 Unlike the ER1, the cars in the ER2 trainsets were not permanently coupled, which allowed their length to be adjusted according to traffic levels.To facilitate this, from 1964-1970 and from 1981-1984 the Kalinin and Riga plants produced 133 separate driving trailers (to allow the splitting of trainsets into shorter sections); in 1967-68, the Riga plant produced 52 separate power cars to go with the driving trailers; from 1967 onward, 173 intermediate 2-car sections were produced (to lengthen trainsets as needed); from 1973 onward, 58 head-end 2-car sections (with an engineer's cab) were produced; and in 1980, 4 intermediate trailers were built.Production of the ER2 trainsets was ended in September 1984, the Riga Railroad Machinery Plant switching to production of the improved ER2R and ER2T trainsets (basically ER2s, but fitted with rheostatic braking).