Bank Station is a London Underground station located in the City of London financial district. It is a key interchange served by five existing lines. The Bank Station Capacity Upgrade (BSCU) aims to relieve heavy passenger congestion during peak hours for boarding, alighting and interchange. The capacity upgrade comprises the construction of a new southbound platform tunnel and associated length of running tunnel for the Northern line, connecting passageways to the existing station tunnels, and the provision of step-free access from King William Street. The total length of tunnels is 1,300m with tunnel cross sections that range from 10m2 up to 90m2.