A public-private partnership has revitalized Liberty Bridge in Bay City, Michigan, and it opened to traffic at the end of last year.

“This is a truly remarkable day for the city of Bay City,” said Bay City Mayor Kathleen L. Newsham at the grand opening of the bridge. She also thanked everyone involved for their hard work on the project.

Plans have changed since the initial announcement for the Independence Bridge, a second Bay City structure, which will now be rehabilitated rather than rebuilt.

The city owned the four-lane Liberty Bridge, a dual-span drawbridge, which was built in 1983. It carries about 17,000 vehicles daily and opens about three times each day, according to a December 2018 report for the city by OHM Advisors of Detroit. The city also owns the dual span Independence Bridge. It opened in 1973 and carries about 23,800 vehicles each day and also opens about three times daily. Both bridges span the Saginaw River, a vital summer shipping channel in the state.

The Michigan Department of Transportation owns the other two bridges in the city – the Lafayette and Veterans bridges. A 2018 OHM report indicated the municipality was considering multiple options for the two bridges it owns, including repairs or removal of one or both of the structures and building a new bascule bridge. The consultant recommended removing Liberty Bridge and replacing Independence Bridge with a new structure.

However, the city and United Bridge Partners (UBP) of Denver – a company that funds, designs, builds, operates and owns private toll bridges – came up with another solution. UBP operates as Bay City Bridge Partners (BCBP) for the Michigan structures. The company entered into an acquisition and development agreement in 2019 with Bay City for the Independence and Liberty bridges and paid the city $2 million as an installment on the $5 million development fee for the two bridges. BCBP also entered into an operations and maintenance contract for both bridges.

The private entity agreed to provide 100 percent of the financing – provided by American Infrastructure Funds of San Francisco – for upgrading the bridges the city has spent repairing at about $700,000 annually. Both needed extensive repairs. The Liberty bridge was experiencing concrete cracking and delamination.

At Liberty Bridge, BCBP rehabilitated the footings, foundation, superstructure and bascule electrical and mechanical systems. The company also widened existing bike and pedestrian paths, added decorative lighting and rehabilitated the tender house.

Original plans called for BCBP replacing the 1,211-foot-long Independence Bridge with a new four-lane bridge and a bike path. But in November 2022, BCBP has told the city the structure can be rehabilitated instead of replaced, explaining supply chain issues and inflation as reasons for the switch. The rehabilitation plan includes a new deck, structure repairs, new and repaired mechanical and electrical systems, and aesthetic improvements.

TransSystems of Kansas City, Missouri; Stafford Bandlow Engineering, a Division of Wiss, Janney, Elstner Associates of Doylestown, Pennsylvania; and Rowe Professional Services Co. of Flint, Michigan, designed the project.

The joint venture team comprised of Granite of Watsonville, California, and Kraemer North America of Plain, Wisconsin, received the $125 million construction manager/general contractor (CMGC) contract from United Bridge Partners for the Bay City Bridges Project in January 2021.

This procurement approach involves the contractor during the design and planning phases, increasing value for the stakeholders and promoting collaboration. It also enabled Granite to understand the hard work that occurred to ensure large projects go through permitting, environmental surveys, and other steps to ultimately be built.

“The most interesting part of our project has been all the engineering and teamwork involved in the preplanning, discovery, engineering, and rehabilitation of the moveable machinery,” says Mike Punches, Project Executive with Granite. “Being on a CMGC, the collective team, the owner – Bay City Bridge Partners, the City of Bay City, and contractor – Granite-Kraemer Joint Venture, recognize the historical significance of the structure and feel a responsibility to rehabilitate the structure to minimize its maintenance and maximize its long-term longevity.”

Work began in January 2022 on the 2,344-foot-long, 22-span, movable Liberty Bridge, starting with some light demolition work.

“Moveable bridges act as a crossroads for vehicular and boat traffic,” Punches says. “There are several types of moveable bridges. Most utilize electric motors in order to operate the moveable element.”

Owners typically opt for movable bridges in locations without land for a long approach or if a longer bridge would be cost prohibitive.

“Working on moveable bridges is a specialty niche, where additional engineering, custom manufacturing, complex electrical and often marine equipment is a prerequisite,” Punches adds.

Granite-Kraemer removed the mechanical components that allow the bridge to lift and sent them for rehabilitation.

“While the components were being rehabilitated and re-installed, the bridge was lifted manually via crane and pinned into the open position to facilitate construction operations in the interim,” Punches explains. “Our engineering teams worked long hours to devise a safe workplan that utilized a crane on a barge, assisted by two air winches, to lift the moveable span leaves into place. The plan was smoothly executed.”

Environmentally, before starting work, a pre-job Mussel survey was undertaken. Crews were not able to work in the water during fish spawning season, so the marine work could only take place in early spring.

“We were also able to work with the Michigan Department of Environment, Great Lakes, and Energy to get our temporary frontage roads approved,” Punches says.

Original plans called for both bridges to remain open with one lane of traffic in each direction during construction, but in March 2022, the Liberty Bridge was closed to traffic because of concrete deterioration due to freeze/thaw episodes over the winter, which led to a major pothole.

The Liberty bridge opened December 22, 2022. Completion of the entire project is scheduled for the end of 2023.

“We’ve had more than 120,000 hours worked in less than 12 months,” Punches concludes. “We’re proud of every worker we have that chooses to work safely and participate in our safety culture.”

Photos courtesy of Granite Construction