60.2 Physical safeguards for restricted areas. The physical safeguards
applied to a facility are dictated by the sensitivity of the information
processed. Safeguards may include: a range of guards, perimeter security
fencing, gates, clear zones, window bars, secure doors, intrusion detection
alarms, electronic surveillance devices, and other similar measures. Certain
types of facilities (SCIFS, ADP, communications centers, cryptofacilities,
etc.) have more restrictive requirements prescribed for physical security
safeguards as an element of facility accreditation or approval.
70. Protective barriers. Protective barriers are normally used to define
the practical physical limits of a restricted area and effectively control
access to the area. Protective barriers are divided into two major
categories - natural and structural. Natural protective barriers are
mountains, deserts, rivers, gorges. or other similar terrain that is
difficult to traverse. Structural protective barriers are man-made devices
such as fences, walls, floors, roofs, grills, bars. roadblocks, or other
types of construction that inhibit access to the restricted area. The use of
barriers offers two important benefits to a physical security program.
First, barriers create a psychological deterrent to those individuals who may
contemplate unauthorized entry into restricted areas. Second, barriers have
a direct impact on the number of security posts needed to secure a restricted
area. The facility designer has little control over natural barriers. The
guidance that follows concentrates on structural barriers.
70.1 Structural barriers. Structural barriers (such as fences or walls) are
required for the entire perimeter of limited or exclusion areas and should be
considered for all controlled areas. Specific types of facility barriers
cannot be designated for all situations, but should incorporate structural
perimeter barriers and provisions for access authorization verification at
points of entry.
70.1.1 Fence design criteria. Four types of fencing are authorized for use
in protecting restricted areas: chain link, barbed wire, concertina, and
barbed tape. Choice of fence type depends primarily upon the degree of
permanence of the facility, availability of materials, time available for
construction, and requirements/specifications of the responsible department
or agency. Generally, chain link fencing will be used to protect permanent
limited and exclusion areas. All four fencing types may be used to augment
or to increase the security of existing restricted area protective barriers.
70.1.2 Barrier wall design criteria. Barrier walls are those free standing
walls that are not an integral structural component of a facility. Walls are
seldom used as a perimeter barrier due to the cost of installation. When a
masonry wall is deemed necessary as a positive barrier, tile minimum height
must be 7 feet (2.1 m) and must have barbed wire top guard that is sloped
outward at a 45-degree angle and carries at least 3 strands of barbed wire.
The top guard should increase the vertical height of the total barrier by at
least 1 foot (0.3 m).
70.1.3 Utility openings. Sewers, air and water intake and exhausts, and
other utility openings of 10 inches (250 mm) or more in diameter that pass
through perimeter barriers must have security equivalent to that of the
barrier(s) penetrated. Interior manhole covers 10 inches (250 mm) or more in