Security Tip #1
ACCESS CONTROL LOCKING DEVICES - Part 1 of a 5 Part Series on locking devices
Submitted by Roy N. Bordes, President/CEO, The Bordes Group, Inc.

When designing an access control system, one of the most important factors is being able to select the appropriate locking device for the controlled portal. If any readers have ever attended one of the ASIS Physical Security Workshops, you will remember that we spend a considerable amount of time discussing locking devices. While this tip will not go into great detail on any of these items, the following general details on each type of locking device should be followed:

1. Magnetic Locking Devices:

One of the most common locking devices is the electromagnetic lock or "mag" lock. This lock is basically a magnetic holding device that requires power to operate. Therefore the performance received from this lock depends upon the design. For example:

1. Fail-safe which means that the lock is unlocked when power is removed. This configuration is most commonly used on fire doors because when the fire alarm system is triggered, the locks will automatically open, thereby allowing for emergency egress from the facility.
2. Fail-secure simply means the opposite. When the power is removed from the lock, the unit remains locked. Therefore, power is required to actually open this particular configuration of the lock. When you select to have your locks designed to operate in a Fail-Secure mode, you must have stand-by power or battery backups to ensure the locks will operate should you lose building power. Additionally, we would never recommend this configuration be used on any door that, even though not designated, may be needed for emergency exiting.

The two basic styles of this type of lock are what is known as "Direct-Hold" and "Concealed" or "Jamb"locks. Each of these units consists of a locking device (magnet) and a striker plate.

The direct hold mounts on the surface and works very well for doors that are constructed of glass with small frames or doors that do not fit properly. Also the surface mount lock is easier to service because all of the mechanism is exposed. The locking device is attached to the door frame, and the striker plate is attached to the door.

A couple of things to watch for on surface mounted magnetic locking units is:

1. Which way does the door swing? You do not want your magnetic locking unit to be outside the protected area because the door swings inward; and
2. Ensure the striker plate which is attached to the door cannot be removed from the outside, because the perpetrator can simply remove the nuts from the bolt and the magnetic lock will hold the striker plate while the door is opened.

The "jamb" locking device is a little more tricky to work with. For example, one thing to remember is that the lock is powered at all times, therefore there will be heat generated and if your door frame has light wood or a painted finish, there may be problems with warping or discoloring of the finish. Additionally, "jamb" locks are much more difficult to install in retrofits. However, there are always areas where "jamb" units are required and they may work very well for your application. Some of their advantages are; 1) they are invisible to the user; and 2) they are less subject to tampering.

The standards set forth for magnetic locking devices are measured in holding power. For example, the Class I lock has a holding power of 1500#, Class II is listed at 1000#, and Class III is listed at 500-600#. There are other locking devices on the market that go up to 3000# holding power. These should be used for extremely high-risk asset protection applications. It must remembered however, that the door, door frame, and wall also have to be taken into consideration when using a lock of this magnitude. Do not put a 2000# holding power lock on a wooden door in a wooden frame surrounded by a dry-wall area. The surrounding area kind of defeats the intent.

This is part 1 of a 5 part series concerning locking devices. The other segments of the series will address the Electric Strikes, Electric Locksets, Electric Dead Bolts, and using locking devices that comply with ADA/Fire requirements.

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