London Underground carriages thought to be a District Railway first class, but now thought likely to be a cutdown Metropolitan Railway eight-wheeler. A Jubilee Stock first class carriage was restored to carry passengers in January 2013 during the Met's 150th anniversary celebrations. The Bluebell Railway has four 1898–1900 Ashbury and Cravens carriages, and a fifth, built at Neasden, is at the London Transport Museum. The Vintage Carriages Trust has three preserved Dreadnought carriages. London Underground carriages The London Underground opened in 1863 with gas-lit wooden carriages hauled by steam locomotives. The Metropolitan and District railways both used carriages exclusively until they electrified in
London Underground The London Underground is frequently studied by academics because it is one of the largest, oldest, and most widely used systems of public transit in the world. Therefore, the transportation and complex network literatures include extensive information about the Tube system. For London Underground passengers, research suggests that transfers are highly costly in terms of walk and wait times. Because these costs are unevenly distributed across stations and platforms, path choice analyses may be helpful in guiding upgrades and choice of new stations. Routes on the Underground can also be optimized using a global network optimization approach, akin to routing