. What is the spacing between relieved face crater boreholes?
7 feet between boreholes, center to center