Identification of defects and incipient failures before the breakdown of the equipment is recognized as an important maintenance activity in the railroad industry to improve efficiency and safety of the operation. It is well known that a proper implementation of condition monitoring improves the overall equipment reliability and reduces unexpected field failures. Traction motor faults can result in critical damage and unsafe operation, if not rectified in a timely manner. Some notable faults include bearing failures, shaft fatigue, and rotor eccentricity. For example, there are documented instances where an individual motor shaft failure induced cascaded failures, which resulted in critical system-wide failures. Electrical failures include stator winding short circuit due to insulation break down. This proposal is intended to investigate the feasibility of developing an intelligent diagnostic condition monitoring system for in-service traction motors so that the incipient failures can be detected and preventive measures taken to avoid serious incidences.