Environmental Engineering Reference
In-Depth Information
• Chemical storage and feed equipment
• Meters
• Sampling equipment
• Instrumentation
Much of this equipment is installed in remote locations or in areas where the
public can access it.
One of the most effective security measures for protecting aboveground
equipment is to place it inside a building. Where this is not possible, enclos-
ing the equipment or parts of the equipment using some sort of commer-
cial or homemade add-on structure may help to prevent tampering with the
equipment. Equipment enclosures can generally be categorized into one of
four main configurations:
• One-piece, drop-over enclosures
• Hinged or removable-top enclosures
• Sectional enclosures
• Shelters with access locks
Other security features that can be implemented on aboveground, outdoor
equipment enclosures include locks, mounting brackets, tamper-resistant
doors, and exterior lighting.
Active Security Barriers (Crash Barriers)
Active security barriers (or crash barriers) are large structures that are placed
in roadways at entrance and exit points of protected facilities to control vehi-
cle access to these areas. These barriers are placed perpendicular to traffic to
block the roadway, and traffic can only pass the barrier if it is moved out of
the roadway. These types of barriers are typically constructed from sturdy
materials, such as concrete or steel, so vehicles cannot penetrate them. They
are also situated at such a height off the roadway that vehicles cannot go over
or under them.
The key difference between active security barriers, which include wedges,
crash beams, gates, retractable bollards, and portable barricades, and passive
security barriers, which include immovable bollards, jersey barriers, and
planters, is that active security barriers are designed so they can be easily
raised and lowered or moved out of the roadway to allow authorized vehi-
cles to pass them. Many of these types of barriers are designed so they can
be opened and closed automatically (i.e., mechanized gates, hydraulic wedge
barriers), while others are easy to open and close manually (swing crash
beams, manual gates). In contrast to active barriers, passive barriers are per-
manent, immovable barriers that are typically used to protect the perimeter
