BY ADAM K. THIEL AND KATHERINE IVEY THIEL
All across the United States, in cities large and small, so-called “Tech Hotels”1 are springing up to support the continued Internet, wireless, and telecommunications booms. New buildings are being constructed and existing ones renovated to house the vast arrays of switches, routers, servers, cables, and other hardware required to send and receive data through cyberspace. These data centers are called “Tech Hotels,” since, customarily, the space is rented to occupants on a short- to long-term basis. A vital part of the growing E-commerce infrastructure, they present significant challenges to fire departments that protect them. Some important firefighting considerations for this type of occupancy are outlined below, as are practical suggestions for safe operations within them. Of course, nothing can replace early identification and preplanning of such facilities located in your community.
 Photo 1 |
BUILDING DESIGN
Data centers are typically quite large; they may be located in almost any type of structure and are operated by specialized private firms for the most part. According to industry expert Salomon Smith Barney’s estimates, the gross estimated capacity of data centers worldwide will almost triple in 2001, from the current 15 million square feet to 45 million square feet!2 This expansion will be concentrated in the United States, and many cities across the country are eager to occupy previously vacant buildings of all shapes, sizes, and construction types with these types of facilities.
The ideal data center structural design features a large, open floor plan; limited entry and exit points; few or no windows; easy access to cables running across, above, under, and between floors; high-capacity heating, ventilation, and air conditioning (HVAC) systems; heavy-duty utility (gas and electric) service; backup power capability; close proximity to external, high-speed fiber-optic data transmission lines; thick walls, floors, and roof to limit outside radio and electromagnetic interference; and fixed fire protection systems. It is also desirable for data centers to be located near potential customers, including almost any organization needing high-volume, direct access to the Internet.
Photo 1. This FM-200T clean-agent extinguishing system protects only this customer’s space and operates independently of the overall building fire protection system. (Photos by author.)
 Photo 2. |
ENTRY AND ACCESS
Security systems. Because of their critical nature, data centers can be extremely high-security installations. Often, these centers are located in nondescript buildings that show no obvious or outward indications of the center’s presence. In addition to sophisticated entry control systems (including fingerprint, voice recognition, and even retinal scanners), video surveillance, intrusion detection devices, and 24-hour armed security personnel may be present. Since some of the individual companies leasing space at a given site are potential competitors, it is likely that the data center contractor’s security officers will not have access to every space in the building. Getting through the front door is only part of the access challenge; you will probably have to force inside doors secured with a range of high-security hardware, anything from tubular deadbolts to electromagnetic and cipher locks.
Photo 2. Because of high rental and operating costs, data centers are crammed with computer hardware. Although most data centers have fixed fire protection systems, in a renovated structure, the rapidity of fire spread and intensity of a fire involving racks of computer equipment may overwhelm the original fire protection system design.
Interior layout. Interior spaces may have separate rooms or chain-link cages filled with computer hardware. Use extreme caution if you have to breach a wall adjacent to an interior door to gain access, since high-voltage electrical equipment could be located on the other side of the breaching point. Also, do as little damage as possible during operations, since the data center’s equipment is quite expensive and may contain irreplaceable data, without which a company cannot do business.
Interior layout. Interior spaces may have separate rooms or chain-link cages filled with computer hardware. Use extreme caution if you have to breach a wall adjacent to an interior door to gain access, since high-voltage electrical equipment could be located on the other side of the breaching point. Also, do as little damage as possible during operations, since the data center’s equipment is quite expensive and may contain irreplaceable data, without which a company cannot do business.
Preplanning. As with any type of target hazard, it is ultimately the fire department’s responsibility to identify prior to an emergency data centers in its jurisdiction. Contact the owners/occupants to share concerns and devise preincident response plans that account for the firefighters’ operational and life safety concern and the data center occupants’ business continuity issues.
FIRE PROTECTION SYSTEMS
Most structures that house data centers, whether new or renovated, are equipped with sophisticated fire alarm and protection systems. Whatever the type of system required within your jurisdiction, be aware that companies leasing space within a center may have their own completely separate fire detection and notification systems. So, don’t be surprised if on arrival at a data center you are greeted by a security official who tells you “nothing’s wrong.” Conduct a thorough investigation on every call, since the building occupants may or may not have notified security.
Fire protection systems may include automatic wet- or dry-pipe sprinklers, but because of the sensitive nature of the equipment protected, the fire protection system may more likely be a preaction sprinkler, water-mist, or clean-agent system. Clean-agent halon alternatives such as FM-200T (see sidebar) are popular; you might also find carbon dioxide (CO2) flooding or older halon systems (in critical government or military applications) still in use. To prevent the possibility of getting trapped and asphyxiated inside a room with a clean-agent system, always wear full structural firefighting gear and positive-pressure SCBA to any incident (including suspected false alarms) in a data center.
