The Northern Line and Bakerloo Line parts of present Charing Cross station were originally opened as two separate stations but were combined when the Jubilee Line was opened.
The Bakerloo Line platforms were opened as ‘Trafalgar Square’ by the Baker Street & Waterloo Railway. The line was constructed by the Underground Electric Railways Company of London Limited and opened between Baker Street and Lambeth North (then called Kennington Road) on 10 March 1906. The line was extended to Elephant & Castle five months later, on 5 August. The contraction of the name to ‘Bakerloo’ rapidly caught on and the official name was changed to match in July 1906.
Trafalgar Square station had two side platforms 291 feet in length with unique brown, green and cream tile pattern to help passengers identify the station without seeing the name. The station name appeared on the platform wall tiles in brown letters 15" with ‘way out’ and ‘no exit; signs also incorporated into the tiling. There were no surface buildings with steps from Trafalgar Square leading down to an underground booking hall.
The Northern Line platforms were opened as ‘Charing Cross’ by the Charing Cross, Euston & Hampstead Railway on 22nd June 1907 and formed the southern terminus of their line.
Although both lines were owned and operated by the Underground Electric Railways Company initially there was no direct connection below ground and passengers interchanging between the lines had to do so via two sets of lifts and a surface walk. In an effort to improve passenger interchange, the CCE&HR was extended in 1914 the short distance south under Charing Cross main line station to connect with the BS&WR and the District Railway at Embankment station.
From 6th April 1914, the original CCE&HR terminus was renamed ‘Charing Cross (Strand)’ and the new station and the BS&WR station to the south of the main line station was named ‘Charing Cross (Embankment)’. These names lasted only a short time; on 9th May 1915, Charing Cross (Strand) was renamed ‘Strand’ and Charing Cross (Embankment) reverted to its earlier BS&WR name of ‘Embankment’. At the same time, the separate Strand station on the Piccadilly Line was also renamed ‘Aldwych’ to avoid confusion.
Trafalgar Square was provided with four lifts in two shafts plus a spiral staircase in a third shaft. The lifts were replaced by escalators on 13th April 1926 and the upper lift landing was incorporated into an enlarged booking hall.
With the approach of war Trafalgar Square station was closed temporarily on 27th September 1938 for ‘urgent structural work’ which involved stopping up the tunnel where it went under the Thames with a concrete plug. When Neville Chamberlain returned from Munich with his uneasy peace the concrete was drilled away and the station reopened on 8th October. Like many stations on the underground Trafalgar Square station was used as a shelter during WW2. On 12th November 1940 seven people were killed when a bomb fell on the station.
The Northern Line’s Strand station was closed on 4th June 1973 to enable the construction of the new Jubilee Line platforms. These platforms were constructed between the Bakerloo Line and Northern Line platforms and for the first time an underground interchange between the two stations was provided. The Jubilee Line platforms and the refurbished Northern Line platforms opened on 1 May 1979. From this date, the combined station including Trafalgar Square was named Charing Cross.
Although Trafalgar Square station is still open as Charing Cross, the original Trafalgar Square lower lift landing is still extant, dating from the opening of the station on10th March 1906. One lift shaft has a walkway over the open well joining the entry and exit sides of the lower lift landing. The second shaft now contains a fan for ventilating the Bakerloo Line; the third shaft contained the spiral stairs. These were removed sometime ago as they were structurally unsafe and the shaft now provides the air intake for the adjacent fan. At the bottom of these shafts are two small sumps to provide drainage for any ground water that accumulates.