The city of Minneapolis has already had some nibbles from potential buyers of the St. Anthony Parkway Bridge that it's trying to peddle.

That's the word from Ole Mersinger, an engineer in the city's transportation planning and design section.

"There's been some inquiries on it, but I don't know how viable they are," Mersinger told MPLS this week.

Proposals are due by April 30 for trusses from the five-truss bridge that is scheduled to be removed in 2015 so a new bridge (right) can replace the outmoded crossing that carries the parkway over the Northtown railyard.

But only four of five trusses are on the market, Mersinger clarified. The fifth will be retained in the area for historical interpretation that's to be incorporated in the bridge's landscaping plan.

Ordinarily, the city wouldn't need to offer a worn-out bridge for sale. But the bridge's location on the Grand Rounds parkway system and over the railyard, both considered eligible for listing on the National Register of Historic Places, means the city needs to take extra steps. A memo negotiated with various state and federal agencies requires that the bridge be marketed to be preserved as an historic structure -- even if in a new location.

A view from the current bridge

The city's bridge contractor, to be selected in after bidding this summer, will remove the five trusses and relocate them nearby. Then the submitter of the winning proposal will be responsible for disassembling it for transport and hauling it to a new location. The city's request for proposals specifies that the winning proposer must reuse the bridge for public transportation.

That requirement, and the likely costs associated with carrying out any reuse proposal, pretty much rule out all but a proposal from another government unit, the city said. But it's possible that the trusses could be split among more than one interested buyer, Mersinger said.

Mersinger said that the bridge is the first he's aware of that the city has offered publicly. But there's precedent for reusing spans. When the Broadway Avenue Bridge was replaced in 1987, one of its spans was floated downriver to bridge the East Channel between SE Main Street and Nicollet Island. However, the bridge load is actually supported by modern beams underneath the historic span.

Perhaps a better example for the current city offer is the nomadic history of the Silverdale Bridge. The 1870s wrought-iron truss bridge began service in Sauk Centre, Minn., then was relocated in 1937 to a state highway in Koochiching County (below). In 2011, it was reassembled to carry bikes and pedestrians on the Gateway Trail over Manning Avenue in Washington County.