Environmental Engineering Reference
In-Depth Information
• The
lock
, which connects the door to the door frame. Use of the lock
is controlled through various security features, such as keys, combi-
nations, etc., such that only authorized personnel can open the lock
and go through the door. Locks may also incorporate other security
features, such as software to track overall use of the door or to track
individuals using the door.
Each of these components is integral to providing security for a doorway.
Upgrading the security of only one of these components while leaving the
other components unprotected may not improve the overall security of the
doorway. Many facilities upgrade door locks as a basic step toward increas-
ing their security, but if a facility does not also modify the door hinges or the
door frame then the door may remain vulnerable to being removed from its
frame, thus defeating the purpose of installing the new door lock.
The primary attribute for the security of a door is its strength. Many secu-
rity doors are 4- to 20-gauge hollow metal doors consisting of steel plates
over a hollow cavity reinforced with steel stiffeners to give the door extra
stiffness and rigidity. This increases resistance to any blunt force applied in
an attempt to penetrate through the door. The space between the stiffeners
may be filled with specialized materials to provide fire, blast, or bullet resis-
tance to the door. The Window and Door Manufacturers Association has
developed a list of performance attributes for doors:
• Structural resistance
• Forced-entry resistance
• Hinge-style screw resistance
• Split resistance
• Hinge resistance
• Security rating
• Fire resistance
• Bullet resistance
• Blast resistance
The first five items relate to the resistance of a door to standard physical
breaking and prying attacks. Tests are used to evaluate the strength of the
door and the resistance of the hinges and the frame in a standardized way.
The
rack load test
simulates a prying attack on a corner of the door. A test
panel is restrained at one end, and a third corner is supported; loads are
applied and measured at the fourth corner. The
door impact test
uses a steel
pendulum to simulate a battering attack on a door and frame with impacts of
200 ft-lb; the door must remain fully operable after the test. It should be noted
that door glazing is also rated for resistance to shattering, etc. Manufacturers
will be able to provide security ratings for these features of a door, as well.
