One of the tasks assigned Panel M-16 (Modernization of Propulsion Shaft System) of the Society's Technical and Research Program, under the guidance of the Ships' Machinery Committee, is the Investigation and evaluation of various types of shaft bearings with their related problems under simulated and actual operating conditions. This report was prepared as a panel effort to summarize and disseminate available information on only one phase of this extensive program. It is their hope that these recommendations will be of assistance in the repair of cast copper base tail shaft liners. These recommendations deal with repair methods that are employed to recondition cast copper baseliners on tail shafts when periodic examinations reveal repairs to be necessary or desirable.