A mineral mining machine having an electric motor, at least one cutter unit and haulage drive mechanism for moving the machine along a mineral face, said cutter unit including a cutter element and a variable speed gear-train interposed between said electric motor and said cutter element to drive said cutter element, torque sensing means associated with part of said cutter gear-train to sense the torque transmitted by said gear-train and to provide a signal when the torque transmitted by said gear-train exceeds a predetermined level, load sensing means associated with said electric motor responsive to current flow through said electric motor to provide a signal, said haulage mechanism having an hydraulic motor, a source of hydraulic fluid, a variable output pump for feeding said hydraulic fluid to said motor, and control means in an hydraulic circuit responsive to said signals from the torque and load sensing means to control the hydraulic pump output and thereby effect reduction of the haulage speed.