SEARCH CONCERNS
Life hazard. The Internet’s global nature means it is “on” 24 hours a day, 365 days a year. Expect data centers to be occupied any time, day or night. Security personnel and network engineers can be found on-site around the clock and may be located deep within the building. Security personnel usually maintain building access logs, which you should quickly locate and use to determine the severity of the life hazard present at any given time.
Large, multistory data centers contain many occupants with no rhyme or reason for their comings and goings. No matter what the entry log says, in a fire or clean-agent system activation, firefighters must perform a primary search of all spaces within the building to ensure occupants are safe. On-site security guards are perhaps the best source of information on who and what is inside the building, so have them stay near the command post throughout an incident.
Alarm delays. An on-site security force may give building occupants a false sense of security and increase the potential for delayed notification if security personnel check on the validity of an alarm before calling the fire department. Identify and address these issues before an incident through education, preplanning, and code enforcement. The well-sealed construction of these buildings will often prevent fire and smoke from showing on arrival. Do not be complacent; the potential for hidden fire and rapid propagation is very real.
 Photo 3. |
OPERATIONAL CONCERNS
Toxic atmosphere. The hardware within a data center represents a significant fire load. Most of the components are constructed of various plastics with varying degrees of combustibility. All have relatively high rates of heat release and produce extremely toxic combustion products including heavy metals such as cadmium and arsenic, aromatic hydrocarbons, and polyvinyl chlorides (PVCs). Computer equipment involved in fire may create large volumes of heavy, acrid smoke, even in a relatively minor fire. For this reason and because of the expensive equipment involved and the vital data stored, firefighters should bring inside a selection of portable extinguishers including dry chemical and CO2. Even though most of these buildings have fixed fire protection systems, in a renovated structure, the rapidity and intensity of a fire involving racks of computer equipment may overwhelm the original fire protection system design.
Photo 3. Narrow aisles and exposed cabling present firefighters with a severe maneuvering challenge and entanglement hazard.
Large fire volume. Data centers are often constructed with large, open floor plans that can allow fire to spread unchecked away from the point of origin in a relatively short time. Considering the necessary response time to arrive on-scene, make entry through multiple security layers, and locate the fire, be prepared for a large volume of fire, and select an appropriately sized attack line. This is difficult since, given the high rental costs typical of such facilities, equipment will be tightly packed and maneuverability will be a primary concern. Floor-to-ceiling racks of servers, routers, and switches make the interior of a data center maze-likeoften with only one combined entry/exit. Interior crews operating away from the hoseline must use disciplined search techniques or risk getting lost with little chance of finding a window or unsecured exit door from which to escape. Strict personnel accountability and crew integrity are vital for ensuring member safety.
Void hazards. Hardware components inside data centers are connected with thousands of feet of cable, with additional cable running outside to buried fiber-optic lines. The cabling inside a data center may run in raceways along the walls, in a drop ceiling, or underneath a raised floor. The latter are especially common and present a severe hazard to unwitting firefighters. Fire spread can occur rapidly within void spaces containing cables that run between remote areas and floors. Network engineers may also enter spaces under the floor to run cable. Even under nonfire circumstances, cabling presents potentially severe entanglement and electrical shock hazards.
Building construction. Year-round climate control is required for reliable operation of temperature and humidity-sensitive computer equipment. Data centers will likely have more roof-mounted HVAC units than their general office counterparts, thereby increasing roof loads. Expect satellite dishes and other instruments also. Newer buildings may often feature concrete “tilt-up” construction; expect metal bar joist trusses supporting a built-up roof. Since roof leaks can damage computers, look for an added “rain roof” over the original roof, which further increases the risk of hidden fire spread in the cockloft.
Data center roofs may have additional reinforcement to support HVAC units and help prevent external interference from electromagnetic radiation. For the same reason, and to promote security, data centers usually have very few doors or windows. Windowless structures are common, and some may even have “false” windows veneered onto the outside of the building to blend in with the architecture of the neighborhoods in which they are located.
Obviously, the combination of reinforced roofs with minimal horizontal openings makes ventilation difficult; consider positive-pressure ventilation. As with any type of occupancy, all bets are off when a data center is located in a renovated structure. Preplanning is essential for determining the specific types of building construction hazards present.
