Published in the August 2008 Coal USA Magazine

The Robinson Run No. 95 mine in Harrison County, West Virginia, began production in 1965 as a single active section room and pillar operation. Its longwall was installed in 1973, and today its shearer runs daily along with a total of four continuous miners in other parts of the mine.

“Significant change” is not a phrase the operation is unfamiliar with; at present crews are working to seal the older sections of the mine to enhance ventilation and make it smaller and more efficient overall. Also, a trip to the active sections that took its 372 workers nearly 90 minutes just two years ago now takes 10 minutes with the construction of a new portal – easing a supply and output transport headache as well.

With a shorter ride to work, the operation has definitely seen the enhancements in its production numbers. Even with two scheduled longwall moves this year, the 6.3 million clean tons budgeted for 2008 is well on its way to being met.

Robinson Run also proves the old adage that older is wiser, with development, ventilation, haulage and worker logistics that redefine efficiency. The mine’s gate panel fleet includes Voest-Alpine ABM14 miners, Joy 14BU loaders, Joy 10SC32 shuttle cars, Stamler BDF 14 feeder breakers and Fletcher DR 13/15 center bolters, and advancement there averages 270ft daily.

Development at the mains involves just as diverse a group of OEMs, from its two Joy 14CM miners, two Joy 14BU loaders and four 10SC32 shuttle cars to its Stamler BDF 14 feeder breaker and DR15 center bolter by Fletcher.

Its overburden is common for the Northern Appalachian region within the Pittsburgh No. 8 seam, averaging about 1000ft. With no significant roof control issues, Robinson Run’s support plan of 8ft and 12ft coupled tension point anchor bolts and supplemental 12ft to 16ft cable bolts works well with the mine’s design.

With crews keeping so much coal flowing out of the mine six days a week on three eight-hour shifts, a cutting-edge, reliable ventilation design has been key, according to mine officials. The production areas of the operation are ventilated by two high-pressure 1500hp centrifugal bleeder fans and three dual-compartment 3000hp vane axial fans, all of which are exhausting.

Face ventilation is achieved with 100hp dual-rotor vane axial exhaust fans and 18in tubing. One management individual noted that while the mine had encountered some ventilation issues in the past, it was now “excellent” – in fact, the mine is one of the few that do not have to turn air around at the longwall’s tailgate to send it out, as that process is not necessary with its plan.

The longwall crew also has efficiency and effective practice down to a science, with crews of seven utilizing a hot seat method throughout the day to keep the Joy 7LS shearer with 62in diameter drums spinning along the active panel that is supported with 195 Bucyrus two-leg shields, each featuring PM4 electronics and an 800t yield.

As the longwall system cuts away at a budgeted retreat of 88ft daily, coal falls to a 1m face conveyor by Longwall Associates, atop which sits 42mm Thiele conveyor chain powered by triple 800hp motors at about 311fpm.

The stageloader is also by Longwall Associates featuring Thiele chain, but this time the 38mm links are powered by a single 450hp motor that keeps the links moving at 460fpm. The entire group, management noted, is kept running with a brand-new dual Line Power transformer system made up of one 7MVA power car and one 4MVA power car with integral starters.

One feature on the new system is a recent addition to Line Power’s product line, the Down Time Saver, which allows for quicker and easier troubleshooting when electrical issues arise. “It’s been a good decision for the mine,” one noted.

As longwall panels at Robinson Run measure an impressive 1000ft by 11,000ft on average, longwall moves must be well planned and executed. Not a problem, according to mine management, as crews can typically tackle the job easily in the budgeted timeframe of six days thanks to preplanning and proper execution.

That preparation and fluid process for panel changes is even more important when Robinson Run’s future plans for longwall production are so big.

Longwall equipment availability at the Robinson Run operation averages about 95%, and mine officials noted that its preventive maintenance planning program played a significant role in that. The program, which it has installed as a formal process with dedicated responsibilities assigned to its maintenance crew, has kept many nuisance issues seen at other mines from occurring in the first place.

The longwall shearer, stageloader, crawler tailpiece, pump car and face conveyor drives, for example, are rotated out with a second set and are rebuilt with each and every panel. At the time of that change, 25 shields are also taken to the surface for rebuild on a rotating schedule.

“Six maintenance foremen are responsible for scheduling and planning routine maintenance of all face equipment including spare parts and materials orders and availability,” noted management, while two mechanics and one maintenance foreman are dedicated solely to daily servicing and 100-hour diesel equipment checks.

The mine’s transportation equipment is evaluated on a daily basis and serviced by four mechanics assigned to each shift, including battery maintenance, and another mechanic is responsible for the daily maintenance of scoop batteries alone.

Equipment wear is also kept at a minimum and availability and effectiveness to a maximum through a series of oil sampling and analysis checks. Conveyor belt drive gear case evaluations are performed every 90 days with one mechanic in charge of ensuring all belt drives are checked twice weekly for oil levels and greasing.

At the longwall, the conveyor drive and shearer gear cases are given a sampling and analysis review every month, and the conveyor belt, longwall gear cases and motors are given routine vibration analyses. Meanwhile, daily checks are conducted on the longwall and development equipment for greasing and any needed servicing.

While all of the mine’s ongoing processes take a lot of financial planning, so do the capital projects underway at the operation and those that are on the table to be done in the short term. In addition to the new portal and many significant safety improvements, the operation has also seen large changes to its conveyor system.

In fact...click here to read on.