Tunnel Trouble
A spate of recent fire and smoke incidents in Washington, D.C.'s Metro system highlights fire and life safety concerns in subways worldwide
BY ALEXANDER REID
ON January 12, 2015, a Virginia-bound Yellow Line train in Washington, D.C.’s Metrorail subway system left the downtown L’Enfant Plaza station, one of the system’s busiest, and headed for Pentagon Station. It was early in the afternoon rush hour, and the train held about 380 passengers.
About 800 feet beyond the L’Enfant Plaza station platform, the train stopped abruptly due to smoke in the tunnel, according to a report from the National Transportation Safety Board (NTSB). The smoke became heavier as the train sat in the tunnel, and began to seep into the cars. Passengers began having problems breathing, and some shared inhalers. Some people collapsed, and a 61-year-old woman from Alexandria, Virginia, died. In total, 91 people were injured, most from smoke inhalation, including passengers, emergency responders, and employees of the Washington Metropolitan Area Transit Authority (WMATA), according to the NTSB report. The cause of this “smoke accident,” according to the scathing NTSB report, was a fire triggered by electrical arcing from the high-voltage third rail. The short circuit had gone undetected and unrepaired because of what NTSB termed “WMATA’s ineffective inspection and maintenance practices.”
While the fatality and injuries made the event exceptional, it was far from isolated: smoke and fire are regular occurrences in D.C.’s Metro system. According to a recent WMATA report, roughly 50 smoke and fire incidents were reported in the system during the first three months of 2016. Another source, IsMetroOnFire.com, compiled through Twitter, reports more than 70 incidents during that period.
Washington, D.C. isn’t alone. Across the country and around the world, smoke and fire are common hazards in subway systems, with thousands of incidents reported annually. In April, subway service on Pittsburgh’s Port Authority T was disrupted by an electrical problem in a tunnel. Thousands of commuters in Toronto were affected by a fire at a subway station in May, days after yet another subway fire in Washington, D.C., that set off a chain of rush-hour delays.
While many incidents are minor—loss of life in these facilities is rare, according to NFPA data—others require large-scale evacuations of platforms or stations. NFPA 101®, Life Safety Code®, characterizes platforms and stations as assembly occupancies, with provisions requiring egress systems that facilitate a rapid and efficient evacuation in an emergency. NFPA 101 also works in tandem with NFPA 130, Fixed Guideway Transit and Passenger and Rail Systems, which specifies fire protection and life safety requirements for underground, surface, and elevated fixed guideway transit and passenger rail systems and includes guidelines on fire protection requirements and emergency ventilation systems.
A number of changes have been made to the 2017 edition of NFPA 130 to further improve the standard and help mitigate hazards associated with fires and other hazards in subways. (A consent document in this revision cycle, NFPA 130 has been forwarded to the Standards Council for issuance; the issuance date for consent standards was May 13, with an effective date of June 2.) “The technical committee’s unyielding mission is to provide ridership with safe, reliable, and cost-effective transportation services,” says Harold Levitt, PATH–WTCC Design & Construction Liaison for the Port Authority of New York and New Jersey and chair of the Technical Committee on Fixed Guideway Transit and Passenger Rail Systems for NFPA 130. “The standard is the only all-encompassing rail transit and passenger fire and life safety standard in the world that incorporates all of the components of a fixed guideway transit and passenger rail system within its covers.”
Maintenance vs. Ridership
To address the problem of fires and other technical issues in the system, in March the D.C. Metro took the extraordinary step of closing the entire system for a day to conduct inspections and make repairs.
According to published reports, 27 instances of problems related to power cables or connections were discovered and fixed during the inspections, issues that were related to those believed to have caused the deadly smoke incident in 2015. In April, another fire disrupted service and forced the evacuation of passengers from smoke-filled subway cars, but the Metro determined that the event was caused by “a metal part of a rail car becoming dislodged and making contact with the electrified third rail.”
In its report on the 2015 incident, released in May, the NTSB revealed how an aging infrastructure, flawed safety response, and oversight deficiencies on the part of local and federal agencies all contributed to the event. It pointed to the district’s beleaguered WMATA system for failing to properly install and maintain third-rail power cables, causing them to become damaged by water and other contaminants. NTSB also faulted Metro for a lack of smoke detectors in its tunnels, for ventilation fans that didn’t work properly, and for not training its employees on how to use the fans. It also blamed D.C.’s fire department and its 911 call center for delays in responding to the fire. Dispatchers took more than four minutes to send out emergency crews; radio service was so unreliable that emergency teams resorted to runners, and a Metro worker sent one crew down the wrong tunnel. Passengers waited on the smoke-filled train for more than 30 minutes before the first emergency responders arrived.
