Civil engineer guide to fighting positions, shelters, obstacles

AFH 10-222 Volume 14 1 August 2008 68
3.4. Reinforced Concrete Bunkers. Reinforced concrete bunkers are used
extensively in the expeditionary environment to provide immediate shelter
from imminent or repeated attacks. Figure 3.14 shows reinforced concrete
culvert bunkers commonly found in SWA and a different type of reinforced
concrete bunker developed by the USACE’s Engineer Research and Development
Center (ERDC). The entrances of reinforced concrete culvert bunkers
can be blocked by concrete barriers, additional sandbags, or some other barrier
to prevent the effects of blasts and fragmentation from entering the structure.
The ERDC bunker is designed to eliminate a direct line of entrance for
blast and fragmentation into the structures. These structures are usually designed
to accommodate 25 to 30 personnel and can be placed above or below
the ground (based on the threat). It is important to note that these bunkers are
not effective against direct hits from 120 mm mortars and 122 mm rockets.
Therefore, these bunkers should be fully buried in a cut and cover configuration
or covered by several layers of sandbags. Cover the roof of the bunkers
with 2 to 3 layers of sandbags for protection against quick-fused 82 mm and
120 mm mortars. Cover bunkers with approximately 48 inches of sandbags or
bury them with approximately 48 inches of soil cover for protection against
quick-fused 122 mm rockets. Place at least layers of sandbags along the bunker
walls for protection against blast and fragmentation effects of near-miss
(4 feet) hits from 82 mm and 120 mm mortars and 122 mm rockets. Reinforced
concrete bunkers can be manufactured locally or acquired through the
Logistics Support function. For additional information on these and other
types of bunkers, obtain access to TCMS. The ERDC should also be contacted
at www.erdc.usace.army.mil for the latest designs since these structures
are constantly being tested and improved.