London's New "Hush-Hush" Coaches "Best In World" -- The new, streamlined bus photographed at Chiswick today. It is claimed to be the world's most advanced public vehicle. An experimental double-deck Green Line coach, claimed to be the world's most advanced bus, bus just been completed at Chiswick Works under "hush-hush" conditions. It is to be tried out in London streets very soon. It has a streamlined front with chromium "mounth-organ" grilled, and automatic air change system which keeps the vehicle at 60 degrees even when it is freezing outside, push-button doors, and airliner type "sink in" seats. February 01, 1949. (Photo by Fox Photos).