Mining began at the Center Mine in 1970.

In areas of thick overburden, a hydraulic excavator and a fleet of end dump trucks are used to remove part of the overburden prior to dragline operations. The excavator and truck overburden removal step was introduced into BNI’s mining process in 2012.

The primary overburden removal tool at the Center Mine is the dragline. These machines can remove overburden up to 120’ thick and place it in piles 140’ high. The buckets of these draglines are larger than a typical school bus. They are powered with electricity produced from the same lignite they uncover.

Since 1970, lower stripping ratios have facilitated the economic recovery of coal at the mine. However, the ratios have steadily increased and currently in areas exceed 10:1.

After the lignite has been uncovered with the dragline, it must be broken into smaller pieces before it can be hauled to the power plant. This operation is done with bulldozers. The bulldozers at BNI are equipped with a large ripper shank built specifically for breaking coal into pieces small enough to be placed into BNI’s haul trucks.