Chester Henry, assistant chief engineer in charge of construction for the Pennsylvania Railroad, discusses railroad facelifting for both trains and tracks. He comments that a railroad is never complete because of its responsibility to change in industry. Mr. Henry explains the car classification operation at Conway Yard near Pittsburgh, and a film further elaborates on the process, including the role of the hump conductor. Railroad engineers must see the overall picture to construct a line with minimum cost and maximum efficiency. For example, they must find the best route by using aerial photography. Film clips show techniques developed by engineers to unload shipments of foreign ore onto railroad cars. Electronic and mechanical engineers also develop new railway technology, such as track safety features; maintain rolling stock, as at the Hollidaysburg, PA freight car repair shop; and design experimental passenger cars, such as the stainless steel Budd cars and the GM Aerotrain. Carl Bergman notes that inspecting and maintaining track and allied structures acquaints railroad engineers in training with all aspects of the job, even though most maintenance jobs are now mechanized. He explains the composition and construction of a track and narrates a film showing a machine that detects defects in the rail and other maintenance equipment. Both men recommend that interested high school students take math and general science courses followed by a college degree in engineering. There are about 172 different railroad job classifications, including positions in the clerical and accounting departments for women.