This appendix provides "how to" guidance for the:

• Selection of defensive positions in built-up areas.

• Preparation of buildings as defensive positions.

• Selection of defensive positions for armored vehicles.

Analysis of the type of area in which the building is located and the individual characteristics of the building is basic to selecting a building as a defensive position (appendix A). As a minimum, leaders consider the following factors to determine a building's suitability for defense:

• Cover.
• Fields of Fire.
• Covered Routes.
• Concealment.
• Dispersion.
• Fire Hazard.
• Observation.
• Preparation Time.

Select buildings that provide protection from direct and indirect fires. Reinforced concrete buildings with three or more floors provide suitable protection. Buildings constructed of brick, block, or other light material must be reinforced for sufficient protection. One- or two-story buildings without a strongly constructed cellar are vulnerable to indirect fires and will require construction of overhead protection for each firing position. (See appendix A for comparative building protection.)

Covered Routes

Defensive positions should have at least one covered route that permits resupply, medical evacuation, and reinforcement or withdrawal from the building. This route may be established:

• Through walls of adjacent buildings.

• Through an underground system.

• Through communication trenches.

• Behind protective buildings.

Avoid establishing a position in a single building when it is possible to occupy two or more buildings that will permit mutually supporting fires. A position in one building, without mutual support, is vulnerable to bypass, isolation, and eventual destruction by assaults from any direction.

Observation

The building should be of sufficient height to permit observation of adjacent defensive sectors.

Fields of Fire

To prevent isolation, positions should be mutually supporting and capable of firing in all directions. Clearing fields of fire may require destroying adjacent buildings with explosives and bulldozers.

Figure C-2 Fields of Fire

Concealment

Avoid selecting buildings that are obvious defensive positions. For example, in the preceding figure, buildings 1, 2, and 3 are not selected because they are located on the village edge and will probably be targets of direct fire weapons. Buildings 4 and 5 are not selected because of their exposed corner locations. Buildings 6 through 10 are not selected because of their exposed location along the edge of an open area. Each of these buildings may be subjected to long-range direct fires. Buildings 11 through 15 are concealed by other buildings and should provide protection against direct fires and offer the best position for engaging advancing enemy with surprise fires. In certain situations, requirements for security and fields of fire will require the occupation of exposed buildings. In such cases, additional reinforcing construction is necessary to provide suitable protection.

Fire Hazard

Avoid older, Type 1 buildings (appendix A) found in Areas A and B. This type of building represents the greatest fire hazard in built-up areas. If these structures must be occupied, extensive efforts are required to reduce the dangers of fire.

Time

Time to prepare the defense may be the most critical factor in selection of building positions. Buildings that require extensive reinforcement with sandbags, timeconsuming fire prevention measures, fields of fire clearance, and other manual labor requirements should be avoided. Conversely, buildings located in desirable areas that require minimal construction and improvement will probably become the main center of defense.

PREPARATION OF BUILDINGS

Each weapon is assigned a primary sector of fire to cover enemy approaches to the position. Alternate positions that overwatch the primary sector are also selected. Building characteristics permitting, alternate positions are selected in an adjacent room on the same floor. Where possible, several alternate positions for each weapon are selected. Each weapon is assigned a supplementary position to engage attacks from any direction. Each weapon is assigned a Final Protective Line (FPL).

PREPARATION OF WEAPON POSITIONS

To avoid establishing a pattern of always firing from windows, loopholes are prepared in the wall.

Loopholes

Several loopholes are generally required for each weapon (primary, alternate, and supplementary position), but the number of loopholes should be kept to a minimum because they may weaken walls and reduce protection. Loopholes are made by punching or drilling holes in walls. Blasting loopholes, unless done by experts, generally results in an exaggerated hole that can easily be seen by the enemy. The figure below illustrates where loopholes may be placed. The general rule to follow in preparing loopholes is to place them where they are concealed and where they are unexpected.

