Locating and Rescue of Trapped Miners 1998 Mine Safety and Health Administration (MSHA)

more at http://quickfound.net/

'Describes the equipment and methods used to locate trapped miners in an underground mine environment.'

Originally a public domain film from the National Archives, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.

The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).

https://en.wikipedia.org/wiki/History_of_coal_mining_in_the_United_States

Wikipedia license: http://creativecommons.org/licenses/by-sa/3.0/

The history of coal mining in the United States goes back to the 1300s, when the Hopi Indians used coal. The first commercial use came in 1701, within the Manakin-Sabot area of Richmond, Virginia. Coal was the dominant power source in the United States in the late 1800s and early 1900s, and although in rapid decline it remains a significant source of energy in 2019.

Coal became the largest source of energy in the 1880s, when it overtook wood, and remained the largest source until the early 1950s, when coal was exceeded by petroleum. Coal provided more than half of the nation's energy from the 1880s to the 1940s, and from 1906 to 1920 provided more than three-quarters of US energy...

1800s

At the start of the 19th century, coal mining was almost all bituminous coal. In 1810, 176,000 short tons of bituminous coal were mined in the US, versus 2,000 tons of anthracite. US coal mining grew rapidly in the early 1800s, doubling or tripling every decade. Anthracite mining overtook bituminous coal mining in the 1840s, and from 1843 through 1868, more anthracite was mined than bituminous coal. But the more limited deposits of anthracite could not satisfy the increasing demand for coal, and from 1869 on, bituminous coal was the predominant grade of coal mined. Another reason for the decline in anthracite was the decline in its use in iron smelting, where it was displaced by coke in blast furnaces after the Civil War. Coke stayed hard and porous and was able to support the heavy column of ore and fuel in the large blast furnaces it enabled.

Anthracite (or "hard" coal) exploitation began before the War of 1812 spurred by the interest and opportunism of the Wurt brothers of Philadelphia. Burning clean and smokeless, anthracite became the preferred fuel in cities, replacing wood by about 1850, the same pattern seen in Europe. The East became deforested, driving up price of fuel wood. Anthracite from the Northeastern Pennsylvania Coal Region and later from West Virginia was valued for household use because it burns cleanly with little ash. It was also used in the early foundries of Philadelphia, New York, Newark and Allentown. The rich Pennsylvania anthracite fields were close to the big eastern cities, and nearly every major railroad in the Eastern United States such as the Reading Railroad, Lehigh & Erie, Central Railroad of New Jersey, Pennsylvania Railroad and Delaware and Hudson Railroad, extended lines into the anthracite fields. Many railroads began as mining company shortline railroads. By 1840, annual hard coal output had passed the million-short ton mark, and then quadrupled by 1850, and as it grew it pushed railroad construction, mining and steel production in a synergistic symbiosis.

In the mid-century Pittsburgh was the principal market. After 1850 soft coal, which is cheaper but dirtier, came into demand for railway locomotives and stationary steam engines, and was used to make coke for steel after 1870.

1900-1943, 1944-1999

Total coal output soared until 1918; before 1890, it doubled every ten years, going from 8.4 million short tons in 1850 to 40 million in 1870, 270 million in 1900, and peaking at 680 million short tons in 1918. New soft coal fields opened in Ohio, Indiana and Illinois, as well as West Virginia, Kentucky and Alabama. The Great Depression of the 1930s lowered the demand to 360 million short tons in 1932...