London Underground coaching stock London Underground coaching stock In 1989, the first 'Steam on the Met' event took place, and London Underground, hired British Rail coaching stock for the excursions. It was found that it was actually cheaper to buy the coaches instead of hiring them. Thus, London Underground has acquired numerous former British Rail coaching stock for these special excursion trains on the Metropolitan line, usually hauled by either steam locomotives, or the preserved electric locomotive No. 12 "Sarah Siddons". The fleet consisted of several Mark 1 and Mark 2 vehicles, and eight former British Rail Class 438 electrical multiple unit trailer set
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,