Power Station in Chelsea. Busier stations were modernised; Bank and Shepherd's Bush stations received escalators in 1924, Tottenham Court Road and Oxford Circus in 1925 and Bond Street in 1926, which also received a new entrance designed by Charles Holden. Chancery Lane and Marble Arch stations were also rebuilt to receive escalators in the early 1930s. On 5 November 1923 new stations were opened on the Ealing extension at North Acton and West Acton. They were built to serve residential and industrial developments around Park Royal and, like East Acton, the station buildings were basic structures with simple timber shelters on the platforms. The poor location of British Museum station and the lack of an interchange with the GNP&BR's station at Holborn had been a considered a problem by the CLR almost since the opening of the GNP&BR in 1906. A pedestrian subway to link the stations was considered in 1907, but not carried out. A proposal to enlarge the tunnels under High Holborn to create new platforms at Holborn station for the CLR and to abandon British Museum station was included in a CLR bill submitted to parliament in November 1913. This was given assent in 1914, but World War I prevented any works taking place, and it was not until 1930 that the UERL revived the powers and began construction work. The new platforms, along with a new ticket hall and escalators to both lines, opened on 1933, British Museum station having closed at the end of traffic the day before. Between March 1926 and September 1928, the CLR converted the remaining gate stock carriages in phases. The end platforms were enclosed to provide additional passenger accommodation and two sliding doors were inserting in each side. The conversions increased capacity and allowed the CLR to remove gatemen from the train crews, with responsibility for controlling doors moving to the two guards who each managed half the train. Finally, the introduction of driver/guard communications in 1928 allowed the CLR to dispense with the second guard, reducing a train crew to just a driver and a guard. The addition of doors in the sides of cars caused problems at Wood Lane where the length of the platform on the inside of the returning curve was limited by an adjacent access track into the depot. The problem was solved by the introduction of a pivoted section of platform which usually sat