This year, one longwall face was added to Coal Age’s U.S. Longwall Census and two longwall faces were removed. White Oak Resources started a new longwall system in Illinois. Alpha Natural Resources is only operating one longwall face at the Emerald mine in Pennsylvania instead of two. Energy West announced that it would close the Deer Creek mine in Utah. Year-on-year, the total number of mines remains the same (42), but the number of longwall faces dropped to 47 from 48. Five mines operate two longwall faces.

Total production from U.S. longwall mines grew at a surprising clip last year. Collectively, U.S. longwall installations produced more than 207 million tons in 2014, a 10.1% increase over 2013. The four top-producing longwall complexes operate two faces each and three of them produced more than 10 million tons. Last year, 20 longwall installations produced at a capacity of 5 million tons per year (tpy) or more.

Among the top four, CONSOL Energy’s Bailey and Enlow Fork mines in Pennsylvania continued to hold the No. 1 and No. 2 positions, respectively. Last year, Bailey produced more than 12.3 million tons. Murray American Energy’s Marshall County mine in West Virginia (formerly known as McElroy) moved above the 10-million-tpy mark last year. Foresight Energy’s Sugar Camp mine in Illinois produced more than 9 million tons.

The three top longwall operators are Murray Energy, CONSOL Energy and Foresight Energy. Murray Energy produced 60 million tons from 10 longwall mines (11 longwall faces), an 8.8% increase from 2013. CONSOL Energy produced more than 30 million tons from four mines (six longwall faces), a 14.9% increase over 2013. The Harvey mine added 3.2 million tons to the CONSOL Energy mix. Foresight Energy grew production organically to more than 21 million tons from three longwall mines (four longwall faces), a 17.8% increase over 2013. On a productivity basis (tons per man-hour), the three Foresight mines were ranked highest in 2014. As a group, these three coal companies produced 111.3 million tons from 21 longwall faces, which amounted to a 12.1% increase of 2013.

Several mines operating individual longwall faces posted some impressive numbers in 2014. BHP’s San Juan mine in New Mexico moved into the No.5 position. It produced 8.8 million tons in 2014, compared to 6 million tons in 2013. Alliance Resource Partners’ Tunnel Ridge mine in West Virginia produced 5.6 million tons, a nearly 2-million-ton increase over 2013. Alpha Natural Resources’ Cumberland mine in Pennsylvania produced 7.4 million tons last year, a 32.5% increase over 2013. Production also increased at Alpha’s Emerald mine in Pennsylvania during 2014. The company, however, idled one of the two longwall faces at Emerald. It will continue to operate the face with the 2-m shields until the longwall-minable reserves are exhausted at year-end.

Murray American Energy’s performance last year would silence anyone questioning its ability to operate the mines it acquired from CONSOL Energy. In addition to the performance of the previously mentioned Marshall County mine, the other four mines — Harrison County (Robinson Run), Ohio County (Shoemaker), Marion County (Loveridge) and Monongalia County (Blacksville) — all posted double-digit percentage increases in production last year. In fact, most of the mines controlled by Murray Energy performed well last year.

With 13 faces, West Virginia remains the longwall leader, followed by Pennsylvania (7), Illinois (7) and Alabama (5). Looking at the numbers, the average U.S. longwall mine operating in coal produces 4.4 million tpy. On average, it has a cutting height of 91.4 in., a panel width (or face length) of 1,228 ft, and a panel length of 12,117 ft. Last year, those numbers were 91 in., 1,188 ft and 11,307 ft, respectively. Seven longwall faces have face lengths of 1,500 ft or greater. A total of 17 longwalls operate in the Pittsburgh No. 8 seam. The maximum overburden on average reaches 1,145 ft. Except for a few mines in Utah, most are developed with three entry gates. Using a 1,866-hp double-drum, ranging-arm shearer, they take a 40.5-in. cut. The average yield setting on the shield is 1,072 tons. All of the faces except for four are high voltage (4,160 volts).

As far as extremes, the deepest longwall mine is the West Ridge mine in Utah, operating at a depth of 3,000 ft. The Powhatan No. 6 mine in Ohio operate