Automatic Doors come in a variety of configurations, but they all share one thing in common — they all have an automatic operator. Automatic Doors are not complicated. The basic Automatic Door has a door, an automatic operator, and sensors with logic circuitry to initiate the automatic operator when someone approaches the door. Most older folks got their first introduction to automatic doors at a grocery supermarket.

Although basic automatic doors are simple, they become more complicated when coupled with electronic access control systems. Why? Because the door must lock until the automatic operator kicks into action. For the automatic operator to open the door, a mechanism must first unlock the door. This must be repeated in reverse order when the door is closed by the automatic operator. For doors with a higher security requirement, the coordination with the automatic operator can become significant. A typical automatic door interface for a high-security door can include:

Most automatic operator manufacturers offer control circuitry for this purpose (Figure 15.1).

Automatically operated access controlled doors may include:

A Man-Trap is a sequence of two doors, enclosing a vestibule (Figure 15.2). Each door is electrically locked and the two doors are interlocked such that only one can open at a time. This makes certain that the enclosed space always has one door closed, thus ensuring security for the enclosed space.

Man-Traps require an interlocking circuit and special care to handle emergencies. Remember the basic mantra: Life Safety above everything. The interlocking circuit is as critical for Life Safety as is the Life Safety circuit itself. To that end, every Man-Trap must be equipped with both a Fire Alarm Interface and should also have an Emergency Man-Trap Override Switch within the Secure Space near the Inner Door. This may be in the form of a large red Mushroom-Shaped Push Button or as a special switch such as a Fire Pull-box (usually colored blue).

The basic Man-Trap interlock circuit interfaces to:

The interlock operates as follows:

Man-Traps require fire code variances in every jurisdiction. Several electrified lock manufacturers manufacture off-the-shelf Man-Trap Interface Circuits that have been approved by various Fire Authorities. Although custom-made relay and Programmable Logic Circuit (PLC) devices have been used, from a dependability and liability standpoint most designers utilize an Interface Circuit that is manufactured for this specific purpose.

Full-verification Portals add a little something extra to Man-Traps (Figure 15.3). The idea of a Full-verification Portal is that it adds Visual Verification to the process of admitting authorized users through a Man-Trap.

As the User's credential is authorized by the Electronic Access Control System, it initiates a display of the photo of the authorized user on a video monitor at a Security Post located at the Man-Trap. The person in the Man-Trap is compared against the photo of the authorized user on the computer monitor at the Man-Trap Security Post.

The Security Officer then releases the Inner Man-Trap Door using a Door Control Panel within the Security Post at the Man-Trap.

This adds a high level of certainty to the operation of the Man-Trap for very high-security facilities.

“Positive Access Control” is when you want to be sure that every person entering a controlled or secured space is authorized to enter. One of the best ways to ensure Positive Access Control is to use a turnstile that operates on the principle of one authorization, one grant of access.

While we are all familiar with the old-fashioned tripod style stadium turnstiles, Electronic Turnstiles are designed for commercial building environments. The most famous Electronic Turnstiles are those at the CIA Headquarters Building, which have appeared in countless movies and news photos. Electronic Turnstiles come in three main varieties: Simple Electronic Turnstiles, Paddle-type Turnstiles (Figure 15.4), and Glass-wing Turnstiles.

All three types of turnstiles utilize a tunnel comprising a pair of stainless steel panels enclosing a short passageway (usually 1 to 1-1/2 m or 36 to 60 inches) in length. There is a card reader at each end on the right-hand side. In the case of the Paddle-type and Glass-wing Type Electronic Turnstiles, the user is presented by a physical barrier barring his/her path. For the Simple Electronic Turnstile, there is no physical barrier. An authorized user approaches the turnstile and presents his/her card. There is usually a red indicator that changes to green upon card authorization signaling the user to enter the turnstile.

With the Paddle-type or Glass-wing Type Electronic Turnstile (Figure 15.5), these elements open to allow passage. As the user transits through the turnstile, he/she breaks a series of infrared beams at ankle and thigh-high levels that track his/her progress through the turnstile.

If a person on the opposite side tries to enter from the wrong direction while the paddles or glass wings are open, sensors on that end of the turnstile sense the presence of an unauthorized person and a local alarm is sounded and the paddles or glass wings close to bar entry of the unauthorized person.

If a person attempts to enter the turnstile without authorization, the Infrared Beams sense this and sound a local alarm.

If an unauthorized person attempts to follow an authorized person through the turnstile while it is still open, the Infrared Beams sense this and the paddles/glass wings close immediately behind the authorized user stopping the unauthorized user. The local alarm is also sounded.

