Staying Connected

The following article appeared in the July/August, 2000,  issue of NFPA Journal.
©2000 NFPA Journal. Used with permission

NFPA 76, Telecommunications Facilities, is one of the newest documents to be proposed in the NFPA codes- and standards-making system, created in response to the telecommunications industry’s need for a consensus-based document that addresses the unique fire protection requirements of telecommunications facilities.

The telecommunications industry is growing, changing, and evolving at an astounding pace, thanks in large part to the Telecommunications Act of 1996, which deregulated much of the industry and allowed companies to expand into a variety of arenas in which they hadn’t previously been able to compete. Telephone companies now offer cable services, Internet providers dabble in telephone and video, and cable television companies offer broadband Internet access. On top of everything else, mergers and acquisitions are changing the landscape of the industry. According to Federal Communication Commission (FCC) Chairman Kenneth William Kennard, “The American telecommunications consumer has more choice of providers and services, at faster speeds and at lower prices, than ever before. This is truly the beginning of a new era in which high-speed, broadband access will be as ubiquitous as the dial tone is today.”

According to the FCC, there were 66.7 million cable subscribers in 1998. An estimated 50 million homes had personal computers, and 100 million people were Internet users by 1999. Between 1996 and 1999, the number of Internet host computers had grown from 14 million to approximately 44 million.

In addition, the cellular system grew from 32 systems and 91,600 subscribers in 1984 to more than 3,000 systems and 69 million subscribers in 1998. As the FCC notes in its report, Telecommunications @ the Millennium—The Telecom Act Turns Four, “In 1994, most Americans could choose between, at most, two competitors for their wireless service. Today, 94 percent of Americans have three or more providers in their home market, and over 75 percent have at least five operators competing for their business.” 

The nation’s fiber communications system has also grown, from less than 100,000 miles in 1993 to approximately 225,000 miles today. And the number of homes with additional residential lines grew from 2.3 million in 1988 to almost 18 million in 1997.  This increase was driven, in part, by the growing trend toward telecommuting and increased use of the Internet.

Finally, E-commerce, which depends heavily on a reliable telecommunications infrastructure, has grown from an industry with minimal revenue in the early ’90s to one that generated $70 billion in 1999.

Infrastructure needs

This demand for services requires a highly reliable infrastructure with a low incidence of service interruption caused by fire. To date, fire loss in telecommunications facilities has been relatively low, but the potential impact of a single incident can be enormous (see Table 1). In 1988, for example, a fire in the Hinsdale, Illinois, central office disrupted phone service, including the air traffic control towers at O’Hare International Airport. And the Los Angeles telephone exchange fire of 1994 interrupted 911 service in the city for 16 hours.

The telecommunications industry welcomed the development of a standard that addresses its specific fire protection requirements. Existing building codes don’t address these requirements in sufficient detail, which can sometimes create a conflict between the occupancy’s code requirements and the specific needs of a telecommunications facility. 

One example of such a conflict concerns sprinkler protection. While sprinklers are often appropriate in an office building, sprinkler protection in a telecommunications room may be inappropriate because the fire potential of the equipment is low compared to the damage water can do to the equipment.

“One of the reasons for developing this standard,” says Mike Madden, a principal with Gage-Babcock and Associates and a  member of the Telecommunications Committee, “was that the larger telecommunications companies have had good fire protection policies in place for a long time, but in dealing with local code authorities, there are requirements for sprinklers and other issues that may not apply in telecommunications. They can use the telecommunications standard as a reasonable alternative.”

The NFPA committee developing NFPA 76 brought together a number of people to provide critical input. 

“We felt we would take the experiences of the major providers,” says Ralph Transue, senior vice president for RJA and committee chair. Chuck Yaunches, another committee member with Bell Atlantic, adds, “A lot of people looked into the standard, especially from the telecommunications company perspective, thinking they had the answers. However, a lot of them walked away with some changed ideas and concepts. This committee became a medium for sharing the best practices among companies.”

Overview of the standard

NFPA 76 is divided into 10 chapters, with an appendix that provides explanatory material. Chapter 1 contains the scope, purpose, applicability, design options, and definitions.

Chapter 2, entitled “Risk Considerations,” provides the reader with guidance in evaluating the impact of the loss of a particular service,  from cable to 911 emergency communications. Once the standard’s user determines the level of risk involved in his or her facility, he or she can begin to define the appropriate level of fire protection.

Years ago, this level of fire protection generally meant designing telecommunications facilities that could withstand any environmental catastrophe nature could throw at them.

