The failure background of an isolated rock wall in soft fractured rock mass of a mine shaft bottom is introduced.

And the Fuzzy-follower is applied in shaft bottom coal conveyor of a medium-sized coal mine and gives good results. Thus, it solves the problem of power balance of double-motor driving system.

They worked with hand trowels, a plywood form for lining the shaft with concrete, inch by inch, and a sturdy hand-built crank for lowering a man to the bottom and sending up buckets of sand.