support unit 9 which is located u2014 in the direction of movement 19 u2014 behind the coal cutting machine 21 is advanced in the direction toward the mined coal face likewise the following longwall support units 8 7 6 5 and 4 are in the process of advancing in the direction toward the longwall or the mined coal face the coal face catcher on these longwall support units has already been lowered again the support units 3 2 1 have finished their approach and remain in this position until the coal cutting machine approaches again from the right as a function of the movements and the instantaneous position of the coal cutting machine the control of these movements occurs in part automatically in part by hand to this end a separate mining shield control device 34 is associated to each of the longwall supports 1 18 a separate longwall control device 33 is associated to a group of longwall support units or mining shield control devices each of the mining shield control devices 34 is associated to one of the longwall supports 1 18 and separately connected to the pilot valves 45 and main valves 44 of all biasing means of the longwall support units 1 18 via a valve control device microprocessor 40 each of the mining shield control devices serves as a central longwall support control however a group of a plurality of mining shield control devices can be superposed by a longwall control device 33 or also the entirety of the mining shield control devices can be superposed by a central.