Pelham Line is the second longest line in the Bronx with underground & elevated stations [18]. It's started in 1918, #6 line the whole route from Pelham Bay Park to Brooklyn Bridge. In the Bronx, Local or express [weekdays only] route, then local in Manhattan's East Side. With a pair of fleets, R62A & R142A. https://en.wikipedia.org/wiki/IRT_Pelham_Line https://new.mta.info/document/9456
