A Burning Issue: How to Save Lives
Fire has been one of history’s most destructive forces. Conflagrations destroyed ancient Rome in the first century, razed London during the seventeenth century and, more recently in the United States, left 300 people dead and 500,000 homeless as it swallowed up Chicago in the second half of the nineteenth century.
While much progress has been made in containing fire’s destructiveness, it remains a serious threat. The National Fire Protection Association reports that in the United States in 2007 (the most recent year for which final numbers are available), structure fires killed 3,000 civilians. In addition, 15,350 people were injured in those fires.
But fire’s devastation isn’t only calculated in lives lost. The cost to structures in that same year was $10.6 billion.
Then there are the ancillary costs. According to a 2004 National Institute of Standards and Technology (NIST) report, the long-term costs from firefighters hurt on the job total between $2.8 and $7.8 billion in workers’ compensation payments and insured medical expenses each year.
New technologies now in development offer the potential to lessen these losses by addressing such thorny problems as how to track firefighters in a burning building, how to detect fires much earlier, and how to control a raging fire’s path. Here are three of the most promising.
When firefighters run into a burning structure, they enter an alien, hellish world. Flames, heat, and smoke conspire against them, making it easy for them to lose their bearings.
“They become trapped, they become lost, they become disoriented in a fire, they run out of air,” explains Steven Edwards, director of the Maryland Fire and Rescue Institute (MFRI) at the University of Maryland.
One wrong move can spell disaster, and when a firefighter gets lost or trapped, there isn’t much his comrades can do for him without putting themselves in jeopardy. Even when firefighters have tried to rescue colleagues caught in such circumstances, conditions inside the building have bested them.
“[Rescuers] have actually crawled over hurt firefighters and not found them,” says Carole Teolis, CEO of TRX Systems, Inc., an engineering firm working closely with MFRI on personal motion-tracking systems—one technology that may help to solve the problem.
The fire service has long sought the ability to track firefighters as they move through a structure. Tracking would allow for fellow firefighters to come to the assistance of a hurt or trapped colleague. The capability, however, has been beyond technology’s grasp.
Everyone has sought a way to track firefighters—it’s the holy grail of firefighting, says Steve Kerber, a fire protection engineer at NIST’s Building and Fire Research Laboratory. “People have tried step-counting, tried global positioning systems (GPS), tried node networks, and none of these things, even put together, have been able to track a firefighter.”
Another problem firefighter-tracking systems face is how to get the information out of the building and into the hands of the incident commander. Modern buildings, with all their steel, concrete, and electrical interference, make it difficult to create a system that can accurately relay the location of a firefighter inside a structure to the incident commander outside.
TRX Systems and MFRI believe they have found a solution to both tracking and communication: inertial tracking and MESH networks.
Inertial tracking. Historically, inertial tracking systems have been used by the military to track missiles in flight and by NASA to track satellites orbiting in outer space. Such systems use inertial sensors, such as accelerometers, which measure acceleration in a linear direction, and gyros, which measure an object’s rate of turn, to predict and track an object’s trajectory through space.
Humans, of course, are not instruments designed through mathematical models that follow a programmable path. They follow random, unpredictable paths.
“We’re trying to figure out where they are going on little information,” Teolis says. “We can’t predict where they are going to go based on where they went last.”
Complicating the issue is the fact that inertial tracking systems accumulate errors pretty quickly. It also doesn’t help that TRX’s tracking system uses less sophisticated inertial sensors, which are more error prone. Those sensors are used because they are less expensive. If the company didn’t opt for that approach, no fire department could afford the finished product, explains Teolis.
But the company found a cost-effective way around the problem by tweaking the algorithm used by the inertial sensors to pinpoint a destination. How did they do it? “Our secret,” she says.
That solution addresses only one-half of the problem, however. Even if TRX’s system can track firefighters’ movements through a structure, that data must be able to get through the interference of modern buildings. That’s where mesh networking comes in.
Mesh networking. By connecting each firefighter’s wireless radio to the others, TRX creates a wireless network that is synched to a base station outside. The system is designed to send the tracking information through the network until it finds a firefighter’s radio that can transmit the information outside the structure.
During recent tests in Silver Spring, Maryland, TRX had four people hooked up to the tracking system walk around an 18-story building randomly. “Ninety-five percent of the time, we could get the data out,” she says.
Design and function. TRX’s Sentinel Tracking System has two main components: a tracking module and a communications module. The tracking module, which must be worn around the firefighter’s waist, uses the inertial sensors to calculate where a firefighter is within a structure and relays the information to the communications module.
