London Underground L Stock London Underground L Stock London Underground L Stock was a clerestory-roofed rail stock built for the District line in 1932 and subsequently absorbed into the London Underground Q Stock, being redesignated Q31 Stock. The L Stock trains were built to provide additional rolling stock for the eastward extension of the District Line from Barking to Upminster. Two new electrified tracks were added parallel to the existing steam-operated LMS lines, including several new stations such as Upminster Bridge. Forty-five cars were built by the Union Construction Company, eight were driving motor cars and the rest were trailers. The eight motor cars,
London Underground Transport, and discontinued the use of the London Transport brand in favour of its own brand. The transfer of responsibility was staged, with transfer of control of the London Underground delayed until July 2003, when London Underground Limited became an indirect subsidiary of TfL. Between 2000 and 2003, London Underground was reorganised in a Public-Private Partnership where private infrastructure companies (infracos) upgraded and maintained the railway. This was undertaken before control passed to TfL, who were opposed to the arrangement. One infraco went into administration in 2007 and TfL took over the responsibilities, TfL taking over the other in 2010.