I-94 / I-69 Black River Bridge

Bridge Documented: July 11, 2003, July 6, 2007, April 23, 2010

Primary Photographer(s): Nathan Holth

Key Facts

	Bridge Name	Facility Carried / Feature Intersected	Location	Structure Type	Construction Date and Builder/Engineer
!	I-94 / I-69 Black River Bridge	I-69 / I-94 Over Black River and Riverside Drive	Port Huron: St. Clair County, Michigan	Metal Deck Girder, Fixed and Approach Spans: Metal Stringer, Fixed	1950 By Builder/Contractor: Fry and Cain / Walter Toebe Company and Engineer/Design: Michigan State Highway Department

Technical Facts

Main Span Length	Structure Length	Roadway Width	Main Spans	Approach Spans	NBI Number
146 Feet (44.5 Meters)	766 Feet (233.5 Meters)	56.8 Feet (17.3 Meters)	3	7	77177111000B030

View National Bridge Inventory PDF Sheet - Has Additional Details and Evaluation

This bridge is slated for demolition and replacement in 2011!

View Some Original Plan Sheets For This Bridge

Although not the most beautiful bridge in the world at the time of demolition, this bridge was a noteworthy bridge that although on I-69/I-94, actually pre-dates the Interstate Highway System, and has some technologically significant details. This bridge was built in 1950, and was originally part of M-146, a short trunkline road that was long ago decommissioned. M-146 was a short route that ran from 24th Street, to Lapeer Avenue, then to what is today M-25. When built, this bridge would have looked a lot more beautiful, because it appears to have had Michigan's signature type R4 railings like those seen on Sigler Road. These attractive railings would have complimented the modest architectural detailing on the piers and abutments of this bridge. The architectural details of the piers and abutments managed to survive on the bridge, but the R4 railings were replaced with New Jersey barriers, which greatly diminished the aesthetic value of the bridge.

Structurally, the bridge consists of three deck plate girder spans and seven steel stringer spans. The bridge was technologically significant for its uncommon cantilevered deck plate girder design which includes an 86 foot suspended span which is connected to the bridge by a pin and hanger type system. The Michigan State Highway department built a number of cantilevered deck plate girders across the state, and a number of them remain today. Not all of them have the pin and hanger detail however. The anchor arm main spans on either side of the cantilever span include a field splice connection where the built-up plate girders were attached during erection. Also, the bridge was designed so that the main spans of the bridge function at two separate parallel bridges sharing a single pier. There are two pairs of deck plate girders under the bridge, each with their own set of floorbeams. At certain locations under the bridge a tiny gap in the deck is visible demonstrating this two bridge design. Finally, adding to the complexity of this bridge was the seven approach spans which turn the bridge into a relatively long (for Michigan) bridge of 766 feet. Also, the bridge had an 18 degree skew.

 Unfortunately, this bridge ended up being sentenced to the dumpster. As a 1950 bridge that was not designed with the Interstate Highway System in mind, the bridge was very narrow and a serious bottleneck for expressway traffic, lacking an acceleration lane for the Water Street ramp, and also lacking sufficient shoulders. Structurally however, the bridge was still in decent condition. The steel superstructure appeared to be in very good condition, with the only areas of significant rust and deterioration being around expansion joints. The abutments and piers had some areas of spalling, but nothing severe that could not be corrected by rehabilitation. The deck was the only part of the bridge in extremely bad condition. One could not complain too much about the deck however, since it appeared to be the original 1950 deck, which is impressive given the massive volume of heavy truck traffic this bridge has carried as an I-69/I-94 bridge. The replacement of this bridge was part of a larger project to completely reconstruct I-69/I-94 in the immediate area, and this greater project was designed to compliment a planned expansion of the toll and customs plaza for the Blue Water Bridge.