The communications module uses the wireless radio to communicate with the base station, even from miles away. It can be worn anywhere on the firefighter’s body. Firefighters in danger also have the ability to press a red distress button, which transmits an immediate alarm to the base station.
From the base station, ideally a durable laptop mounted in a fire engine, an incident commander would track his firefighters as they made their way through a structure. On the interface, the firefighters tracked on screen resemble tiny pellets from a Pac-Man game.
TRX Systems’ engineers were originally developing the program with the idea that building plans for any building being responded to would be input so that the software could plot the firefighters’ trajectory throughout the floor plan. But the system’s developers learned that fire departments don’t usually have access to a building’s floor plans.
This realization led the company to build in “smart algorithms” that can build a floor plan as firefighters progress through a building. “The importance of that is when you’re trying to go in and find somebody,” says Teolis, “you want to know where they are relative to the structure of the building.”
In addition to tracking movement, the system can also track firefighters’ vitals. The program has been designed to allow add-ons, such as off-the-shelf heart-rate monitors so that the incident commander can monitor the health of his men in real time, says Teolis.
The idea is to eventually be able to detect firefighters showing signs of distress and to rescue them before they’re actually in danger, she explains.
The system allows information to be distributed to as many command posts as needed. Edwards of MFRI sees revolutionary potential in the new technology. He recounted a day more than 16 years ago when he was chief of Prince George’s County, Maryland, Fire Department. In that case, firefighter Kenneth Hendricks rescued a child from a one-story house, then returned for another run-through. Searching the basement of the house, Hendricks became trapped. No one knew he was down there. By the time his comrades found him, he was dead.
Edwards says that if TRX’s system existed then, Hendricks likely would be alive today. “It would have immediately indicated that he was in trouble, and it would have immediately indicated where he was,” he says.
In April, TRX Systems and the MFRI team demonstrated the system at the 2008 Metropolitan Fire Chiefs Conference and received a positive reception from attendees, says Edwards.
Chief Dennis Rubin of the District of Columbia Fire Department also got a look at the system during a live demonstration at a training seminar at MFRI a few months ago.
“This new system offers a higher degree of accuracy [than previous prototypes],” says Rubin, “and offers an easier application to know who is at the incident, where they are in the incident, what they are doing in the incident, and under what conditions.”
Other demonstrations have consisted of tests at MFRI, in the 18-story building in Silver Spring, and on the campus of the University of Maryland, College Park, says Edwards. Some of these have been under fire conditions.
TRX Systems and MFRI are planning to launch a pilot program with the fire departments of Prince George’s and Montgomery counties in Maryland as well as with the District of Columbia fire department before the end of the year. The firefighter tracking system will be given to one station per fire department, says Edwards.
The tests will allow firefighters to use and evaluate the system under nonemergency conditions. Their comments and criticisms of the system will then be fed back into the development process to perfect the system.
Fire, Camera, Action
From the rafters of an energy plant, a new type of camera is on guard. Two men enter its field of vision. One lights a fire. Within seconds, a red-square appears around the fire’s image on the monitor connected to the camera. From the command center, security personnel receive an alert signal and visually verify on their monitors that a fire has broken out. They then contact the fire department.
The camera has, in a sense, replicated the way a human eye communicates with the brain. It not only saw the fire, it recognized it as fire, and alerted security of its presence. But how?
“The underlying technology is software algorithms,” according to Mac Mottley, CEO of AxonX, makers of the SigniFire IP Camera.
To explain, Mottley asks a question: “How do you know what a fire looks like when you look at one?” Before I can answer, he says, “You identify it because it’s a really bright object, it flickers according to a certain pattern, it smokes, it expands at a certain rate. We almost model the software algorithm on how humans try to look at it.”
Casey Grant, program director at the Fire Protection Research Foundation, which sponsors research into innovative antifire technologies, says AxonX’s camera is an example of video imaging or video analytics.
Video-imaging systems harness the power of algorithms to construct neural networks, similar to the neurological structure of the human brain, which allows the camera’s software to make a decision based on what it observes.
When placed in a fire-detection context, says Grant, video-imaging technology offers certain advantages. For instance, large building spaces have long frustrated fire detection experts. Such spaces have usually relied on either sprinkler or suppression systems to guard against fire. But oftentimes, the fire has to reach a particular size to activate the systems, making property damage from flames, heat, and smoke more likely. Furthermore, sprinklers can damage whatever is stored in the space, while suppression systems can leave that space uninhabitable for humans after the suppressant has been released.
