UP Lawrence Avenue Bridge (Lincoln Square)

View an article discussing this track elevation project (digitalized by Google)

This bridge once carried the Union Pacific North Line over Lawrence Avenue near Ravenswood Avenue in the Lincoln Square neighborhood of Chicago. During the late 19th Century, railroad traffic within the City of Chicago posed a serious hazard to the general population. Starting in the mid-1890s, the City of Chicago passed a number of ordinances mandating the elevation of tracks within the city. An ordinance was passed on March 30th, 1896 requiring the elevation of the Milwaukee Division of the Chicago & North Western Railway (C&NW) between Diversey Parkway and Balmoral Avenue. Construction began soon after, and was largely completed in 1897. This section of track elevation required relatively few retaining walls, and the fill was constructed of sand shipped from Indiana. This project was one of the first large scale track elevation projects in Chicago.

This bridge was constructed in 1897 as part of the track elevation project between Diversey Parkway and Balmoral Avenue. The bridge consisted of a 43-foot and two 20-foot through plate girder spans, set onto steel bent piers and stone abutments. The girder spans were typical for early track elevation projects, consisting of a traditional floor constructed of stringers and floorbeams, covered by a sheet metal deck. In addition, the ends of the girders utilized a rounded taper, typical for C&NW bridges. The bridge was initially constructed for three tracks, although the westernmost track had been removed in the 1980s. Lassig Bridge & Iron Works fabricated the girders for this track elevation project. This company fabricated numerous spans for the C&NW, and had its shop along this line at Wrightwood Avenue. However, the industrial lead into the Lassig shops was too sharp to allow the spans for this project to be shipped whole, and the pieces were instead assembled at the division shops before being installed. Stone for the abutments was quarried at a railroad owned quarry near Duck Creek, Wisconsin, and the abutments and retaining walls were constructed by contract.

This type of structure was initially popular for grade separations in Chicago, but fell out of favor as trough floor spans and concrete spans became more economical. The metal floor of this design of bridge was susceptible to pooling water, which would cause corrosion to the steel. In addition, the through girder design limited horizontal clearances on the bridge. By the early 2010s, Metra sought to replace 11 bridges between Balmoral Avenue and Grace Street. The bridge was replaced in stages, and the west track was initially removed in 2011 to allow for construction of the new west track. Once the west track was completed in 2017, the center track was replaced between 2018 and 2019. After the center track was completed, the eastern track was removed. The replacement bridge consists of a double track through plate girder span, set onto new concrete abutments. The eastern portion of the stone abutment was capped with concrete, and remains unused. Overall, the bridge was in poor condition at the time of replacement, with significant section loss and deterioration seen throughout the superstructure. The author has ranked this bridge as being locally significant, due to the common design.