https://www.usa.gov/copyrighted-government-workshttps://www.rawpixel.com/image/12290523Edit ImageSaveSaveEditCropCustom TextChicago, Illinois. A retarder operator at the south hump at an Illinois Central Railroad yard. From his control board he operates all the retarders and switches on his track. Sourced from the Library of Congress.View public domain image source hereMorePublic DomainFree CCO U.S. Government image for Personal and Business useInfoView CC0 LicenseEditorial use only JPEGTIFFSmall JPEG 1133 x 1200 px | 300 dpiLarge JPEG 3304 x 3500 px | 300 dpiBest Quality JPEG 4796 x 5081 px | 300 dpiTIFF 4796 x 5081 px | 300 dpi | 46.51 MBFree DownloadChicago, Illinois. A retarder operator at the south hump at an Illinois Central Railroad yard. From his control board he operates all the retarders and switches on his track. Sourced from the Library of Congress.More