SELECTED
CONSTRUCTION SPECIFICATIONS
Direct fire weapons penetrate either by their momentum (like a small arms bullet) or by a chemical reaction (like an RPG or shaped charge). These weapons are fired DIRECTLY at the position and are therefore more likely to strike the position than an indirect fire projectile. Shaped-charges have been defeated in the past using a "stand-off" which prematurely detonates the projectile before striking the postion.
Indirect fire causes damage from either Blast or Fragmentation. Blast creates a shock wave which knocks apart walls or roof structures and can cave in excavations. Fragmentation damage depends on the location of the burst (air or ground/delay) with an air burst causing the greatest damage from fragments.
Material thickness in inches required to protect against direct hits by small arms (7.62mm and less) at 100 yds.
| Sandbags filled with | Loam (Dry) | -30" | (Wet) | -45" |
| Sandbags filled with | Sand (Dry) | - 20" | (Wet) | - 40" |
| Parapets (berms) of | Clay (Dry) | - 42" | (Wet) | - 84" |
| Parapets (berms) of | Loam (Dry) | - 36" | (Wet) | - 54" |
| Parapets (berms) of | Sand (Dry) | - 24" | (Wet) | - 48" |
| Material between boards | Clay (Dry) | - 36" | (Wet) | - 72" |
| Material between boards | Loam (Dry) | - 24" | (Wet) | - 36" |
| Material between boards | Sand (Dry) | - 12" | (Wet) | - 24" |
Material thickness in inches required to protect against direct hits by HE Shaped-Charges weapons (RPG, Sagger, etc):
| Rock | Min 24" | Max 36" |
| Soil | Min 66" | Max 100" |
| Steel | Min 14" | Max 24" |
| Wood | Min 72" | Max 108" |
Material thickness in inches required to protect against indirect fire fragmentation and blast exploding 50 FEET away:
| MATERIAL | MTR 82mm | MTR 120mm | RKT 122mm | HE 122mm | HE 152mm | BOMB 100lb | BOMB 250lb | BOMB 500lb | BOMB 1000lb |
| Loose earth between boards | 12 | 12 | 12 | 12 | 16 | 24 | 30 | - | - |
| Sandbag (Clay)* | 10 | 18 | 18 | 18 | 20 | 30 | 40 | 40 | 50 |
| Sandbag (Sand)* | 8 | 16 | 16 | 16 | 18 | 30 | 30 | 40 | 40 |
| Berm (Clay)* | 12 | 20 | 20 | 20 | 30 | 36 | 48 | 60 | - |
| Berm (Sand)* | 10 | 18 | 18 | 18 | 24 | 24 | 36 | 36 | 48 |
* Double values if material is wet
SELECTED CONSTRUCTION SPECIFICATIONS ROOF CONSTRUCTION
Thickness of wood to use as a base for overhead cover (plywood):
| Thickness
of Earth Cover, ft | Span Length, ft | |||||
| 2-1/2' | 3' | 3-1/2' | 4' | 5' | 6' | |
| 1-1/2' | 1" | 1" | 2" | 2" | 2" | 2" |
| 2' | 1" | 2" | 2" | 2" | 2" | 3" |
| 2-1/2' | 1" | 2" | 2" | 2" | 2" | 3" |
| 3' | 2" | 2" | 2" | 2" | 3" | 3" |
| 3-1/2' | 2" | 2" | 2" | 2" | 3" | 3" |
| 4' | 2" | 2" | 2" | 2" | 3" | 4" |
Center-to-Center spacing for steel pickets:
| Number of Sand bag layers | Span Length, ft | ||
| 3' | 6' | 9' | |
| Single-Picket Beams* | Center-to-Center Spacing, in | ||
| 7" | 7" | 6" | |
| 6" | 5" | 4" | |
| Double-Picket Beams** | |||
| 7" | 7" | 7" | |
| 7" | 7" | 7" | |
** Two pickets are welded every 6 inches to form box beams.
Table
of Contents
Astro
Azimuth Control Technique
Battery
Commander Responsibilities
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