By Lee Buchsbaum
When things go wrong 4,000 feet into the mountain and two miles away from the nearest county road, or virtually anywhere on mine property, there is no 911 to call. Of the innumerable dangers facing coal miners every day, perhaps none is as omnipresent or potentially damaging as the outbreak of a fire. Underground or on the surface, the industry has learned the hard way to be ever vigilant. Between 1991 and 2000, there were 137 mine fires reported to MSHA, 76 of these were in underground coal mines. New technologies, innovations, applications and products continue to be introduced to snuff out fires the moment a spark is detected or to ensure the right tools are available to prevent further damage.
Historically most fires have been treated with water. But with the march of progress, newer dry and wet chemical agents have replaced most water-based products. Today a variety of foams, nitrogen and compressed air foam systems (CAFS) are in use or standing by throughout most mines. Chemical foams have the advantage of low surface tensions, absorb heat quickly, penetrate most fire fuels and create a vapor securing barrier. CAFS go one step further by having a nearly uniform very low surface tension (created by injected air), and have stronger bubble structures and projection capabilities than just pure foam. Nitrogen-enriched CAFS remove and displace oxygen and thus render the fuel source inert. According to the 1998 Fireline Handbook, most wet chemical foams are 40% better and more efficient at producing knockdown or flame reduction than water. CAFS are 79% better than water and 64% more efficient than just foam.
Green Kills Red: Kidde’s New Environmentally Friendly System
Industry leader Kidde Fire Systems, a UTC Fire & Security company, introduced its AquaGreen XT product in November 2009. Primarily known for its Sentinel System dry chemical agents, this new product contains Kidde’s proprietary AquaGreen environmentally-friendly, non-reportable wet firefighting agent. It is Factory Mutual approved for primary fire fighting. Together with a full range of related products, Kidde’s system is engineered for extreme environments. The company’s dual agent systems combine wet and dry foams for ultimate protection. The wet chemical agent allows for quick clean up, a wide operating temperature range, and no need to report usage.
A compact, fully featured control and detection system, Kidde’s new Sentinel SA1 Control unit works with either multipurpose dry chemical foam or the new AquaGreen XT wet agent suppression systems. The SA1 uses linear heat sensing cable, “Detect-A-Fire” heat detectors, or Infrared IR-1A detectors. The IR-1A infrared detectors use a dual spectrum infrared sensor, providing flame detection in as little as 100 milliseconds to sense danger and automatically trigger fire suppression. The SA1 uses a durable aluminum enclosure, designed to cope with the riggers of the vehicle life cycle.
The Kidde SA1 Detection and Control System is coupled with Sentinel dry chemical or wet chemical suppression to provide protection for small to medium vehicles. Cost effective to install and to service, they provide fast, reliable fire protection for a wide range of hazard conditions. The SA1 is offered with a ‘primary cell’ battery (without direct connection to the vehicle power), on vehicle power with no battery backup, or on vehicle power with a one-hour rechargeable battery backup.
Kidde’s Sentinel NET control system is designed to protect large haulers, graders, shovels trucks and other machines from fire. Sentinel NIM provides the interface through which authorized personnel and the vehicle operator run the system. It provides the operator with up to two interface units that provide real-time status information via high quality two-line display. Each Sentinel NET control unit can control two detection zones and two suppression releases and up to six control units can be networked on a single system. Flexibility in the programming configuration allows the designer to select sequential discharges, discharge and/or relay delays, or ‘double-knock’ detection schemes as needed. The Sentinel NET can be accessed via a standard USB and programmed with or without a laptop computer. Virtually all of Kidde’s electronic components are plug and play. The system program, which includes a 4,000-event log, is stored on every controller on the network.
The NET Detection and Control System are industry approved, has a high-quality dimmable alphanumeric display, features Triple-R Protection-False alarm immunity, has two alarm relays and one trouble relay. It is powered from the network loop that interconnects it with other modules. Up to two Sentinel NIMs can also be employed on a single network along with up to six NET Control Modules.
The detection system uses “Triple R Protection” to ensure both release circuits are protected by a triple failure safeguard system to prevent against unwanted discharge. In order to release the suppression system, two release commands must be combined with a third signal from the “watchdog” timer.
