An apparatus for stabilizing a shaft in an essentially horizontal position while an anchoring object at one end of the shaft is replaced without removal of an object at the opposite end of the shaft that would otherwise tend to destabilize the shaft from its essentially horizontal position includes a half-spool member configured to clamp above and around the shaft to resist torque around the rotor, under supports configured to attach to the half-spool member and clamp an underside of the shaft below the half-spool member, and a hydraulic or mechanical brake configured to resist torque on the shaft when the brake is engaged.