Deering Bridge

• 1855: 45 miles completed from Chicago to the Illinois State Line by the Chicago and Milwaukee Railroad
• 1855: 40 miles completed from Illinois State Line to Milwaukee, Wisconsin by the Green Bay, Milwaukee & Chicago Railroad
• 1857: GBM&C acquired by the Milwaukee and Chicago Railroad
• 1863: M&C and C&M become part of the Chicago and Milwaukee Railway
• 1881: C&M acquired by the Chicago, Milwaukee & North Western Railway
• 1882: Second track constructed from Chicago to Evanston
• 1883: CM&NW acquired by the Chicago & North Western Railway
• 1888-1895: Second track constructed from Evanston to Milwaukee
• 1898: Third track constructed from Chicago to Rose Hill and track elevated
• 1910: Third track constructed from Rose Hill to Wilmette and track elevated
• 1911: Realignment in Chicago for new station
• 1966: National Avenue (Milwaukee)-Capitol Drive segment abandoned
• 1981: Third track removed from Chicago to Wilmette
• 1981: Metra begins operations between Chicago and Kenosha as the Union Pacific North Line
• 1987: Second track removed from Kenosha to National Avenue
• 1995: Chicago & North Western purchased by Union Pacific Railroad
• 2009: Wiscona-Capitol Drive segment abandoned, acquired for trail use
• 1984-Present: Metra operates the Union Pacific North Line from Chicago to Kenosha
• 1995-Present: Union Pacific operates the Kenosha Subdivision from Chicago to National Avenue
• 2014-Present: Oak Leaf Trail runs between Milwaukee and Wiscona

Located along Ashland Avenue in the Logan Square neighborhood of Chicago, this massive lift bridge carries the UP North Corridor over the North Chicago River.
Built in 1916 to replace a far smaller and lighter double track swing bridge which dated to 1887, the current bridge is one of the largest movable bridges in Chicago. The bridge was designed to carry three tracks, an oddity.
One of the main challenges of constructing this bridge was the amount of trains using the tracks daily, as almost 200 trains per day would use the old structure.
Because of this, the construction required extreme amounts of staging and precision to avoid significant disruptions to traffic. A temporary wooden approach was constructed to the old bridge to help with construction, and the new bridge was constructed in a raised position around the old bridge.
Because this bridge is a bascule design, the counterweights at the end would block railroad traffic in a raised position. To help avoid this, an unusual counterweight design was used, with each counterweight running parallel to the tracks, instead of one solid concrete block.
In an 18-hour period on July 30th, 1916; the old bridge would be quickly demolished and the new bridge lowered into place.

Photo showing construction process. From The Contractor; October 15th, 1916. Digitalized by Google.

The current bridge at this location features a Strauss Heel Tunnion style bascule bridge with a single leaf. The truss on the bridge is arranged into a 6-panel, riveted Warren Through Truss design. Construction was done by the Kelly-Atkinson Construction Company of Chicago, and the main span was designed by the Strauss Bascule Bridge Company. The bridge also rests on concrete substructures, and features large concrete counterweights. These counterweights are unusual due to the nature of the construction of the bridge. A single deck girder span also approaches the bridge on the north end.
While the third track has not been used in some time, it is apparent that plans are being made to use the track again. In 2019, the bridge was rehabilitated, and a third track installed on the bridge, although not connected at either end. A series of grade separation bridges to the north are in the planning phase for replacement with triple track structures.
In addition to this site, Historicbridges.org has done an excellent job of documenting this bridge.

Bridge Construction Photo; from the Strauss Bascule Bridge Company catalog, 1920

Overall, the bridge appears to be in good condition, and should be in service for many years to come.
The author has ranked this bridge as being regionally significant, due to the design.
The photo above is an overview from Ashland Avenue.