from potential vantage points. Options include: (1) the use of natural or
manmade obstructions such as trees, fences, land-forms, or buildings to
obscure sight paths; (2) siting the facility at a high point, if possible, to
force aggressors to fire up toward the target; and (3) causing the RPG to
strike protective surfaces at an angle, reducing the effectiveness.
Sacrificial Areas. Sacrificial areas in the building can be
employed above, below, and around the critical area in the building to be
protected. The walls, doors, etc., of this sacrificial area may be damaged,
but will provide a standoff region to reduce the effectiveness of the RPG jet
for the critical area. In general, to facilitate this the critical area
should be low and internal to the building and well away from exterior walls.
Barrier Construction and Predetonation Screens
1) Walls. The only practical wall construction material to stop a
direct RPG attack is the use of massive concrete in combination with sand and
a predetonation screen. The design tradeoffs are shown in Figure 69. In
general, the use of sand is more appropriate to a temporary situation where
the function of the facility may change and the sand can be removed later.
If an RPG threat against the building is likely to be permanent, the use of
concrete by itself or in combination with a predetonation screen is more
a) Predetonation screens. Predetonation screens may
consist of wood fences, chain-link fencing, expanded metal mesh, or heavy
woven-fiber fabric. Wood fences can be made of wood slats or plywood panels
a minimum of 3/8 inch (9.4 mm) thick. If they are made of slats, the slats
should be spaced no more than 1/4 inch (6.4 mm) apart. Spaces in metal
fabric screens must be 2 inches (50 mm) by 2 inches (50 mm) maximum and the
fabric a minimum of 9 gauge (3.8 mm). The effectiveness of screens of
various sizes is shown in Table 52. This data suggests that 2-inch (50-mm)
chain link presents the minimum risk of an RPG passing through the screen
with no effect. An RPG which strikes a predetonation screen either detonates
on impact or is dudded. Dudded refers to a round being damaged so that it
will not detonate. The residual effects of a predetonated round on a
building are more severe than the effects of a dudded round. Therefore, in
the design one need be concerned only with predetonated rounds. After
predetonation, the RPG jet and the spent rocket engine from the RPG continue
past the screen. The screen should be located away from the wall a standoff
distance appropriate to the concrete wall construction (see Figure 68). For
other materials allow a minimum of 40 feet (10 m).
b) Predetonation walls. Solid walls constructed of CMU or
other material can also be used if they can be constructed at the proper
height and location. These are 100 percent effective in predetonating RPGs.