Civil engineer guide to fighting positions, shelters, obstacles

AFH 10-222 Volume 14 1 August 2008 100
5.2. Berms. Time available to conduct comprehensive planning during initial
stages of deployments can be very limited. Logistical support needed to
immediately implement force protection measures may also be difficult at the
height of a military campaign. Initially, earthen berms may be the engineer’s
best option for protecting military personnel and mission-critical assets.
Properly sited, constructed, and maintained, berms can mitigate blast and
fragmentation effects from near-miss explosions caused by mortars, rockets,
or artillery shells. They are particularly effective against explosions that produce
blast effects moving at high velocities and generating low-angle fragments
along the ground’s surface. In austere environments, berms can be used
to define boundaries, act as barriers, reduce noise, and obstruct lines of sight.
The height of force protection berms can be anywhere from 6 to 12 feet.
Required heights are usually based on the height of equipment or structures to
be protected and known threats within the area or region. While berms and
other types of revetments, such as those constructed from sandbags or timber,
provide similar stopping ability for high-explosive detonations and projectiles,
earth berms provide better protection against multiple or repeated attacks.
When an earth berm is hit, its mass tends to engulf the round, and
ejected matter falls back onto the berm. Berms can be freestanding, supported
by different methods of revetting, or built directly upon structures for
protection. They can also be used to reinforce other protective measures such
as reinforced fences, concrete structures, sandbags, or earth-filled containers
structures. Regardless of the purpose or type of berm being constructed, much
soil will be needed. Berm construction also requires heavy equipment (i.e.,
dump truck, backhoe, bulldozer, roller compactor, etc.) to move large masses
of soil around and skilled equipment operators. Engineers must take these
factors into consideration while planning for force protection. It is important
to note that earth berms, because of their shapes (i.e., low-sloped faces, limited
heights, etc.), have limited effectiveness in protecting certain weapon
systems and critical aircraft support operations; therefore, additional measures
may need to be employed. The next few paragraphs describe the use of
berms in the expeditionary environment. Additional information on different
types of berms can be downloaded from TCMS.