Published in the August 2007 American Longwall Magazine

Revolution extracts from the Powellton Seam that laces through Boone County in southern West Virginia, is under between 500 and 1000 feet of overburden. Both the mine and longwall are well into their groove, with the start of production in 1997 and the first pass at the face two years later.

Thanks to the development of the new Potato Branch slope at a capital cost of $10 million that has allowed the removal of 19,000 of belt line exposure, Massey will begin feeling the positive effects of a shorter haulage infrastructure including less maintenance and more rapid processing of the output from the operation's one miner section and one longwall face.

Mine president Billy McCoy explained the inception of the operation as Revolution, which was idled by another company and purchased by Massey in 1995 due to what he called "strategic location and synergy" with other Massey operations. "Due to its large contiguous reserve of Powellton seam - not common in central Appalachia - the decision was made to longwall mine the reserve," he said.

The trip to the face, incidentally, is a quick 15-minute ride via one of the mine's Brookville rubber-tired diesels and once at the initial crosscuts, via one of several battery-powered Brookville track-based mantrip atop new rail line. Since the shearer was turned in 1999, Revolution has mined out 10 panels and has retreated 99,000 feet total; the longwall panels in planning are estimated to be 1000ft wide and 10,000ft long.

Now in their eleventh panel, McCoy said the progress being made at the face is like a well-greased wheel, as some of their monthly averages have been upwards of 600-900 ft (30fpd). The face uses a Joy 7LS1A shearer with a 46in tram height and 62in drums. The Joy shields at panel 11 total 176, each two-leg unit having an 875t capacity and shield range of 46 to 88in.

Seam heights at Revolution are between 42in and 72in, but cutting height is typically 72 to 84in. Management noted this is for clearance purposes on the track and headgate entries.

"We currently have a Longwall Associates’ low profile panline which lowers total height by 1.75 inches," McCoy noted, adding that the stageloader consists of a 300hp crusher and a dual 250hp drive motors, which has extended 20ft by the operator to increase chain life and wear.

Coal is carried off at a mean of 3500tph using a system made up of 60in longwall belts with a 4500tph capacity and 42mm face chain that feed onto a 60in, 5500tph mainline belt and then a 72in, 5500tph slope belt at a 12% grade. Revolution's transfer belts measure 72in and 5500tph and carry output to a 100ft stacking tube and stockpile at the surface.

After each panel move, all major components of the system are rebuilt, he said. "All rebuilds of shearers and AFC gearcases are strictly OEM (Joy) with some fabrication work awarded through competitive bidding."

Gas is not a significant issue at Revolution, and no pre-drainage is carried out ahead of mining. Management noted a dilution method is used for ventilation, where blowing fans are incorporated on the intake side, exhaust bleeder shafts and high-pressure/high volume exhaust fans; this allows more ventilation air to be delivered to the face.

In general, McCoy said of the ventilation circuits that include belt air use: "Revolution is basically a push-pull system ventilated by an intake ventilation shaft with a blowing fan, return shaft with exhausting fan and [the] longwall bleeder shaft. [It] also has a belt slope, a mantrip-supply slope, an elevator shaft an additional intake shaft and three draft openings."

As opposed to gas, Revolution officials say geology is more the primary issue with regards to the mine. "The main challenges we face at Revolution are the successful handling of typical longwall problems [including] deep cover area, mining in swag areas and sandstone roof areas," he explained of the operation's own situation, as it sits amid typical Appalachian geology of shale roof (3-6 feet) and a sandstone main roof.

Also relating to roof control, Revolution's strata control procedures are well in line with other neighboring mines in the southern West Virginia region. A typical 4 by 4 spacing is utilized, with 6ft TT bolts and 10 to 12ft cable bolts in the headgate ad tailgate; bolts are drilled for and secured with a Fletcher RRII on the section and Fletcher Can Bolters and HDDR's outby and at the longwall.

There are seven entries with 100 by 105 average centers in mains development and three in gate development (coming in at 110 by 105 on the tailgate side and 90 by 105 on the headgate), with all progression made using a continuous miner supersection. Two Joy 12-12CMs take on the labor of development, while the balance of the fleet at the active section includes three Joy 10SC-32Bs, a BF-17 permissible feeder, DBT and Fairchild scoops, AL Lee forklifts and DBT shield haulers.

As the CM advances at an average 265ft daily, Massey crews are careful about roof and rib control. Primary roof support, according to McCoy, consists of four to five 6ft torque tension bolts per row with wire mesh, and additional tailgate support, including propsetters, is made up of two cable bolts measuring 12ft each, placed every other row.

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