 As ridership increased on Line 1, the trains were rearranged into eight-car trains in the 1980s.As this rearrangement occurred, seven of the trains lost their four motor cars, which were given to the other 14 cars.In place, 26 motor cars were manufactured in Korea between 1980 and 1981 for four of the seven donor trains; one received only two motor cars and ran as a four-car train on the Yongsan-Seongbuk shuttle line, and the other two (four driving cars) were held out of service.