"There are four lines of plate girders, two under each track, of a uniform depth of 7'. Beginning on the east end there are two 75' plate-girder spans on a rocker bent; then six 45' plate girder spans, alternating with six 75' plate-girder spans. The 45' plate-girder spans carried on and form the tops of towers consisting of four columns each, rigidly braced together on all sides. The 75' plate-girders span the opening between consecutive towers.
"This bridge is one of the last projects of noted bridge engineer George Morison, who died two years after the structure was built. The bridge was the longest and heaviest viaduct of its time, and may be the longest extant double-track railroad viaduct in the world. It is listed in the National Register of Historic Places.
"This document was prepared as part of the Iowa Historic Bridges Recording Project performed during the Summer of 1995 by the Historic American Engineering Record (HAER). The project was sponsored by the Iowa Department of Transportation. (IDOT)."
Report of the Historic American Engineering Record