Abstract: An auxiliary bearing system for supporting a rotating shaft including a first auxiliary bearing coupled to the rotating shaft. A first inertia ring is coupled to and circumscribes the first auxiliary bearing. A second inertia ring circumscribes the first inertia ring. A radial clearance is defined between the first and second inertia rings when the rotating shaft is supported by a primary bearing system, and the first inertia ring engages the second inertia ring when the rotating shaft is not supported by the primary bearing system. A second auxiliary bearing is engaged with an outer surface of the second inertia ring.