... drilling rig: 1)Drilling depth,7000m, 2)Hook load, 4500kN, 3)Drawwork power,2000kw, 4)Auxiliary brake:E.T. N brake ZJ70/4500D rig ... by drawworks, the main brake of which is hydraulic disc brake, the auxiliary brake is electromagnetic ... satisfy the requirement for explosion-proof, safety, drilling engineering and equipment installation, dismantling and easy maintenance ... (42)141 (43)148 (45) drilling rig