FM 3-34.22 - Army Electronic Publications & Forms - U.S. Army

Chapter 6
� Defend a strong point. A strong point is a heavily-fortified BP that must be tied to a natural or
reinforcing obstacle. It requires significant engineer effort, roughly requiring a one-day effort
from an engineer unit the same size as the unit defending the strongpoint.
� Defend a perimeter. A perimeter defense is a defense oriented in all directions used by a unit
for self-protection or to protect other units located within the perimeter. The commander can
employ the perimeter defense as an option when conducting an area or mobile defense. A
successful perimeter defense relies on aggressive patrolling and security operations. Engineers
employ tactical obstacles (including the integration of hasty protective obstacles) in support of
the established perimeter. (Similar engineer considerations are discussed in chapter 4 in support
of an area security mission.)
Note. See FM 3-90, FM 3-90.5, and FM 3-90.6 for more information.
URBAN AREAS AND COMPLEX TERRAIN CONSIDERATIONS
6-113. Offensive and defensive operations may be conducted in urban areas, jungles, forests,
mountainous areas, deserts, extremely hot areas, and arctic and cold regions. Each environment presents its
own challenges to planning and conducting engineer operations and may require engineers to employ
specialized knowledge, skills, techniques, and equipment. The following paragraphs present characteristics
of five special environments that impact engineer operations. They are intended only as an overview of
those environments. For additional information, see FM 3-34.170 and FM 5-103. Each has sections on
urban areas and complex terrain that are focused on reconnaissance and survivability, respectively.
URBAN AREAS
6-114. Engineers are enabled and challenged when operating in urban areas. When forces are required to
operate in urban areas, significant engineer augmentation is likely required. Engineers provide unique
geospatial products for the complex terrain of cities (3-D terrain and subterranean visualization products).
Assured mobility is an important framework for maneuver commanders to consider in determining how to
shape and dominate in urban terrain. Considerations for minimizing collateral damage during the reduction
of EHs (IEDs and UXOs) are especially important in an urban setting. General engineering tasks are
prevalent throughout all operations, especially during the transition to stability or civil support operations.
(See appendix H, FM 3-06, and FM 3-06.11, for additional information on operations in urban terrain. FM
3-06 provides a new framework (understand, shape, engage, consolidate, and transition) for visualizing
UO.)
JUNGLES AND FORESTS
6-115. Jungles are humid, tropic areas with a dense growth of trees and vegetation. Visibility is typically
less than 100 feet, and areas are sparsely populated. Mounted infantry and armor operations are limited in
jungle areas, and jungle vegetation provides excellent concealment from air and ground observation.
Vegetation does not provide adequate cover from small-caliber weapons, direct fire, artillery, or indirect
fire fragments. Adequate cover is available using the natural ravines and gullies produced by erosion from
the high annual rainfall of the area. Few natural or locally procured materials are available in jungle areas.
Other considerations that often require aboveground protective construction are high water tables, dense
undergrowth, and tree roots. (For more information on operations in this special environment, see FM 90-
5.)
MOUNTAINOUS AREAS
6-116. Characteristics of mountain ranges include rugged and poorly trafficable terrain, steep slopes, and
altitudes greater than 1,600 feet. Irregular mountain terrain provides numerous places for cover and
concealment. Because of rocky ground, it is difficult and often impossible to dig belowground positions;
therefore, boulders and loose rocks are used in aboveground construction. Construction materials used for
6-24 FM 3-34.22 11 February 2009