Loopholes are cone-shaped to enable engagement of targets above and below the firer's position and to reduce the size of the exterior aperture. The edges of a loophole,

especially in brick walls, splinter when hit by bullets. Where possible, protective linings, such as an empty sandbag held in place by wire mesh, will reduce splintering effects. When not in use, loopholes are covered with sandbags to prevent the enemy from firing into or observing through them.

Loopholes are also prepared in interior walls and ceilings of the building to enable fighting within the position when necessary. Interior loopholes should overwatch stairs, halls, and unoccupied rooms. Interior loopholes are concealed by pictures, drapes, or light furniture. Loopholes in floors permit the defender to engage enemy personnel on lower floors with small arms and/or to drop grenades. These holes must be covered when not in use.

Protection

Although walls provide frontal protection, they should be reinforced with sandbags or furniture filled with dirt. Each position should have complete overhead and perimeter protection. Protection is increased by proper firing through loopholes. Avoid firing directly through a loophole. Use the wall as protection and fire at an angle.

The following figures portray types of weapon positions in buildings.

Figure C-4a Side View

Figure C-4b Top View

Figure C-4c Rifle Positions on Lower Floor

Figure C-5 Machine Gun Position

Figure C-5b Cellar Firing Position

Figure C-6a Attic Position

Figure C-6b Corner Firing Position.

Figure C-6c Interior Wall Position

Figure C-6d Interior Wall Position Covering Stair and Hall

Window Positions

When using window positions, soldiers use the wall on either side of the window to provide a protected kneeling or standing position. To provide the ability to fire downward from upper floors, tables or similar objects placed against the wall should provide sufficient elevation. When using an elevated platform it must be positioned to prevent the weapon from protruding through the window. Prone positions do not always permit sufficient freedom for firing at widely varying angles or at targets above the position.

Figure C-7a Window Position

OTHER CONSTRUCTION TASKS

Figure C-7b Stairways/Hall

Ground Floors

• All doors not used by defenders are locked, nailed shut, and blocked with furniture or sandbags. Outside doors are boobytrapped by trained engineers, or other trained personnel.

• Hallways not required for the defender's movement are blocked with furniture and tactical wire.

• Stairs not essential to defense are blocked by furniture and tactical wire or removed. Boobytraps are employed as required.

• Windows. All glass is removed and the windows not used are blocked with boards or sandbags.

• Walls are reinforced with sandbags to gain additional protection.

• Floors. If there is no basement, foxholes are dug into the floor for additional protection against heavy direct-fire weapons.

• Ceilings are reinforced with supports to withstand the weight of rubble from upper floors.

• Unoccupied rooms. Rooms not required for defense are blocked with tactical wire and small boobytraps.

The basement requires preparation identical to the first floor. Any underground system not used by the defender that may provide enemy access to the position must be blocked.

Upper floors

The upper floors require essentially the same preparation as ground floors. Windows are not blocked, but covered with wire mesh. The wire is loose at the bottom to permit dropping of grenades by the defender, while blocking grenades from being thrown in windows.

Figure C-8 Wire-protected Window

Interior Routes

Sufficient routes are required to permit defending forces to move within the building to engage enemy forces in any direction. Additionally, escape routes are planned and constructed to permit rapid evacuation of a room or the building. Small holes are made in walls to permit movement between rooms. These holes are concealed behind furniture and blocked with sandbags when not in use. Movement between floors is accomplished by knocking holes in ceilings/floors and using ropes or a ladder that can be quickly installed or removed. Once the defender has withdrawn to upper floors, these holes are blocked with timbers and furniture. Building evacuation routes re clearly marked for day and night identification. All personnel are briefed and practice evacuation over different routes.

Fire Prevention

Buildings that have wooden floors and rafter ceilings will require extensive fire prevention measures. The attic and other wooden floors are covered with approximately one inch of sand or dirt. Buckets of water or sand are positioned for immediate use. Water basins and bathtubs are filled as a reserve for firefighting. All electricity and gas are turned off. In Areas A and B firebreaks are created by destroying buildings adjacent to the defensive position. In other types of buildings, firefighting material (dirt, sand, fire extinguishers, and blankets) should be located on each floor for immediate use.

