POLI 100K, Railroads and American Politics: Topic 5, The Evolution of Railroad Technology


The Evolution of Roadbed and Track
  1. The early railroad roadbeds and track were adapted from those used in mining. Many early railroads used wooden beams surfaced with strap iron for rails. Others used strap iron bars mounted on granite sills.

    By the late 1830s the standard roadbed and track had emerged. It was quickly discovered through trial and error that railroad vehicles should have single-flanged iron wheels with the flange on the inside of the rail (simple physics -- with the flange on the outside the vehicle tended to ride-up on the rail under a lateral force). The rails should be solid rolled "T" iron mounted on wooden ties on top of a crushed stone foundation. This provided cushioning as well as proper drainage.

    The illustrations below were made by the great German engineer Franz Anton von Gerstner. He traveled throughout the U.S. in 1839 examining in great detail all the canals and railroads then in operation or under construction. He made detailed engineering drawings of everything he had seen and wrote highly detailed reports. These have been reprinted as Early American Railroads, edited by Frederick C. Gamst, Stanford University Press, Stanford, CA, 1997.

    1839: Mohawk & Hudson 2.5" by 9/16" Strap and Saratoga & Schenectady 2.5" by 1/2" Strap

    1839: Philadelphia & Columbia 41.25 lb Iron T Rail
    Camden & Amboy 42 lb Iron T Rail

    1839: Baltimore & Ohio 51 lb Iron T Rail


  2. Below is an ad for switch plates from the November 1999 industry journal Railway Gazette. Note that after more than 160 years the basic rail is still the same.

    1999: An Ad for Switch Plates


  3. Below are the front and back covers to the November 1999 Railway Gazette. The front cover shows a machine that removes, cleans, and replaces ballast, a job that used to require several large crews of men.

    The back cover shows a vendor of wheel sets. Note that the wheels and axle are a single unit. Railroads discovered very early on that this design kept the whole unit in gauge much better than allowing the wheels to rotate around a fixed axle. In addition, the single unit wheel set made efficient bearings and lubrication possible.

    1999: Front Cover of Railway Gazette

    1999: Back Cover of Railway Gazette