By John J. Strauchs, CPP
Reducing the risk of terrorism at new hotels in high-risk locales requires innovation and thoughtful planning at the design and architecture phase.
There is an old saying favored by terrorists: “Why attack the mighty lion when there are so many sheep to be had?” That mind-set, shared by many violent extremists, explains why terrorists attack soft targets—especially hotels and resorts.
Since 9-11, there have been at least 62 attacks against hotels in 20 different countries. Among major recent examples are the 2008 assaults on the Oberoi Trident and Taj Mahal Palace hotels in Mumbai, India, in which 71 people were killed and more than 200 injured. During the same year, the Marriott in Islamabad, Pakistan, was reduced to rubble by a dump truck filled with explosives. At least 54 people were killed and 266 injured. In 2009, suicide bombers attacked the Jakarta, Indonesia, Marriott and Ritz-Carlton hotels. Nine people died there and 53 were wounded.
In the face of this type of threat, property owners, architects, and engineers responsible for lodging properties must find ways to balance their desire to make guests feel welcome with their need to keep guests as safe as possible.
While many security experts would agree that the most effective terrorism countermeasures for a hotel or resort are administrative and operational, also important is the ability of architects and engineers to mitigate risk in the design process.
A combination of innovation and rational planning at the architecture and engineering (A/E) design phase can yield cost-effective solutions that will help mitigate the risk of a terrorist attack. For that creative process to occur, however, those in charge must be open to the possibilities. They must fight institutional cynicism and avoid risk-assessment methodologies that stifle innovation and nudge architects and planners toward expensive one-size-fits-all strategies. An unfortunate example of the latter is that every U.S. federal courthouse is now mandated to have virtually the same level of security regardless of whether it is in Bangor, Maine, or in midtown Manhattan.
During the A/E design concept stage, architects and engineers should work with security professionals to develop a series of likely security scenarios and possible design responses ranging from basic security countermeasures to high concepts. These should be discussed with the facility owners and adjusted based on their preferences, goals, andbudget constraints.
Some, or even most, of the high concepts may be impractical for most sites, but each should be carefully evaluated. Similarly, with regard to innovative proposals, none should be dismissed out of hand. It is too easy to miss innovative opportunities if new ideas are perfunctorily discounted or if, at first glance, something seems to be unrealistic because it has never been attempted or doesn’t conform to conventional thinking. Even an idea that is ultimately deemed unworkable can potentially contain the germ of a new approach, but the idea has to be vetted for that seed to be discovered.
These deliberations must include discussions about designing against and responding to bomb blasts and armed attacks. An overarching goal is to create effective countermeasures to these threats. The challenge is to do so without negatively affecting the facility’s aesthetics or inconveniencing guests.
Three primary categories of bomb threats should be addressed: improvised explosive devices (IEDs); vehicle-borne improvised explosive devices (VBIEDs); and walk-in suicide bombers wearing explosive vests. The input of a qualified blast engineer should be sought when designing these countermeasures.
In all of these cases, a primary consideration is collapse mitigation. During the Oklahoma City bombing in 1995 , half of the building crumbled within minutes of the detonation of the 5,000-pound truck bomb and caused an estimated 80 percent of the fatalities. Beams, girders, and columns should be carefully designed to prevent a sudden progressive collapse.
As a simplified example of this type of structural failure, the loss of an exterior column should not result in the upper levels immediately giving way. The building connections can be engineered so that even after a major explosion within the facility, the structure will survive long enough to allow occupants to evacuate.
The facility should be hardened at vulnerable, critical, and high-risk locations, especially areas where security and life-safety systems are vulnerable. In the security command center and throughout the hotel, electronic systems supporting security operations should be designed to survive a detonation. Adequate sources of emergency electrical power should also be incorporated into the design.