To choose the right system, Kidde “walks the client through a decision matrix, doing a survey on each specific vehicle. Are there a lot of Class A type materials, dirt and dust build-up or Class B combustible flammable hydraulic fuels or other liquid materials on-board? What’s the ambient temperature and how much maintenance and what tweaks are permissible? Would they want a dry chemical system? How complicated should the controls be and should they be networked?” asked Kate Houghton, director of marketing, global fire suppression, Kidde Fire Systems. “Most of these vehicles are worth millions of dollars and it’s not like the vehicle manufacturers have another hauler in their lots waiting to deliver.
“We continue to offer the dry chemical as our standard, cost effective solution. The Kidde Sentinel line has both (wet and dry agents). The downside of using a dry chemical is that it tends to be messy, it does not have as wide a temperature application, but it’s flexible and very effective in knocking down a fire,” said Houghton.
Once the system is installed, however, maintenance is key. “It is important for the end users to realize that the system can get damaged in the course of normal operations, which is often overlooked. Typically it needs to be looked at every 1,000 hours to ensure that the detection systems are still intact, the cylinders are full, the power normal and the system is ready to deploy at the instant its needed,” said Houghton. The Sentinel control systems include a programmable service timer that warns the operator that scheduled maintenance is due. “Our system offers supervision of the suppression cylinder pressure and the entire control system is supervised—if the lights are green you know the system is going to perform,” said Houghton.
To Hell and Back: USF Equipment & Services
Based out of Longview, Texas, USF Equipment & Services LLC, is a sister company of US Foam Technologies. USF Equipment & Services was created so it could focus solely on coal mine fires and mine fire technology. Developed largely by professional industrial firefighter Alden “Al” Ozment, U.S. Foam technologies provides the Mine Fire Fighting Foam (MFFF) to USF Equipment & Services. USFE&S works to provide mine owners and operators with a robust array of advanced technology for both active and abandoned coalmine fires. Using its patented systems, USF has fought recent underground fires in Utah, Colorado, Kentucky, and Virginia.
The company’s Sentinel system combines CAFS technology with nitrogen injection. Using a patented mixing chamber for confined area foam solution consistency, the system produces a fast fire knockdown underground, with the compressed nitrogen allowing for a long discharge and fire reach distance. All combined, this creates a significant cooling effect and heat reduction which minimizes personnel exposure. The inert properties of the nitrogen enriched foam minimizes a fire’s ability to rekindle itself as well, therefore increasing a CAFS’ fire fighting capacity. USF’s system also has a higher discharge visibility than most dry chemical units, enabling a firefighter to better evaluate where they need to concentrate their sprays. The Sentinel system also comes equipped with on-site refill capabilities for extended fire fighting periods.
One of USF’s flagship products, the Sentinel 30 firefighting unit is a self-contained fire-fighting system, most effective when used with USF’s “First Strike” C-Mine Fire Fighting Foam (C-MFFF). Weighing in at a loaded weight of 951 lb, the skid mounted unit has a maximum discharge rate of 300 gallons per minute (gpm) of finished foam, spraying up to 75 ft. Its fast recharge rate allows it to be back in service in roughly five minutes after discharge. It also comes equipped with 50 ft of 1-inch hard MSHA-approved rubber hose. USF also has a line of hand-held extinguishers with a loaded rate of just over 45 lb. With a 60 gallon capacity of premixed foam, each unit can discharge itself in roughly 60 seconds to a distance of up to 30 ft. Once depleted, they can be recharged again in 3 minutes.
USF also carries the Hellfighter product line, specifically designed to be used fighting underground coal mine fires. Each system comes with a processing and dispensing unit, chemical foam proportioner, mine foam concentrate (MFFF), a nitrogen generator and optional power generator and water pumps. Only available through USF, the Hellfighter produces up to 94,500 SCFH of 95% pure nitrogen enriched foam and is capable of reducing the output fire suppressant to 45ºF. It is fully automatic with pressure switches, pre-filters and pressure regulators, it also has a built-in oxygen analyzer. Designed to withstand all of the extreme environmental conditions generally found in off-road, remote work sites, it can be shipped by truck, ship or aircraft. When on-site it can be fork-lifted or hoisted into place as well.
It has been tested in operating temperatures between -15ºF to over 125ºF.