As Ron Marts of Telcordia notes, it was often said that, “the only thing left after a nuclear explosion would be cockroaches and central offices.” Today, it’s not only a case of building a strong infrastructure, but of building redundancy into the system, as well. Even if a building or facility is severely damaged by fire, the redundant routes and facilities built into the system make it possible to restore a customer’s service with little or no interruption.

“Historically, there’s been the big building down the block that’s the telephone company central office,” says Yaunches. “Same with the cable industry. Now, they’re dispersing the offices in the cable industry, and the same thing is happening in the telephone industry.” 

This is because “the value of the service is more important than the equipment itself,” according to Madden. “The protection is geared toward the service.”

However, Yaunches points out that certain tradeoffs must be made. While redundancy spreads out the risk and reduces the potential that a catastrophic event will bring down the whole system, detection and response criteria become more stringent. Response to these facilities becomes critical. 

Chapter 3, “Performance-Based Approaches,” provides guidance on performance objectives, performance criteria, fire scenarios, methods of assessing performance, and documentation requirements.

Perhaps one of the more significant features of NFPA 76 is that it was developed with a performance-based option, as well as a prescriptive design option. According to NFPA 76 staff liaison Mark Conroy, the committee had always wanted this.  

The industry is changing so rapidly, it’s difficult to predict what the future will bring in terms of facilities, so a performance-based design option was important.

 “We can’t know what future facilities are going to be like,” says Transue. “We can describe the goal of uninterrupted service…If you can describe the maximum fire size or interruption, then the fire protection scheme can be matched to the performance requirement.”

Chapters 4 and 5 provide protection criteria for small and large telecommunications facilities, large facilities being those over 2,500 square feet (232 square meters) and small facilities being those under. According to committee member Bruce Fraser, business development manager for Simplex, facilities were divided by size to allow the committee to address the different hazards from different perspectives.

 “In large buildings, such as central offices, you have building separation that allows you to put the switchgear in a different compartment than some of the hazards,” he notes. “In a smaller one, all of the different hazard areas are included in one room without any separation within them.”

Chapter 6, “Fire Protection Elements,” deals with passive fire protection measures, such as fire barriers and compartmentation, and the various types of fire alarm features, such as alarm processing and fire detection systems. Automatic suppression systems are also covered, including fire sprinkler systems, clean agents, halon, and water mist fire protection systems.

Sprinklers in telecommunications facilities are a great concern because telephone switchgear doesn’t react the same way a typical computer does when it’s sprayed with water. 

“It’s possible to dry off a computer and get it operational again,” says Marts. “With telephone switchgear, if it gets hit by water, it loses its programming and it’s down.”

According to the Federal Communication Commission’s 1993 report Network Reliability: A Report to the Nation, the corrosive damage water causes when used as a suppression agent in telecommunications areas containing powered electronic equipment can be as extensive as that caused by a fire or corrosive smoke.

When the effect of water on electronic telephone equipment became apparent in the wake of the Hinsdale fire, the state of Illinois formed a committee to determine how to avoid another catastrophic service interruption. As a result, sprinklers are now required in non-equipment spaces of telecommunications facilities in Illinois, but not in the equipment areas.  Transue feels that this could become a pattern for the future.

Before sprinklers even become necessary, however, a facility’s early detection systems should provide warning of a problem. Aspirating smoke detection systems are used to detect the smoke generated by small fires early enough to initiate a quick response. If the fire can be detected in its earliest stages, potential damage can be minimized by an action as simple as unplugging the involved piece of equipment.

Smoke management is another critical component of any fire protection design, because it’s often the smoke that causes significant damage, not the fire itself. According to the Network Reliability report, an estimated “95 percent of the fire damage in telephone central offices is attributed to the smoke products, and only 5 percent is caused by the thermal effect of fires.” One reason for this is that burning equipment and cabling gives off hydrochloric acid (HCL).

In the Hinsdale facility, fire damage was limited to an area of 30 by 40 feet (9 by 12 meters), but the report prepared by the Illinois Office of the State Fire Marshal and the Illinois Commerce Commission noted that “the smoke and combustion by-products from burning cable insulation penetrated the entire building,” irreparably contaminating much of the communications equipment.

Chapter 7, “Fire Prevention,” which focuses on the steps one can take to prevent a fire from starting in the first place, attempts to identify potential ignition sources and fuel loads, while Chapter 8, “Pre-Fire Planning,” outlines the steps that can be taken up front to minimize the impact of a fire on the building’s occupants, responding firefighters, and the community.

Because depowering equipment may be a critical component of the response, it’s important to identify the electrical service panels that provide the power. A number of facilities use color-coding to help first-responders isolate power to a given area. Anyone entering a facility to isolate the “blue” switchgear can simply follow a series of blue arrows to the appropriate electrical service panel.