Designers should consider the use of pressure-release walls to direct blast overpressures away from areas where there would normally be a lot of people. (Overpressure is the pressure caused by the explosion that is over and above the normal atmospheric pressure. That is what constitutes the bomb blast or shock wave. At a certain level, it can shatter glass . At another level, it can cause catastrophic organ failure and instant death.) They should also carefully consider where emergency assembly areas will be outside of the hotel following either an interior or exterior blast. These areas may be the planned location for a delayed secondary detonation, either by another bomb or by a suicide bomber—a recent evolution of terrorist tactics. To help defend against this, all possible post-primary incident assembly points should be away from areas with a lot of glass.
The building’s windows, frames, and walls can be designed to withstand higher PSI (pounds per square inch) loads on the basis of a blast analysis. The amount of glass in exposed facades should be reduced or the orientation of glazed areas changed to minimize the effects of blast overpressures.
Glass shards cause the majority of injuries during a bombing. Laminated glass is the preferred glazing to reduce shards. It should be used for all glazing, especially at vulnerable locations, such as external walls near streets where a truck bomb could be parked. This type of special glass consists of layers of glass held together by interlayers of sticky materials like polyvinyl butyral.
Another way to mitigate the risk of shards is to cover windows on the inside with window treatments, such as blast curtains. Film appliqués can also be applied to prevent or minimize flying shards by retaining the shards on the film. This is, however, the most expensive option because the film must be periodically replaced due to normal wear and tear.
Setback. Outside, there should be as great a distance as possible between the facility and the likely positioning of VBIEDs, because the overpressure or blast shock wave gets weaker as it travels. Known as “setback” or “stand-off,” the importance of this distance to mitigate the effects of explosions cannot be overstated, but it is equally important to acknowledge its limitations.
It is not widely publicized that setback standards and guidelines are usually based on comparatively small explosive-charge weights. The U.S. federal government restricts revealing the amount of TNT-equivalent explosives used to calculate minimum acceptable setback distance, therefore, it cannot be revealed here. It must suffice to say that it is a low figure. As a result, private-sector enterprises meeting these setback standards in good faith can be operating under a dangerous false sense of security.
The setback distances required to adequately protect against large bombs can be great. For example, a safe setback for a large truck filled with 4,000 pounds of explosives may be more than 900 meters (or slightly more than half a mile). The attack on the Islamabad Marriott involved at least one ton of explosives and large charge weights have been employed by terrorists in other attacks, such as 10,000 pounds in the attack against the Khobar Towers in Saudi Arabia in 1996.
As noted, the idea of the setback is to put the building out of the range of the explosive blast or shock wave as much as practical. The effects of explosive overpressure are calculated on the basis of the inverse of the cube of the distance apart. Because the value is cubed, the destructive effects of a blast lessen exponentially as distance increases. Therefore, every meter of setback is vitally important. This said, such massive setbacks are unrealistic for many project sites, especially in dense, urban environments.
Optimal setback is rarely achievable, but other design elements can help to mitigate the risk. All vehicle ingress and egress routes, including the delivery and loading dock, trash pickup area, and guest and visitor parking locations should be planned to minimize the effect of VBIEDs. If possible, roadways that are perpendicular to the hotel should be blocked because of the high speed an approaching vehicle could attain. A location where vehicles can be inspected should be established at a safe distance. The distance between this vehicle control point and hotel entry points should be as great as possible.
Another facet of the design should be a hardened and protected post from which armed security officers can monitor the vehicle control point without likelihood of being entirely suppressed during an attack. Yet another part of the plan might be to subtly design vehicle entry control points that “lock-in” vehicles while they are being inspected and the driver’s credentials are being examined.
Designers should avoid creating underground parking beneath the hotel. For the possible consequences, we only need look to the 1993 attack on the World Trade Center when a 1,336-pound truck bomb was detonated below the North Tower, beneath the lobby of the Vista Hotel. If an underground garage can’t be avoided, robust columns and thicker upper floor slabs in parking areas should be used and connections made more ductile. Beyond design would be policies and procedures that control access to the garage as well as monitor for suspicious activity.
