rotating a turbomachinery rotor 12 at variable speeds for the purpose of performing multiple service operations including but not limited to lathe turning milling welding and low speed dynamic balancing the rotor 12 is represented as a steam turbine rotor though it should be understood that the invention is not limited to any particular type of rotor or rotor construction the shaft 16 of the rotor 12 is shown in fig1 as coupled to a spindle 20 extending from a headstock enclosure 14 the apparatus 10 further includes bearing pedestals 22 for supporting the rotor 12 along its axial length the apparatus 10 preferably has a load capacity sufficient for very large rotors for example up to about 140 tons about 127 metric tons the headstock enclosure 14 is shown in fig2 as including a headstock 24 that supports the spindle 20 and a motor 26 and gearbox 27 for rotating the rotor 12 at relative high speeds in part the motor 26 is chosen based on the desired capability to both continuously and intermittently rotate the rotor 12 at speeds for performing operations such as machining stress relief dynamic balancing etc necessitating a high torque capability the output speed capability of the motor 26 may be for example a motor armature speed of up to about 1750 rpm and a suitable power output for the motor 26 is about 200 horsepower about 150 kw though it is foreseeable that motors with speed and power outputs outside of these ranges could also be used a preferred motor 26 also has a stall torque capability of about 500 ft lbf about 680 j motors with these.