FIELD: mining, particularly, plants for drilling of hard rocks. SUBSTANCE: plant has boom hinged with frame and turning relative to boom axis, hoisting cylinder between boom and frame, feed bar installed on boom other end and hinged to it, and turning on axle, and turning cylinder between feed bar and boom. In this assembly, hoisting cylinder has three cylindrical cavities, first and second of which may be connected with working fluid source for hoisting and lowering of boom. The third cylindrical cavity is found inside hollow piston rod, and cylinder has fixed servopiston extending inside piston rod. The third cylindrical cavity is connected with turning cylinder, with its first cylindrical cavity and the second cylindrical cavity of turning cylinder may be connected either with working fluid source or with its receiver simultaneously with the first cylindrical cavity of hoisting cylinder. EFFECT: higher plant efficiency due to reduced time for face drilling off. 3 cl, 2 dwg