None of this has to appear to guests and visitors as overwhelming security. For example, hotel staff drivers at the control point could take over arriving vehicles, including those of guests who have chauffeurs. This can be presented as a service while it simultaneously allows security to carefully inspect the vehicles and to control their movement. It also allows the hotel to control all vehicles entering underground parking. This practice was implemented by the Vista Hotel following the 1993 New York City World Trade Center bombing. Most guests welcomed the valet parking and being treated like VIPs and only a few recognized it as an antiterrorism countermeasure.
The architecture and engineering design process can mitigate the risk of armed attacks using many of the same countermeasures applied to bomb threats. There are, however, some critical additional design criteria to address this specific threat.
The property boundary should be studied to discover any feature that might enhance or hinder both terrorists and counterterrorism response forces. These features may include bodies of water; natural barriers such as boulders, hedges, and bushes; and topographic features such as hills or culverts. One high-concept idea to assist counterterrorism forces is to include secret entrance routes from the perimeter, as well as interior passages, for use in a terrorist hostage taking.
Additionally, the A/E design plan can include thermal imaging cameras to view heavily foliated areas of the perimeter as well as to monitor the status of vehicles parked close to the property. These thermal cameras can monitor the temperature of the engine compartment to detect whether a vehicle has been there many hours or was recently parked. This technique was effectively used by the World Trade Center before 9-11.
Barriers. Barriers and other design features can be used to prevent vehicles from crashing through the perimeter. Any barriers should be matched to the likely weight and speed of the attacking vehicle. The highest rated barriers—for example, those that have earned a K12 certification from the U.S. Department of State—are expensive and not needed if the only vehicles that could possibly access the area are less than 15,000 pounds in weight or if they could not attain a speed of 50 miles per hour due to the design of the roads leading to the facility. Robust overhead physical barriers can also be designed to prevent large trucks from entering areas intended only for passenger vehicles.
Vents. A flexible HVAC design can be used both for quarantine and for venting contaminants. HVAC air intakes should be placed either high on exterior walls or on the roof to make it more difficult for a terrorist to use those openings to carry out a chemical or biological attack. Airtight smoke dampers should be designed to allow security to remotely shut down or change air circulation.
Water. Potable water systems should be protected and fire water storage should be tapped in a way that preserves enough water for fire suppression but also allows for emergency potable water. Enhanced protection of fire system controls can be provided so that an alarm is annunciated if attackers attempt to shut down sprinkler and fire detection systems. On-site fuel storage should also be protected.
Covert features. A high-concept idea is the use of concealed remote-control security doors to allow certain areas of the hotel to either lock out invading terrorists or to lock them in to prevent them from reaching other guest areas. Another is to install entirely concealed video cameras with audio capabilities to allow responders to view the actions and movements of any persons who have taken over the hotel and are holding hostages.
Whether the plot calls for a VBIED or an armed attack, terrorists usually spend many weeks, if not months, carrying out surreptitious surveillance and rehearsals beforehand. Terrorists use both fixed and mobile positions to watch the intended target. To possibly gain forewarning, static posts can be designed for use by hotel security officers trained to recognize such surveillance . If this is not possible, dedicated CCTV cameras with analytic software can be used to monitor contiguous areas that may be used by terrorists for surreptitious surveillance. Security could also use automated vehicle license plate reader cameras and intelligent video analytics to spot vehicles that repeatedly drive by the property.
Line of sight. Designers should avoid convoluted designs for the face of the building and for interior corridors and entrances. Each hidden alcove, kink in a corridor, and recess in exterior walls might require a video camera at an average installation cost of $5,000 or more. Moreover, security guards are more effective when they have an unimpeded line of sight and can view clean, clear areas.
Hotels will remain terrorism targets for the foreseeable future. But with creative design and careful planning, they can mitigate the risk without ruining the lodging experience that guests seek.
John J. Strauchs, M.A., CPP, owned and operated a professional security and fire protection engineering firm for 23 years before starting his current private practice. Strauchs helped develop the U.S. Department of State, Office of Diplomatic Security, Antiterrorism Assistance training program for foreign law enforcement agencies. He is a member of the ASIS International Council on Hospitality, Entertainment, and Tourism.