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,
Chesham tube station Chesham tube station Chesham is a London Underground station in Chesham, Buckinghamshire. It is served by the Metropolitan line and is the terminus and only station on the Chesham branch, which runs from Chalfont & Latimer. The station is in London fare Zone 9 (previously zone D). The station was opened on 8 July 1889 by the Metropolitan Railway (MR). It is a Grade II listed building. The distance between Chesham and Chalfont & Latimer is the longest between adjacent stations on the whole London Underground network at , and Chesham station is north-west of Charing Cross, making it the