Care must be taken in the selection of the Electronic Turnstile to be certain that it will comply with the business culture of the organization and that it will operate fast enough to handle the peak traffic flow. A traffic flow study is critical to determine how many Electronic Turnstile lanes are required to maintain peak traffic flow.

Electronic Turnstiles should be used in conjunction with a Visitor Management System (see Chapter 21) to ensure that visitors as well as employees have credentials to pass through the Electronic Turnstiles.

A variation on the Electronic Turnstile is the Anti-tailgate System, which uses a single column of Infrared Beams to sound a local alarm if two people pass through a door on a single card authorization (Figure 15.6).

The Anti-tailgate alarm interfaces to the Access Control System to acknowledge each card read by the card reader. Typically the Access Control Panel Door Lock Relay is set to zero seconds (i.e., it pulses but does not hold itself open), and this signals a circuit controlling the door lock. Upon that signal, the Anti-tailgating System Control Circuit releases its own Door Lock Relay, which holds the door lock unlocked for a longer time period, typically five to ten seconds. The Anti-tailgate alarm is suppressed for one authorized user. The authorized user can turn the lever and enter the door. This time delay also allows the door to be open while a second authorized user presents his/her card allowing a second authorized user to enter without triggering the Anti-tailgate alarm. Any number of authorized users can present their access cards and enter without triggering the Anti-tailgating alarm. However, the first unauthorized person to try to “tailgate” behind an authorized person causes the alarm to sound.

High-Security requires Physical Security. High Security Barrier Gates are used to prevent crash-through entries into secure facilities such as ports and nuclear facilities (Figure 15.7). Crash-rated gates are rated by the U.S. Department of State (DoS) and the U.S. Department of Defense (DoD). The current standard is SD-STD-02.01, Vehicle Crash Testing of Perimeter Barriers and Gates, Revision A, dated March 2003. Crash-rated gates are available in four ratings:

Crash-rated gates actually carry two ratings, K/L, where the “K” indicates the DoS/DoD certified barrier's maximum vehicle impact speed and the “L” indicates the test vehicle's distance of penetration upon impact with the barrier (Figure 15.8).

When combined, a crash-rated gate is listed in both dimensions, such as K12/L3, which would stop a 15,000 pound vehicle traveling at 50 mph in 3 feet or less penetration (typically that would be the windshield flying out of the vehicle). To be DoS certified at any rating, the penetration of the cargo bed of a truck must not exceed 1 m beyond the pre-impact inside edge of the barrier. Thus, most crash-rated gates are L3 gates (Figures 15.9 and 15.10).

Crash-rated gates are available in a variety of designs including:

Sally ports are a secure, controlled entry-way for vehicles having two gates, similar to a Man-Trap in operation (Figure 15.11). The entrance is typically part of an outer perimeter such as a secure fence line or prison perimeter wall, and the interior gate is also fortified against easy entry. The purpose of a sally port is to deter, defend, and delay against unwanted entry (or exit). The name sally port comes from two words: port from the Latin word portus meaning door and sally from the Latin salire (to jump) or sortie, a military maneuver designed to delay and harass an opposing force. A sally port is a delaying area in which an opposing force can be trapped to permit the friendly force to overwhelm and stop the offender. Gates on a sally port are usually wider and higher than normal vehicle gates to provide for greater security.

Sally ports are usually operated remotely by a Security Officer from a separate secure space where he/she can supervise the entry and exit. Only one sally port door is ever opened at a time to ensure that no one can sneak in (to a military compound) or out (for a prison). The remote security officer will have some method to verify the credentials of the people requesting passage through the sally port and can supervise the passage in its entirety from his/her remote location, typically using video cameras or another guard with a radio.

Sally ports require caution to prevent a person from being trapped during an emergency. Emergencies could include a fire at the facility or a security event related to the sally port itself. The size of the middle space must be adequate for the largest vehicles that could ever transit the port. The middle space is typically much wider than a normal vehicle lane to permit a thorough search of the vehicle seeking passage. It is common to require all occupants of vehicles to stand down and be searched before being authorized to proceed. Vehicles are also searched completely including inside, under hoods, within trunks, and under the vehicle. Accordingly, it is common for sally ports to have multiple entries and exits all controlled to allow for the safety of any occupants during any type of emergency. If all is not as it should be, the sally port is locked down and unauthorized users are taken into custody. Sally ports are also used in maximum security prisons to control passage from one area to another of a quantity of prisoners, similar to a Man-Trap, but for a much larger number of pedestrians, and completely under the control of a remote security officer.