Roadblocks To Disaster

Cars and trucks are an American icon and the basis of the nation’s transportation and commerce, but for security professionals, vehicles can represent a distressing threat. Like the Trojan horse, vehicles can carry danger to the front door — or worse yet, through the walls — directly into a facility.

Vehicle deterrence devices have increased in popularity and in sophistication in the past five years, but available products can vary in capabilities, construction and cost.

Bollards and Barriers

Devices created to keep vehicles outside a designated perimeter range from stationary concrete posts or planters to automated hydraulically-powered metal posts and steel plates that rise up against the invading vehicle.

While stationary vehicle obstructions, such as planters or concrete barricades called Jersey barriers, keep unwanted vehicles from restricted areas, they are not suitable as gates for entrances and exits. To supplement the carefully guarded perimeters of their facilities, security professionals need versatile, mobile access control devices — and they must be powerful enough to stop a speeding vehicle.

Bollards (or vehicle deterrents in the form of heavy-duty posts) are a balance of function and aesthetics. Even the sturdiest types, those able to repel a speeding tractor-trailer — are offered in ornamental or architecturally-consistent sleeves or finishes. Others can be painted.

Experts say bollards are less disruptive to pedestrian traffic, and are easily accepted by the public.

Bollards are available in several varieties:

• Fixed bollards are cost-effective ways to protect large areas permanently, and serve the same purpose as concrete planters, for example, protecting the perimeter at airports. Some decorative planters even have a bollard built in to add strength.

• Removable bollards are effective for creating an emergency passage. These bollards may include a mechanism to lock them in place when in use, and caps to cover the holes when the bollards are removed. These devices may not fulfill U.S. State Department safety requirements because the bollard base and foundation may not reach far enough below ground. However, adding diameter will increase stopping capability.

• Retractable or automatic bollards, operated by hydraulic or pneumatic power units, can be lowered below ground to allow entry. Special emergency settings allow the posts to return to an upright setting in case of a security threat. These units are available with a self-contained hydraulic power unit, or more commonly, multiple bollards with internal pneumatic or hydraulic workings can be controlled by an external hydraulic power unit.

• Manual retractable/semi-automatic bollards are suitable for less-used entrances and exits and are more cost-effective. Manual bollards are counter-balanced, allowing ease of movement up or down, and the devices lock in either position. When semi-automatic bollards are in the upright position, a key may be inserted and turned to unlock, allowing the operator to press the bollard until it locks in the down position. Then when unlocked by key again, a compressed gas cylinder raises the bollard to an upright, locked position. The ascent may also be completed with a manual screw crank or pull system.

  Many facility managers choose to pair bollards with high-security gates or barricades.

• Crash gates are steel rods or pickets that slide across a roadway on a track. Cantilevered versions avoid the potential difficulties of a track (which must be kept free of ice or large amounts of sand) by sliding the gate through a stanchion which borders the roadside.

• Wedge barriers are steel rectangles that raise a formidable edge above the surface of the road. Steel plate barriers also rise from the road to a 45-degree angle. When raised, the barrier’s angle, along with the barrier’s foundation pad, deflects the vehicle’s force.

• Drop arm barriers look much like a parking lot drop arm, with crash or cable beams rising to allow vehicles to enter, but stopping an unauthorized vehicle when in the lowered position.

  A similar version of the drop arm employs a one-inch steel cable to lasso any vehicle attempting to drive under a U-shaped gate, thus destroying the front of the vehicle.

• Portable (or mobile) barriers are praised for their speed of installation and mobility. With a swift set-up time — from 15 minutes to a few hours — portable barriers offer less strength than barriers set in concrete, but they allow perimeters to be created quickly when security issues require a larger area of safety around a facility. Portable barriers also require no excavation, thus allowing installation on existing roads or even level compacted soil.

Some portable barriers consist of a crash beam or a rising plate barrier, set on both sides with buttresses — boxes filled with a heavy substance, or 55-gallon drums filled with concrete and placed in ornamental crates. In the 55-gallon drum version, the drums can be removed, allowing the barrier to be easily moved and reinstalled. If the boxes are filled with concrete, they may become a one-time-use-only device. Water, sand and gravel may be more easily removable. A portable plate barrier on wheels can be towed into place and installed in 20 minutes.

While some of these portable solutions pass crash tests, positioning must be carefully considered, as they tend to move when hit with a vehicle. However, movement can be somewhat limited with the addition of support buttresses.

What To Consider When Purchasing

For first-time buyers, the array of vehicle access control products can be overwhelming. Security professionals working for government facilities, or businesses which often work with the government, must know the difference between crash-rated products and crash-tested products.

