Tetsuo Shimomae received his Master's degree in Electrical Engineering from Nagoya Institute of Technology in 1966 and joined the Japanese National Railways (JNR) the same year. In1967, he started working with the Railway Technical Research Institute (RTRI), developing an overhead catenary equipment inspection vehicle and improving the Shinkansen pantograph. In 1974, he received the Ohm Award from the Promotion Foundation for Electrical Science and Engineering. In 1987, when JNR was split into several private companies, he belonged to the JR Central Company which took over the Tokaido Shinkansen. There, he served as head of the Shinkansen division's electrical department, deputy general manager of the Engineering Department, manager of the Safety Management Department (director), and Shizuoka Branch President (managing director). After leaving the company, he served as president and chairman of Shinsei Technos Co., Ltd., a subsidiary of JR Central in charge of construction and maintenance of railway electrical equipment. In 2008, he became chairman of the Japan Railway Electrical Engineering Association whose members are railway electrical engineers, manufacturers, and associated construction companies, and has been an advisor since 2012.