Mining apparatus is disclosed in which a cutting wheel supporting a plurality of roller-cutters rotates about a horizontal axis and is supported on a slewing boom for cutting a tunnel with a flat floor and roof and elliptical walls as it slews across a mining face. The slewing boom is supported on a main beam assembly, the front end of which rests on powered crawler tracks and the rear end of which passes through a gripper assembly which may be clamped between the floor and roof of the tunnel, and against which the main beam assembly may be urged forward for engaging the roller-cutters with the mining face. A preload crawler is urged against the roof of the tunnel above the powered crawler tracks to locate the main beam assembly rigidly relative to the tunnel such that the roller-cutters may cut the rock in the mining face with minimal loss of cutting force due to vibration. Apparatus for automatically controlling one or more of cutter penetration depth, cutter penetration rate and cutter slew rate, which includes a sensor for sensing a given mining machine parameter, a processor for processing the given mining machine parameter to provide one or more of an optimum cutter penetration depth, cutter penetration rate or cutter slew rate value, and a controller for controlling one or more of cutter penetration depth, cutter penetration rate and cutter slew rate based on the derived optimum value.