The company commissioned a Cat longwall system at its Bogdanka mine, near Lublin in eastern Poland, during March 2010 and within six months had raised the bar to nearly 17,000 mt of raw coal per day. Since then, Bogdanka has continued to increase its daily output, with a plow face that began mining in the new 7/VII/385 panel last October having taking the world record to new levels. And, as well as achieving record output, the plow face advanced more than 27 meters at a 1.63-m cutting height. “We thought this achievement would be impossible for any shearer in seam heights as low as this,” said Zbigniew Stopa, vice president of Bogdanka.

“The fact that Bogdanka uses arch supports makes the world record even more impressive,” said Michael Myszkowski, product support manager for Cat plow systems. “Bogdanka is very ambitious, and they have been putting a lot of effort into technical and organizational improvements at the mine. We have worked together on the system to make this new world record possible.

“The record is clear proof of just how productive our automated plow systems can be in the right hands,” Myszkowski said. Later this year Caterpillar is set to deliver a second plow system to Bogdanka, for use in the mine’s new Nadrybie section.

When Bogdanka awarded Caterpillar the initial order for a complete automated longwall plow system, its requirement was for a daily output of 10,000 mt. Right from the start, however, it was clear the face could produce far more than the company’s target, with an impressive 13,000 mtpd achieved during the commissioning period.

Bogdanka’s success has been built on the huge advances that have been made in plow automation and technology, especially over the past 10 years. Advances in the drive, control and transmission systems—with more powerful motors, stronger plow chains, faster plows, greater transverse push forces, precise control of the plowing depth, and plow bit improvements—mean that Cat plows can be used for high-volume production in any coal hardness. In addition, Cat plow systems have more installed cutting power than those of any other manufacturer—up to 1,600 kW. Designed for high productivity in very hard coal, these are the systems of choice for seams up to 2.3-m thick.

Supplied on a turnkey basis, the Gleithobel GH 1600 plow system installed at Bogdanka has 2 × 210/630 kW of installed power for the plow, and 2 × 800 kW for the armored face conveyor (AFC) equipped with the intelligent CST drive system. Each of the 173 roof supports, with a support range of 950 to 2,000 mm, is equipped with its own PMC-R electrohydraulic roof support control. Other units from the Cat Programmable Mining Control family are used for overall face automation and visualization, as well as for drive control. The longwall is equipped with a PF4/1032 face conveyor, a PF4/1132 entry conveyor, and a SK 1111 crusher. Caterpillar also provided the power supply and pump station equipment.

The Cat plow longwall installed at Bogdanka works in automatic mode, which means that fewer people are needed on the face to control the plow and to advance the shields during operation.

An automated Cat plow face does not need real operators on the face—unlike shearers.

Incremental plowing is used, which means the plow cuts to a precisely defined depth, set as a function of coal hardness, regardless of seam structure or faults. The cutting depth is electronically preset using accurate stroke sensors and an advanced software algorithm. Horizon control provides precise control of the plow angle, ensuring the plow does not dig or climb unless required to do so by the seam geology. This allows the system to follow the seam-floor boundary accurately, as well as enabling it to follow undulating seams.

Against a backdrop of gradually declining hard-coal production in Poland, Lubelski Wegiel Bogdanka has been the only company in the country to buck this trend. One of Poland’s major mine operators, it produced 5.8 million mt of clean coal in 2011 and is planning to increase its output to 11.5 million mt in 2014.

It is estimated that some 30% to 35%—or 1 billion mt—of Poland’s coal reserves lie in thin seams. The Polish mining industry abandoned plow technology in the 1990s because of its low productivity at that time, when systems were low-powered and lacked any automation. Today, however, the success of Caterpil-lar’s new-generation plow systems is causing a renaissance, and at Bogdanka alone, Cat plow technology will increase the mine’s recoverable reserves by some 100 million mt.