Joy Stamler BH10H AC sets new performance standards

Introduced to the mining industry less than three years ago as what Joy Mining Machinery describes as “the most innovative, most advanced underground battery powered articulated hauler available today,” the Joy Stamler BH10H AC continues to meet and exceed every expectation according to Donnie Evans, Battery Hauler Product Manager in the Stamler Battery Hauler Engineering and Development Group.

“This machine, capable of running as fast with a full load of coal as it does when it’s empty, is setting new performance standards,” Evans said, “nearly doubling the battery life gains realised since first going into operation just a year ago,”

The new JOY STAMLER battery hauler alternating current (BHAC) articulate hauler recently completed Phase II in its planned evolutionary development, according to Evans. “In this phase, continued refinements were made to further enhance the shift battery life power discharge cycle; thus increasing the performance and productivity of the entire battery hauler line of equipment. These ‘state-of-the-art’ electronic designs are setting a new pace in underground haulage, the result of continuous product development, testing and refining of the BHAC’s revolutionary concepts,” he said.

According to Evans, with the introduction in PHASE II of ejector hydraulics and electronic controls, battery life of the mid-seam BH10H AC battery hauler operating on an extended super section in the American Midwest Illinois Coal Basin was increased 10%. This nearly duplicated the 10 to 12% improvement in per discharge cycle gained during the Phase I implementation period (September 2006 through March 2007), as compared to similar model machines with DC motors and electrical drive packages.

“The major advantages of AC drives over the traditional DC drives are that more power can be provided to drive the machine in the same space previously occupied by the DC motors, along with more simple servicing and maintenance,” Evans explained.

“In addition, the brushless AC motors eliminates the possibility of contaminants entering the motor when brushes were changed, as is the case with DC motors. Further, the AC drive machine’s traction motors maintain machine speed and torque when pulling loaded up a grade, a result of the high efficiency of the drive and motor package combinations. The Joy Stamler BHAC, with its patented electronics and innovative design places this battery hauler product line as one of the most innovative in the industry,” Evans said.

“After a year’s operation and continuous fine-tuning under Phase I of its development, the BHAC system has more than proven the original development goals,” Evans said. “Namely: Extended battery life, high motor efficiency and east of maintenance utilising brushless alternative current motors, combined with variable frequency drive (VFD) controls and cutting-edge diagnostics and data acquisition,” Evans said.

“The goal of Phase II, in the project, was to further enhance the shift battery life per discharge cycle and therefore increase the performance and productivity of the machine to yet another level. With the release of Phase II ‘ejector hydraulics with electronic controls’, the results indeed not only are meeting, but are exceeding expectations.”

According to Evans, the continuous development of the BHAC battery hauler since its introduction at MINExpo and through its initial application at the Midwest underground coal mine a year ago, have “raised the bar” for underground haulers and have resulted in “high levels” of efficiency and productivity, along with a high degree of operator acceptance.

In Phase II, the BH10H AC machine was placed back into service in the same mine application as in the benchmark Phase I period in order to achieve an “apples-to-apples” comparison and data retrieval process, Evans said. “Overall battery life per discharge cycle associated with these type haulers always has been a product of many variables,” he said, “tangible variables in design as well as intangible variables such as overall mining conditions and even machine operators. While the intangibles are beyond the control of the manufacturer, in Phase II Joy Stamler not only reined in and controlled the tangible design variables, with the introduction of AC VFD systems, coupled with the new hydraulics design, the line of battery powered haulers has taken overall battery life per discharge cycle to a new level.

“Also, in Phase II we introduced a battery assembly that is physically the same overall dimensions as the original batteries utilised in Phase I but which provided a larger amp hour/kW capacity. All of which translates into more productivity per battery cycle for the mining operation,” Evans said, adding: “Since implementation of Phase II at the Midwest coal mine, they are realising 9 to 9 ½ hours of operation per discharge cycle with the original battery design and 10 ½ to 11 hours of continuous operation per discharge cycle with the larger amp hour capacity battery. And that,” he noted, “was accomplished in some rather adverse conditions. It has been a real test of the BHAC system’s capabilities, a test met and passed.

“This mine,” Evans said, “has some fairly adverse conditions. Unlike most coal operations in the Illinois Basin, this Midwestern mine produces a compliance product. However, seam conditions are often less than desirable; the seam pitches and rolls. In fact, the mine actually has hills underground, something that is uncommon to most of the other underground mines in the Midwest, and it’s relatively shallow, with less than 45 m of overburden in places. A room and pillar operation, the coal seam varies widely in thickness and elevation and it has partings, which makes it unsuitable for longwall mining, and the variability of the seam also precludes continuous haulage as a serious consideration. The mine operates with four walk through super sections, each with two continuous miners, four battery powered haulage vehicles, two dual-boom roof bolters, as well as a Joy Stamler feeder breaker.

“Historically, rubber-tyred haulage has proved best for the mine currently operating the BHAC machine,” he continued. “Here, the BHAC has been operating along with other Joy Stamler battery haulers in one of the walking super sections. With the rolls and undulations in the mine, as well as the occasional soft bottom, this mine has offered a good proving ground for battery haulers in general,” he said.

As Evans noted, because there is no trailing cable, an advantage to battery-powered haulage is in providing the mine operator with far more flexible haulage routing, while still delivering low speed/ high torque operation. “Obviously, diesel powered haulage would provide the same cable-less flexibility,” Evans said. “However, with battery powered haulers there is no requirement for any additional face ventilation and these machines operate much cooler than diesel, effecting both even more additional ventilation and operator comfort. Finally, Joy Stamler haulers offer the ‘vertical articulation’ terrain compensation feature that provides unmatched versatility in undulating bottoms inherent with rolling seams.”

With vertical articulation, Evans explained, Joy Stamler actually designed into the machines a midsection that provides an additional pivot point so that the operator can pivot the hauler up and down at the center for a total of a 25-degree movement. “A terrain compensation feature, if you will, for operating in undulating bottoms,” Evans said.

Additionally, with the articulated midsection, the operator actually can place the trailer end of the machine onto the ground, allowing for the direct loading and unloading of components, parts and other supplies. This feature also allows the use of the battery hauler in moving up battery charging stations during a move, Evans said. “There is no lost time waiting for other transportation equipment. More than a few coal operators have commented on the advantages of this ability in making moves easier, quicker and safer; all of which translate into less time involved in moving, and more time mining and hauling coal.”