The same heavy equipment that is so instrumental to the U.S. construction industry has garnered a disparaging reputation as the leading cause of fatalities at underground and surface mining operations.
“When looking at fatal accidents, haul trucks, conveyor belts and drive units, front-end loaders, continuous miners and dozers are the top five leading types of equipment involved,” said Mark Skiles, director of technical support of the Mine Safety and Health Administration (MSHA) based in Arlington, VA.
Two recent tragedies in West Virginia coal mining communities have focused the eyes of the nation on the need for enhanced safety at mine operations. Twelve miners died after an explosion rocked the Sago Mine in Upshur County in early January and two more men were killed a few weeks later when fire erupted at the Aracoma Alma Mine in Logan County.
Although neither incident involved heavy equipment, the deaths have sparked a federal investigation into mine safety in general. MSHA has worked with numerous equipment manufacturers in recent years regarding safety improvements and the continued education of miners.
Skiles said partnerships have been formed with J.H. Fletcher & Co., Caterpillar and Volvo in an effort to quickly disseminate information to the mining community about safety enhancements and equipment recall notices. The information is readily available on MSHA’s Web site at www.msha.gov, which contains links to equipment-related accidents from 1995 through 2005.
There are many factors that can contribute to accidents involving underground coal mining equipment.
“Roof and rib control requirements can restrict the clearance of a mine’s travel ways. Most often, equipment travel ways are 20 feet or less in width, which restricts equipment clearances with the walls,” said Skiles. “Coal seam height also limits visibility for the equipment operators as canopies on equipment used near the mining face are required. These factors can present crushing and pinching hazards to miners who work in and around such equipment.”
The safety of roof-bolting machines has been enhanced in recent years with the installation of two-handed fast-feed controls, hydraulic panic bars and load-locking valves on continuous mining machine cutter booms and tail booms. The valves prevent booms from dropping while maintenance work is being done on the equipment.
Since 1988, there have been 26 fatal crushing or pinning accidents involving the operation of remote-control continuous miners. These machines can pivot very rapidly and unexpectedly, pinning or crushing the machine operator. In many instances, the victim was located within the danger zone around the machine.
Other equipment is electrically powered and requires trailing cables, which can create a risk for electrocution. Likewise, high-pressure hoses and connections needed to operate certain underground equipment should be examined and maintained on a regular basis to prevent failures that could injure nearby miners. Accidents also have been caused by supply material spillage and the overheating of belt conveyor systems.
Intersections where moving equipment travels also require constant awareness of the surroundings by operators. In addition, ground-engaging equipment must be watched carefully because sudden movement could result in contact with miners.
“MSHA has begun several projects to introduce proximity-protection technology to the mining industry,” said Skiles. “Proximity protection is a system that can be installed on equipment and programmed to send warning and machine shutdown commands when a miner enters a danger area.”
Two commercially available proximity-protection systems will be tested on underground continuous mining machines in the near future.
Skiles noted that support equipment used to haul supplies and systems employed to transport the coal to the surface also can pose a hazard to workers. As a direct result of a fatality involving a haul truck in the mid-1990s, MSHA worked with Euclid Trucks to create a test procedure for braking systems. Skiles said the procedures were developed for a variety of truck brakes. A service bulletin was later published, relevant to testing brakes on trucks ranging in size from 22 to 85 tons.
Heavy equipment used in surface mining can malfunction or lead to accidents just based on its size and the blind areas around the machinery. These blind-area hazards have been decreased in recent years with the installation of video cameras and better mirrors. The cameras and proximity-detection equipment are used on a voluntary basis, but are not standard design.
“Falling from equipment is also a leading cause of accidents and fatalities in the mining industry and mechanics are especially at risk,” said Skiles. “Manufacturers have made some improvements on a new design with stairways instead of vertical ladders along with the use of retractable ladders and power lifts. However, older equipment that requires engineering redesign and retrofit has not seen the needed change.”
Bulldozers, for example, do not have ladders or stairs and, therefore, operators must use the crawlers as part of the climb to the operator’s compartment.
Equipment manufacturers who have worked with MSHA on various safety issues said the redesign is a market-driven change that will require sufficient time to implement.
Conversely, the same heavy equipment also has played an instrumental role in several of the rescue attempts. For example, dozers were used during the Quecreek Mine Rescue in Pennsylvania to build roads for the rotary drills, which provided a link between the surface and the underground mine. The holes enabled rescuers to inject compressed air into the mine and served as an escape route for trapped miners.
The escape capsule in the Pennsylvania mishap was lowered into and pulled from the mine with a crane. High-capacity dewatering pumps also were vital to reducing the amount of water that had flooded the mine.
During the recent accidents in West Virginia, dozers were used to clear wooded areas to provide stable ground to support the rotary drills which, in turn, were used to bore holes into the mine to sample the gases and attempt to locate the miners.
The process of implementing overall mining safety in West Virginia has been rapid. Within days of the second mining disaster, state lawmakers passed legislation to enhance mine safety regulations.
The West Virginia bill mandates a faster emergency response, enhanced communication and more underground supplies of oxygen. According to the new law, mine operators are required to notify federal mine safety officials within 15 minutes of an accident occurring. Failure to do so will result in a $100,000 fine. The law establishes the Mine and Industrial Accident Rapid Response System and statewide hotline to expedite rescue efforts.
West Virginia’s legislation also requires all mines to store reserve oxygen supplies underground. In addition, all miners must be provided with emergency communicators and tracking devices.
Other states, including Kentucky, Tennessee, Virginia and Pennsylvania, are heeding the wakeup call from West Virginia and examining their own mine safety laws to determine if changes are necessary.
Congress also is reviewing safety legislation introduced in February by a delegation of legislators from West Virginia. The legislation focuses on expanded use of advanced safety technologies, tougher penalties for habitual safety violators, emergency communications, better oxygen equipment and rapid notification and response.
“The West Virginia delegation is sending a strong message to the Bush Administration and the Department of Labor that enough is enough,” said Cecil Roberts, president of the United Mine Workers of America (UMWA) in Fairfax, VA. “The time to take strong corrective action on behalf of miners in America is now.”
The Bush Administration has been criticized by federal lawmakers and the UMWA for cutting staff at the MSHA, which is responsible for inspecting and enforcing mine safety. MSHA officials also have been targeted for being lax in the type of fines they have assessed in cases where safety violations have been discovered. CEG