Minimum fence height is 6 feet (1.8 m) for new fencing,
excluding top guard (outrigger).
Posts, bracing, and other structural members should be inside
of the fence fabric. Nine-gauge (3.8-mm) galvanized steel
tie-wires must be used to secure the fence fabric to posts and
other structural members.
The bottom of the fence fabric should extend to within 2
inches (50 mm) of firm ground. Surfaces should be established
in areas where loose sand, shifting soils, or surface waters
may cause erosion and thereby assist an intruder in
penetrating the area. Where surface stabilization is not
possible or is impractical, concrete curbs, sills, or other
similar types of anchoring devices extending below ground
level should be used.
(d) Drainage culverts and utility openings under fences.
Special protective measures must be designed for culverts, storm drains,
sewers, air intakes, exhaust tunnels and utility openings that pass through
cleared areas, traverse under or through security fences, or have a cross-
sectional area of 96 square inches (0.06 square meter) or greater with the
smallest dimension being more than 6 inches (150 mm). Such openings and
barrier penetrations should be protected by securely fastened grills, locked
manhole covers, or other equivalent means that provide security penetration
resistance of approximately 2 minutes. MIL-HDBK 1013/10 provides detailed
design options, some of which are illustrated in Figures 17 through 20. The
reader is referred there for details.
Vehicle Barriers. Vehicle barriers are used to stop vehicle bomb
threats at a preselected standoff distance (Figure 13) consistent with the
hardness of the facility against blast effects. Available barriers are
addressed in Section 8 in conjunction with designing the facility to sustain
bomb blast. MIL-HDBK 1013/10 also presents enhancements to chain link fences
to resist vehicle attacks.