Electricians are a vital part of coal mining operations, as they install and maintain the electrical systems in mines. More importantly, their specialized skills are essential to keeping mining sites safe. Over the decades, the mining industry has gained a better understanding of electrical hazards by examining and improving upon past system designs and practices. Today’s mining electricians must address hazards linked to past electrical injuries, as well as consider the hazards that new technologies might pose.
Training for Coal-Mining Electricians
The training requirements for mine electricians vary by state. Before becoming an apprentice electrician in a mine, an individual must first earn a coal mining certification and be enrolled in an approved electrical training program, according to the West Virginia Coal Association. During the apprenticeship program, an aspiring electrician receives hands-on and classroom training to become a certified underground mine electrician. Some states allowed individuals with low-medium voltage electrical certifications to work as mine electricians, while others require individuals to have high voltage electrical certifications.
The experience necessary to become a mine electrician varies by state and underground mining position. In Kentucky, for example, an underground miner must have at least one year of experience to become an electrical worker. Electrical inspectors need five years of experience. Certification tests cover topics such as electrical theories, circuits, equipment, mine laws and national electrical codes.
History of U.S. Coal-Mining Electricians
- 1910: The U.S. Bureau of Mines begins investigating mining methods in relation to electricity and mining. It acknowledges that mine conditions greatly differ than surface conditions, thus making it a unique branch of electrical engineering. By this year, mines used electricity underground for drills, cutting machines, lighting, driving pumps, fans, hoists, haulage, detonating explosives, trolleys and more. The bureau set up an experimental station in Pittsburgh, Pennsylvania, to determine the causes of mining accidents involving electricity.
- 1911: The bureau begins testing explosion-proof electric motors in environments rich with natural gas. Engineers also test high-wattage carbon filament lamps in similar settings, leading to the introduction of electric cap lamps.
- 1920s: Miners begin using coal cutters, the first electrically powered coal mining machine. The bureau investigated the fire- and explosion-related hazards that the batteries posed. The mining industry also published best practices related to the importance of grounding mine electrical systems.
- 1921: The bureau approves the first storage batteries for mining locomotives and machines.
- 1923: The bureau approves a number of electrical devices for use in mines, but underground mines continue using unapproved equipment. Approved devices included drills, battery locomotives, electric cap lamps, and coal-cutting machines. During this year, the industry released an electrical safety inspection guide.
- Mid-1930s: The bureau adds air compressors, pumps, room hoists and rock-dust distributors to the approved list of electric-powered devices. During this decade, researchers began testing and improving upon trailing cables, which endured abuse by locomotives and rail-mounted cars.
- 1951: A study demonstrates that combining a fuse with a short-circuiting contactor helps protect against short circuits as well as expensive circuit breakers.
- 1952: The Federal Coal Mine Safety Act calls for annual safety inspections.
- 1960s: The use of alternating currents began rising in popularity in mines. Since this time, industry organizations have published guides about mine power system designs.
- 1969: The Coal Mine Safety and Health Act expanded the Bureau of Mines’ research regarding electrical safety. The act required the monitoring of ground conductor continuity to prevent electrocutions using a special device.
- 1970s: The industry improved upon trailing cable splicing procedures and splice kits. Research led to best practices regarding the prevention of electrical burns due to arc flash incidents in mines.
- Early 1980s: The Mine Electrical Laboratory in the NIOSH Pittsburgh Research Laboratory becomes one of the premier facilities in regards to examining mining safety issues. The laboratory published a guide related to the design of explosion-proof electrical enclosures, which helped the Mine Safety and Health Administration develop new regulations regarding the use of high-voltage long-wall machines.
The mining industry also investigated the use of sensitive ground fault relays to mine power circuits to improve personnel shock protection.
- 1980s: Engineers develop novel ways to measure internal cable temperatures and ampacity derating factors using imbedded optical fibers, and begin developing new ways to make trolley wires safer.
- 1990s: The industry develops cost-effective solutions to detect and warn about line contacts to reduce the number of incidents involving high-reaching equipment (e.g. cranes and ladders) contacting power lines in surface mining operations and ground mine surface facilities.
Working as a coal-mining electrician involves keeping up with the latest industry standards and best practices to increase the awareness of electrical shock, burn hazards and ignitions. The exhaustive training that the specialists receive not only help a mining operation run efficiently, but also saves lives.