Published in the May 2006 American Longwall Magazine

Follow the line up a grade past a large stacking tube spilling over with coal and the Alma A portal of Mountaineer comes into view. The building canopy leading out to the mantrip loading area is an extension of the operation’s careful planning.

The mantrip passes Mountaineer mine’s first portal opening, which closed in 2005, and the longwall moved to what is referred to as the Alma A in early 2001. The operation (which originally began longwall operations in 1992) initially mined some 70 feet above current workings in the Lower Cedar Grove seam, while the current active mining is in the Alma A seam.

Mountaineer Alma A at the Ben Creek complex is one of southern Appalachia’s many drift mines and travel time is relatively short to the first of its three continuous miner sections. The trip to the longwall takes a bit longer; its 14 Right panel is about 40 minutes on one of the mine’s DC-powered man buses. As expected in this mountainous area, depth of cover has a significantly wide range of 200-1100ft.

Panel lengths at Mountaineer mine complex vary between 3000 and 11,000ft, and the current panel width is 1000ft. At the face, the most notable features are the significant difference between the seam height of 45 inches and the cutting height of 72 inches.

Workers are able to move around fairly comfortably under the shields. The Joy 7LS shearer equipped with 1500HP and 58-inch drums chews away coal and sandstone. One may guess that such a large differential between cutting height and seam height would affect production speed.

Engineering manager C Wayne Hawley has noted that the issue raises problems with production. “If that’s shale or some sort of softer rock, we’re okay, but when we get sandstone roof and floor with the low seam conditions, [it] causes us hard cutting problems.”

By contrast, the roof control issues that may be assumed in an operation working underneath a mined-out area are not what Hawley cites as a challenge. There are 176, two-leg, 800-ton yield, DBT shields holding up the roof, each with a working range of 54-96 inches.

Despite cutting issues, the Joy meter-wide conveyor carries the ROM coal at 3500tph. Along with 1000mm, 2x42, 400 fpm Thiele chain, the 3x600 HP face conveyor carries coal to a 54in panel belt with a 3500tph capacity. Continental Conveyor serves as the operation’s major OEM belt supplier.

When longwall moves arise, the entire process can be completed in an efficient four to five days. Move planning is conducted, according to mine management, and the strata do not require any special bolt-up processes.

“We sit down and develop a plan for each move and meet with our people so everybody understands everything that’s going on,” Hawley said.

Exploration methods are also employed at the operation prior to and during activity, typically through corehole, channel sample and outcrop.

Longwall shifts at Mountaineer consist of two 10-hour shifts, allowing for a four-hour maintenance window. Hawley said the operation is proud of their methods for preventive maintenance.

“We have a preventive maintenance program through our computer systems called Ellipse. We have preventive maintenance people, maintenance technicians and a maintenance planner that stay on top of the hours (logged) on equipment and predict when we need to make changes. We try to do [both] preventive and predictive maintenance,” he said, “with growing emphasis on predictive maintenance.”

Because workers are often in hard-cutting conditions, Hawley added that extra maintenance is done during those times as needed. “We try to predict when we need to [make] change[s]. The conditions vary hour by hour, but … we do a lot of oil sampling and testing and that’s where we … do more of our predictive work.”

With three continuous miner development units and a longwall, Mountaineer is lucky to not have to contend with large amounts of methane gas. To ensure safety, Mountaineer has an intricate ventilation system including four fan installations, an intake shaft with blowing fans above it and bleeders on the east and west sides of the longwall.

Hawley noted that a push-pull system is utilized with its bleeder shafts, for which an exhaust fan is installed on each shaft.

“The majority of our [workings are] above drainage, and typically don’t have a lot of methane problems above drainage.”

Roof strata are also under control at the mine, with 4-foot resin bolts installed in a 4ft x 4ft pattern using Fletcher dual-head roof bolters.

Across the valley at the Black Bear preparation facility, heavy media vessels, heavy media cyclones, spirals and froth flotation are used for coal cleaning to prepare the output for shipment, which is all sent by rail to its customers, which include US Steel. The facility has a 2000tph capacity and currently runs at approximately 40% yield.

In 2005, the mine produced 2.4 million tons clean coal with longwall mining, which will cease in late 2007. Continuous mining seems to be this operation’s future, as Hawley noted Mountaineer’s remaining reserves will be taken by using continuous miners.

In contrast to the longwall, CM units work Monday through Friday with two nine-hour shifts. Sometimes, he noted, a sixth day will be added to the normal schedule. One underground miner confirmed that both longwall and CM workers will often volunteer extra hours and that there is never a shortage of personnel signing up for additional work.

Arch’s new Mountain Laurel operation has tentatively scheduled its longwall installation to start around the same time Mountaineer will be shutting down its shearer and retiring the longwall.

Some workers will take advantage of the timing by transferring, while others may stay at Ben Creek or choose retirement. In either case, the company is proud of its staff of 300-plus employees.

Safety and environmental stewardship are of primary concern at Mingo Logan and Arch Coal. The Ben Creek operation has won numerous environmental awards from the state’s Department of Environmental Protection (WVDEP) as well as the Office of Surface Mining (OSM). In fact, the operation is recognized as one of the safest operations in West Virginia and MSHA District IV.

“Our goal is for every worker to return home safely to their families at the end of their shift,” said general manager Jim Mullins.

“Our objective is to do our work in a safe and environmentally responsible manner, be a good neighbor and do our jobs efficiently.”