View of the driver’s cab of a District 1920 F-stock motor car, displaying the Type 20 EP brake controller, to the left of the driving equipment and deadman’s handle. The American Westinghouse Type 20 driver’s brake valve was based on the electro-pneumatic design then in use in New York. Between 1928-30 all the F-stock was equipped with the Type 20 brake controller; it became known as the ‘A’ Type when adopted by other Underground rolling stock. Note the large elliptical window.