Crash rating describes an engineering analysis. Vehicle deterrence devices that are described as “crash tested” have actually met a vehicle in an independent test lab. While there are many commercial labs in operation, the U.S. State Department and Department of Defense only approve certain labs.

Careful consideration of each site’s needs is important, suppliers say. Most will ask several key questions as they help buyers match products to security demands.

• What type of vehicle are you trying to stop and how fast can that vehicle travel when approaching vulnerable areas of your facility? A major measurement of a vehicle’s hitting power is its kinetic energy — derived from its velocity and its weight. Upon impact, some of the vehicle’s energy is converted to heat, sound and permanent deformation of the vehicle. But the barrier must absorb the remainder of this energy.

  The amount of kinetic energy presented by a vehicle changes as a square of its velocity. Therefore, an armored car weighing 30 times as much as a Volkswagen and moving at 10 mph would have less hitting power than the Volkswagen moving at 60 mph. Because velocity weighs so heavily into the damaging power of a vehicle, security engineers often design entrances to force a vehicle to slow down before it reaches the barrier.

  If a vehicle approaching a facility must make a 90-degree turn, its velocity will be decreased, and the use of a less invasive barrier might be suggested. However, if the vehicle entrance is at the end of a long straightaway, barrier manufacturers may suggest their strongest-rated devices. The types of vehicles typically entering the site are also considered; a business that has tractor-trailers entering and exiting frequently will require different security measures than a site where the only visitors are cars and pedestrians.

• How often will the entrance/exit be used? If the barrier will operate only a few cycles per day or week, a manual option would be acceptable. Automatic barriers can open and close more than 100 times a day, but some options are slower than others.

More to Consider

Other environmental factors must also be evaluated before a final selection is made. If excavation is impossible, shallow-mount barriers would be necessary. If the area is prone to colder conditions, strip heaters would be needed to keep equipment above 32 degrees. Warning signage and signal lights are also helpful to alert visitors to the presence of barriers.

Manufacturers say vehicular access control devices work best when operating as part of a larger access control system. To this end, most can be operated by a combination of methods, including radio, remote control, card readers, keyswitch, numeric keypad, or manually on a push-button panel. Most hydraulic units will also have back-up provisions in case of power failure.

Manufacturers also suggest that bollards and barriers be kept in the closed or upright position until an approaching vehicle has been cleared for entry.

Many suggest installing additional warning systems. A velocity sensor, consisting of digital wire loops embedded in the roadway a distance away from the facility entrance or guard booth, will trigger an early warning alarm or raise barriers if a vehicle is approaching at high speeds.

Vehicle-sensing loops placed in the roadway directly in front and behind the barricade stop the raising of barricades or bollards while an authorized vehicle is in the way. The coupled loop detector suppresses accidental operation, while an emergency mode allows the safety loop to be overridden in a crisis.

An Open Door For Innovation

While many barriers are similar across the industry, manufacturers continue to produce creative variations. One company offers concrete barriers in the form of precast animals; with optional water spray attachments for water park use.

Another manufactures its bollards separate from its casings. End-users can buy and install the casings now, and purchase the bollards with their decorative finishes after construction, and any changes to the architectural appearance, have been completed.

While most barriers and bollards have traditional push-button operating systems, some now include flat-screen monitors with touch-screen buttons. Operators can view graphic representations of the actions being commanded, with colors representing closed or open positions.

For areas where hydraulics and the trenching and installation of electrical wiring are impractical, one bollard model runs on a city’s water supply. Approximately 60-90 psi will lift the 750-pound bollard — the only byproduct is water.

Sometimes security is needed on the water, as well. One manufacturer is perfecting a water-borne barrier. Two buoys connected with chains and a 1-inch stainless steel cable can stop a 21-ft. boat from approaching a dam or other sensitive area.

Another manufacturer has designed electromechanical versions of bollards and crash gates, as electromechanical operating systems are more suitable and safer for high-traffic areas such as public or commercial facilities. While many hydraulic units must be housed close to the barriers they operate, an electromechanical power unit can be positioned in a closet 1,000 feet away.

While the options may seem endless, the goal remains the same. With unauthorized vehicle deterrence systems in place, security professionals are once again backed by technology in their pursuit of safety.

PERIMETER SPOTLIGHT

Security On The Hill

As one of Washington, D.C.’s most historic districts, Capitol Hill — referring to the area encompassing the U.S. Capitol Building, the U.S. Senate Buildings, and the Capitol Police headquarters — has a myriad of sensitive areas requiring protection.

When Clinton, Md.-based Nasatka Barriers first began helping with ongoing security upgrades in the district, the site required a variety of vehicle access control measures, recalls John Scolaro, Nasatka’s international sales director.

Security measures on Capitol Hill have not only been inspired by the terrorist events of Sept. 11, 2001, but also by the shooting of two Capitol Hill officers in July 1998.

