London Underground rolling stock the 150th anniversary of the opening of the Metropolitan Railway special services ran in January 2013 using a restored 1892 "Jubilee" carriage, 1898–1900 bogie carriages, steam locomotive No. 1 and electric locomotive "Sarah Siddons". Further events are planned in 2013 for Locomotive No. 1, "Sarah Siddons" and the Jubilee carriage, including a "Steam back on the Met" scheduled for May. To celebrate the 150th anniversary of the District Railway the London Transport Museum are restoring a three-car Q Stock train to run on the District Line as special services during 2018. After the District Railway had electrified in 1907 it
London Underground has expanded to 11 lines, and in 2016–17 carried 1.379 billion passengers, making it the world's 11th busiest metro system. The 11 lines collectively handle approximately 4.8 million passengers a day. The system's first tunnels were built just below the surface, using the cut-and-cover method; later, smaller, roughly circular tunnels—which gave rise to its nickname, the Tube—were dug through at a deeper level. The system has 270 stations and of track. Despite its name, only 45% of the system is underground in tunnels, with much of the network in the outer environs of London being on the surface. In addition,