The London Underground network has seen a variety of rolling stock since its conception in 1863. The rolling stock began being powered by steam, however, this changed in the early 1900s with the use of electric powered trains.
The rolling stock on the London Underground network is made up of two types:
Deep Level or Tube stock: primarily running on the Bakerloo line, Central line, Jubilee line, Northern line, Piccadilly line, Victoria line and Waterloo and City line
Cut and Cover or Surface stock
Primarily operated on: Circle line, District line, Hammersmith and City line and Metropolitan line
These are railways or lines that where constructed using the cut and cover method, tending to be shallow, running inside a trench just below the streets. These railways or lines began operating steam, however, in 1900 these began to be converted to electric with the project being completed in the 1960s. These railways or lines have recently been upgraded and now operate one of two variations of the same rolling stock.
Deep Level or Tube stock
Primarily operated on: Bakerloo line, Central line, Jubilee line, Northern line, Piccadilly line, Victoria line and Waterloo and City line
These are railways or lines that where constructed using the tunnel shield method, tending to be a twin bore deep tunnel with a single railway track that runs in a single direction. These railways or lines began using electricity, although the major innovation that is used on these railways or lines is Automatic Train Operation (ATO) which allows the trains to operate automatically between stations. These railways or lines are currently being upgraded, which encompasses new rolling stock for the Bakerloo and Piccadilly lines which are currently operating the oldest rolling stock on the network.