Lesson 2.0: Track Profiles

Since most railroads were born of the 19th Century here in the Western U.S., most archaeologists make the assumption (the mother of all evils) that any set of railroad tracks they stumble across exceeds the >50 years of age threshold.  Many railroads, however, with the advent of mechanized earth-moving equipment, increased tonnage/traffic and diesel-electric locomotives, rebuilt and relocated large portions of their mainlines in the Western U.S. over the first half of the 20th Century.  In addition, trains inflict a great deal of wear and tear on the track.  The faster and heavier the trains, the higher the turnover of rails, ties and ballast.

To provide a modern example of this, the former Great Northern (GN) mainline from Minot to Williston is currently being rebuilt from the ground up and expanded from a single track to a double track mainline.  This is a direct result of a significant increase in the amount of originating (oil) and terminating (frac sand) traffic related to petroleum extraction in the Bakken.  When the project is complete, there will be little to nothing left of the original GN mainline across northwestern North Dakota.

So how can you confirm (with any assurance) that the railroad tracks in question are fifty years of age or older?

Answer: Track Profiles.

Chicago, Milwaukee, St. Paul and Pacific Railroad (Milwaukee Road) Track Profile of the Trans-Missouri Division (February 1958)

Track profiles were produced en masse on an annual basis by the engineering departments of most railroads.  They depict various engineering and technical aspects of a specific mainline, branchline, spur and their associated sidings.  Most include notations as to the type of rail along the line, when it was installed along with locations of culverts, bridges and other associated features.  All U.S. railroads use a system of mileposts as a frame of reference (not unlike a datum).  The profiles utilize this system They can be found through numerous sources.  A number of historical associations (NPRHA, GNRHS, etc.) have scanned them and make them available through online repositories.  Original profile books and reproductions can also be obtained through resellers and through other online sources such as eBay.  Levels of detail and data in the profiles will vary between railroads and generally increased with the use of computers in the drafting process (mid-late 1970s).

Key from the Milwaukee Road Washington Division Track Profile (1976)

Union Pacific Railroad (UPRR) Track Profile, Yellowstone Branch (1988); an example of a track profile produced with the aid of a computer.

Here in North Dakota, profiles of the former Northern Pacific (NP) lines can be obtained through the Northern Pacific Railway Historical Association (NPRHA).  The Milwaukee Road (MILW) mainline cut through a small portion of southwestern North Dakota with branches that served rural communities in the southern and southeastern portions of the state.  MILW profiles can be obtained through Michael Sol's Milwaukee Road Archive.