Abstract: A rotating shaft assembly comprising a rotating shaft 1 mounted within a casing, and a primary bearing assembly in bearing engagement with the shaft and the casing and positioned between the shaft and the casing; the assembly further comprising a secondary bearing assembly comprising a secondary bearing normally radially spaced from the shaft and arranged to engage with or contact the shaft in the event of failure of the primary bearing normally in contact with the shaft, and means for insertion and/or removal of an inspection member to provide an indication of frictional engagement of the secondary bearing with the shaft.