The historic Bertram “Blue” Bridge in southeast Cedar Rapids twisted and sustained significant damage Monday as crews worked to lift the structure off its foundation as part of a planned bridge replacement and relocation project, Linn County officials said.
Bertram Road was already closed to traffic – and still is – because the area is an active construction site. No one was injured in the incident.
The 146-year-old bridge was to be moved to the Indian Creek Nature Center for use on the trail system at the Nature Center. However, due to the damage sustained while lifting the bridge, the Linn County Secondary Road Department does not think the structure is salvageable, according to a news release. Engineering contractors will evaluate the bridge structure to make a final determination.
“We are disappointed that the Blue Bridge most likely will not be moved and reused at the Nature Center as planned,” Linn County Assistant Engineer Garret Reddish said. “Due to the age of the bridge, it was always a possibility that the structure could be damaged during the lifting and moving process, and that’s what happened.”
The Bertram bridge was built in 1876 by the Wrought Iron Bridge Company (WIBCo) using a design patented in 1876, and was presumably one of the first bridges to use the new design. WIBCo’s patented design was a variation of a standard Pratt truss configuration, employing double-intersecting counter members radiating outward from the center of the span. This early wrought-iron truss features four timber stringer spans at its north approach and is supported by a combination of stone and timber abutments. With no alterations on record, this bridge continued to serve vehicle traffic until 2022 at 146 years old.
This bridge survived many floods, most notably in 1993 and 2008. Thankfully, the high water was mostly backwater from the Cedar River, which did not carry a damaging current. Multiple repairs have been made to the bridge over the years. Per inspection records, the timber deck surface was replaced in 1926, 1940, 1954, 1987, and 1996 and the timber approach spans were completely reconstructed in 1987. To protect the integrity of the steel, the truss was painted several times, most notably in 1991 when it received a royal blue treatment, earning it the “Blue Bridge” nickname.
The rest of the Bertram Road and bridge replacement project will continue. The project includes removing the existing road, realigning the road for the new bridge, installing new culverts, and replacing the old truss bridge with a new IDOT standard concrete beam bridge.
Road closures were already in effect around the project, and many of the closures will remain in effect until the completion of the entire Bertram Bridge project in October.
The Bertram “Blue” Bridge was a registered historic structure. Due to this designation, Linn County was required to mitigate its loss as part of the planned replacement for the bridge. The mitigation plans included moving the 146-year-old bridge to the Indian Creek Nature Center for use on its trail system and placing an informational kiosk at the new location, as well as signage to mark the original location of the bridge.
Linn County officials say they plan to keep the signage portion of the mitigation plan in place and will explore other options to preserve the bridge’s 146-year history.
