Abstract: A mining apparatus for working a horizontally and longitudinally extending seam having a vertical face has a longitudinal row of walking props extending along the face and each having a roof-engaging cap, a floor-engaging foot, and a jack vertically interconnecting the respective cap and foot and expansible to press the cap up and foot down. Upper and lower long-wall mining machines each having a predetermined height substantially less than the distance between the mine roof and floor are each provided with a cutter for working the face and a longitudinal conveyor for carrying off material cut from the face. The upper machine is suspended from the caps well above the floor level and the lower machine is carried on the feet of the promps below the caps thereof generally at floor level and spaced back towards the props from the props so that the upper machine moves on a step above the lower machine and the two machines can simultaneously work the seam at respective vertically and horizontally offset levels.