CN Quincy Avenue Bridge

Located near Carnarvon, this concrete slab bridge carries a former Illinois Central Railroad line over Quincy Avenue. The first bridge at this location was likely a timber pile trestle, constructed when the line was first built. Several structures along this line were initially built as timber bridges, which allowed for approach embankments to settle without damaging more expensive permanent bridge work. Between the late 1900s and early 1930s, the approach embankments had satisfactorily settled, and the IC undertook a program to construct permanent bridges at waterway and roadway crossings. The present bridge at this location was constructed in 1911. Currently, the bridge consists of two 19-foot concrete slab spans, set onto concrete substructures. The superstructure follows a standard design, with heavily constructed spans and decorative paneling stamps. The substructures also follow a standard design, with a an art deco pier and abutments with stepped wing walls extending parallel along the roadway. The pier uses two columns, which are flared at the top and connected by a concrete beam. It is unclear if the bridge was constructed by railroad company forces or by an unknown contractor. Concrete slab spans were popular for railroad use, as they were durable, cost effective and could be constructed offsite and installed with minimal interruption to railroad traffic. Since the initial construction, the bridge has seen no significant alterations, and remains in use. Overall, the bridge appears to be in fair condition, with significant spalling noted on the superstructure. The author has ranked this bridge as being locally significant, due to the common design.

Immediately east of this bridge, a through truss span once carried the IC over a Chicago & North Western Railway secondary line (Bridge #WA422.7). This bridge was constructed in 1899 during the initial construction of this line, and consisted of a heavily skewed 112-foot, 5-panel, pin-connected Pratt through truss span set onto stone abutments. The span used a combination of built-up beams and eyebars, and also featured an unusual double pin-connection at the end panels. American Bridge Works fabricated the span, while it is unclear if the stone abutments were constructed by railroad company forces or by an unknown contractor. This bridge was filled in approximately 2000, and was one of the more unique spans along this line. A photo of this bridge is included above.