Video fire detection (VFD) systems, such as AxonX’s SigniFire IP camera, can help a facility avoid both direct damage from the fire and associated damage from extinguishing systems by ensuring early detection. Because the system relies on visual analytics, it can identify a smoke plume before it has time to waft up and set off a conventional spot-type smoke detector. With its ability to recognize flames, it can also identify a fire before it gets large enough to kick up enough smoke to set off smoke detectors. This process allows security personnel to respond to the fire before it gets out of control and put it out without having to resort to a facility’s sprinkler or suppression system or the fire department.
The system also cuts down on false alarms—or at least makes it easier to quickly assess whether an alarm is valid. When a spot-detector or sprinkler system goes off, there’s no way to verify that a fire set the instruments off without going to that location. “Usually what happens is that someone gets sent out to check to make sure it’s a fire before they call the fire department,” says Mottley.
VFD systems, like all detectors, do sometimes generate false alarms. Distinguishing between an actual fire and other nonfire events such as conventional building lighting, hot work, or lightning can be challenging, says Grant. But at least, with the VFD, “we start streaming video, and people can identify it as a fire very quickly,” he says.
UTC Fire & Security, another company developing a VFD system, has created a fusion algorithm designed to cut down on false alarms. Essentially, it analyzes data from many different individual algorithms, and the system won’t sound the alarm unless all the criteria for fire and smoke are satisfied.
“For example,” says Alan Finn, a research fellow at UTC, “if the system sees certain combinations of motion and color that mimic the characteristics attributed to fire, such as an orange leaf moving in the wind, but other important factors—like smoke—are not present, the system won’t alarm.”
Another advantage of VFD systems is that they also offer surveillance capabilities, giving companies the ability to watch over a location for unwanted intruders as well. Understanding the convenience of this two-in-one solution, AxonX’s camera allows users to set up motion-detection zones that will alert the command center when someone moves through a secure area. “You get speed of response, and you get situational awareness,” says Mottley.
And by combining fire protection with video security systems, companies could save money. “When you start combining security with fire detection, then you’re killing two birds with one stone,” says NIST’s Kerber.
To gain trust in the marketplace, new technologies, such as VFD, must satisfy the relevant National Fire Protection Association (NFPA) fire codes. The most important code for VFD systems to satisfy is the National Fire Alarm code, or NFPA 72. The code not only governs how the product performs but also how it is installed, tested, and maintained, says Lee Richardson, staff liaison for NFPA 72.
According to NFPA 72, VFD systems must be “listed” or “approved” by a product-testing company, which means the product meets certain standards. The two most recognized in the United States are Factory Mutual Global (FM Global) and Underwriters Laboratories (UL). The former is more concerned with testing fire and smoke detectors in commercial and industrial settings, while the latter tests smoke detectors in a life-safety setting, such as hotel rooms. In January, FM Global listed AxonX’s SigniFire system as a fire-detection system suitable for use in commercial and industrial applications.
Because the system uses a video camera, the company doesn’t see the “technology in hotel rooms, bedrooms, and the like, which are dominant in the life-safety market,” he says. “We see a lot of interest by commercial and industrial applications that have large volume, high risk, or high asset-protection requirements. Therefore FM is more applicable and desirable to us than a UL listing.”
Customers in a life-safety setting interested in using SigniFire must first satisfy their relevant fire codes. The system can then be added on for more redundant detection of flames, smoke, and intrusion, according to Lynch.
Taming the Flames
The third advance that has the potential to change how fires are fought is also the least sophisticated of the technologies. Its origin lies in an incident that occurred nearly a decade ago.
On December 18, 1998, three New York City firefighters died while fighting an apartment fire on the tenth floor of a building on Vandalia Avenue in Brooklyn, New York. They had been searching on various floors for an elderly woman they thought was still inside, although she had already been evacuated.
As they made their way through the building, the firefighters were engulfed by a fireball that streamed out of an apartment into the hallway where they were, and toward an open apartment door at the end of the hallway. The temperature spike caused by the fireball melted the firefighters’ oxygen masks off their faces. They died soon after of smoke inhalation and burns.
This phenomenon is known as wind-driven fire. It can occur in any structure, though it is more prevalent in high-rise buildings. NIST’s Kerber, along with his colleague Dan Madrzykowski, has studied what happened at Vandalia Avenue in hopes of understanding the wind-driven- fire phenomenon and how to combat it.