When the first-responder is from an outside agency, such as the fire department, it’s important that they be familiar with the facility’s basic layout and know how best to minimize the damage that may occur as a result of the fire or the suppression efforts.

Indeed, the sheer size of many of these facilities makes fire department orientation critical. In Bell Atlantic’s system, Yaunches estimates there are 2,700 central offices, 6,000 controlled environmental vaults, which are essentially sophisticated manholes, and 4,000 cell sites. To make these facilities more accessible, Bell Atlantic has developed orientation videos and materials for the fire service. Other companies have similar programs to ensure that first-responders have the information they need to allow them to mitigate the damage and ensure continued network operation.

Getting the network operational again following a fire is another critical component of any emergency response plan. In the United States, for example, Bell Atlantic has 15 to 20 cells on wheels (COWs) positioned in strategic locations. Should a cellular site be severely damaged, the nearest COW can be moved into place quickly to restore service. This type of planning can pay off by providing a temporary means for maintaining network service while the permanent repairs are made.

The future

What will the future bring for the telecommunications industry? With the explosive growth of the Internet, the ever-growing number of mergers among communications companies, and the need for more high-speed communications, industry changes are difficult to predict. Jennie Nelson, fire engineering manager for AT&T, believes that telecommunications facilities will be installed in occupancies that don’t typically house them, such as apartment buildings and malls, just to handle the volume of traffic. Because of its performance-based options, however, Transue is confident that NFPA 76 will be able to address any of the demands the future may bring.

Sidebar

When Fire Affects Communication

In  July 1999, a fire in Toronto, Canada, proved just how dependent we’ve become on telecommunications in today’s society. The fire shut down telephone lines, automated teller machines (ATMs), and Internet service—all things we’ve come to rely on in our daily lives—for hours.

According to Walter Schachtschneider, associate director of Risk Control at Bell Canada and a member of the NFPA Technical Committee on Telecommunications, the fire began in an electrical room when four electricians started working on electrical switch gear without shutting down all of the electrical services, as is required in their work procedures. One of the workers allegedly dropped a bus bar 18 inches long and 5 inches wide inside the switch gear cabinet, where it hit the energized bus, causing major arcing. According to a spokesperson for the Toronto Fire Department, the arcing lasted for about 20 seconds, vaporizing many of the switch gear cabinet’s critical components. The heat from the arcing also destroyed other nearby components.

The fire department received the alarm at 7:26 a.m. and dispatched two engines, a ladder, and a command officer. Ultimately, a third alarm assignment, made up of 14 fire units and 56 personnel, was required.

Due to the nature and location of the fire, electrical power to the entire building had to be shut down until the area was deemed safe, which resulted in a partial power failure in the building. Firefighters managed to extinguish the fire, but the water on the floor had to be removed before power could be restored, and the equipment had to be air-dried before it was reenergized. Damage caused by the arcing made it impossible to connect critical equipment automatically to either the commercial or standby power sources.

Although the equipment had battery backups, the batteries were designed to provide power for only  three hours. At about 10:00 a.m., they began shutting down as the voltage dropped, and the service interruptions began.

The biggest disruption occurred in downtown Toronto, where the fire affected approximately 113,000 lines. In addition to the loss of telephone service, the fire interrupted banking and retail operations in the metropolitan area. Store customers couldn’t use their credit cards because credit card transactions rely on telephone lines, and ATM transactions were disrupted when the ATMs, which communicate with their bank’s host computers over phone lines, couldn’t make contact. According to Sharon Wilks from the Canadian Bankers Association, the incident had a major impact on the association’s member institutions.

The incident didn’t directly affect the Toronto Stock Exchange, but a number of brokers were unable to place orders due to the lack of telephone lines. The Derivatives Market, located in the affected area, switched to manual processing at about 2:00 p.m., according to a spokesperson for the Stock Exchange.

The fire also had an impact on the city’s 911 system when the number of lines available dropped. Fortunately, the Toronto Police Department  reported no significant incidents during the outage, and the public didn’t overwhelm the 911 system with general inquiries, as is sometimes the case.

By midafternoon, the damaged switch gear had been bypassed with temporary cabling and breakers, enabling authorities to restore power. As a precaution, the building was evacuated, and fire crews stood by until the electricity was back on. Fortunately, there were no problems, and most service in the area was restored that afternoon, allowing residents to get back to their daily routines.

Ed Comeau is the principal writer for writer-tech.com, a technical writing firm.  He was previously the chief fire investigator for NFPA and a fire protection engineer for the Phoenix Fire Department and Prime Computer.