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,
Grange Hill tube station Grange Hill tube station Grange Hill is a London Underground station on the Central line which lies in the parish of Chigwell in the Epping Forest district of Essex. The boundary with the London Borough of Redbridge is immediately to the east of the station buildings. The station is between Hainault and Chigwell stations. The station has been in Travelcard Zone 4 since 2 January 2007. The station was opened by the Great Eastern Railway on 1 May 1903 on their Fairlop Loop line between Woodford and Ilford. As a consequence of the 1921 Railways Act, the GER was merged