The Tube: Going Underground - Season 1 Episode 1
Overview: Discover the secret army battling to keep the Tube running during the twice-daily onslaught of rush hour. Travelling the equivalent of six times around the world every day, the repair workshops must work round the clock to keep trains on the tracks. At Earl's Court station, Charlotte must find a way to keep the Piccadilly Line running despite an epidemic of flat wheels on their trains.