Minneapolis city officials say they’re still hopeful that their plan to remove the 1925-vintage St. Anthony Parkway bridge over the Burlington Northern Santa Fe (BNSF) Railroad yard, and replace it with a new bridge, will pass historic-preservation tests and proceed to design and construction phases. But that’s not likely to happen for a while yet.
More than a year ago, the plan ran into a historic-preservation snag with the federal government, which is set to provide about a third of the funding for the project.
Federal officials said they were not convinced that the city explored every available avenue to repair and preserve the existing bridge before deciding to replace it.
City, state and federal officials conducted another review of the repair and replace options over the past year, and Jack Yuzna, a city engineer, said the Federal Highway Administration (FHWA) has now concurred that replacing the bridge is needed.
A lot of work is needed to plan and design the new bridge, he said, and “we’re still hoping for having a bid-letting next year,” which could allow for construction to begin in 2014.
Earlier, a citizens advisory committee worked with city officials and a consulting firm to examine the options. While there was support for fixing the existing bridge, the group determined that while the initial investments would be comparable—fixing it would cost a little more than replacing it—the repairs would likely last only about half as long as a new bridge would last.
Historians have said the bridge is significant because of its design. It uses a Warren truss design, which, according to historical accounts, was patented in 1848 by its designers, James Warren and Willoughby Theobald Monzani. It uses angled cross-members in the shape of equilateral triangles to spread the load as vehicles cross the bridge. According to a 2000 city report, only two other Warren truss bridges are in service in Minnesota, both built before 1913.
There still could be a snag at the state level, however.
The city’s replacement plan, along with the FHWA’s letter of concurrence, was forwarded to the State Historic Preservation Office, Yuzna said, and “they weren’t ready to concur.” They sent the project to the state’s Advisory Council for Historic Preservation for review, which Yuzna said will probably take a couple of months.
“I believe we’ve done our due diligence,” he said, and that he hopes the only remaining issue is determining “the mitigation for the adverse effects of losing the structure.
“That will have to be determined and negotiated,” he said.
According to Minneapolis City Engineer and Public Works Director Steve Kotke, the mitigation could range from a thorough documentation of the existing bridge to an interpretive center that would demonstrate the bridge’s significance in the area’s history.
Yuzna added that the “repair” alternative has another flaw. Repairing the bridge so it would carry a full weight load for decades to come would require replacing three fourths of the steel on the bridge. “It really doesn’t preserve the structure,” he said. “There wouldn’t be that much left.”
He said the historic preservation reviewers have indicated that the city’s repair formula might not be accurate. “They thought that our rehabilitation alternative was too severe,” he said. “They thought we were taking too much steel off the structure.”
The FHWA reviewers, however, he said, eventually endorsed the replacement alternative.
The bridge replacement alternative has a cost of about $28 million, Kotke said, with almost $9 million coming from the federal government, $12.7 million coming from state sources, $5.4 million coming from city sources, mostly net debt bonds, and about $1 million requested from BNSF.