London Underground and the mechanisms are regularly degreased to lower the potential for fires. The only wooden escalator not to be replaced was at Greenford station, which remained until October 2015 when TfL replaced it with the first incline lift on the UK transport network. There are 426 escalators on the London Underground system and the longest, at , is at Angel. The shortest, at Stratford, gives a vertical rise of . There are 184 lifts, and numbers have increased in recent years because of investment making tube stations accessible. Over 28 stations will have lifts installed over the next 10 years,
Mile End tube station tunnels by the strong crosswinds. In November 2009, part of a plastic barrier broke off from a departing train and struck three commuters. One woman suffered a 5 cm cut in her forehead, and London Underground Ltd faced a fine of up to £20,000 after admitting liability in the case. Mile End is the only station in a tunnel on the network that offers cross-platform interchange between 'tube' (Central line) and 'sub-surface' (District and Hammersmith & City line) trains. The station takes its name from the A11 Mile End Road, which itself is named after a milestone signifying the point