Communications

Telephone lines are laid to the building through adjacent buildings, through underground systems, or buried in shallow trenches. Radio antennas are concealed by locating them among civilian TV antennas, up the side of a chimney, steeple, or by placement out a rear window away from enemy observation. Telephone lines within the building are laid through walls and floors.

Rubbling

Rubbling a part of the building provides additional cover and concealment for weapon emplacement. Rubbling should be attempted only by skilled engineers.

Figure C-9a Rubbled Building Weapon Position

Roofs

Positions in flat-roofed buildings require anti-helicopter obstacles. Roofs accessible from adjacent structures are covered with tactical wire and guarded. Entrances to the building from the roof are blocked.

Exterior structure

Any structures on the outside of a building that would assist scaling to gain access to upper floors or to the roof are removed or blocked with tactical wire.

Obstacles

Obstacles are positioned adjacent to the building to stop tanks and delay infantry (See appendix D). Buildings in proximity to the defensive position that provide cover for enemy infantry movements or are suitable weapon positions are:

• Destroyed.

• Mined/boobytrapped.

• Filled with barbed wire.

• Blocked at doors and windows.

• Combinations of the above.

Fields of fire are improved around the defensive position as time permits. Selected buildings may be destroyed to enlarge fields of fire. Obstacles to ATGM flight are cleared as required.

TANK/APC POSITIONS

The factors of cover, concealment, fields of fire, etc. considered in selecting other defensive positions are also applicable when selecting positions for combat vehicles. In addition, the physical layout of the built-up area, the condition of its structures, and the amount and type of rubble present directly influence the selection process. Within a built-up area, tank and APC positions can be classified in general terms as hull-down or hide positions.

Hull-down positions utilize any type physical barrier available, such as low walls or piled-up rubble, to protect the vehicle by reducing its target silhouette.

Hide positions, as the name implies, are used to deny the enemy direct observation of a tank or APC until it is time for target engagement. In some cases it may be possible to hide a vehicle within a building to gain additional cover and concealment. However, caution must be exercised to insure that building floors will support the vehicle.

Figure C-9b Typical Hull-down Position

NOTE: Engineers may be required to evaluate the floor strength and to prepare an entrance and exit for the vehicle.

Building hide positions may also serve as firing positions if the structure will withstand firing overpressures and probable enemy return fires.

Normally, vehicles will be hidden behind structures within the built-up areas and moved to a prepared, hull-down firing position as necessary. Camouflage, particularly overhead screening, is required when hide positions are to be occupied for any significant period of time. Because the vehicle crew cannot see advancing enemy forces from a hide position, observers from the section or nearly dismounted units are needed to select targets and control the movement of the vehicle from its hide position to a firing position. Routes from each firing position to alternate hide or firing positions should be selected and prepared in advance.

Figure C-10 Hide Position

As indicated in appendix A, narrow winding streets and limited fields of fire may restrict the effective use of tanks or APCs in Type A built-up areas (dense, random construction). Type B areas, on the other hand, with their closed-orderly block layout and rectangular pattern of wider streets, offer greater possibilities for the employment of these combat vehicles. Extended fields of fire may be established along main thoroughfares. Hide positions are available in courtyards, alleys, and side streets. The construction of hull-down firing positions at street intersections and the use of smoke to screen movement will frequently be required.

Figure C-11 Closed-Orderly Block Area (TYPE B)

The other categories of built-up areas provide many possibilities for employing tanks and APCs. A wide variety of hide and firing positions are frequently available. In many cases it is possible to establish mutually supporting fields of fire between adjacent positions.

The following illustrations show typical defensive positions for Type C, D, and E built-up areas.

Figure C-11 Dispersed Residential Area (TYPE C)

Figure C-12 High-rise Area (TYPE D)

Figure C-12b Industrial/Transportation (TYPE E)