Met Council shares Kenilworth bridge concepts for Southwest LRT

Written by Jenifer Nunez, assistant editor
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A Thin Deck Concept is one of three options being considered to replace an existing wooden bridge.
Metropolitan Council

Three bridge concepts presented for the Kenilworth channel crossing on the Minneapolis Southwest LRT (Green Line Extension) would reinterpret the existing wooden railroad bridge with new, low-profile structures.

 The project designers’ concepts feature arches, angled piers and a thin deck reminiscent of the existing railroad bridge and are fashioned to fit in with the natural surroundings, as initially recommended by several parties. These parties include the Minnesota Department of Transportation, the state Historic Preservation Office, the Minneapolis Park and Recreation Board, the city of Minneapolis and Kenwood Isles Area Association.

Structural engineers tested the concepts and designers presented them to these parties and staff of the five corridor cities and Hennepin County.

“These are not full-blown designs. They are just in the idea stage for discussion as part of our consultation process for historic properties,” said Jim Alexander, director of design and engineering for the Southwest LRT Project.

The consultation, a federal requirement, will continue throughout the design process in 2015 for the freight railroad bridge and the combined LRT/trail bridge over the channel between Cedar Lake and Lake of the Isles.

The three bridge concepts are called arched pier, thin deck and steel pier with estimates ranging from $4 million to $7 million. To minimize the visual impact and hazards for channel users, all three bridge concepts would be supported from below only with just three rows of piers, down from the six on the existing wooden railroad bridge.

Poles holding the overhead wires that carry electricity to power the trains would not be located on the bridge. In the current concepts, they would be set substantially back from the banks of the channel.

The concepts are based on initial input from the consulting parties with initial recommendations to maximize light between new freight railroad bridge and the LRT/trail bridge, which would be nine feet apart; recognize relationship between bridges and embankment; restore vegetation and consider treatment of partially eroded embankments; consider relationship between abutments and embankments; create more space for skiers, canoeists and kayakers by reducing the number of piers from six rows on the existing wooden railroad bridge; use natural materials; employ a utilitarian design; reinterpret existing wooden railroad trestle and construct using modern techniques.

Project staff will present the three bridge concepts at the Dec. 3 Southwest Corridor Management Committee meeting for feedback; staff will seek public input in 2015.

 

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