Well into the second half of the 20th century, coal remained the world’s major primary energy source. Throughout most of the century, the relative importance of coal declined—that is, as a fraction of total energy production coal decreased. Worldwide coal use increased steadily, but the major production centers shifted. The coal industry changed fundamentally.
Two world wars changed the world and the coal industry. During both wars most industrial countries pushed their steel production, and hence their coal production, as high as possible. Due to the wartime destructions, both wars were followed by severe coal shortages. In response, coal-producing nations pushed hard to increase coal production. In both cases, the demand peak was reached quickly and subsided quickly. A large overcapacity developed on both occasions, resulting in steep drops in coal prices, in major production cutbacks, and in severe social and business dislocations. After the second world war, two major changes impacted coal: railroads converted from steam to diesel and heating of houses and buildings switched to fuel oil and natural gas. (Diesel replaced coal in shipping after World War I.) In the United States, railroads burned 110 million tons of coal in 1946, 2 million tons in 1960. Retail deliveries, primarily for domestic and commercial building heating, dropped from 99 million tons in 1946 to less than 9 million tons in 1972. One hundred fifty years of anthracite mining in northeastern Pennsylvania was ending.
A remarkable aspect of the coal user industry is the growth in efficiency in using coal. Railroads reduced coal consumption per 1000 gross ton-miles from 178 lbs in 1917 to 117 lbs in 1937. One kWh of electrical power consumed 3.5 lbs of coal in 1917,
1.4 lbs in 1937. A ton of pig iron required 2,900 lbs of coking coal in 1936, down from 3500 lbs in 1917. Improvements in use efficiency continued until late into the century. Coal consumption per kWh of electric power dropped from 3.2 lbs in 1920 to
1.2 lbs in 1950, and to 0.8 lbs in the 1960s. After that efficiency decreased somewhat due to inefficiencies
required to comply with environmental regulations. Super efficient steam generating and using technologies in the 1990s again improved efficiencies. Even more dramatic was the efficiency improvement in steel production (i. e., the reduction in coal needed to produce steel). Concurrent with the loss of traditional markets came the growth in the use of coal for generating electrical power, the basis for the steadily increasing demand for coal over the later decades of the century and for the foreseeable future.
Major shifts took place in worldwide production patterns. Britain dropped from first place to a minor producer. Early in the century, the United States became the largest coal producer in the world and maintained that position except for a few years near the very end of the century when the People’s Republic of China became the largest producer. Most West European countries and Japan reached their peak production in the 1950s, after which their production declined steeply. In the much later industrialized eastern European countries, in Russia (then the Soviet Union), and in South Korea, the peak was reached much later, typically in the late 1980s.
In Australia, India, and South Africa, coal production increased over most of the century, with major growth in the last few decades. The large production growth in China shows a complex past, with major disruptions during the 1940s (World War II) and the 1960s (cultural revolution). The recent entries among the top coal producers, Colombia and Indonesia, grew primarily during the 1980s and 1990s.
Worldwide production patterns have changed in response to major transportation developments. Large
bulk carrier ships reduced the cost of shipping coal across oceans. While some international coal trading existed for centuries (e. g., from Newcastle to Flanders, Paris, and Berlin and later from Britain to Singapore, Cape Horn, and Peru), only during the second half of the 20th century did a competitive market develop in which overseas imports affect domestic production worldwide. Imports from the United States contributed to coal mine closures in Western Europe and Japan during the 1950s. Imports from Australia, South Africa, Canada, Poland, and the United States contributed to the demise of coal mining in Japan, South Korea, and most of Western Europe.
Inland, unit trains haul coal at competitive cost over large distances: Wyoming coal competes in Midwestern and even East Coast utility markets. It became feasible to haul Utah, Colorado, and Alberta coking coal to West Coast ports and ship it to Japan and South Korea.
Coal mining reinvented itself over the 20th century. A coal hewer from 1800 would readily recognize a coal production face of 1900. A coal miner from 1900 would not have a clue as to what was going on at a coal face in 2000.
The most obvious and highly visible change is the move from underground to surface mining (Fig. 3). Large earthmoving equipment makes it possible to expose deeper coal seams by removing the overburden. Although large-scale surface mining of coal started early in the century, by 1940 only 50 million tons per year was surface mined, barely over 10% of the total U. S. production. Not until the 1970s did surface production surpass underground production.
By 2000, two-thirds of U. S. coal production was surface mined.
Room and pillar mining dominated underground U. S. coal mining until very late in the century. Early mechanization included mechanical undercutting and loading. Conventional mining, in which the coal is drilled and blasted with explosives, decreased steadily over the second half of the century and was negligible by the end of the century. Continuous mining grew, from its introduction in the late 1940s (Fig. 4), until very late in the century, when it was overtaken by longwall mining (Fig. 5). Modern mechanized longwall mining, in which the coal is broken out mechanically over the entire face, was developed in Germany and Britain by the middle of the century. Geological conditions made room and pillar mining impractical or even impossible in many European deposits. In the last two decades of the century, American (and Australian) underground coal mines adopted longwalling, and greatly increased its productivity. In conjunction with the increased production arose a serious safety problem: coal is being mined so fast that methane gas is liberated at a rate difficult to control safely with ventilation systems.