Utilities. Utility service to data centers is extremely heavy-duty. Three-phase electrical utility service is likely, along with high-pressure natural gas or propane service. Utility control should be accomplished with great care, since service interruption can profoundly impact occupants’ businesses.
Furthermore, don’t assume that utilities controlled “at the pole” or “in the street” are entirely shut off until this is confirmed from the inside. Backup power is essential for data centers, and backup generators will often have enough capacity to maintain operations for hours. Backup generator fuel supplies may be diesel or natural gas; both present hazards for responders. Remember that if utility control is absolutely necessary, backup power supplies must be taken down as well.
For further redundancy, individual machines inside the building might also be connected to uninterruptible power supplies (UPSs) consisting of large batteries that can continue to supply power. Don’t let the size of computer hardware components fool you; they can pack a lot of juice. Consider everything live with the potential to kill until confirmed otherwise at the point of potential contact. This is especially true if water is the extinguishing agent.
Communications. Two-way radio communications from inside a data center may be hampered by thick walls, the absence of building openings, and shielding added to prevent electromagnetic and radio frequency interference. Identify these conditions prior to an incident.
Data centers are vital to the worldwide economy of the digital age. While firefighter safety is the principal concern at these high-tech facilities, they also demand a “high-touch” approach.
 Photo 4. |
Salvage should be an initial tactical objective after life safety and fire containment. Furthermore, incident commanders should attempt to communicate early (ideally, during preplanning) with building occupants to determine where to focus salvage efforts. Restrict the use of water for fire extinguishment; use only what is necessary, limiting so-called “hydraulic overhaul.” After initial knockdown and completely stopping fire spread, limit the use of extinguishing agents until completion of salvage efforts in the immediate fire area. Protect sensitive equipment in adjacent rooms and on floors above and below. Properly conducted salvage inside a data center may be very labor-intensive, but the positive effects on business continuity and goodwill are immeasurable.
Photo 4. Many data centers have raised floors under which there may be miles of cable. Cables may also run in raceways along the walls or inside dropped ceilings. Fire spread can occur rapidly within these void spaces that run between remote areas and between floors. Network engineers may also enter spaces under the floor to run cables. Even under nonfire circumstances, cabling presents potentially severe entanglement and electrical shock hazards.
The key to safely and effectively mitigating an emergency incident in a “Tech Hotel” is the same as that for any other high-value target hazardpreplanning saves lives. Even if your department is in a suburban or rural area, data centers will be in your future.
Endnotes
1. Spinner, Jackie. “Tech Hotels Check In,” The Washington Post, Business Section, H1, 12/10/2000.
2. Ibid.
ADAM K. THIEL, MPA, NREMT-P, is a career lieutenant with a major metropolitan fire and rescue department in northern Virginia. He is assigned to a hazardous materials/heavy rescue company and is currently pursuing a Ph.D. in public policy at George Mason University.
KATHERINE IVEY THIEL is a former volunteer firefighter/EMT and works as a product manager with a large Internet services firm located in Fairfax County, Virginia. She graduated from Duke University and has a master’s degree in information systems from the University of Virginia.
FM-200T FIRE EXTINGUISHING AGENT
Fire protection engineers currently have a range of clean extinguishing agents for sensitive applications such as protecting the computer hardware found in “Tech Hotels.” One typical agent used in many data centers is FM-200®, manufactured by Great Lakes Chemical Corporation.
The chemical name for FM-200 is 1,1,1,2,3,3,3-heptafluoropropane. It is a halogenated alkane with the chemical formula C3HF7. Stored in cylinders and activated by a preaction-type alarm system and/or a manual pull station, FM-200 is usually discharged from ceiling-mounted nozzles, since it has a relatively high vapor density of 6.04 (Air=1.00). It is an odorless, colorless, nonflammable gas. A local alert warning occupants to exit immediately should precede system activation. Although the agent itself is considered nontoxic, it will rapidly displace the oxygen in an enclosed space, causing asphyxiation. Under fire conditions, FM-200 may thermally decompose to produce corrosive, toxic, or asphyxiant gases including hydrogen fluoride, carbon monoxide, and carbon dioxide. To protect firefighters from asphyxiation and the by-products of FM-200 thermal decomposition, positive-pressure SCBA must be worn throughout any emergency incident, including during overhaul.
NFPA 704: 1-Health, 0-Flammability, 0-Reactivity, 0-Other.
UN ID Number: 3296.
Hazard Class: 2.2 (nonflammable, nontoxic compressed gas).
Source: Great Lakes Chemical Corporation, Material Safety Data Sheet Number 00057, 4/7/98.
