Most of the photos on this site were extracted from reference images (high-resolution tiffs, 20 to 200 megabytes in size) from the Library of Congress research archive. (To query the database click here.) Many were digitized by LOC contractors using a Sinar studio back. They are adjusted by your webmaster for contrast and color in Photoshop before being downsized and turned into the jpegs you see here.

December 1942. "Chicago, Illinois. Work goes on twenty-four hours a day at this Chicago and North Western Railroad yard." View full size. Medium format negative by Jack Delano for the Office of War Information.
This a hump yard, where a locomotive pushes cars up a small hill (behind the camera) and the cars are uncoupled individually or in groups to roll down the other side of the hump to their respective tracks. The thing on the ground around the rails is a pneumatic retarder that slows the cars to a safe coupling speed by gripping the wheels. The switches are controlled by the towers in the photo. It's an interesting operation to watch.
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