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26 www.coalage.com November 2018 high-hp moters Modern Motor Solutions Offer Glimpse of History, Future of Coal Mining Modern solutions speak to a deep, cyclic history of innovating for safety, efficiency and savings by jesse morton, technical writer If the state of the domestic longwall mo- tor solution market is any indication, then the U.S. coal sector in general appears to be on the mend. "We're getting back to what was normal before Obama, almost," longtime longwall motor solution mogul Scott Mohler said. "Pre-Obama and post- Obama are very similar, although we had to build back up in the post-Obama-era." Similarly, Greg Hite, who has been in the business almost as long, reported his com- pany is now "constantly building" high-hp motor drive solutions for the coal space, although with the caveat that those drives see some demand "no matter what the market situation is." Even if the longwall motor solution market is not a perfect barometer of big- ger economic trends, it does provide a snapshot of some trends in the evolution of underground coal mining technologies. What follows is a quick glance at the lat- est news coming from some of the bigger players in the space. Dependability, Made in the USA Approximately 30 years ago, Mohler Technology Inc. (MTI) released its first water-cooled motor prototype, which would provide the basis for the company's Mine Safety and Health Administration (MSHA)-certified explosion-proof motors for longwall coal mining and other under- ground mining applications. That release forever changed both the company and underground coal mining in general. The shortcomings of the prede- cessor solutions on the market at the time served as a foil to the host of benefits of- fered by new motors. In 1988, the motors available for long- walls and similar applications were en- closed-fan cooled. "They were failing these motors because a lot of them would get buried," said Scott Mohler, president, MTI. Because they were buried in coal, "you don't have ambient air around them and it becomes impossible to cool the motors," said Steve Mohler, account manager, MTI. "We were made aware that, at these mines, on some of the equipment, they were us- ing water-cooled gearboxes." Taking that concept and applying it to longwall motors represented low-hang- ing fruit, well within reach of a company previously dedicated to repairing motors from almost any manufacturer and min- ing application. When a fellow Indianan, Old Ben Coal Corp., probed for solutions to recurrent air-cooled longwall motor conundrums, MTI seized the opportunity. "I recom- mended the change to water-cooled mo- tors," Scott Mohler said. "At that time, there were none running on underground mining machines in the U.S." MTI was "the first to come up with se- riously considering telling a customer that this was a possibility," Steve Mohler said. "And then, getting deeper into it, we found that no one actually manufactured anything like it." There was a reason. "The motors that were running underground had to be MSHA explosion-proof certified ma- chines, not just any motor," Steve Mohler said. "Secondly, the method for mounting the motors to the equipment being built by the longwall equipment manufactur- ers was a D-flange." The unique mounting bolt pattern was a design barrier for many water-cooled motor manufacturers com- mitted to existing designs. MTI initially sought to farm out the task. "We looked for suppliers, and there weren't any that could build this motor," Scott Mohler said. "So, we chose to build it ourselves." And the company was positioned to handle it. "We had load-test capabilities here, dynamometers to test new-designed motors, which you have to have if you are going to design something to make sure it produces the torque values and everything that you want," Scott Mohler said. "The only thing that we did was de- sign a motor based off the bolt pattern it took to mount it to the tunnel housing that they mount it to on a longwall." MTI "did have to get laminations, stamp and die and everything running for the first design," Scott Mohler said. Those hurdles bested, "when we received In 1988, Mohler Motors develops its water-cooled longwall motor prototype. Above, Scott Mohler underground. (Photo: Mohler Technology Inc.)