“They needed a large range of stopping abilities, depending on the location at Capitol Hill,” he says. Entire roadways, parking lots, and various entrance and exits needed to be protected.

One solution requiring minimum excavation and a relatively short installation time was the steel plate barrier. “They needed something that wasn’t going to affect the environment drastically, so they didn’t want a lot of excavation in roadways,” Scolaro says. The steel barriers’ hot dip galvanized finish was also helpful in protecting against harsh conditions caused by weather and frequent construction.

Because many areas have been under construction during the last few years, changing entrances and exits in need of protection, mobile steel plate barriers were also used. The barriers-on-wheels enabled flexible perimeters, and could be moved and re-deployed in 30 minutes.

One common factor that was of less concern to the security staff at Capitol Hill was aesthetics. “They weren’t really looking at the aesthetic features because they wanted people to know they were serious about unwanted vehicles not entering,” Scolaro says.

Over the last several years, the extensive site has employed 60 percent of Nasatka’s steel plate barrier models. Like most government entities, Capitol Hill’s security professionals knew what they needed, Scolaro says.

“Really what they’re looking at is which product best fits the application, and they’re looking at durability,” he says. “These sort of agencies do a lot of research. They know who they’re looking for and they have an idea what they’re looking for, but they do value our suggestions as to what product best fits their need.”
— Corrina Stellitano

PERIMETER SPOTLIGHT

Terror On Trial

Vehicle anti-terrorism devices become most important, perhaps, when the formidable institution of terrorism itself is being challenged.

When the federal case of the United States vs. Osama bin Laden was slated to begin in New York City’s Daniel Patrick Moynahan U.S. Courthouse and the old Foley Square U.S. Courthouse in Feb. 2001, construction crews hastened to install a safe perimeter around the courthouses. Safety was of the highest priority and concern: bin Laden’s alleged followers were on trial for the 1998 bombings of the U.S. embassies in Kenya and Tanzania that killed 224 people.

In the two months preceding the trial, barriers and bollards were installed, cordoning off the entire block housing the two courthouses.

Hydraulically-operated barricades, manufactured by Valencia, Calif.-based Delta Scientific Corp., blocked each end of the street.

Designed to stop a 7.5-ton truck moving at 80 mph, the thick steel plates would pop out of the ground within 1.5 seconds during an emergency. The barriers were accompanied by bulletproof guard booths.

A series of Delta bollards also guarded the front of the U.S. courthouse. The bollards were designed to destroy the front suspension, steering linkage, engine crankcase and portions of the drive train of any 15,000-pound non-armored vehicle that collided with them at 62 mph. The bollards were also intended to stop a 15-ton vehicle traveling at 44 mph, raising and lowering into the ground in one second.

Hours before the trials began each day, the bollards and barriers were raised to create a secure area. Cameras and ground surveillance contributed to the overall security precautions.
— Corrina Stellitano

PERIMETER SPOTLIGHT

Crash Ratings

Government agencies, and the companies who contract with them, typically use products certified in approved labs.

As the State Department’s crash rating system is the most widely used, manufacturers will often explain the capabilities of their products using the following ratings.

A K4-rated barrier can stop a 15,000-lb. vehicle traveling at 30 mph.

A K8-rated barrier will stop the same vehicle going 40 mph, and K12 refers to 50 mph.

Ratings of L1 through L3 describe the distance any part of the vehicle will travel past the barrier upon impact.

(For instance, L3 means that the vehicle or major components of a vehicle will travel no more than three feet after striking the barrier.)

Research Contributions

The following people and companies were helpful in explaining the technologies described in this article:

David Dickinson, senior vice president, Delta Scientific Corp., Valencia, Calif. Delta Scientific manufactures vehicle barricades, parking control equipment and guard booths.

Mark Perkins, national sales manager, Automatic Control Systems, Port Washington, N.Y. The Automatic Systems Group manufactures pedestrian and vehicle access control devices, including six models of electromechanical vehicle barriers.

Scott Rosenbloom, vice-president, ARMR Services Corp., Fairfax, Va. ARMR Services Corp. manufactures crash-rated vehicle barriers and parking control equipment.

Paul Schumacher, sales manager, Petersen Manufacturing Co., Denison, Iowa. Petersen Mfg. manufactures fixed bollards and planters in a variety of shapes and sizes.

John Scolaro, international sales director, Nasatka Barrier, Clinton, Md. Nasatka Barrier specializes in vehicle access control barriers.

R. Shelton Vandiver, product manager, bollards and barriers, Norshield Security Products, Montgomery, Ala. Norshield Security Products manufactures bullet-resistant doors, windows and enclosures, and vehicle access control barriers.