Gates and Electric Gate Operators

The electric gate operator is one of the most vulnerable attack points on a vehicle gate. Electric gate operators are justified only for gates that are so heavy or large they cannot be opened and closed manually by one person. Almost without exception, electric gate operators are installed for convenience, not necessity. They are used so someone does not have to get out of the car or truck and open or close the gate. Whether the gate is a swinging gate or a sliding or rolling gate, an electrically operated gate usually has several vulnerabilities:

• Several seconds may pass between the time when the gate opens enough for a vehicle to pass and the time when the gate is closed enough to stop another vehicle from passing. Vehicle drivers usually don’t stop after driving through the open gate. This allows an unauthorized vehicle or pedestrian to pass through the gate behind them while the gate is still open. This problem is a human failure, not an equipment failure. Solutions include:
  
  
  • Requiring drivers to stop and wait immediately after driving through a gate, observing the gate until it has closed fully. This is the simplest and least-expensive solution.
    
    
  • Installing a second electrically operated gate a short distance past the first one. The distance should be just long enough to allow the longest vehicle using the gates to wait between the first and second gates. Wire the electric gate operators so that one gate must close completely before the second gate will open. The two gates create a vehicle trap that allows just one vehicle at a time to pass through each gate. This approach is costly, but it is appropriate for high-security facilities.
    
    
• Usually, the mechanical connections (particularly chain drives or swing-arm pivot points) between the electric gate operator and the gate are unprotected and easily attacked with handtools. Often, these connections and the electric gate operator are the only mechanisms holding the gate closed.
  
  
• An electric gate operator is designed to open and close the gate, not to secure the gate and hold it closed. Never rely exclusively on the electric gate operator and its mechanical components to hold a gate closed. The gate must be held closed by a lock or secondary barrier that operates independently from the electrical gate operator. Solutions include:
  
  
  • Electromagnetic locks that hold the gate closed. These locks work well, but typically they are held locked by the continuous flow of electric current through an electromagnet. An appropriate sensor must be installed to detect and immediately notify responders of any interruption of current flow that would allow the gate to be opened.
    
    
  • Extendable and retractable hydraulic or pneumatic bollards. These bollards can be installed in the ground to prevent the gate from opening even if the electric gate operator has been fully compromised. These are expensive to install and maintain, and they must have a well-secured manual override that allows the bollard to be retracted manually in an emergency.
    
    
• Usually the drive mechanism and electronic processors for the electric gate operator are in a metal box near the gate. More often than not, the cover on this box can be removed after loosening or removing one or two sheet metal screws or hex-head machine screws. Once the cover has been removed, an attacker will have access to the same switches and circuits the gate technician uses to open and close the gate during routine service calls.
  
  
• If access to the gate operator’s electronic processors is not restricted, an intruder can install a remotely controlled receiver and relay over the top of existing controls. The existing controls will continue to work properly, but an attacker with a transmitter will be able to operate the gate remotely. Solutions include:
  
  
  • Without exception, install the drive mechanism, the processors, and all associated connecting hardware inside the secured area. Never install this equipment outside!
    
    
  • Lock out power to the electric gate operator. Require that the gate be opened or closed by a security guard or other trusted employee. Ideally, the employee controlling the gate will be able to observe the gate continuously to verify that only the authorized vehicle passes through.
    
    
  
  • Use several machine bolts with tamper-resistant (security) heads to hold the electric gate operator’s cover in place. Lock the cover with at least one and preferably two locks. If the locks are padlocks, protect their shackles so they cannot be cut by a bolt cutter.
    
    
  • Install a tamper switch inside the box’s cover to send an immediate signal to the alarm system whenever the cover is removed.
    
    
  • Consider video surveillance of the gate and its associated equipment.
    
    

• Remote activation devices, such as key-operated locks, digital keypads on posts outside the secured area, or radio-operated remote control systems, are vulnerable. Post-mounted opening devices outside the secured area must have reinforced housings that are highly resistant to forced entry. They also must have tamper sensors that indicate attempts to remove the housing. Ensure that these devices cannot be “triggered” by electrostatic discharge voltage applied to the housing.
  
  Radio-operated remote control gate openers should not be used. An attacker can read the signals being transmitted to the receiver and install them in a clone transmitter.

Gates in chain-link fences often are “secured” by a hardware store chain and a padlock. This practice diminishes the gate’s security. Bolt cutters or a hammer and cold chisel will cut the chain faster than someone with a key can unlock the padlock. Don’t waste your money on the padlock. If for some reason, it is necessary to hold a chain-link fence gate closed with a chain rather than with the appropriate hardware, use a long length of chain and “maypole” it from top to bottom around both the movable post on the gate and the stationary post next to it.

Secure the chain at the top and at the bottom with peened bolts that cannot be reached from outside the gate. This method requires an attacker to cut the chain and unwind it from around both posts. The amount of time required to do so can be increased by increasing the number of bolts between the top and bottom. More bolts means more chain links must be cut before the chain can be removed completely.