A contrast in railway giants . Motorisation is coming so swiftly to the American railways that already an evolution in equipment is taking place . Photo shows , a Burlington passenger locomotive used to pull the crack aristocrat train on the Chicago Denver service , and a photo sketch of the Burlington Zephyr , which is claimed to be the last word in motorisation due to it ' s full aero dynamic lines and its 600 horsepower Diesel , engine capable of a maximum speed of two miles a minute . The older type locomotive with its fuel tender weighs 359 tons , while the Zephyr complete weighs 85 tons . 12 January 1934