Page 54 - Advances In Productive, Safe, and Responsible Coal Mining

40 Advances in Productive, Safe, and Responsible Coal Mining

management of risk at a level that results both in appropriate productivity and safety
performance that must be the goal.
There are seven characteristics of coal-mining risk:

1. Constant change. The essential nature of a coal mine is to exploit the ore body as a means and
indicator of the extraction of coal from the ground. Change as a dynamic variable increases
the potential for risk to result in harm to both people and equipment. The more change that
occurs, the greater the difficulty in understanding and controlling risk. Coal miners most
commonly experience fatal injuries when nonstandard geological conditions, work tasks,
and behaviors occur. Change is more often than not a promoter of increasing risk.
2. The three-dimensional nature of geological risk, especially in underground mines. Whether
it is strata, gas, equipment, or tools, risk is present above, below, in front of, and behind
miners while they work. In both surface and underground operations, the potential for miners
to be exposed to rock falls, subsidence, uplift, bumps, falling equipment, proximity to mobile
equipment, inundation, uncontrolled energy sources, etc. is omnipresent.
3. Imperfect understanding of rock mechanics and rock behavior. While the industry’s accu-
mulated knowledge of coal geology, geophysics, and rock mechanics continually increases,
it remains incomplete in terms of the ability to exactly and consistently predict the behavior
of coal and its host rock. There is a substantial body of knowledge regarding coal charac-
teristics and behavior that is supplemented with new research findings and new information
and perspectives derived from mining operations. However, the history of coal-mining inci-
dents reflects retrospective recognition of unseen or inadequately characterized geological
risks that contribute to increased risk.
4. Chemical-physical properties of coal. By its nature, coal has the potential to contribute to
fires and explosions at surface mines, but especially in underground mines. Of course, con-
tending with materials that are potentially combustible, flammable, and/or explosive is not
unique to mining [17]. The petroleum industry is primarily defined by this risk from explo-
ration to retail distribution and use of gasoline and other products. Offshore petroleum pro-
duction and the refining process are at the center of that industry’s risk profile, but they
substantially minimize risk by isolating exposure to flammable gases and liquids through
comprehensive controls. When operators or maintenance personnel are exposed to explosive
hydrocarbons during instances when the otherwise closed process unties, risk assessment is
required; yet, in underground coal mining where potentially flammable and explosive con-
centrations of gas and dust are present, operators and maintenance personnel actually work
inside process equipment that is analogous to petroleum refining; i.e., coal mine drifts, cross-
cuts, and adits.
5. The scale of mining equipment and tools. As mining mechanization and economics of scale
grow, the size of fixed and mobile mine equipment concurrently grows in relation to miners
who assemble, operate, and maintain them. Surface mine haul trucks are the size of a three-
story building, drag lines often eclipse 10 stories in height, and longwall installations can
reach more than 1000ft in length. There has also been a proportional increase in the size
of tools used to assemble and maintain mining equipment. It is common to see wrenches
in mine maintenance shops that are more than 36in. in length and weigh in excess of 100
pounds. The greater the size differential between equipment and those who interact with
it, the greater the risk. Larger hand tools, trucks, shovels, longwalls, conveyors, etc. are nec-
essary to leverage economies of scale in the vast majority of operating mines today. The size
and complexity of equipment increases while size and susceptibility of miners remain static
and in some instances can be worse as in the case of aging workforces with declining reaction
times, strength, and flexibility, among other measure of health and fitness.