Randolph Railroad Crossing

View an article discussing construction of the Milwaukee, Sparta & North Western Railway (digitalized by Google)

Located near Randolph, this large through truss bridge carries the former Chicago & North Western Railway mainline over the Wisconsin & Southern Railroad (former Chicago, Milwaukee, St. Paul & Pacific Railroad) and Schilling Road. Built in 1911 as subsidiary Milwaukee, Sparta & North Western Railway constructed a new line across central Wisconsin, the bridge consists of a 150-foot quadrangular lattice through truss span, approached by a 30-foot deck plate girder span on the east end. The entire bridge is set onto concrete substructures, and was constructed for a single track. The truss span is heavily constructed, using large built-up members. The endposts are comprised of heavy beams, which use a solid plate on the outside and heavy X-lacing on the inside. The top and bottom chords consist of channels, connected by extensive X-lacing and V-lacing. The diagonal members are constructed of a combination of rolled beams, solid plates and built-up beams comprised of heavily V-laced members. Typical for spans of this design, the portal bracing uses an A-frame design, comprised of built-up beams with heavy V-lacing. The top lateral bracing consist of V-laced plates, and the bottom lateral bracing consists of steel bars. The floor is traditionally composed, with plate girders forming the two stringers and floorbeams. The deck girder also uses a standard design, with shallow girders and an open deck. Typical of bridges along this line, the abutments are constructed of an elongated U-abutment, while the pier is a diamond shaped structure. Pennsylvania Steel Company fabricated the superstructure, while the Bates & Rogers Construction Company constructed the substructure. All substructures are founded on timber piles, typical of construction along this line.

This type of truss design is relatively uncommon throughout the United States. However, a few railroads preferred the design, such as the Chicago, Rock Island & Pacific Railway (Rock Island), the Chicago & North Western Railway (C&NW) and the Omaha Road. Spans constructed in the late 1870s and early 1880s for the C&NW featured an arched and pedimented lattice portal bracing, light sway bracing and laced members. The second generation was nearly exclusively constructed by Lassig Bridge & Iron Works between 1884 and 1900, and featured heavier members and a pedimented portal bracing. While the design fell out of favor for the Rock Island and Omaha Road around the turn of the 20th Century, the design remained popular with the C&NW into the 1920s. 19th Century versions of this design were primarily constructed out of iron, while 20th Century versions of this design used much heavier members and were constructed of steel. The C&NW preferred this design, as it was both strong and demonstrated great resilience in case of a derailment. A handful of spans using this design were constructed along this route, primarily to cross large rivers and other railroads. Since the initial construction, the bridge has seen few alterations and remains in regular use. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked this bridge as being moderately significant, due to the truss design.