Part of the problem is that firefighters are trained to meet the fire—which firefighters refer to as the dragon—head on. It’s part of the mystique of the business, says Jerry Tracy, a Fire Department of New York battalion chief. Nevertheless, he says, “We’ve lost everytime,” referring to wind-driven fires.
The goal of the NIST research is to find alternative strategies of attack that can allow firefighters to battle structure fires under wind-driven conditions while minimizing the risk to their lives.
What Kerber and Madrzykowski discovered is that it’s all about pressure. When an opening is created in two different locations in a structure—whether it is by the fire service opening an evacuation or ventilation path, by people fleeing their apartments, or by windows breaking due to the heat—fire can hurtle from the high-pressure opening down along its low-pressure path. This can have horrific consequences for anyone caught in that path, especially for firefighters, as the Vandalia Avenue incident showed.
Those three firefighters died because a sudden shift in pressure occurred inside the building when the window in the fire apartment broke. As the window failed, the wind rocketed the fire out of the apartment like a blowtorch, down the hallway, and towards an apartment that had a door and window open. The hallway became, in effect, a chimney as the fire flashed through it, according to Grant, whose foundation also sponsors research into wind-driven fires.
“When you get a high wind, and there are a number of open doors between the fire and where the fire wants to go,” says Kerber, “then unfortunately, firefighters have found themselves in that path with essentially no protection, nothing to do.”
To gain a better understanding of this natural phenomenon, NIST partnered with the fire departments of Chicago, New York City, and Toledo, Ohio, to conduct wind-driven-fire experiments. The experiments used abandoned high-rise buildings packed with flammable furniture—what Kerber and other fire experimenters call “fuel packages.”
They then created openings that would cause the fire to rush from a high-pressure area to a low-pressure area, simulating conditions firefighters face when they fight real wind-driven fires. What they discovered both surprised and scared them.
“Conditions change even more dramatically than we realized,” says Grant. “The temperatures immediately exceed, in literally seconds, well beyond what the gear is capable of withstanding. So if they don’t get out of there within 10 seconds, it just becomes too much.”
The experiments led to the development of solutions as brilliant as they are crude from a technological standpoint. All it takes is a few fans, some crooked nozzles, and flame-retardant blankets to reduce the unpredictability of wind-driven fires. The results, says Tracy, “have been profound.”
Positive-pressure ventilation. One solution is called positive-pressure ventilation (PPV), which uses specialty fans manufactured by Super Vac and Tempest to flood a certain space, such as a stairwell, with air, says Kerber. “They’re designed to move a heck of a lot more air than your typical Home Depot fan,” he says.
By positioning these fans of varying sizes a few feet away from a doorway and placing them strategically throughout a building’s stairwell, the air blown into the stairwell seeks to equalize, if not increase, the air pressure in the stairwell as compared to the air pressure on the fire floor.
The first fan should be positioned at the base of the stairwell. If needed, another fan should be positioned not more than two to three floors below the fire floor. Additional fans may be needed every ten floors, depending on the building height. This tactic prevents fire and smoke from entering the stairwell, creating a safe haven for refuge and a means of evacuation during a fire for both firefighters and civilians.
PPV also allows firefighters to extend their hoses into the fire hallway from the stairwell and begin pumping water into it. Fighting the fire safely from the stairwell, they no longer have to expose themselves to the risk of a wind-driven fire event.
Pressurized stairwells also allow firefighters to reach each floor of a fire without using up precious oxygen from their air packs, crucial in a high-rise fire. Air packs only provide 11 to 15 minutes of work time for firefighters, says Tracy, and an additional six minutes for evacuation.
Many firefighters, Tracy explains, have to “take the feed,” which means taking off their mask before they evacuate the structure, because they outlasted their oxygen supply. This practice causes long-lasting damage to firefighters’ health.
“That’s why we’re dying young,” Tracy notes. The extra time provided by PPV-created refuge areas could help alleviate this problem.
At the NFPA annual World Safety Conference and Exposition in Las Vegas this June, I watched as Kerber showed video of the PPV experiments to a room full of fire stakeholders, mainly firefighters. The video showed black smoke pouring into a stairwell from an open door leading to the fire floor. The smoke obscured the firefighter who was hunkered down on the stairs. Suddenly, the fans turned on and the smoke retreated back through the hallway door, seemingly wretched back by a supernatural force. Once the stairwell pressure rose to meet that of the fire floor, a “pressure barrier” was created, says Kerber, which acted as an invisible force field that kept fire, heat, and smoke out of the stairwell.
