 Northern line trains first served the station on 3 July 1939 . After completion of the electrification of the line to High Barnet , Underground services were extended northwards on 14 April 1940 . The station continued to be served by LNER steam trains from Highgate until 2 March 1941 when that service was discontinued . The inner platforms are now used only by northbound trains entering service or southbound trains terminating at East Finchley on their way to or from Highgate Wood depot south of the station . 
