July, 1970: Model 80 electric cars of 81- 93 were altered one by one in order to use them for two-car train operation (the conversion to two-car train operation was completed in January 1972).
1970年（昭和45年）7月-80形電車81～93を順次2両連結編成に改造（1972年1月までに2両固定編成化完了）。