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,
Romford–Upminster line the refurbishment work was transferred to Wakefield in Yorkshire and the transfer was done by road. The point-work which was half installed is still visible from the eastern end of platform five at Upminster. The line is entirely within Travelcard Zone 6. Services are currently operated by London Overground, which replaced the previous operator, Abellio Greater Anglia, in May 2015. Trains are typically formed by a Class 315 or Class 317. As of December 2015, the service pattern on the route is one train every 30 minutes between approximately 6:15 am and 10 pm Mondays to Saturdays, and approximately 8:30