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,
Theydon Bois tube station Street were a regular feature in the timetable until the underpass from Leyton to Stratford was built. As part of the New Works Programme, 1935–1940, the LNER branch was transferred to London Underground, to form the part of the eastern extension of the Central line. In 2015, advocacy by a local group forced a proposed 80-space commuter car park to seek planning permission before being constructed on land adjacent to the station. The station was one of the first on the Underground network to operate without a staffed ticket office. Theydon Bois tube station Theydon Bois is a London Underground