Trains Unlimited: Railway Marvels

The episode covered, stone arch bridges, some are still in service and outlasted iron bridges. The one arch Carrolton Viaduct (1829) is the oldest in the U.S., and the 8 arch Thomas Viaduct (1835) just west of Baltimore is the next oldest. The Rockville Bridge over the Susquehanna 1902 replaced earlier wooden (1849) and iron (1879) bridges. Tunkhannock Viaduct/Nicholson Bridge 2,300 feet length, 240 feet above the community of Nicholson, PA., built in 1915 was given as the ultimate example.