Bertram Bridge Replacement & Relocation Project
The Bertram Bridge, also known as the Blue Bridge, relocation project includes replacing the current bridge with a new IDOT standard concrete beam bridge and relocating it to the Indian Creek Nature Center where it will be used on their trail system. Due to the existing truss bridge being a registered historic structure, the Linn County Historic Preservation Commission is participating in this project with the Secondary Road Department and Indian Creek Nature Center to ensure the bridge is preserved and properly signed in its new home.
The projects were let on December 22, 2021 and both were awarded to Peterson Contractors Inc. of Reinbeck, Iowa. The bridge replacement project (new bridge) will cost $2,425,608.45 and the truss relocation project will cost $184,373.00. The projects are both funded with Local Option Sales Tax (LOST) money. Construction is expected to begin in November 2022 and the road is scheduled to be open on Friday, October 6, 2023.
The Linn County Secondary Road Department will provide updates throughout this project. Sign up to receive text or email updates on the Bertram Road Bridge Replacement Project under the Alert Center on the NotifyMe page. View previous updates.
|November 1, 2022||Tree Clearing and Grubbing||Completed|
|Winter 2022-2023||New Bridge Substructure Construction||Completed|
|Summer 2023||New Bridge Superstructure Construction||Completed|
|August/September 2023||Relocate Historic Truss Bridge to Indian Creek Nature Center||Completed|
|Late September / Early October 2023||Project Completion||On Schedule|
History of the Bridge
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 has 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.