small buildings housed a machine shop, woodworking shop, blacksmith shop, locomotive repair shop, and foundry. These facilities were later demolished to make room for continuing expansion. By 1926, the Altoona Works occupied and consisted of four units: the Altoona Machine Shops, Altoona Car Shops, Juniata Shops, and South Altoona Foundries. The Altoona Machine Shops consisted of over a dozen buildings and performed locomotive repairs, plus made locomotive repair parts and non-metal castings. The Altoona Car Shops were built beginning in 1869. By 1926, it included a dozen buildings, built passenger and freight cars, and repaired same. The Juniata Shops were built out of need for more shop space at Altoona, in 1889. These shops consisted of 10 buildings, and constructed locomotives and performed heavy repairs of locomotives. The South Altoona Foundries were built, again, out of need for more space at Altoona, in 1904. The shops primarily made gray iron castings. In 1875, the Altoona Works started a Test Department for Pennsy equipment, both built and purchased. In following years, the Pennsylvania Railroad led the nation in the development of research and testing procedures of practical value for the railroad industry. Use of the testing facilities was discontinued in 1968. By 1945, the Altoona Works had become one of the largest repair and construction facilities for locomotives and cars in the world. Since 1968, many of the structures of Altoona Works were demolished. Yards The Pennsylvania Railroad had several railroad yards (rail yards) throughout its system. Conway Yard was built in the 1880s, northwest of Pittsburgh in Conway, Pennsylvania. Conway was built strategically in the middle of the Pennsylvania's system and started as a poling yard. The yard was made into a hump yard in 1901 to increase the volume of cars handled. By 1957, it was the world's largest automatic classification yard. Crestline Yard was built by the Pittsburgh, Fort Wayne & Chicago Railway around 1863 and significantly improved in the early 1920s by the Pennsy to speed Chicago shipments and eliminate east and westbound freight classification at Fort Wayne. Crestline is located about halfway between Pittsburgh and Chicago in Crestline, Ohio, and could hold over 1,600 cars. Enola Yard was built in the early 1900s and lies across the Susquehanna River from Harrisburg. The yard grew from humble beginnings of 12 tracks to over of tracks, capable of handling thousands of freight cars and becoming the world's largest