Technological advances depend on equipment manufacturers. Surface mining equipment size peaked in the 1960s and 1970s. The largest mobile land- based machine ever built was the Captain, a Marion 6360 stripping shovel that weighed 15,000 tons. Big Muskie, the largest dragline ever built, swung a 220cuyd bucket on a 310 ft boom. The demise of the stripping shovel came about because coal seams sufficiently close to the surface yet deep enough to warrant a stripping shovel were mined out. While the stripping shovel was exceedingly productive and efficient, its large cost required that it operate in a deposit that could guarantee a mine life of at least 10 to 20 years. Capital cost for a stripping shovel was markedly higher than for a dragline.
Large draglines shipped during the 1980s were mostly in the 60 to 80 cu yard bucket size range. A few larger machines (120 to 140cuyd) were build in the 1990s. By the end of the century, the conventional mine shovel reached a bucket size approaching that of all but the largest stripping shovels ever built.
Worldwide research was conducted in support of the coal industry. The U. S. Bureau of Mines was established in 1910 and abolished in 1996. Its mission changed, but it always conducted health
and safety research. The Bureau tested electrical equipment for underground coal mines, permissible explosives, designed to minimize the chances of initiating a gas or dust explosion, and improved ground control. The Bureau produced educational materials for health and safety training. In 1941, Congress authorized Bureau inspectors to enter mines. In 1947, approval was granted for a federal mine health and safety code. The 1969 Coal Mine Health and Safety Act removed the regulatory authority from the Bureau, and transferred it to the Mine Safety and Health Administration (MSHA).
Organizations similar to the Bureau were established in most countries that produced coal. In Britain, the Safety in Mines Research and Testing Board focused on explosions, electrical equipment, and health, the latter particularly with regard to dust control. In West Germany, the Steinkohlenbergbau – verein was known for its authoritative work in ground control, especially for longwalls. CERCHAR in France, INICHAR in Belgium, and CANMET in Canada studied coal mine health and safety. In the Soviet Union and the People’s Republic of China, highly regarded institutes ran under the auspices of their respective National Academy of Science.
Over the course of the 20th century, the classification of coal took on ever more importance, resulting
in a proliferation of classification methods. Early in the century, when international coal trade was not common and user quality specifications less comprehensive, national and regional classifications were developed. As international coal trade grew, over the second half of the century the need arose for classification schemes that could be applied worldwide.
In situ coal gasification has been demonstrated and could be developed if economics made it attractive. Conceptually simple, a controlled burning is started in a coal seam to produce gas containing CO, H2, CH4, and higher order hydrocarbons. The complexity of the fuel, the variability of the deposits, and the potential environmental impacts complicate implementation.
You can’t dig coal with bayonets.
—John L. Lewis, president, UMWA, 1956
You can’t mine coal without machine guns.
—Richard B. Mellon, American industrialist
Difficult labor relations plagued coal mining through much of the century in most free economy countries that mined coal. In many parts of the world, coal miners formed the most militant labor
unions. The West Virginia mine wars, lasting for most of the first three decades of the century, were among the most prolonged, violent, and bitter labor disputes in U. S. history. In Britain, the number of labor days lost to coal mine strikes far exceeded comparative numbers for other industries. Intense violent labor actions, frequently involving political objectives, have recurred throughout much of the century in Britain, France, Germany, Belgium, Australia, Canada, and Japan. During the last few decades of the century, strikes in Western Europe, Poland, Japan, and Canada were driven largely by mine closure issues. Strikes in Russia, the Ukraine, and Australia dealt primarily with living and working conditions. Coal miners in Poland, Serbia, and Rumania were leaders, or at least followers, in strikes with primarily political objectives. The last major strikes in Britain also had a strong political component, although pit closure concerns were the root cause. In the United States, the last two decades of the century were remarkably quiet on the labor front, especially compared to the 1970s.
The structure of the coal mining industry changed significantly over the course of the 20th century. In the United States during the 1930s, many family – owned coal mining businesses were taken over by corporations. Even so, the historical pattern of coal mining by a large number of small producers continued until late in the century. Production concentration remained low compared to other industries and showed an erratic pattern until late in the century. In 1950, the largest producer mined 4.8% of the total, in 1970 11.4%, in 1980 7.2%. In 1950, the largest eight producers mined 19.4% of the total; in 1970, 41%; in 1980, 29.5%. High prices during the energy crisis of the 1970s facilitated entry of small independents. The top 50 companies produced 45.2% of the total in 1950, 68.3% in 1970, 66.3% in 1980, confirming the significant reduction of the small producers.
During the 1970s, oil and chemical companies took over a significant number of coal companies because they believed widely made claims during that decade of an impending depletion of oil and gas reserves. As the hydrocarbon glut of the 1980s and 1990s progressed, most of these coal subsidiaries were spun off and operated again as independent coal producers.
Toward the end of the century, there was significant consolidation of large coal producers, domestically and internationally. Even so, the industry remained characterized by a relatively large number of major producers. In 2000, the 10 largest private companies controlled barely over 23% of the world production. In the United States the largest producer, Peabody, mined 16% of U. S. coal, the second largest one, Arch Coal, 11%. Coal remained highly competitive, domestically and internationally.