High-rise evacuations have always posed problems. Many impractical solutions have been proposed—such as slide chutes and parachutes—says Chief Bobby Halton, editor-in-chief of Fire Engineering Magazine and a member of the International Association of Fire Chiefs.
By contrast, Kerber and Madrzykowski’s work offers a simple solution. As the tests in Chicago, New York City, and Toledo prove, firefighters using PPV “can rapidly create a tenable environment for people to escape in” without any added or unnecessary risk, says Halton.
High-rise nozzles. The second tool firefighters demonstrated during the NIST experiments was an assortment of high-rise nozzles. Crafted by the FDNY’s Research and Development Department, the nozzles are shaped to allow a firefighter to send water at different angles, rather than straight ahead as is the case with traditional fire hoses. This configuration allows firefighters to safely battle a fire from the window below the source of the blaze.
Consider a case in which a fire erupts on the tenth floor of a high-rise apartment building and firefighters determine that wind-driven-fire conditions present a risk. Rather than go to that floor, the firefighters could go down one floor, find a window that offers a shot at the fire, break a window in the apartment where the fire is located, and shoot water up into the fire.
The first-floor-below nozzle has a 60-degree angle so that a firefighter can place the nozzle out the lower-floor window and spray water into the apartment above through that window. There is also a second high-rise nozzle that is equipped with a hook that a firefighter can latch onto the windowsill above before releasing water into the apartment. Either way, the firefighter can safely battle the fire without accessing the fire floor.
“Everybody realizes this is a nozzle to be used when you can’t meet the dragon head-on, because the conditions are so severe,” says Tracy. Presently, 16 engine companies have been issued the high-rise nozzles.
Wind-control devices. The last solution that Kerber and Madrzykowski studied for fighting wind-driven fires was flame retardant fire blankets and curtains.
The idea for the products—also known as wind-control devices—came from firefighters within the FDNY. In 1999, one particular firefighter, John Norman, approached the department about purchasing flame retardant blankets for the purpose of stopping wind from entering a room through the window when there was a fire inside. He succeeded and blankets began to be distributed between 2000 and 2001.The blankets, specially made for larger windows, measure 10 by 12 feet and take at least two firefighters to deploy.
The curtain, however, is a newer device. Measuring 6 by 8 feet, it can be carried and deployed by a single firefighter. Kerber and Madrzykowski’s job has been to test the curtain and devise proper protocols for their use in the field.
During experiments at an abandoned high-rise building at Governors Island, sandwiched between Manhattan and Brooklyn in Upper New York Harbor, wind-control curtains worked well during high-rise fires under wind-driven conditions. Firefighters first had to locate which side of the structure the wind was hitting. Next, they draped the curtain over the open or broken window where the fire was located. They then either tied or held it in place. (They similarly secured the blankets.)
The devices stopped the wind from fanning the flames, thereby depriving the fires of pressure and oxygen. Essentially, the fires were smothered.
The results, Tracy says, were shocking. “Not only does it stop the wind, it drops the temperature in the fire apartment in half…like a light-switch.” This drop in temperature allows firefighters to extend their hose lines further into a space. If that does not subdue the fire, says Tracy, firefighters will find another vantage point from which they can wield high-rise nozzles to help extinguish the blaze.
Kerber foresees a time when firefighters will deploy fire blankets over any windows near the fire to avoid blowouts and rapid changes in a fire’s growth. The key will be to train firefighters in how to diagnose wind-driven- fire conditions when they arrive on the scene.
The FDNY currently has a pilot program underway that uses all three of the tools validated by Kerber and Madrzykowski’s Governors Island experiments under real high-rise fire conditions. Ladder companies on Manhattan; Rockaway Peninsula, Queens; and Coney Island, Brooklyn, have been equipped with fans, high-rise nozzles, and wind-control devices, says Tracy.
So far, only the fans have been needed to battle the blazes confronted. Nevertheless, Tracy expects all three tools to be adopted into the FDNY’s arsenal of firefighting techniques when the pilot program ends in October.
The novelty of Kerber and Madrzy-
kowski’s three-pronged tactical assault on wind-driven fires is that each tactic, whether alone or in tandem, allows firefighters to battle unpredictable fires without unnecessarily exposing firefighters to danger. The goal, says Kerber, is to make sure another Vandalia Avenue does not happen.
Whether by tracking firefighters in a structure, by alerting them to fires as soon as possible, or by reducing the likelihood of wind-driven fires, technology is reducing the risk of firefighting. The result will be fewer lives lost for firefighters and for the people they dedicate themselves to saving.
Matt Harwood is an assistant editor at Security Management.