Fire Prevention Technologies

By: Bill Reid
Managing Editor

    Ronald S. Conti is a Fire Prevention Engineer for the Pittsburgh Research Laboratory, NIOSH and has more than 30 years of government service in fires and explosions. Conti is currently the principal investigator of the Mine Rescue and Response Project and has been conducting research in areas dealing with emergency responders, mine fire prevention and preparedness, and fire suppression. Conti manned the NIOSH booth at the recent National Mine Rescue, First Aid, Bench and Preshift Contest and took time to discuss fire prevention technologies with Coal Leader.
    Over the last several years, NIOSH has been looking at inflatable devices for fire suppression and personnel escape. One of these is an inflatable air lock that was originally designed to manage smoke during an escape procedure underground. The device is a lightweight bag that could be strategically located, either manually or remotely deployed during a mine emergency. Miners escaping in a smoke filled environment with a self rescuer or W65 would pass through the smoke, come to the bag, then pass through it, and be in fresh air.
    “Working with the rescue teams, the bag has been redesigned several times and we use it as an air lock chamber so rescue teams can establish a fresh air base and then pass through the bag into the smoke filled environment,” said Conti. “That’s how they basically traverse back and forth to the fresh air base.”
    The high expansion inflatable bag was also designed for high expansion foam generators so that a partition can be erected quickly. The bag can be inflated in 15 minutes with compressed air, blowers, or inert gas, and interface with a 6000 cfm high expansion form generator. Thus, the foam making process can be started quickly.
    Over the last decade, according to Conti, NIOSH has been doing work with mine rescue teams and emergency responders developing and evaluating realistic training simulations. The Lake Lynn facility near Pittsburgh, a former limestone mine, is used for mine rescue training. “During the mine rescue training we can generate oxygen deficient areas, we can generate methane zones, heated areas, and can vary visibility of non-toxic smoke from zero to several feet,” explained Conti. “We observe the rescue teams as they are traveling through the entries and their hand held sensors go off. We design training simulations for the rescue teams, such as how to fight conveyor belt fires. We have temperatures of 400 or 500 degrees Fahrenheit. CO levels are 1700 parts per million and the teams travel into the smoke. We turn on the watersprays and the fog stream and we show them that you can’t fight the fire unless you see the flames.” It is necessary to control the rollback smoke and once the fog is turned on within a few feet of that dense smoke, the rescuers start to see the flame. At that point they start to adjust their water nozzles to solid streams and they start fighting the belt fire itself. 
    Conti discussed the technology that can be used for emergency responders like mine rescue teams and discussed a lighted line. It’s a link line that uses luminescence technology, which allows other team members to have flexibility of sliding, compared with the previous link line, which was fixed at 7’ intervals so it has alleviated tripping and falling problems. It also made tasks like setting up ventilation controls or roof support a lot easier, because of freedom of movement. It’s also illuminated so in the smoke, the rescue team members can easily find their fixed position on the line itself.
    Laser technology is also being examined at NIOSH. The rescue team captain is usually fitted with a green laser on his cap lamp and the tail person is fitted with a red laser on his cap lamp. In the smoke, there is a beam of light, “We suggest they shut their cap lamp off and allow the lasers to guide them through the smoke-filled environment, so when the laser beam turns into a spot, they know there is an obstacle there, such as a rib or roof,” said Conti. “By having different colors, the teams can tell where the captain and tail man are and when they need to go back to exploring. It lines them up a lot better in the smoke environment.” 

    NIOSH is also looking at thermal imaging cameras, which are an invaluable tool for emergency responders. “It doesn’t matter how thick the smoke is, you can’t hide from a thermal imaging camera,” said Conti. “Usually the thermal imaging camera can detect temperature changes of a half degree Fahrenheit and it’s a very useful tool for finding people that may be unconscious in a smoke filled environment or lost in smoke. It’s also an excellent technology for fire bossing preventive maintenance.” A thermal imaging camera can be used to observe the normal operation of a belt drive, electric trolley lines, power centers, electric cables, and spontaneous combustion problems. When a change in temperature is detected, this is an indication that something is failing and the issue can be addressed before it becomes a hazard.
    Conti is a firm believer in hands-on training and believes that mine rescue teams are a special breed of miners who often place their lives in danger to save other people. “I believe they should be well-trained and physically fit, provided with the latest personal protective equipment, and understand the hazards that may await them during emergency operations,” he said. “We’re doing a lot of hands-on training for rescue teams, but we are also doing a lot of hands-on training at the mine sites, giving miners an opportunity to see what it is like to travel through a smoke-filled environment in their mine and also evaluate the type of technology we have.”
    Emergency response drills are carried out at mine sites with some mine operators hosting these drills. The rescue teams come to the mine sites and company officials and representatives of MSHA participate. The mine rescue teams become familiar with the mines that they may be coming to in the future, but it also gives the mine operators a better understanding what may happen if there was an emergency at their mine. They can see firsthand that the rescue teams remain calm, the type of news media that may be there, and the different types of agencies that will be on site. 
    Conti said that there were on average around 10 to 12 reportable fires each year, but there were a lot of non-reportable fires, that is fires that last less than 30 minutes due to possibly welding/cutting operations, perhaps electrical cable, maybe a spontaneous combustion problem that the detection system picks up or a miner smells or sees smoke and they can extinguish it. “So, fire is a constant. It’s always going to occur. It’s just how you react to it, how you detect it,” said Conti. 
    NIOSH has assisted in several recent cases both in training and actual fire fighting. “We were involved with the Willow Creek mine fire back in 1988 and brought our inflatable devices there for fire suppression and personnel escape,” said Conti. “We were involved with Quecreek available with technology and not sure what the rescue scenario was going to be so the technology was there.” NIOSH was asked to come to the Mine 84 mine fire with some of their firefighting nozzles and they worked with the mine rescue teams from CONSOL Energy. NIOSH also attended the Loveridge mine fire when the Queensland Mine Rescue Service jet engine from Australia was put to use.
    “It is very encouraging and very positive to hear the rescue teams talk about their fire fighting experiences at the Mine 84 fire and VP8 fires and that they felt that the training they received at the NIOSH Lake Lynn Laboratory experimental mine was invaluable and that they were very prepared to deal with that type of an emergency,” said Conti. cl

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