This is a CSX Freight Car Diagram Book for covered hoppers. Railroads issued diagram books such as this for freight and passenger cars, steam locomotives, cranes, floating equipment, etc. They were used in a variety of purposes. They were a ready reference publication that could be used by the accounting department, mechanical officials, maintenance officials and workers, foremen, agents, and for freight and passenger cars even sales representatives and officials. Printed with the standard "blueprint" diazo process, the pages were updated as needed and sent to all holders of each book, who destroyed the old page replacing it with a new one.