Caterpillar is building on its Bucyrus acquisition with the recent signing of another contract to deliver an automated longwall coal plow system to Chinese company Gasification Co part of Lvliang Dongyi Group.

The system marks the 11th plow system from DBT/Bucyrus/Caterpillar for delivery to Chinese mines. The system will be delivered in the first quarter of 2013 and will go to work in the Xinyan mine in Shanxi province. The system will mine a metallurgical coal seam with a height of 1 to 1.2 meters and the face length will be 240 meters.

The Cat GH800 plow will be paired with a Cat armoured face conveyor using PF3 line pans, and the Cat PMC-R roof support control system will manage roof support advance. Automation enhances safety, as there is no need for an operator to be at the coal face during operation.

In China, automated plow longwall faces from the Caterpillar predecessors, DBT and Bucyrus, hold all of the production records for seams of less than 2 m thickness. Tiefa Coal Mining Group, with a 50% share in the joint venture project with Dongyi, owns four such systems already and has publicly indicated that the plow systems enable them to profitably mine thin seam reserves that otherwise would be uneconomic.

As an example of the robust design and power of Cat plow systems, the gliding plow guide is welded to the face side of the armoured face conveyor. Plow chains up to 42 mm can be used, allowing power installations up to 2 x 800 kW.

On older-style systems, the cutting depth was typically controlled by adjusting the shield advancing ram pressure. As a result, cutting depths varied with coal hardness. A modern Cat plow system, however can cut a precisely defined depth, regardless of coal hardness and seam structure.

Cat plows are claimed to offer a unique horizon control system and incremental plowing that allow the plow angle to change to follow the seam and to easily traverse geological faults. They also offer overload protection and load sharing to maximize efficiency.