ADP 3-90, page 76

Chapter 4 4-16 ADP 3-90 31 July 2019 throughout an AO and closely control their use. Commanders may allocate mobility resources to maintain main supply routes to support units and supplies moving forward and to evacuate personnel and equipment to the rear. Commanders coordinate movements with affected organic and external Army aviation, fire support, air defense units, and ground maneuver units. As required, military police protect movements, prevent congestion, and respond to maneuver plan changes. Military police can provide necessary convoy escorts, or maneuver units can use their resources, to provide necessary convoy security. In some circumstances transportation units can provide their own security. Survivability Operations 4-96. An attacking enemy force usually has the initiative. A defending commander must take a wide range of actions to reduce the risk of losses, including developing a survivability plan. Survivability in the defense prioritizes hardening command posts, artillery positions, air and missile defenses, and other critical equipment and supply areas. It also includes preparing individual, crew-served, and combat vehicle fighting positions. 4-97. To avoid detection and destruction by enemy forces, units move frequently and quickly establish survivability positions. To provide flexibility, units may need primary, alternate, and supplementary positions. This is particularly true of units defending key or decisive terrain. Units enhance their survivability using concealment, military deception, decoy or dummy positions, dispersion, and field fortifications. Commanders increase security during defensive preparations because an enemy force will attack lightly defended areas whenever possible. 4-98. When preparing area and mobile defenses, engineer units assist maneuver and supporting units prepare survivability positions. Commanders locate these positions throughout a defending unit’s security area, MBA, and support area. Requirements beyond the capabilities of BCT engineer battalions pass through a higher headquarters to an attached Army maneuver enhancement brigade or any functional engineer brigade supporting the division or corps. These engineer units also prepare any strong points required by the division or corps concept of operations. 4-99. Survivability tasks include using engineer equipment to help in constructing trenches, command post shelters, and artillery, firing, radar, and combat vehicle fighting positions. Commanders provide guidance on the level of protection (such as hull defilade, turret defilade, or overhead cover), system priorities, and early employment of specialized engineer equipment that can construct survivability positions. (See ATP 3-37.34 for additional information concerning the construction and maintenance of survivability positions.) 4-100. Commanders use dispersion to limit the damage done by enemy attacks. Enemy forces should never be able to put a unit out of action with just a single attack. Dispersed troops and vehicles force attacking forces to concentrate on a single small target that may be missed. The wider the dispersion of unit personnel and equipment is, the greater potential for limiting damage it has. Commanders position forces and installations to avoid congestion, but they do not disperse them to the extent that there is a risk of defeat in detail by an enemy employing conventional munitions or weapons of mass destruction. 4-101. Commanders protect supply stocks against blast, shrapnel, incendiaries, and CBRN contamination using dispersion and constructing survivability positions. Forces can protect vehicles carrying supplies against almost anything but a direct hit by constructing berms large enough to accommodate the vehicles and deep enough to keep supplies below ground level. The echelon staff advises sustainment operators about storage area site selection that reduces the requirements for engineer survivability support without reducing the required degree of protection. 4-102. Units also use cover to limit the amount of damage and casualties that they can receive because of an enemy attack. Folds in the earth, natural depressions, trees, buildings, and walls offer cover. If a commander deploys in flat terrain lacking cover, digging in or sandbagging can offer some protection. Units employ obscuration if they are moving and cannot use natural cover or cannot build fortifications.