However, rail service through Oppsal is older, having opened as part of a suburban tram line in 1926.[1] It was opened by operator Akersbanerne as part of an extension from Bryn. There was a balloon loop here. It remained the terminus of the Østensjø Line, until 1957, when it was extended to Bøler. The station was opened as a subway station on the 29th of October 1967. P.A.M. Mellbye was the station's architect.[2]
