Bucyrus automated plow systems have just completed ten years of successful operation in a number of Tiefa mines located in the northern Chinese province of Liaoning. The first Gleithobel plow commenced operation in January 2001 and is still in operation today. This was the first automated plow system in China. Equipped with 2 x 315 kW drives and designed for cutting very hard coal, the plow operates on a 200-m face with a seam height of 1.25 m. Bucyrus’s modern, automated plow systems are making a significant contribution to the coal production throughout the world, in countries including China, Russia, Czech Republic, Germany, Kazakhstan, Mexico, Poland, Ukraine, and the US.Since a former Bucyrus company invented the plow in 1937, Bucyrus has stayed on the cutting edge of plow technology by adding numerous new features as well as boosting installed power to allow faster extraction. In contrast to a shearer – which requires considerable height to operate – the very compact plow can practically operate in seams as low as 0.8 m. Bucyrus offers two types of plow: The Reisshaken or base-plate plow designed for extremely thin seams and the Bucyrus Gleithobel (GH or gliding plow), the world’s most powerful longwall mining system for maximum productivity and minimum cost of ownership in medium and thin seams – even in hard coal. Bucyrus plow longwalls can be fully automated with no operator required at the face. This not only enhances productivity, but is also a great safety feature.
Over time Bucyrus plow systems have shattered world production records for thin-seam longwall production and productivity – and the combination of this experience, ongoing R&D and a passion for continuous improvement maintains Bucyrus’s world leadership in this specialised area of coal mining. Today, Bucyrus automated plow systems provide reliable and superbly engineered mining technology. With installed power of up to 2 x 800 kW, Bucyrus plows extract coal at rates of up to 3,500 t/h.
As one example, on August 25, 2010 a Bucyrus Gleithobel® GH1600 plow with an installed power of 2 x 800 kW achieved the European daily output record respectively world record for road ways with arch supports of 16,894 t in Bogdanka’s mine Puchaczów in Poland (See International Mining’s March 2011 issue for a full report on that mine). And back in May 2000, US Steel’s Pinnacle mine – the world’s first fully automated longwall face – achieved the still existing world record for rectangular gate roads of 20,593 t/d using a Bucyrus Gleithobel plow with only 2 x 400 kW of installed power. The mine is now owned by Cleveland Cliffs and Bucyrus’ new GH 1600 Gleithobel plow system with 2 x 630 kW of installed power has started operation not too long ago with the expectation to set yet another world record.
Incremental plowing – a feature offered from a single-source supplier only by Bucyrus – means that the plow cuts to an exactly defined depth, regardless of coal hardness, seam structure and faults. Bucyrus says “competitors’ systems only allow the DA ram pressure to be set; with the result that cutting depth varies with coal hardness.” Bucyrus horizon control ensures that the plow does not dig or climb unless required by the seam geology.
Sophisticated technology is also used to protect the plow chain from overload. Power consumption of motors is constantly monitored to allow load sharing between the individual drives. Variable Frequency Drive (VFD) motors are now available; allowing the plow speed to be varied between 0 and 120% of nominal, while maintaining constant torque throughout a broad speed range. Also, an innovative shock absorber – an elastic coupling installed between the chain and the plow sledge – reduces peak forces applied to the chain.
As a result of their unique features and high performance, Bucyrus automated plow systems are the preferred mining method for seams below 1.8 m.