After Alma, Lessons Learned and Problems Solved by Mine Lifeline
Logan County, W.Va., is a tight knit mining community. Rocked by witnessing the Alma mine fire and the subsequent Aracoma prep plant fire, Mine Lifeline founder and Logan County coal operator Rick Abraham of Chapmansville, W.Va., has taken a “never again” stance, not just for his mine but for the entire industry. After listening to expert testimony, reviewing reports and through his experiences, Abraham along with his son Jeremy, realized while the mining industry has a long history of fighting fires, taken as a whole, mine rescue teams are far from professionally trained firefighters. Moreover, because of the specific rules and MSHA regulations, the methods, tools used and overall paradigm of the industry is very different than most municipal and professional firefighting squads.
Historically mine rescue teams to some extent function as first responders to a mine fire for which they are, in reality, ill equipped. By federal law, rescue teams only have to be able to respond to an alarm within one hour. Those precious first minutes are critical to preventing the fire from getting out of control, as with each moment the heat spreads and disaster looms. Once on site, without the ability to don proper bunker gear, a rescue team or the relatively rare trained fire brigade, can only get so close to a blaze before they are overwhelmed by the heat. Often their tools are inadequate, fittings fail as the hoses are extended and deployed, and as the responders themselves find themselves in wholly unfamiliar territory off the mine rescue field and literally into the fire.
In various training scenarios Abraham learned that one of the most frustrating and debilitating findings was when called upon, simple but critical components failed. Unable to mate 2.5 inch national standard hose fittings with whatever was in a mine, desperate first responders might have to waste precious moments creating makeshift splices, or racing for the nearest hardware store for the right hose couplings or other absent basic parts that rendered firefighting gear almost useless.
For years the industry has accepted plastic hoses, much like common garden hoses, crimped together with “Band-it” ends, and coiled in plastic lidded garbage cans scattered about a mine. Untested, these have often proved to be unreliable fire hoses. The maker and distributor of various underground plastic coated steel wire “Lifelines” used to help guide miners to safety in the case of smoke or fire, Abraham realized that here was another safety gap that needed to be breached. His company has begun to create and assemble professional braided fire hose “kits” that come in 100- or 500-ft lengths, connected with proper uniform couplings, the hoses are hydrostatically tested, lapped instead of coiled—as professional fire teams do, banded by Velcro and placed into rugged Pelican cases that sport reflective stickers to locate them better.
“Each hose is tested. We examine every hose when it goes into the box to make sure it’s the right thread. We place it with a nozzle, a spanner wrench, and close the box, seal it and tag it. Each box is numbered and can be tracked. You know what you have precisely, you know where it’s been, and you know when it’s last been inspected to prove that, if called upon, it will work. In a year we’ll bring you the same box and take away the old one and test it. We document it for you and you receive software that can be used to track it yourself. All of the sealed boxes have serial numbers that document where they have been placed into service and when, as well as showing when a unit was last inspected. There is a complete record of it,” Abraham said.
Mine Lifeline also sells smaller kits for use in prep plants. Though most plants always have plenty of hose around for wash down purposes, they rarely have hoses designed to couple together and reach across multiple stories. “Operators have asked us to package 100-ft single braid, polyester jacketed hoses with a nozzle into smaller reflective Pelican cases that can be strategically deployed around the facility,” Abraham said.
Abraham is also offering a line of industrial strength nozzles that replace the mainly plastic gear most common in today’s mines. Similar to what has been used in the forest fire services, these nozzles don’t produce projected water volumes when they are crimped down, and thus limiting your ability to fight a spreading fire. “What we sell are full bore, even as they change from stream to fan spray, it does not affect flow rate delivered to the fire. You’re getting 100 gpm of water regardless of the shape of the spray pattern,” Abraham said.
Abraham worries that most operators go to work every day thinking they are both in compliance and safe. If they’ve never actually deployed or used their firefighting gear, they probably are unaware of the problems they might have when what has commonly been an ad-hoc hodgepodge of equipment fails under real life conditions. “Unless you’ve had a fire, you probably didn’t know what you have or what problems you have,” said Abraham. “I would hate to think that a mine would risk millions of dollars in assets and lost production for want of a $0.50 fitting or because your fire team had to travel 30 minutes to the nearest store to purchase the right parts that somehow were missing when you needed them most,” Abraham said.
Buchsbaum is a Denver-based freelance writer and photographer specializing in industrial subjects. He can be reached through his Web site at www.lmbphotography.com or by phone at 303-746-8172.