Passengers and firefighters aboard a subway train affected by a "smoke crisis" in Washington D.C., in January 2015. One person died and scores were hospitalized in the incident. An NTSB report found that smoke was pulled into most of the cars through their fresh air intakes. Photograph: Getty Images
Incidents like the D.C. fire have transit agencies, municipal officials, and fire officials around the country taking a closer look at the safety features of subway systems in their own communities. According to a 2013 report card on the nation’s infrastructure compiled by the American Society of Civil Engineers (ASCE), rail systems are some of the oldest assets still in use, especially heavy rail systems in cities like New York, Chicago, and Boston. (Boston has the oldest subway tunnel in the country that is still in use, dating from 1897. The subway system, known as “the T,” is also one of the most financially distressed transit agencies in the country, The American Prospect reports. The nation’s fifth-largest mass transit network has about $9 billion in debt and a maintenance backlog of about $7 billion.) Rail systems have also become a major area of growth in recent years, especially in light rail projects like those constructed in Denver, Salt Lake City, Charlotte, and elsewhere.
Whether dealing with aging or newer systems, transit authorities are facing a major financial challenge to keep their systems in good working order. The ASCE report card found that rail-based systems carry just over a third of all transit trips (35 percent) but have the greatest maintenance needs of all transit modes, with a backlog of $59 billion compared to $18 billion for nonrail systems. In addition, these systems have larger-than-average annual normal replacement needs, the annual costs required to maintain a state of good repair—$8 billion compared to the average of $6 billion across all other modes of transit. Compounding the maintenance costs is the problem of some transit agencies failing to conduct regular assessments of their systems to monitor conditions and identify potential problems.
A more troubling perspective on the issue of fire protection in subways and tunnels—unrelated to maintenance problems or financial issues—emerged from a recent Bloomberg News review of the Global Terrorism Database, a compendium of incidents dating back to 1970 that is housed at the University of Maryland. It revealed scores of attempted bombings, shootings, and other attacks that took place in recent years across every mode of transportation, rail and subway included, in the United States, Canada, and Western Europe. The database did not include recent terrorist plans to bomb subway systems in New York and Washington, D.C., because the attackers were arrested before planting the explosives. It did, however, cite an incident in 2011 where police near Philadelphia found an improvised explosive device adjacent to tracks that carry Amtrak trains and a commuter rail line.
Commuters in Toronto crowd onto a platform after fire affected one of the city's subway stations in May. Photograph: Graeme Roy/The Canadian Press via AP/Wide World
These conditions persist at a time when Americans increasingly favor public transportation options in a way that they haven’t in decades. According to the American Public Transportation Association, Americans took 3.9 billion trips on subways, defined as heavy rail, in 2015.
Jeff Tubbs, chair of NFPA’s Assembly Occupancies Technical Committee and a principal at the global engineering firm Arup, stresses the importance of code adoption and enforcement as critical tools for communities developing public transportation resources. “As communities, both nationally and internationally, move forward with expanding, renovating, or building transit systems, our hope is that our standards on design and life safety features will be adopted,” Tubbs says. “Those standards are robust and comprehensive.”
Key changes to NFPA 130
During preparation of the first edition of NFPA 130, which appeared in 1983, several significant fires occurred in fixed guideway systems. The committee noted then that the minimal loss of life in those incidents was due primarily to chance events more than any preconceived plan or the operation of protective systems.
The current committee seeks to build on the original safety requirements, with important proposed revisions including:
→ To test ventilation systems, reliability analysis will be conducted with one fan out of service. With this provision, expert analysis can determine if the system can meet its ventilation objectives during testing.
→ Under emergency procedures, the relationship between the transit system’s operations control center (OCC) and command post will be specified with a clear division of responsibilities.
During normal operations, the OCC will maintain primary control for the operation and supervision of the transit system.
During emergency operations, the command post will be established at the scene of the emergency to control supervision and coordination of personnel and equipment working to correct or alleviate the emergency.
The OCC will maintain its responsibility for operation of the transit system except for the immediate emergency area. The command post and OCC will coordinate to have efficient operation.
→ Agencies such as fire, police, ambulance, and medical service will use direct telephone lines or designated telephone numbers to contact the OCC during emergencies involving the transit system. The OCC will identify the location of the incident, whether third-rail power has been shut off, the function of the ventilation system, and many other topics.
→ The OCC represents the vital hub of the transit system’s operation and communication. It should be located in an area separated from other occupancies by two-hour fire-resistant construction. In the event that the primary OCC is out of service, an alternate OCC location will be provided.
→ An emergency communications system will be designed, installed, commissioned, inspected, tested, and maintained in accordance with NFPA 72®, National Fire Alarm and Signaling Code. The objective here is to create a more robust system and eliminate inconsistencies that exist between the older NFPA 130 requirements and what is required by NFPA 72.
→ Equipment will be available and used for recording radio and telephone communications during an emergency. Recorded information can be used for post-incident debriefing.
While these changes are substantial and address important issues for transportation systems, Levitt says the technical committee is already looking ahead at possible future changes to NFPA 130. Ideas under consideration for the 2020 edition of the standard include further development of methods for incorporating on-board fire suppression systems onto vehicles; development of a standardized way to formulate fire heat-release rates for vehicles; and additional methods for safe ways to exit stations during emergencies. “The standard is for new construction and it provides guidance for the rehabilitation of older tunnels and stations should the operator adopt it in that manner,” Levitt says. “Like all other NFPA standards and codes, NFPA 130 provides minimum requirements. It’s incumbent upon the designers, operators, and authorities having jurisdiction who are involved in the planning and development of a project to meet or beat those requirements.”
Alexander Reid is a writer in Boston. Top Photograph: Newscom